AFRB Abstracts: Alaska Fishery Research Bulletin - A Fishery Journal of the Alaska Department of Fish and Game

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ALASKA FISHERY RESEARCH BULLETIN

CATEGORIES	ONLINE ISSUES
SALMON	VOL. 1 NO. 1 (1994)	VOL. 4 NO. 1 (1997)	VOL. 7 (2000)	VOL. 10 NO. 2 (2003)

SHELLFISH	VOL. 1 NO. 2 (1994)	VOL. 4 NO. 2 (1997)	VOL. 8 NO. 1 (2001)	VOL. 11 NO. 1 (2005)

GROUNDFISH	VOL. 2 NO. 1 (1995)	VOL. 5 NO. 1 (1998)	VOL. 8 NO. 2 (2001)	VOL. 11 NO. 2 (2005)

HERRING	VOL. 2 NO. 2 (1995)	VOL. 5 NO. 2 (1998)	VOL. 9 NO. 1 (2002)	VOL. 12 NO. 1 (2006)

OTHERS	VOL. 3 NO. 1 (1996)	VOL. 6 NO. 1 (1999)	VOL. 9 NO. 2 (2002)	VOL. 12 NO. 2 (2007)

	VOL. 3 NO. 2 (1996)	VOL. 6 NO. 2 (1999)	VOL. 10 NO. 1 (2003)

VOLUME 1(1) - SUMMER 1994

Handling Increases Mortality of Softshell Dungeness Crabs Returned to the Sea
Gordon H. Kruse, David Hicks, and Margaret C. Murphy - Vol. 1(1):1-9. 1994.

Effects of carapace hardness and air exposure duration on mortality were studied on Dungeness crabs Cancer magister off Kodiak Island, Alaska. We captured 516 legal male crabs and marked them with spaghetti tags. Carapace condition was recorded, and crabs were randomly selected for exposure to air for 5, 15, 30, and 60 min. Crabs were then returned to the sea. Subsequent recoveries from commercial catches included 11% of the tagged softshell crabs and 20% tagged hardshell crabs; these differences were statistically different. No statistical difference was found among exposure periods for hardshell crabs; low statistical power due to small sample size precluded similar tests for differences among exposure periods for softshell crabs. Low recovery rates of softshell crabs in Alaska is consistent with previous mark-recapture studies of Dungeness crabs conducted off Oregon and Washington. Previously published results from controlled experiments support our conclusion that differential recovery rates were primarily due to elevated handling mortality of softshell crabs. Our data suggest that softshell crabs experienced 45% higher mortality than hardshell crabs. However, this rate may not be representative of handling mortalities experience during commercial fisheries because (1) during molting periods fisheries catch crabs much softer than those we encountered, (2) We handled crabs much more carefully than would normally occur during commercial operations, and (3) we were unable to derive separate estimates of differential natural and handling mortalities among softshell and hardshell crabs. Findings of handling mortalities of softshell crabs, coupled to considerations of cannibalism in crab pots, indicate that Dungeness crab fishing seasons in Alaska should be structured to avoid major molting periods as is the general practice along the coasts of California, Oregon, Washington and British Columbia. Such regulations will reduce mortality and commensurately increase the abundance of harvestable males and spawning biomass. Extended fishery closures until several months after molting will result in some economic benefits, as well. Meat yield and wholesale value are lowest during molting and increase until peaking several months later. These factors, plus other socioeconomic tradeoffs, should be weighed to determine net benefits to changes in fishing seasons for Dungeness crabs.


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A Summary of 1982-1991 Harvest, Escapements, Migratory Patterns, and Marine Survival Rates of Coho Salmon Stocks in Southeast Alaska
Leon Shaul - Vol. 1(1):10-34. 1994.

Wild juvenile coho salmon Oncorhynchus kisutch were coded wire tagged in three Southeast Alaska streams: Berners River, Ford Arm Lake, and Hugh Smith Lake. Returning adults were enumerated and sampled to estimate total escapement, fishery contribution, removal rates, migratory patterns, age structure, and survival rates. The primary purpose of the program was to index fishery harvest rates and patterns and determine factors affecting adult production. The estimated average harvest rate for the three indicator stocks by the Alaska troll fishery during the 1982-90 period was relatively stable, ranging from a low of 38.1% in 1988 to a peak of 55.0% in 1989. The average harvest rate estimate for the Alaska troll fishery by stock was 47.5% for the Berners River, 52.3% for Ford Arm Lake, and 36.4% for Hugh Smith Lake. The average for all stocks and all years was 44.9%. Harvest rates by all gear types combined varied substantially among stocks. The Berners River stock, which is taken about equally by the troll fishery and the Lynn Canal drift gillnet fishery, was harvested at an estimated average rate of 75.3% (range 61.9-92.9%). The Ford Arm Lake stock was harvested primarily by the troll fishery at an estimated average rate of 55.8% (range 43.6-69.1%). The Hugh Smith Lake stock was harvested by several fisheries at an estimated average combined rate of 66.2%; the 1982-88 average rate of 61.8% (range 52.3-66.5%) increased to 82.1% in 1989 and to 81.1% in 1990. Juvenile coho salmon tagged in the Berners River in late June of 1980 to 1989 survived to adult return, as determined by catch and escapement, at an estimated average rate of 5.3% (range 2.9-8.8%). Similarly, Ford Arm Lake juveniles tagged in July and August survived at an estimated average rate of 9.5% (range 6.0-14.4%), and smolts that migrated from Hugh Smith Lake survived at an estimated average rate of 10.7% (range 4.2-19.1%). Smolts that migrated from the Berners River in 1989 survived at an estimated rate of 19.8%. At Hugh Smith Lake, 5 years of age-.1 coho salmon escapements ranging from 903 to 2,144 produced a narrow range of estimated smolt emigrations (23,480-29,548); no relationship between escapement and smolt production was evident. Recent results continue to support earlier conclusions about the relative stability of coho production from some lake systems and the important effect of marine survival rates on adult production. Determination of spawner-recruit relationships for the Hugh Smith Lake stock and the other indicator stocks was not possible.


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A Model to Predict Pacific Herring Age Composition in Early and Late Spawning Migrations in Kamishak Bay, Alaska
Henry J. Yuen - Vol. 1(1):35-54. 1994.

Observations of a mid-April spawning migration of older-aged Pacific herring Clupea pallasi in Kamishak Bay, Alaska, followed by a younger-aged herring spawning migration in May was supported with a two-sided, two-sample Smirnov test. When a shift in age composition occurred, those in mid-May reflected an influx of age-3 and older herring, whereas late April transitions were due to increased numbers of age-4 and older herring. A model was developed to predict a composite age composition from the early age composition for those years when late age composition samples are absent and the following-year age composition indicates an unexplained recruitment of age-4 herring. The model does not use survival rates and is independent of forecast models.


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Reducing the Size Limit on Alaska Red King Crab: Price and Revenue Implications
Sarah A. Bibb and Scott C. Matulich - Vol. 1(1):55-65. 1994.

A size-structured shellfish population, like Alaska king crab Paralithodes camtschaticus poses special challenges for fishery managers and industry, alike. One often overlooked issue centers on how the size structure of the catch translates into prices and industry revenues. This investigation provides preliminary insight into wholesale price determination for frozen red king crab legs and claws, which are sold by size in the U.S. wholesale market. Bayesian bootstrapping with informative priors was used to estimate the pricing model. Two policy simulations were conducted to assess how a lower size limit might have affected wholesale prices during the 1987-88 and 1988-89 marketing years. The results show that prices-by-size can change substantially and processor revenues can rise slightly or fall depending upon how management policies affect the size structure of the catch.


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A Bayesian Approach for Estimating Hatchery Contribution in a Series of Salmon Fisheries
Harold J. Geiger - Vol. 1(1):66-75. 1994.

Bayesian methods provide an under-appreciated way of analyzing tag or mark data for hatchery salmon stock identification. For example, the otolith bones can now be marked in captive juvenile salmon, these marks remaining visible in the returning adults. Fishery managers can summarize what is known and unknown about the underlying proportion of hatchery fish in these fisheries using Bayesian methods and the beta probability distribution. Close examination of Bayesian probability theory exposes a philosophy in close agreement with common sense and a form of inference that is direct and agrees with the way people use the notion of probability in everyday, colloquial speech. This theory also provides a straightforward means to allocate sampling resources, in a staged manner, based on information obtained from initial sampling.


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Pacific Salmon Management - The View from Alaska
Charles P. Meacham and John H. Clark - Vol. 1(1):76-80. 1994. No Abstract.


Full Article ( PDF file * - 93K )		Top of Page

Results of a Questionnaire on Research and Management Priorities for Commercial Crab Species in Alaska
Margaret C. Murphy, William E. Donaldson, and Jie Zheng - Vol.1(1):81-96. 1994.

A questionnaire was sent to the majority of researchers involved with Alaska shellfish to identify crab research and management priorities. Subjects and commercially exploited crab species were prioritized using a weighted rank frequency. The highest priority research need was assessment of handling/gear mortality in pot and trawl fisheries followed by evaluation of alternative stock assessment methods. Research targeting red king crabs Paralithodes camtschaticus was highest species priority among respondents, followed by golden king crabs Lithodes aequispina, Tanner crabs Chionoecetes bairdi, and snow crabs c. opilio.


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Detection of Ceratomyxa shasta in Alaskan Chum Salmon, Oncorhynchus keta
Jill E. Follett, Jana L. Geesin, and Tamara M. Burton - Vol. 1(1):97-98. 1994. No Abstract.


Full Article ( PDF file * - 35K )		Top of Page

AFRB: A Research Step Toward Better Management
Carl L. Rosier - Vol. 1(1):99. 1994.
(No Abstract) Full Editorial:

When Alaska became a state in 1959, the new state government assumed responsibility for managing most of its fishery resources. At that time, many of the resources had been depleted following an extended history of overharvest. As the new Department of Fish and Game gained regulatory authority and grassroots public support for conservation grew, salmon fisheries began to prosper. The application of limited entry and hatchery technology coupled with increasing control of foreign high seas fisheries in the early 1970s provided fishermen with an economic incentive to support long-term conservation of our fisheries. Databases from the fisheries were gradually assembled, and research was carefully targeted to the needs of management and fisheries development.

Because management jurisdiction of Alaska's fisheries is now more widely integrated with a spectrum of federal and state agencies, interagency heterosis has sponsored increasingly higher standards for research. We need to continue to investigate and accumulate knowledge on population dynamics, ecological relationships, economics, genetics, aquaculture, etc. As oil wealth predictably plummets, expansion of our economy from renewable resources - in particular our fisheries - must be the direction of the future. Only through increasing our emphasis on research and demanding higher standards will we improve management and achieve these goals.

In keeping with these high standards, the research we do must develop strong credibility among our sister agencies, which means it must be validated and authenticated through established scientific peer-review protocols and become part of the formal literature. Grey literature, while still essential for reporting and archiving much or our routine data-collection activities, can no longer be the vehicle to deliver research findings.

An important charge for our research staff is to critically examine the collective data from our past management history and to consolidate and analyze these extensive data sets to ensure continual and timely refinement of our management policies. Only by periodically and critically examining what we have done, can we hope to improve where we are going.

This first issue of the Alaska Fisheries Research Bulletin (AFRB) has evolved from our old monograph series, the Fishery Research Bulletin. This transition to a more streamlined and cost-effective way of doing business was carried over into the AFRB, which represents a more consolidated approach to reporting than its predecessor.

We see this journal reaching researchers from the global community, and we are therefore expanding our editorial board and our peer referees to include a broader range of expertise outside state government. I encourage contributions from staff within the Department of Fish and Game, and I want to personally encourage our staff to dedicate the necessary time and resources to publish your findings. To ensure the broadest perspective on solutions to Alaska's fishery problems, we are pleased to open AFRB to external authors as well. While reflecting the department's commitment to publishing its research in the formal literature, AFRB was primarily created to serve those who may both benefit from and contribute to research that is conveniently aggregated in one journal focusing on the management and development of Alaska's vast fisheries.

The Challenges of Change
Jeffery P. Koenings - Vol. 1(1):99-100. 1994.
(No Abstract) Full Editorial:

It is well known that most organizations are resistant to change, yet challenges brought on by change enable an organization to reinvent itself. Therein lies a challenge in and of itself. The purpose of change is to respond to external and internal needs in a manner that enables the organization to evolve. The Department of Fish and Game has and continues to undergo structural modifications in response to major budget cuts and to the changing values of the fisheries it manages.

Alaska is known as the "Saudi Arabia" of fisheries management; in other words, our fish and shellfish stocks are generally healthy and providing sustainable yields. Nearly 60% of the seafood harvested in the United States is of Alaskan origin. The department's management and research programs have provided all-time record harvests of salmon, the highest of which recently approached just under 200 million fish.

At the same time, the large volume of farmed fish appearing on the international market over the last decade now exceeds Alaska's entire supply. This has reduced fish prices and renewed pressure to reduce the overall size of Alaska's fishing fleets. A need to increase the volume of fish harvested and to compensate for lower prices has put tremendous pressure on managers to harvest all of the yields available. This, in turn, puts far too much pressure on our stocks.

The state's fisheries are also facing significant challenges. Included are the effects of endangered species legislation stemming from losses of sustainable salmon populations throughout the Pacific Northwest, problems with marine mammal populations, and an overwhelming pressure from the seafood industry to enter into new fisheries involving nontraditional species, such as red and green sea urchins, sea cucumbers, and geoducks, to name a few.

Research has improved the fishery manager's ability to protect sustainable yields, to maintain stocks, and to stabilize the industry's market share in the international arena. Working with the proper and most advanced tools is especially important in light of decreasing management dollars within this agency. The results of any research effort can lose its impact if not reported in a concise, efficient manner to peers.

The department is changing the way it reports its research by substantially increasing the number of applied research articles which emphasize a synthesis of information in the format of a highly visible research bulletin. Over time, I envision the bulletin to increase in frequency and to include larger monographs.

The transfer of information from peer-reviewed research and management activities will help this department adapt its management techniques to meet these challenges. Information is useless unless peers can understand and use the results. The purpose of this publication is to rapidly distribute our results to scientists within and outside the boundaries of Alaska. I am confident that changing the scope of our research bulletin will meet the department's need. It will also promote excellence in our programs and allow us to put more focus on input from scientists carrying out research on Alaska's fishery resources.

The bottom line is that the Alaska Fishery Research Bulletin is designed to serve fisheries professionals by simplifying access to contemporary findings and by aggregating research results on Alaskan fisheries issues. Based on the health of our fisheries, it could truly become the first publication to couple management science with applied fishery research.

VOLUME 1(2) - WINTER 1994

Differences Between Inseason and Postseason Stock Composition Estimates for Sockeye Salmon in Gillnet Catches in 2 Districts in Southeast Alaska and in the Stikine River, 1986 to 1989
Kathleen A. Jensen - Vol. 1(2):107-124. 1994.

Linear discriminant function analysis of sockeye scale patterns was used to estimate stock compositions of sockeye salmon Oncorhynchus nerka catches in U.S. and Canadian fisheries that harvest Stikine River stocks. Inseason and postseason estimates were made for U.S. gillnet fisheries in Southeast Alaska Districts 106 and 108 and Canadian gillnet fisheries in the Stikine River. Inseason analysis worked well in 1986, 1987, and 1988, but did not work well in 1989. Most differences between inseason and postseason estimates during 1986 to 1988 were not of practical significance; i.e., management actions based on inseason estimates would have been the same had they been based on postseason estimates. Differences were numerically small, generally <1,000 fish. The season total differences in stock-specific catch estimates ranged from 0.0% to 7.1% in District 106. In 1989 weekly differences were of practical significance and were numerically large, ranging from 12 to 7,882 fish. Season differences in District 106 ranged from 3.2% for transboundary Stikine fish to 28.7% for Nass/Skeena fish. In 1989 use of average historical proportions would have resulted in better stock composition estimates than the inseason analysis did. All practical differences were also statistically significant using log-likelihood ratio analysis with alpha = 0.05.


Full Article ( PDF file * - 1,416K )		Top of Page

On the Discrimination of Sockeye and Chinook Salmon in the Kenai River Based on Target Strength Determined with 420 kHz Dual-Beam Sonar
Douglas M. Eggers - Vol. 1(2):125-139. 1994.

The feasibility of using target strength to discriminate between upstream migrating salmon was examined by computer simulation of the expected sampling distribution of mean target strength for a variety of sampling regimes and mixed populations of Kenai River sockeye Oncorhynchus nerka and chinook O. tshawytscha salmon. The simulations were based on empirically derived parameters for underlying Rayleigh probability distribution for square root of the backscattering cross section and length-frequency distributions observed for Kenai River sockeye and chinook salmon. Computer simulation experiments were conducted to examine (1) the effect of target-strength measurement rate on ability to discriminate fish, (2) whether it was possible to discriminate sockeye and chinook salmon species or age classes of chinook salmon, and (3) the consistency of model predictions and observed target-strength distributions of migrating salmon in the Kenai River. Simulated target-strength distributions were consistent with observed target-strength distributions. Although with high sampling rates it was possible to discriminate certain mixed populations of sockeye and chinook salmon, it was not possible to discriminate between sockeye and chinook salmon with the sampling rates achieved in the Kenai River. Because of high within-fish variability in target strength and low between-fish differences in mean target strength, target strength cannot be used by itself to discriminate between fish in the Kenai River.


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Lingcod Fishery Monitoring in Southeast Alaska
David A. Gordon - Vol. 1(2):140-152. 1994.

Lingcod Ophiodon elongatus have recently become an important commercial fish species in Southeast Alaska. The fishery began in 1987 and occurs along the outer coast of northern Southeast Alaska. Dinglebar gear is the primary gear used in the directed fishery. Lingcod are also caught incidentally in significant amounts in the longline and salmon troll fisheries. The Alaska Department of Fish and Game has monitored the fishery through dockside samples, skipper interviews, and onboard observer trips since 1988. Catch per unit effort is lowest during the summer months. Average length of lingcod caught in the directed dinglebar fishery from 1988-1992 was 81 cm, and lingcod caught in the longline fisheries while targeting other species averaged 91 cm. The largest male lingcod sampled from the directed fishery was 95 cm and the largest female was 127 cm. Male lingcod are caught at a higher rate than females from March through May. Peak spawning occurs in February. Size at which >50% of the female lingcod sampled were mature was 83 cm. Lingcod may shrink up to 8 cm when held in slush-ice.


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Nutrient Treatment of 3 Coastal Alaskan Lakes: Trophic Level Responses and Sockeye Production Trends
Gary B. Kyle - Vol.1(2):153-167. 1994.

Three coastal oligotrophic lakes with variable interannual production of sockeye salmon Oncorhynchus nerka were treated with additions of fertilizer to increase zooplankton biomass for the purpose of producing more numerous and larger smolts. Nutrient additions increased primary production (chlorophyll-a) by as much as 500% and resulted in a sustained higher level of zooplankton biomass than before treatment. Zooplankton biomass
increased from 40% to 700% after nutrient treatment in the 3 lakes. For the 2 lakes in which data were available, sockeye smolt biomass increased from 50% to 250%, and in the third lake the mean weight of age-1 smolts
increased by 35%. For all 3 lakes subsequent adult sockeye production increased. The phosphorus loading rates for these lakes exceeded that of treated coastal lakes in Canada by 2-5 times; however, the oligotrophic status of these lakes was not altered. The sustained high production of zooplankton and the consistent production of larger or more abundant smolts indicated that the higher phosphorus loading rates for these Alaskan lakes were advantageous to rearing sockeye salmon fry.


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A Lightweight, Inclined-Plane Trap for Sampling Salmon Smolts in Rivers
Gary L. Todd - Vol.1(2):168-175. 1994.

The design and use of an inclined-plane trap is described for capturing salmon smolts in medium to large (5-60 m3·sec-1) rivers of Alaska. The trap was designed to minimize fish scale loss and mortality, be lightweight yet durable, minimize debris loading, be readily moved by 2 people, and be easily transported by a small river boat or helicopter. The tapered design allows traps to be stacked inside one another when being transported. This trap style has been in use since the early 1980s in small clearwater streams and large glacial rivers of southcentral Alaska. Catch efficiencies from mark-and-recapture tests have exceeded 10% for a single trap. The highest daily catch to date for 1 trap occurred in June 1994 when 96,979 sockeye salmon Oncorhynchus nerka smolts were caught in the Kasilof River.


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We Don't Do Allocation
Paul Krasnowski - Vol.1(2):176-178. 1994. No Abstract.


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Tanner Crab Survival in Closed Pots
Al Kimker - Vol.1(2):179-183. 1994.

Lost and delinquent commercial and sport fishing gear has gained public notoriety recently because of documented waste of fish and shellfish resources. Shellfish and groundfish pots have contributed to the problem. Although escape mechanisms have been developed to allow egress of captured species from pots, imprecise release time of these devices has generated debate exacerbated by inexact estimates of the survival of captured species. To gain information on Tanner crab Chionoecetes bairdi survival in pots, we captured large, adult male Tanner crabs and held them in cod pots in the outer portion of Kachemak Bay, Alaska. The pot tunnels were secured shut so the crabs had no chance to escape. No external source of food was provided. The pots were pulled periodically over a 119d period. A total of 52 (39%) of the original 132 crabs died during the experiment.


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Compensatory Feeding Capacity of 2 Brachyuran Crabs, Tanner and Dungeness, After Starvation Periods Like Those Encountered in Pots
J. M. Paul, A. J. Paul, and Al Kimker - Vol.1(2):184-187. 1994.

Food usage rates were measured in 2 brachyuran species, Tanner crab Chionoecetes bairdi and Dungeness crab Cancer magister, following starvation periods of 0, 30, 60, and 90 d. F-tests indicated that there was no compensatory feeding. Food usage rates within species were similar among the 4 test groups, regardless of the length of starvation. Food usage rates were approximately 0.4% body weight per day for Tanner crabs and 1.0% for Dungeness crabs. Neither species markedly increased its consumption rate to compensate for the nutritional deficits. Starvation periods as short as 30 d negatively affected survival of both species under laboratory conditions.


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VOLUME 2(1) - SUMMER 1995

Abundance Estimates of Chinook Salmon in the Kenai River Using Dual-Beam Sonar
Douglas M. Eggers, Paul A. Skvorc, II, and Deborah L. Burwen - Vol. 2(1):1-22. 1995.

A real-time system for estimating abundance of upstream-migrating chinook salmon Oncorhynchus tshawytscha using side-looking, dual-beam sonar was developed for the Kenai River, Alaska, in 1984. The feasibility of using dual-beam sonar for counting and determining target strength of passing salmon was established during the initial 2 years of the study. A hydroacoustic system was engineered to insonify that area of the river used by migrating chinook salmon. Procedures were developed for in situ calibration of the hydroacoustic system and for estimating abundance and associated variance. Management-level operation of the project began in early July 1987. The estimates of chinook salmon passing the sonar site were consistent with independent estimates based on mark-recapture methods. The temporal, spatial, and target-strength distributions of the tracked fish were consistent with estimates of these distributions made using independent methods. Dual-beam sonar has proven to be a precise method for providing real-time estimates of the passage of upstream-migrating chinook salmon.


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An Annotated Bibliography of Capture and Handling Effects on Crabs and Lobsters
Margaret C. Murphy and Gordon H. Kruse - Vol. 2(1):23-75. 1995.

An annotated bibliography of 159 references was compiled to document adverse fishery capture and handling practices and their effects on crabs and lobsters. Relevant literature was located through computer searches and review of citation sections of topical references and tables of contents from published journals. References selected for inclusion in the bibliography focus not only on how capture and handling affect crabs and lobsters but also impacts caused by lost gear and ghost fishing. References on tagging effects and historical and comprehensive treatments on the physiology of molting, growth, autotomy, and limb regeneration were not included. Publications were arranged alphabetically by author. Abstracts were included when available; otherwise a short synopsis was provided. References were indexed by keywords describing causative mechanism, resulting effect, species, and major geographic area to provide easy access by subject. The bibliography is believed reasonably complete through 1993, although it excludes some older references considered out of date.


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Initial Behavior of Displaced Yellowtail Rockfish Sebastes flavidus in Lynn Canal, Southeast Alaska
H. R. Carlson, R. E. Haight, and J. H. Helle - Vol. 2(1):76-80. 1995.

Initial behavior and movements of displaced yellowtail rockfish Sebastes flavidus were observed by divers and in telemetry experiments to test response of fish when first released. Active response behavior began almost immediately upon release, and no signs of stress or disorientation were seen. Circling behavior of displaced fish occurred soon after release and was observed repeatedly. Newly released fish promptly displayed movement away from the release site, in most instances toward the homesite. Waters deeper than 100 m appeared to hinder initial homing efforts.


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Professionalism in Scientific Reviews
Robert L. Wilbur - Vol. 2(1):81-82. 1994.
(No Abstract) Full Editorial:

This issue of the Bulletin has posed an ethical question: is it appropriate for our associate editors to publish in the Bulletin? Our affirmative response may be apparent to anyone scanning the listings of associate editors and authors of papers. The attendant problems and reasons for our decision are not as simple.

At least it did not seem simple for participants at the May 1995 Council of Biology Editors meeting who addressed this and related questions in Kansas City. Many journal staffers did not condone associate editors publishing in the journal they served. However, they mostly represented medical journals, which are comparatively numerous within given disciplines and therefore afford no dearth of alternative publication options for their associate editors. Conversely, the journals that did extend publication privileges to their associate editors tended to be from biological fields with far fewer alternative publication options for their associate editors.

The American Fisheries Society, for example, does not feel it is appropriate to penalize their associate editors by prohibiting them from publishing in the Society's journals simply because they have agreed to provide a service to the Society. The editor of Colonial Waterbirds had a similar perspective, again because of the very narrow niche of that journal and few optional publication sources. Instead of prohibiting intrajournal publishing, these journals treat associate editors' manuscripts as any other, seeking the same evenhanded review and publication consideration.

Affording associate editors this freedom, however, erects a question of propriety: does the practice invite bias into the scientific review process? For example, in the interest of maintaining good working relationships with associate editors, editors could be reluctant to reject an associate editor's manuscript, or an author who has experienced unfavorable scientific review by the journal might, as a referee, be unduly critical of an associate editor's manuscript. Other referees may not want to be too critical of an associate editor's manuscript if they plan to submit a manuscript that could end up in that associate editor's in-basket, although this is not very likely under an anonymous peer review system. While these circumstances are undoubtedly unusual, few would disagree that even infrequent problems with review bias should be avoided, if possible.

Double-blinding - that is, the masking of authors' names from referees, and vice versa - may help eliminate biased reviews of both associate editors' manuscripts, as well as those of other authors (non-associate editors). However, this would not help the editor because masking the author's identity from the editor is not realistically feasible. In addition, a referee's familiarity with research in their field may reveal the colleague's identity and render double-blinding moot. Or it could lead to incorrect speculation of the authors' identities and thereby interject the possibility of mistaken identity and bias. Such anonymity failures are particularly likely where expertise in an aspect of research is limited to a handful of specialists.

Given the limitations of double-blinding, excluding associate editors from publishing in the journals they serve may seem more attractive. However, referee and editorial predisposition can intrude upon the scientific review process, regardless of whether the author is an associate editor or not. Therefore, preventing associate editors from publishing in the journal would thwart but a small portion of the potential instances of review bias. Consequently, the Bulletin chooses to rely on a less tangible, but more ubiquitous, solution: reviewer and editor integrity - their professionalism.

In this age that glorifies the professional, it seems ironic that scientific misconduct continues to be manifested across all disciplines. For example, Sandy Shumway, editor of the Journal of Shellfish Research, recently wrote (summer 1995, Quarterly Newsletter of the National Shellfisheries Association) about the surprising occurrence (8 in the past 5 months) of referee recommendations that were totally opposed on the subject of whether to publish or reject a given manuscript. Such dichotomy, she acknowledged, can be based on legitimate scientific disagreement, but she also noted that much is instead "borne of political origin and even jealousy." Acknowledging need for improvements, we must expect and judiciously pursue unbiased reviews and editorial purview. If referees and editors cannot rise above any attendant personality issues and competitive interests and conduct a review that is objective and impartial, then we must ask them to excuse themselves from reviewing that manuscript.

The Bulletin's referees and associate editors are providing an invaluable service with little recognition or appreciation, but the authors and science are correct in expecting and demanding professionalism within the scientific review process. We are confident that the Bulletin's referees and editors will meet this protocol, and this assumption forms the basis of our decision to allow associate editors to publish in the Bulletin.

To strengthen that assumption, the Bulletin is including a brief statement in its instructions to referees that will remind them of their ethical obligations when conducting reviews and request they excuse themselves if they believe they may not be able to be objective. In addition, the merits of double-blinding will be considered by the Editorial Board this November; in spite of its shortcomings, it might provide some additional assurance against the occasional unfair review.


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Bering Sea Simulation Model
David Ackley - Vol. 2(1):83-86. 1994. No Abstract.


Full Article ( PDF file * - 50K )		Top of Page

VOLUME 2(2) - WINTER 1995

Coded Wire Tagging Studies of Chinook Salmon of the Unuk and Chickamin Rivers, Alaska, 1983-1993
Keith A. Pahlke - Vol. 2(2):93-113. 1995.

From 1983 through 1988 wild juvenile Chinook salmon Oncorhynchus tshawytscha were tagged with coded wire tags: 20,531 young-of-year and 42,475 smolts on the Unuk River and 30,501 smolts on the Chickamin River. From 1985 through 1993 a total of 296 Unuk River and 208 Chickamin River tags were recovered from fisheries and escapements. Among-year estimates of smolt populations at the time of tagging ranged from 142,000 to 510,000 fish, and fractions of the juvenile populations tagged annually ranged from 1.0 to 6.5%. Recoveries indicated the 2 stocks rear primarily in the inside waters of southern Southeast Alaska and are available for harvest over their entire oceanic life cycle. Exploitation rates on the Unuk River stock ranged from 14 to 24% overall and from 8 to 22% by the commercial troll fleet, the primary harvester. Chickamin River exploitation rates ranged from 27 to 50% overall and from 17 to 40% by the commercial troll fleet. No area or time strata were identified as the major harvester of the 2 stocks. Distribution and harvest of the stocks were similar to those of Ketchikan-area hatcheries, which have brood stocks developed from those 2 stocks. Age composition of the escapement was similar to other Southeast Alaska chinook stocks: almost all males were age 1.1 to 1.4 and most females were age 1.3 and 1.4.


Full Article ( PDF file * - 1,304K )		Top of Page

Updated Length-Based Population Model and Stock-Recruitment Relationships for Red King Crab in Bristol Bay, Alaska
J. Zheng, M. C. Murphy, and G. H. Kruse - Vol.2(2):114-124. 1995.

A length-based population model for Bristol Bay red king crab Paralithodes camtschaticus was updated and applied to abundance and catch data from 1968 to 1994. The updated model has fewer parameters and assumes constant natural mortality over length and 2 levels of natural mortality over time for males and 3 levels for females. A nonlinear least squares approach was used to estimate abundance, recruitment, and natural mortality. We added confidence intervals for the abundance estimates with a bootstrap percentile method. Natural mortality was estimated to be 4 to 5 times higher in the early 1980s than during other periods. The observed population abundances were well fitted by the updated model. Confidence intervals for legal male abundance were narrower than for mature female abundance. The stock-recruitment data estimated from the updated length-based model provided a good fit to both general and autocorrelated Ricker models. However, recruitment estimates were lower and the relationships were slightly more depensatory than in the previous model.


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Population Model Suggests New Threshold for Managing Alaska's Togiak Fishery for Pacific Herring in Bristol Bay
Fritz Funk and Katherine A. Rowell - Vol. 2(2):125-136. 1995.

The threshold biomass for fisheries on Pacific herring Clupea pallasi that spawn near Togiak, in Bristol Bay, Alaska, was reviewed based on the data collected in the decade following threshold harvest policy initiation in 1987. The current threshold of 31,752 mt (35,000 tons), below which fishing is precluded, was found to be too low. This threshold had been set at 25% of the spawning biomass during a period that included substantial harvests. A threshold set at 25% of the average unfished biomass (AUB) is widely used in other herring fisheries along the Pacific coast. A 1,000-year simulation of abundance was used to determine AUB under several possible spawner-recruit relationships and sets of stock-assessment data. Four alternative age-structured assessment (ASA) models fit to the available data for Togiak herring under different sets of assumptions were used to represent the uncertainty in the stock-assessment data. A large discrepancy between abundance trends from aerial surveys and trends apparent in age-composition data resulted in a large amount of uncertainty about past biomass levels in the ASA model, which was reflected in the AUB estimates. Ricker and empirical spawner-recruit models fit to the information from the ASA analysis were used to simulate density-dependent effects on recruitment. The uncertainty in the basic population dynamics data provoked a wide range of AUB estimates under different sets of assumptions. AUB estimates ranged from approximately 159,000 to 433,000 mt, and the resulting thresholds ranged from approximately 40,000 to 108,000 mt. Based on this information, we recommend that the Togiak threshold be raised to at least 45,000 to 50,000 mt, pending further resolution of the discrepancies between abundance trends from aerial surveys and abundance trends from age compositions. Setting thresholds at 25% of AUB only rarely triggered fishery closures and these fishery closures produced very little reduction in long-term average yield.


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Epizootics of Infectious Hematopoietic Necrosis Virus in an Enhanced Population of Sockeye Salmon Oncorhynchus nerka Smolts at Chenik Lake, Alaska
Jill E. Follett and Tamara O. Burton - Vol. 2(2):137-142. 1995.

Infectious hematopoietic necrosis virus (IHNV) epizootics in emigrating sockeye salmon Oncorhynchus nerka smolts occurred in the spring of 1991 and 1992 at Chenik Lake in Southcentral Alaska. The lake historically supported a natural run of sockeye salmon, but lake stocking was initiated following a substantial population decline. An estimated 32,000 smolts in 1991 and 42,000 smolts in 1992 emigrated from the lake, which was substantially less than the 1.0-1.4 million smolts expected. IHNV was isolated f rom both moribund and apparently healthy smolts. Though smolt mortality was attributed to IHNV, other factors also may have contributed to the reduced numbers. Stressful environmental conditions and high fish density may have precipitated the disease outbreaks. In 1993, smolt abundance was less than expected but IHNV was not isolated. Management plans for the Chenik Lake system include maintaining current escapement levels at 10,000 adults and reducing stocking to between 1.0 and 1.5 million fry.


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Thermal Mark Technology for Inseason Fisheries Management: A Case Study
Peter Hagen, Kristen Munk, Benjamin Van Alen, and Bruce White - Vol. 2(2):143-155. 1995.

Effective management of wild and hatchery salmon stocks in Alaska requires rapid and accurate determination of each component in commercial mixed stock catches. Marking 100% of the hatchery fish with thermally induced bands on their otoliths can potentially reduce uncertainty in the management of mixed stock fisheries, this premise being the subject of our investigation. In 1992 and 1993, adult hatchery pink salmon Oncorhynchus gorbuscha that had been thermally marked by prescribed water temperature manipulation in Gastineau Hatchery passed through commercial fisheries on their return to this Southeast Alaska hatchery. In 1993 we processed otoliths that had been collected from the fisheries in 1992. We also applied an inseason recovery plan to process otoliths from the 1993 run; from a random sample of 400 heads collected from each of 5 commercial and 3 experimental fisheries, 100-150 otoliths were subsampled and examined within 24 h to provide managers with inseason estimates of composition. Later, additional otoliths were processed to increase precision around the estimates and to develop quality control criteria. A total of 3,870 heads from the 1993 fisheries were collected, from which 952 otoliths were processed inseason and 1,359 postseason. The final precision, based on the 95% confidence intervals, fell within ±2% of the point estimate for each fishery. The accuracy of detecting marked otoliths was determined by planting 17 known marked otoliths into samples processed for the inseason estimate. All planted otoliths were correctly identified. Personnel were trained to process and read otoliths as part of this project. Their progress was evaluated through samples containing both known marked and known unmarked otoliths and by determining between-reader agreement. The results confirmed the importance of training and indicated that, when learning to detect thermal mark patterns, individual skill development varies. We found thermal mark recovery in this study to be a timely and cost-effective tool for managing mixed stock fisheries.


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Marine Factors in the Production of Salmon: Their Significance to the Pacific Salmon Treaty
Jev Shelton and Jeffery P. Koenings - Vol. 2(2):156-163. 1995. No Abstract.


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Changes in Chela Heights and Carapace Lengths in Mature Male Red King Crabs Paralithodes camtschaticus After Molting in the Laboratory
A. J. Paul and J. M. Paul - Vol.2(2):164-167. 1995.

Measurements from 64 mature male red king crabs Paralithodes camtschaticus were made in carapace length (CL) and chela height (CH) before and after they molted in the laboratory. Increases in chela height for adult males 72-143 mm CL averaged 3.2 mm (SD = 1.5) at molting, but claw growth was not correlated to initial CH. At all carapace lengths examined there were individuals with both relatively large and small CH/CL ratios. After molting, CH/CL ratios increased in 28%, decreased in 25%, and stayed the same in the remaining 47% of the males. Among mature males, large or small claws relative to CL seemed to be an individual trait that was retained through the molt.


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Bulletin is Now on the Internet
Marla Trollan and Kurt Savikko - Vol. 2(2):168. 1995.
(No Abstract) Full Editorial:

Readers of the Alaska Fishery Research Bulletin may be interested to know that the journal's abstracts are now available on the Internet, and the entire journal may be online in 1997 or 1998, at which time paper production may be gradually phased out. The journal's abstracts are found in the Alaska Department of Fish and Game (ADF&G) web site, along with the guide to authors and editorial policy. The department's general/statewide information page provides a link to listings of publication titles organized by issue and by species group, and to which the abstracts are linked.

The ADF&G web site also provides other useful scientific and general information about Alaska's wildlife and fisheries. The site is about a year old but is really just beginning to evolve; considerable expansion is planned over the coming year. Commercial fisheries information has led the way with scientific report and publication listings, current and historical statistical data, and program descriptions. Similar information is being developed for sport fisheries and wildlife.

The web site structure blends the organization of the agency with subject categories. For example, the Commercial Fisheries Management and Development Division was primarily divided by management region. Beneath this level, the following subject areas were defined: species & fisheries, programs, publications, regulations, general divisional information & frequently asked questions, staff listings & contacts, and permits, licenses and forms. The other divisions are expected to develop similar structures. Statewide and general information include a departmental overview, photo gallery, drawings of Alaska's fish, and links to other relevant sites.

At this time, specific commercial fisheries information now available includes salmon and herring forecasts with prior-year fishery overviews; fishery regulations and policies; current (inseason) and historical salmon catch statistics; descriptions of tag-otolith, pathology, and limnology programs; overview of herring fisheries in Alaska; species descriptions; and commercial fisheries system codes (used in fish tickets, Intent to Operate Reports, and Commercial Fisheries Operator Annual Reports). Department reports are also listed by series: Informational Leaflets, Technical Data Reports, Technical Fishery Reports, Regional Information Reports, Fishery Research Bulletins, and Special Publications. Future additions to the site will include such things as Intent to Operate and Catcher/Seller forms, a variety of fishery-related maps, permit information, inseason shellfish catch statistics, salmon enhancement and mariculture production information, and fishery news releases and management plans.

The site is accessed as follows: http://www.state.ak.us/local/akpages/FISH.GAME/adfghome.htm. Individuals wishing to find salmon catch statistics, for example, would first access ADF&G's home page, select the Commercial Fisheries Management and Development link, next select the Statewide & General Information link (regional links could also be selected for area-specific information), and finally select the Salmon link under the Finfish Species and Fisheries heading.


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VOLUME 3(1) - SUMMER 1996

Spot Shrimp Growth in Unakwik Inlet, Prince William Sound, Alaska
Al Kimker, Wayne Donaldson, and William R. Bechtol - Vol.3(1):1-8. 1996.

Commercial shrimp harvests from the pot fishery in Prince William Sound, Alaska, averaged 2.9 metric tons (mt) annually prior to 1979. Catches increased rapidly after 1978, 110 mt being harvested in 1986. Little was known about adult spot shrimp Pandalus platyceros, which composed the bulk of these harvests. To obtain life history information the Alaska Department of Fish and Game marked 10,168 spot shrimp with streamer tags during 1983-1986. A total of 1,061 tags were recovered, 206 of these being repeat recoveries. The maximum time at liberty was 1,562 d, during which time the shrimp grew 11.5 mm. Mean annual growth was 3.1 mm for the 477 recoveries that molted between recaptures. Data on time at liberty and size at tagging and recapture for individual shrimp were fit to a von Bertalanffy growth equation. Results indicated that shrimp 28.5 to 41.5 mm carapace length were 3 to 7 years old, representing 5 age classes. Combined with previous studies that indicated the juvenile stage of spot shrimp lasts at least 2 years, lifespans of spot shrimp in Prince William Sound probably exceed 7 years. This longevity is much greater than previously assumed and emphasizes the need for more conservative management.


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Abundance of the Chinook Salmon Escapement in the Taku River, 1989 to 1990
Keith A. Pahlke and David R. Bernard - Vol. 3(1):9-20. 1996.

An interagency study was conducted to estimate, through mark-recapture methods, the abundance of large (greater than or equal to 660 mm MEF), spawning chinook salmon Oncorhynchus tshawytscha in the Taku River in 1989 and 1990. Fish were captured with fish wheels from May through July in the lower river at Canyon Island in Southeast Alaska. All fish were marked with back-sewn spaghetti tags, and some were additionally fitted with radiotags. Chinook salmon recaptured in Canadian tributaries showed that fish bound for the Nahlin River generally passed Canyon Island first, those bound for the Nakina River passed next, and fish bound for Tatsatua and Kowatua Rivers passed last. The 1984 year class predominated samples in both 1989 and 1990. Little or no size- or sex-selective sampling among larger fish was evident in samples taken from tributaries. Because many recaptured fish had lost their spaghetti tags, the marked population used for estimating abundance was defined as only those fish with radiotags that had been tracked to their spawning grounds. Recapture proportions were similar among tributaries. Abundance of large fish was estimated at 40,329 (SE = 5,646) for 1989 and 52,142 (SE = 9,326) for 1990. Estimates of abundance from aerial surveys of the Taku River were considerably smaller than estimates from mark-recapture experiments in both 1989 and 1990, a trend repeated in studies at other transboundary rivers in later years.


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Relative Effects of Mixed Stock Fisheries on Specific Stocks of Concern: A Simplified Model and Brief Case Study
Denby S. Lloyd - Vol.3(1):21-31. 1996.

An algebraic model is presented that allows comparison of changes in total catch, stock-specific catch, and stock-specific harvest rate for various fisheries harvesting the same stock of concern under conditions of change in the stock's abundance. The model operates without detailed estimates of each fishery's complete stock composition and without ongoing assessment of each component stock's biomass or population size. Rather, observations or assumptions of the proportional contribution (rho sub x) of the stock of concern to each fishery's total catch, combined with presumptions of change in that stock's abundance (theta sub x), are sufficient to illustrate proportional changes in catch and harvest rate under management prescriptions for constant harvest rate and for constant total catch. Results indicate that mixed stock fisheries, especially those with low rho sub x from a particular stock, are only slightly affected by and exert very small influence upon changes in abundance of that stock, even if total harvests remain constant. In contrast, single stock fisheries with high rho sub x are more directly affected by and exert more substantial influence upon changes in the stock's abundance. Because the presence of other stocks in a mixed stock fishery dilutes its relationship to any stock in particular, such a fishery may not need to be managed nearly so precisely as another fishery for which a common stock supports the bulk of the harvest.


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Relative Effects of Mixed Stock Fisheries on Specific Stocks of Concern: Application to Fixed Escapements and Norton Sound Chum Salmon
Denby S. Lloyd - Vol. 3(1):32-44. 1996.

An algebraic model relating annual changes in harvest rate and catch of various fisheries to the percent of total catch in each fishery contributed by a particular stock is examined to explore implications pertaining to harvest sharing and related escapements. Results indicate that mixed stock fisheries, especially those in which the stock of concern composes a small proportion of the total catch, tend to achieve much of their proportional responsibility for fixed escapement without adjustment of total catch. More terminal fisheries with high contributions from a particular stock must adjust total harvests to achieve similar responsibility. Adjusting total catch of mixed stock fisheries to fully achieve a strict proportional sharing of escapement comes at a cost of many times the number of fish forfeited from the harvest compared to the number of fish added to the stock's escapement. Such additions to the escapement are often insubstantial. Harvest adjustments in single stock fisheries, however, provide a 1-fish benefit to the escapement for each fish forfeited from the harvest, and often such contributions compose a substantial portion of the total escapement objective. Implications for Norton Sound chum salmon Oncorhynchus keta escapements are explored for the South Peninsula June mixed stock fishery compared to more terminal fishing in Norton Sound.


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Can Alaska Balance Economic Growth with Fish Habitat Protection? A Legislator's Perspective
Drue Pearce - Vol. 3(1):45-48. 1996. No Abstract.


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Can Alaska Balance Economic Growth with Fish Habitat Protection? A Biologist's Perspective
Kenneth E. Tarbox and Terry Bendock - Vol. 3(1):49-53. 1996. No Abstract.


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Microscale Abundance of Copepod Nauplii Prey of Larval Fishes in a Glaciated Fiord Measured with a 50-mL Sampler
A. J. Paul and J. M. Paul - Vol. 3(1):54-58. 1996.

Copepod nauplii were collected with a 50-mL sampler in 1995 to examine the microscale spatial heterogeneity of copepod nauplii in the immediate hunting territory of larval fish. The study was done in a glaciated fiord during the spring hatching period for walleye pollock Theragra chalcogramma. From mid April through mid May 50-mL water samples taken at 5- and 10-m depths contained, on average, 0.2-1.0 copepod nauplii 150-350 mm long. By 15 May the average sample counts were typically 1.0-4.0 nauplii at 5 m and 0.4-2.0 at 10 m deep. Based on previous literature values, copepod nauplii in Resurrection Bay exhibited sufficient abundance in these microscale samples to support walleye pollock larvae.


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Aspects of Sockeye Smolt Production in the Egegik River System of Bristol Bay, Alaska
Patrick C. Martin and Denby S. Lloyd - Vol. 3(1):59-63. 1996.

In Becharof Lake a significant positive correlation was found between the total number of sockeye salmon Oncorhynchus nerka, primarily age 1. and age 2., produced by brood year and the proportion of older holdover parr (age 2.) produced by the subsequent brood year. This suggests possible density-dependent effects of grazing pressure by large numbers of parr that reduce the food available to fry in subsequent years, which in turn causes a higher proportion of parr from subsequent brood years to have a longer freshwater residence. Recent, large spawning escapements may affect the rearing capacity of Becharof Lake and thereby reduce the subsequent production of smolts and return of adult sockeye salmon to the Egegik River.


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VOLUME 3(2) - WINTER 1996

Evaluation of Scale Pattern Analysis for Upper Cook Inlet Sockeye Salmon Stocks
David L. Waltemyer, Brian G. Bue, and Kenneth E. Tarbox - Vol. 3(2):69-80. 1996.

We evaluated scale pattern analysis, specifically linear discriminant function analysis and bivariate normal-density contour plots, as a tool to identify sockeye salmon Oncorhynchus nerka stocks returning to Upper Cook Inlet. Overall mean classification accuracy for 3-way, Kenai-Kasilof-Susitna River discriminant models ranged from 62 to 75% for the years 1983-1988. Bivariate normal-density contour plots of scale variables revealed a lack of consistency in size and shape and had significant overlap among stocks. Significant temporal and sexual intrasystem differences in scale variables were detected. Scale pattern has not provided the precision needed to effectively manage salmon stocks returning to Upper Cook Inlet.


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Effects of Formalin and Alcohol Preservation on Lengths and Weights of Juvenile Sockeye Salmon
Patrick A. Shields and Stan R. Carlson - Vol. 3(2):81-93. 1996.

Preserving fish can induce changes in fish tissue and structure that affect subsequent measurements of length and weight. We conducted 3 different experiments to quantify these changes and allow correction factors to be used as needed in analyses of fish growth and production. The experiments were designed to (1) determine temporal variation in the length and weight of juvenile sockeye salmon Oncorhynchus nerka as a result of storage in either 10% neutral freshwater-buffered formalin or 95% ethanol; (2) describe the amount of observed variation in length and weight measurements that can be attributed to reader variability; and (3) formulate conversion equations that allow for back-calculation to fresh lengths and weights. Fish preserved in alcohol for 70 d revealed a mean weight loss of 0.68 g after 16 d (19.7% of mean fresh weight; P < 0.001) and then appeared to stabilize through 70 d (P > 0.05). Length initially decreased by 1.41 mm after 16 d (2.19% of mean fresh weight; P < 0.0001), remained stable through 42 d, and then increased significantly (P < 0.0001) by day 70. Storage of fish in formalin produced various results. One experiment revealed a nonsignificant change in length (P = 0.114) after 70 d in the preservative; weight increased 0.24 g (7.12%; P < 0.0001) after 16 d of preservation, but then stabilized through 70 d. Additional formalin effects ranged from a minor length loss (P < 0.0001) and a substantial weight gain (P < 0.0001) after 106 d of storage to a significant (P < 0.001) loss in length after 30 d and continued loss through 99 d. Although a weight gain occurred after 30 d of preservation (P < 0.0001), no significant difference from fresh weight was found after 99 d. We examined the amount of variation in these results that may be attributed to reader differences. For the formalin group, maximum differences between readers were 3.5% (P < 0.0001) for lengths and 6.5% (P < 0.0001) for weights. For the alcohol group, differences were 1.9% (P < 0.0001) for lengths and 6.4% (P < 0.0001) for weights. Instructing readers on standardized blotting methods resulted in a maximum difference between readers of only 2.5% for weight measurements. Conversion equations that allow for back-calculation to original live lengths and weights were developed.


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New North American Records of the Northeast Pacific Scorpaenids Adelosebastes latens and Sebastes glaucus
James Wilder Orr and David C. Baker - Vol. 3(2):94-102. 1996.

The Aleutian scorpionfish Adelosebastes latens Eschmeyer, Abe, and Nakano, 1979, and the gray rockfish Sebastes glaucus Hilgendorf, 1880, are reported from new North American records from the Aleutian Islands, Alaska. Both records represent significant range extensions of about 2,200 km for each species. New diagnoses and notes on morphology, habitat, and species associations are provided for each species.


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Ovarian Energy Content of Pacific Herring From Prince William Sound, Alaska
A. J. Paul, J. M. Paul, and E. D. Brown - Vol. 3(2):103-111. 1996.

Ovarian energy content (OEC; measured in kilojoules) of ripe whole ovaries and per gram of ovary wet weight (OEC·g^-1) were examined for Pacific herring Clupea pallasi from Prince William Sound, Alaska. Specimens were collected in 1995 and 1996. The OEC of whole ovaries was related linearly to whole body weight, but OEC·g^-1 of ovary was not. Just prior to spawning OEC was typically between 5 and 7 kJ·g^-1 of ovary. There were no significant differences in OEC·g^-1 of ovary between groups of females from different capture sites in the 1995 collections, but in 1996 there were small but significant differences in OEC values related to capture site. When the OEC values from all fish collected in 1995 were pooled and compared to all those collected in 1996, there was no significant difference in OEC·g^-1 of ovary between years. The number of ova present just prior to spawning exhibited no clear relationship to OEC·g^-1 of ovary. About 97% of OEC was expended during spawning. The OEC of whole ovaries was used to estimate the energy from herring spawn added to Prince William Sound beaches from 1988 to 1995. Since 1989, when there was a massive oil spill, the annual amount of energy added to the Prince William Sound ecosystem by herring eggs has decreased from 68 x 10⁹ kJ to 10 x 10⁹ kJ in 1995, which in addition to being a concern for recruitment, could also be important to species relying on herring spawn as an energy source.


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Use of the Littoral Zone by Introduced Anadromous Salmonids and Resident Trout, Margaret Lake, Southeast Alaska
Mason D. Bryant, Brian J. Frenette, and Katharine T. Coghill - Vol. 3(2):112-122. 1996.

Construction of a fish pass around a barrier falls allowed at least 5 species of anadromous salmonids to colonize the Margaret Lake watershed, more than doubling the number of fish species in the lake. Juveniles of these anadromous salmonids, primarily coho Oncorhynchus kisutch and sockeye O. nerka salmon, rapidly and successfully colonized the littoral zone of Margaret Lake. Coho salmon fry and parr were the predominant salmonid species in the littoral zone after the fish pass was opened, and sockeye salmon fry were captured in both the littoral and pelagic zones. Although relatively few cutthroat trout O. clarki were captured throughout the study, they were the primary resident salmonids using the littoral zone before the fish pass was opened and were continually captured in the littoral zone throughout the study. Diel catch varied among species and was inconsistent from year to year. Numbers of fish captured at each site appeared to be associated with the geographic source of recruitment: stream outlets for coho salmon and planting location for sockeye salmon. Growth rates of coho salmon juveniles appeared to be greater later in the summer, whereas growth of sockeye salmon appeared to be greater during midsummer.


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Habitat and Depth Distribution of the Red Sea Cucumber Parastichopus californicus in a Southeast Alaska Bay
Shijie Zhou and Thomas C. Shirley - Vol. 3(2):123-131. 1996.

A field survey of red sea cucumber Parastichopus californicus distribution was conducted June 18-22, 1991, using a manned submersible in Barlow Cove, Southeast Alaska. The density of sea cucumbers counted in transects averaged 20.8 individuals·ha^-1 in the inner, 70.9 in the middle, and 103.7 in the outer stratum of the cove. Six types of substrata were encountered: mud/sand, debris, rock, shell, rock wall, and algae. Sea cucumbers were found at almost all depths from the intertidal zone to as deep as 183 m. Higher densities were encountered in 2 distinct depth zones: above 60 m and between 100 m and 150 m. This bimodal distributional pattern was attributed to the depth distribution of the rock wall substrate, which supported the highest density of sea cucumbers at 234·ha^-1. The higher densities of sea cucumbers along the nearly vertical rock walls are unexplained; rock walls may be preferred to the unstable nature of other substrates on the steeply sloped wall of the cove, or they may be selected for spawning.


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Male Tanner Crab Carapace Widths at Previous Intermolt Estimated from Laboratory Growth, Kachemak Bay, Alaska
A. J. Paul and J. M. Paul - Vol. 3(2):132-135. 1996.

Laboratory growth observations of Tanner crab Chionoecetes bairdi from lower Cook Inlet suggest that only males greater than or equal to 119 mm in carapace width (CW) could recruit to the legal size of 140 mm CW in a single molt. Back-calculated estimates of previous CWs indicated 84% of a sample of males captured in the fishery had CWs of 119-139 mm during their previous intermolt and 16% had CWs greater than or equal to 140 mm. This suggests that some crabs greater than or equal to 140 mm CW molt, but most of the harvested crabs were of sublegal size prior to their last molt.


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Online Bulletin's New Feature
Robert L. Wilbur and Kurt E. Savikko - Vol. 3(2):136. 1996.
(No Abstract) Full Editorial:

The Bulletin is now fully electric, literally, instead of just figuratively. You can access the Bulletin from the Alaska Department of Fish and Game's homepage: http://www.state.ak.us/adfg/adfghome.htm. The Bulletin is available in Adobe^® Acrobat^® Portable Document Format (PDF), which allows us to provide it in a fully formatted layout. It mirrors previous hard-copy versions but is ready for electronic viewing and printing. All that is required to use these PDF documents is a free Adobe viewer available from a link on our website or directly from Adobe. After installation of the viewer, direct access to the PDF documents is only a click away.

For now, the Bulletin will continue to be anchored in its paper copy. This means we will continue to produce printed issues, and the online issues will be posted issue by issue concurrent with the printed distribution. We may in the future become exclusively electronic, which would eliminate paper production costs and provide more timely access. That is, electronic-only journals are not posted by issues but are instead posted paper by paper (whenever a paper is ready, it is posted). This eliminates a paper's delay while the rest of the issue is assembled, which would benefit both authors and readers.

The online Bulletin, however, now offers a significant feature - a postnote - not present in the paper version. The postnote will be appended to the end of some papers after they are published (e.g., see online vol 3, nr 1, p 44) and will contain abbreviated post-publication notes that may be important to the readers of that paper, that is, important subsequent developments they might otherwise overlook or not discover until much later. As such, the postnote is intended as a service to our online readers, one that hopefully will increase their timely access to subsequent and specifically related information.

For example, if there was a particularly pertinent follow-up publication, that publication might be noted in the postnote, and if that related paper was published in a subsequent issue of the Bulletin, it would be electronically linked so the reader could immediately access that paper. The postnote will be especially useful in flagging and accessing subsequently published errata or challenges and rebuttals. In other cases, we might include a reader's contribution of unpublished findings or observations that would provide useful information or insights. However, we do not envision the postnote developing the demeanor of a chat room or bulletin board, so contributions will be carefully examined for their scientific importance and relatedness before acceptance and posting.

For most of our readers the postnote will be a new, unfamiliar feature in scientific reporting. However, we believe that postnotes will enhance the utility of our online service, so we especially encourage our readers to submit items for consideration and possible posting. Past authors are also encouraged to submit relevant follow-up items.

If you have an item you would like to have considered for inclusion as a postnote, please submit it to the editor at the address noted on the inside cover (or email: bobw@fishgame.state.ak.us). Please remember to cite the article your item references. We will notify you shortly thereafter of our decision and of any recommended changes. Inclusions will be filed chronologically within a postnote and include the contributor's name(s) and address. Additions to a postnote will be posted within several days of their approval.


Full Editorial ( PDF version * - 11K )		Top of Page

VOLUME 4(1) - SUMMER 1997

Diurnal Variation in the Catch of Salmon in Drift Gillnets in Lynn Canal, Alaska

Randolph P. Ericksen and Robert P. Marshall - Vol. 4(1):1-11. 1997.

Operators of 4 commercial drift gillnet vessels kept logbooks of their 1991 fishing effort and catch of sockeye Oncorhynchus nerka, chum O. keta, coho O. kisutch, and chinook O. tshawytscha salmon in Lynn Canal, Alaska. Mann-Whitney tests were used to determine if catch per unit effort (CPUE) for each species varied significantly by ambient light phase (day vs night). Two definitions of day and night were employed: one relative to sunrise and sunset and another relative to civil twilight. All data were temporally stratified into 3 fishing periods of 5 or 6 weeks each. Logbook fishers caught 7,840 sockeye, 6,330 chum, 3,579 coho, and 187 chinook salmon in 1,060 sets between June 16 and October 2. Chinook salmon were only caught incidental to other species, and 82% were classified as small (£8 lb) fish. The chinook harvest rate was significantly higher at night than at day, except during the final (fall) strata when very few chinook salmon were caught. During the peak of directed fisheries for sockeye salmon (mid July through August), CPUE for sockeye salmon was highest during the day. During September, CPUE for chum salmon was also higher during the day. Results provide a solid indication that considerable savings in chinook salmon could result from night closures in drift gillnet fisheries of inside marine waters.


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Mark-Recapture Abundance Estimate of Fall-Run Chum Salmon in the Upper Tanana River, Alaska, 1995

Thomas A. Cappiello and Jeffrey F. Bromaghin - Vol. 4(1):12-35. 1997.

The primary objective of this study was to determine the feasibility of a mark-recapture program to estimate inseason and postseason abundance of fall-run chum salmon Oncorhynchus keta in the upper Tanana River. We used 2 fish wheels, each on opposite riverbanks, to capture fish for tagging and 2 additional fish wheels on opposite riverbanks to recover tagged fish approximately 76 km upstream. All chum salmon caught during a daily 6-h schedule were marked with spaghetti tags. From 16 August through 30 September 1995, a total of 3,993 fall-run chum salmon were released with orange tags from the right bank; 181 were released with yellow tags from the left bank. From 18 August to 1 October, the right-bank recovery wheel caught 6,773 chum salmon, of which 103 were recaptures (94 orange; 9 yellow). During the same period, the left-bank recovery wheel caught 3,902 chum salmon, of which 63 were recaptures (55 orange; 8 yellow). Catches from both recovery wheels were pooled because tagged fish were not bank-oriented and there was no statistically significant difference in the marked proportions between each wheel. However, information from yellow-tagged fish was not adequate for estimating abundance. Bailey's closed population model produced a total estimate of 268,173 (SE = 21,597) fall-run chum salmon that passed the tagging site after 16 August. No significant sources of bias from assumption violations were detected. The mean migration rate between tagging and recovery sites was 26 km/d. We concluded that a mark-recapture program using fish wheels for fish capture appears feasible but should continue in a developmental stage to allow further evaluation of its utility under a variety of circumstances. Tagging fish from only the right-bank tagging wheel and tagging more fish, while using 2 wheels for tag recovery, may be necessary to improve precision of the abundance estimate.


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Time Series Outlier Analysis: Evidence for Management and Environmental Influences on Sockeye Salmon Catches in Alaska and Northern British Columbia

Edward V. Farley, Jr., and James M. Murphy - Vol. 4(1):36-53. 1997.

Autoregressive, moving average models were fit and outliers were identified for commercial catches of 9 major sockeye salmon Oncorhynchus nerka stocks in Alaska and northern British Columbia. Distinct patterns in the sample autocorrelation and partial autocorrelation functions indicated stock-specific dynamics. Three types of outliers were considered: level-shift, temporary-change, and additive outliers. Most additive outliers were unexplainable and may represent multiplicative survival at several different life history stages. Additive outliers that could be explained resulted from changes in fishing effort. Temporary-change outliers commonly reflected cold winter temperatures in western Alaska during the early 1970s. Four of nine river systems in our analysis had level-shift outliers, and only one of these had a positive shift in the late 1970s. The level-shift outliers, which indicate a long-term shift in catch levels, appeared to be the result of changes in escapement policy rather than an abrupt change in the production dynamics of the North Pacific.


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Timing of Occurrence and Length Frequency Profiles of Walleye Pollock Larvae in Resurrection Bay, Alaska, Spring 1991
Linda A. Clayton, A. J. Paul, and Judy M. Paul - Vol. 4(1):54-61. 1994.

In 1991 the major cohorts of walleye pollock Theragra chalcogramma larvae in Resurrection Bay, Alaska, initiated feeding when the copepod nauplii population was still at low winter density levels. First-feeding walleye pollock larvae were most abundant between 16 April and 14 May; thereafter, there were very few recently hatched larvae in the plankton. Copepod nauplii did not begin their annual increase in abundance until mid June. Throughout the spring and summer few walleye pollock larger than the first-feeding stage were observed, suggesting that low prey abundance was limiting larval growth. In 1991 the small late-hatching cohorts had the best feeding conditions in the bay.


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Application of a Catch-Survey Analysis to Blue King Crab Stocks Near Pribilof and St. Matthew Islands
J. Zheng, M. C. Murphy, and G. H. Kruse - Vol. 4(1):62-74. 1996.

A catch-survey analysis was conducted on 2 blue king crab Paralithodes platypus stocks near Pribilof and St. Matthew Islands of the eastern Bering Sea. Total annual catch and observed relative survey abundance of legal-sized crabs were classified into recruits and postrecruits by shell age and size and analyzed with a maximum likelihood approach. This analysis separates measurement errors from the true changes in population abundance and converts the relative abundance to an absolute value. The analysis provides smoothed annual estimates of legal blue king crab abundance for both stocks. In both areas, legal male abundances appear to be rebuilding slowly from depressed stock levels of the mid 1980s. Based on a reasonable instantaneous natural mortality range of 0.16 to 0.35 for both crab stocks, (1) postrecruit catchability is about 1.98-2.07 for the Pribilof Islands stock and about 1.20-1.38 for the St. Matthew Island stock, and (2) the ratios of recruit-to-postrecruit catchabilities for both stocks are <1.05. Because of confounded effects among catchability, recruit-to-postrecruit catchability ratio, and natural mortality, additional information is needed to separately estimate 2 of these 3 parameters.


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Are Prince William Sound Salmon Hatcheries a Fool's Bargain
William W. Smoker and Tim J. Linley - Vol. 4(1):75-78. 1997. No Abstract.


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Call For Data: Bering Sea Ecosystem Metadatabase
Bernard A. Megrey - Vol. 4(1):79-80. 1997. No Abstract.


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VOLUME 4(2) - WINTER 1997

Age-Structured Analysis of Pacific Herring from Norton Sound, Alaska
Erik H. Williams and Terrance J. Quinn II - Vol. 4(2):87-109. 1997.

For many exploitable Pacific herring Clupea pallasi stocks in Alaska, age-structured assessment models are used to forecast the abundance of returning herring. The purpose of this study was to develop such a model for Norton Sound herring. Commercial catch and sampling data for Norton Sound herring were obtained from the Alaska Department of Fish and Game. Natural mortality estimates were obtained from analysis of life history parameters. Initial starting values for the age-structured model were obtained from cohort analysis. Better results were obtained when age-composition data for age 10 and older were pooled into a plus group. A parametric bootstrap analysis using a beta distribution by incorporating variability from the age-composition residuals provided standard errors of the estimates. The analysis suggested that aerial surveys underestimated actual biomass in the early 1980s. However, a sensitivity analysis suggested that higher natural mortality in those years could have produced similar results. The fit of this model to the data was comparable to that obtained with age-structured assessments of other Alaska herring stocks. We believe this model can be used as a stock-assessment tool for management of Norton Sound herring.


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Literature Compilation on Tagging Red King Crabs in Alaska from Initial Efforts in 1954 through 1969
William E. Donaldson - Vol. 4(2):110-119. 1997. No Abstract.


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Consequences to Juvenile Sockeye Salmon and the Zooplankton Community Resulting from Intense Predation
J. P. Koenings and G. B. Kyle - Vol. 4(2):120-135. 1997.

Stocking of juvenile sockeye salmon Oncorhynchus nerka into nonanadromous lakes at levels comparable with juvenile densities in anadromous lakes supporting natural sockeye salmon populations effected up to a 90% reduction in zooplankton biomass. The zooplankton communities subsequently became resistant to predation as the vulnerable Daphnia, Diaptomus, and ovigerous Cyclops were virtually eliminated and the more agile (nonovigerous) Cyclops and smaller Bosmina persevered and became predominant. Relying on a standing crop of zooplankton that was severely depressed by intense grazing the previous season, juvenile sockeye salmon experienced at least a 3-fold reduction in numbers and biomass between fry and smolt stages from the previous year. Our experimental results confirmed our empirical findings that, in rearing-limited lakes, smolt biomass production becomes a function of zooplankton biomass. Once restructured by excessive predation, some zooplankton communities were unresponsive or slow to respond to either reduced grazing pressure and/or to subsequent nutrient treatment. This delayed recovery of overgrazed zooplankton populations reduced growth and survival (rearing efficiency) for ensuing cohorts. In response, Frazer Lake sockeye salmon populations fell far below replacement, the dominant-year run segment collapsed, and the amplitude of high versus low return per spawner ratios increased. In contrast, less damaged zooplankter populations responded to nutrient treatments, leading to a 3-fold increase in fry-to-smolt survival and a 6- to 20-fold increase in smolt biomass. The degree to which juvenile sockeye salmon foraging decreases biomass levels and changes the species composition of the zooplankton community ultimately determines the duration of zooplankton recovery and lowered sockeye salmon production.


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Trophic-Level Responses to Nutrient Treatment of Meromictic and Glacially Influenced Coghill Lake
J. A. Edmundson, G. B. Kyle, S. R. Carlson, and P. A. Shields - Vol. 4(2):136-153. 1997.

Prior to a 1990-1994 run decline, Coghill Lake consistently produced the highest single-system sockeye salmon Oncorhynchus nerka catches in Prince William Sound. Although limnological and juvenile fisheries data are not available before the run declined, we hypothesized that sockeye salmon fry produced from 3 consecutive years of high escapements (1980-1982) might have overgrazed the zooplankton forage base and reduced the lake's sockeye salmon rearing capacity. In 1993 the Exxon Valdez Oil Spill Trustee Council approved and helped fund a nutrient enrichment stock restoration project for Coghill Lake to mitigate the oil-damaged fishery resources. During 4 years of nutrient enrichment (1993-1996), the seasonal mean phosphorus concentration increased 22%, algal biomass of mainly genera edible by zooplankton increased 220%, and the standing stock (density) of the prevalent zooplankton (Cyclops) increased 117% compared to pre-enrichment years (1988-1992). The sockeye salmon population averaged 263,604 smolts before enrichment compared to 940,411 during treatment. This increased smolt production is attributed to increases in primary and secondary production because the number of smolts produced per spawner also increased during enrichment. The trophic-level responses to nutrient enrichment in meromictic, glacially influenced Coghill Lake were similar to those observed for other clearwater holomictic and meromictic lakes treated in Alaska.


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Early Marine Residence, Growth, and Feeding by Juvenile Salmon in Northern Cook Inlet, Alaska
Lawrence L. Moulton - Vol. 4(2):154-177. 1997.

Juvenile salmon were captured in June and July 1993 with a surface townet in the northern portion of Cook Inlet, a glacially turbid estuary. Hydroacoustic sampling indicated that most fish targets were in the top 2 m of the water column. Many salmon juveniles, particularly chinook Oncorhynchus tshawytscha, sockeye O. nerka, and coho O. kisutch, moved rapidly out of the sampling area, although residence in northern Cook Inlet extended into mid July. Chum salmon O. keta were more abundant than any other salmon species in northern Cook Inlet, and by July were widely distributed throughout the study area. Diets of juvenile salmon in June were similar to those reported in other studies, calanoid copepods, fish larvae, and other zooplankton being abundant in stomachs. Chum salmon, followed by pink salmon O. gorbuscha, fed most intensively. Drift insects were an important part of chum salmon diets in June and predominated the diet of all species in July. Heavy feeding on drift insects demonstrated by all juvenile salmon was probably a response to high turbidities reducing feeding efficiency and effecting a near-surface orientation. Apparent growth in chum salmon juveniles was within the reported range for other regions. During July, both chum and pink salmon juveniles rearing in northern Cook Inlet achieved growth rates and conditions comparable to those of nearby Prince William Sound, which is not glacially occluded.


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Salmon Stocks at Risk: What's the Stock and What's the Risk?
Harold J. Geiger and A. J. Gharrett - Vol. 4(2):178-180. 1997.

Fisheries managers and fisheries population biologists and geneticists have 2 big problems when talking about salmon stocks at risk: disagreement about what a stock is, and too little to go on about what is at risk. We recommend leaving the word stock to fisheries managers, with the traditional emphasis on groups of fish managed as a unit. We recommend reserving the word deme to mean a smaller-scaled stable population of interbreeding salmon, with the emphasis on genetic discreteness. We hope maintaining this distinction can help promote a freer discussion of fluctuations in run sizes and help direct more attention to biological issues, like the underpinnings of sustainable fish production. Second, we want to turn the question around from "are stocks at risk?" to "what is at risk?" We conclude that if concrete services that humans enjoy from salmon populations were fairly evaluated against activities that put those services at risk, sustainability is undervalued.


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Incidence of Thermally Marked Pink and Chum Salmon in the Coastal Waters of the Gulf of Alaska
Edward V. Farley, Jr., and Kristen Munk - Vol. 4(2):181-187. 1997.

A Gulf of Alaska research cruise during July and August 1996 provided ocean recoveries of 698 juvenile pink Oncorhynchus gorbuscha and 350 chum O. keta salmon thermally marked during incubation at Alaskan and Canadian hatcheries. We obtained the recoveries from 2,343 pink and 1,695 chum salmon examined for thermal marks. The marked salmon migrated westerly; those released from southeastern Alaska hatcheries were caught as far west as Cape Puget and Cape Hinchinbrook, whereas pink salmon released from Prince William Sound hatcheries were found as far west as Mitrofania Island. Our results indicate that a modest research sampling program can collect sufficient numbers of thermally marked salmon for detailed studies of the growth and development of individual salmon stocks.


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VOLUME 5(1) - SUMMER 1998

The Diets and Feeding Habits of Some Deep-Water Benthic Skates (Rajidae) in the Pacific Waters Off the Northern Kuril Islands and Southeastern Kamchatka
Alexei M. Orlov - Vol. 5(1):1-17. 1998.

On the basis of shipboard analysis, the diets of 7 species of deep-benthic skates were examined: Aleutian skate Bathyraja aleutica, sandpaper skate B. interrupta, Alaska skate B. parmifera, B. matsubarai, whiteblotched skate B. maculata, whitebrow skate B. minispinosa, and Okhotsk skate B. violacea. The diet of predatory skates (Alaska skate, Aleutian skate, whiteblotched skate, and B. matsubarai) consisted of large crustaceans, cephalopods and fishes. Benthophagic skates (sandpaper skate, Okhotsk skate, and probably whitebrow skate) consumed mainly amphipods and worms. The consumption of worms and crustaceans (especially small crustaceans) in diets of predatory skates declined with increasing skate size, whereas cephalopod and fish frequency of occurrence increased. For benthophage skates occurrence of amphipods in stomachs declined with increasing skate size and consumption of shrimps and other large crustaceans, as well as squids, increased.


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Relationship Between Wind and Year Class Strength of Tanner crabs in the Southeastern Bering Sea
Gregg E. Rosenkranz, Albert V. Tyler, Gordon H. Kruse, and H. Joe Niebauer - Vol. 5(1):18-24. 1998.

Knowledge of Bering Sea oceanography and the life history of Tanner crabs Chionoecetes bairdi led us to 2 hypotheses about the effects of wind on the formation of year class strength, defined as the number of crabs hatched in a given year that survive to maturity. First, year class strength is limited by food availability during the pelagic zoeal phase and is enhanced when wind-driven turbulent mixing or upwelling transports nutrients into the euphotic zone, increasing primary and secondary productivity. Second, wind-driven advection during the pelagic phase carries zoeae to either favorable or unfavorable habitat for settlement. We investigated these hypotheses by testing for statistically significant correlations between recruitment estimates, derived from a length-based model, and wind data from St. Paul Island in the eastern Bering Sea. We found a significant positive correlation between the intensity of average May-June wind vectors resolved along NE-SW axes and recruitment of male Tanner crabs 7 years later and female Tanner crabs 6 years later; there were no significant relationships when winds were resolved along NW-SE axes. Despite uncertainty about age of recruitment due to our poor understanding of Tanner crab growth rates, we interpret these statistical results as lending support for both the above hypotheses.


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An Economic Analysis of Pot Limits for the Adak Brown King Crab Fishery: A Distinction Between Open Access and Common Property
Mark Herrmann, Joshua Greenberg, and Keith Criddle - Vol. 5(1):25-38. 1998.

A proposed vessel-specific pot limit for the Adak, Alaska, brown king crab Lithodes aequispina fishery failed to be adopted as regulation by the Alaska Board of Fisheries at their March 1997 meeting. A group of fishermen had proposed the pot limit because they believed excessive pot gear on the crabbing grounds had compromised effective management. We suggest that a manageable system of quasi property rights exists in the fishery and that the proposed pot limits would have failed to improve, and could have decreased, economic efficiency. Second, in the absence of a reliable efficiency rationale, the proposed vessel-specific pot limits were solely allocative in purpose. Furthermore, management's goal in this fishery is focused on controlling total fleet fishing power rather than the number of pots fished by individual vessels. If these assertions are true, then it may be preferable to consider the development of alternative regulatory measures that effectively address total rather than per-vessel fishing power.


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Avoidance Behavior of Ovigerous Tanner Crabs Chionoecetes bairdi Exposed to Mine Tailings: A Laboratory Study
Scott W. Johnson, Robert P. Stone, and D. C. Love - Vol. 5(1):39-45. 1998.

Avoidance behavior was examined in ovigerous Tanner crabs Chionoecetes bairdi exposed to mine tailings produced in a pilot plant associated with a proposed gold mine near Juneau, Alaska. Individual crabs were placed in a circular tank that was divided into 4 equal sections containing natural marine sediment (control) and tailings in alternate sections. A time-lapse video camera recorded the position of each crab within the tank over 24 h. Crabs spent significantly (t = 2.43, P < 0.02, df = 24) more time on control sediment (61%) than on tailings (39%). Of 25 test crabs, 19 spent the most time (greater than or equal to 12 h) on control sediment, whereas only 6 crabs spent the most time on tailings. Ovigerous Tanner crabs may avoid areas affected by the submarine disposal of tailings during the life of the mine. Location of potential submarine tailings disposal sites in areas with high natural sedimentation may accelerate recovery of the sea floor by rapid burial of tailings.


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Genetic Variation of Return Date in a Population of Pink Salmon: A Consequence of Fluctuating Environment and Dispersive Selection?
William W. Smoker, Anthony J. Gharrett, and Michael S. Stekoll - Vol. 5(1):46-54. 1998.

A genetic basis for variation in the date that anadromous salmon return to their natal or home stream was demonstrated by significant differences between return dates of pink salmon Oncorhynchus gorbuscha families. Of 120 families made by hierarchical matings of 60 males and 120 females, 118 families survived. The first half (60 families) and second half (60 families) were spawned 28 d apart. The 120 full-sibling families were incubated separately, released as fry with identifying coded microwire tags, and recovered entering the home stream as adults. Families in the first half returned on average 29 d before families in the second half (P < 0.0001). Average return dates differed between families that were spawned on the same day by different fathers (P < 0.045 sons; P < 0.040 daughters). These differences indicate that additive genetic variance contributes to the natural variation of return date. Heritability of timing of anadromous migration in odd-year pink salmon spawned in Auke Creek, Alaska, was very high, perhaps near unity, over the entire population. For segments of the population spawning on the same date, heritability was about 0.2 (SE 0.2) in males and about 0.4 in females (SE 0.2). We suggest that such high genetic variability of a trait closely related to fitness is maintained by the fluctuating environment to which Auke Creek pink salmon must continually adapt or by dispersive selection caused by redd superimposition. In either case, generalizing to other salmon populations, rational management must preserve variability of return timing if the fitness of populations is to be conserved.


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Salmon Run Failures in 1997-1998: A Link to Anomalous Ocean Conditions?
Gordon H. Kruse - Vol. 5(1):55-63. 1998.

In July 1998 Alaska's Governor Tony Knowles submitted a request for federal disaster relief owing to severe economic and social hardships in some western Alaska communities affected by unusually poor salmon runs, especially Bristol Bay sockeye salmon Oncorhynchus nerka and Yukon River chinook O. tshawytscha and summer chum O. keta salmon. Other anomalies were also noted in these runs: late run timing, smaller-than-average fish, altered migration pathways, and anecdotal reports of higher occurrences of parasites and increased signs of predation. Were these poor returns attributable to unusual marine environmental conditions in 1997/98? Decadal changes in salmon productivity have been related to indices of the strength of the Aleutian Low in winter, which may affect feeding success during early marine life. Analysis of return-per-spawner data is needed to determine whether this climate-salmon relationship continues to hold. Additionally, significant changes in ocean conditions occurred in the North Pacific and Bering Sea in 1997/98 that may have had profound effects on the marine ecosystem. Not only was there a very strong equatorial El Niño, but light winds, low nutrients, and high solar radiation led to the first-recorded bloom of coccolithophores in the Bering Sea in summer 1997 and a bloom occurred again in spring 1998. At-sea research is urgently needed on the biotic implications of these conditions, from effects on primary and secondary producers to effects on invertebrates, fish, birds, and marine mammals through the pelagic and benthic food webs.


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Occurrence of an Atlantic Salmon Salmo salar in the Bering Sea
Richard D. Brodeur and Morgan S. Busby - Vol. 5(1):64-66. 1998.

An immature male specimen of an Atlantic salmon Salmo salar was captured in a bottom trawl south of the Pribilof Islands in the Bering Sea in September 1997; this represents the first known capture of this species in the Bering Sea. We provide information on the size, age, and feeding of this fish and discuss the ecological implications of this occurrence.


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A Comment and Response on Time Series Outlier Analysis
Comment: Steven R. Hare and Robert C. Francis and Response: Edward V. Farley, Jr. and James M. Murphy - Vol. 5(1):67-73. 1998. No Abstract.


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VOLUME 5(2) - WINTER 1998

Experimental Effects of Soak Time on Catch of Legal-Sized and Nonlegal Red King Crabs by Commercial King Crab Pots
Douglas Pengilly and Donn Tracy - Vol. 5(2):81-97. 1998.

An experiment was conducted in Bristol Bay, Alaska, to assess the effects of soak time on catch per pot of legal (males greater than or equal to 165 mm carapace width) and nonlegal (females and sublegal-sized males) red king crabs Paralithodes camtschaticus. Soak times of 12, 24, and 72 h were tested because they cover the typical range of soak times in the Bristol Bay commercial fishery. Catch per pot increased with each increase of soak time for both legal and nonlegal red king crabs, but catch per pot per soak-hour decreased with increasing soak time. Additionally, the ratio of nonlegal red king crabs to legal red king crabs decreased with increased soak time, although local conditions were also shown to have a significant effect on bycatch rates of nonlegal crabs.


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A Simple Stratified Design for Mark-Recapture Estimation of Salmon Smolt Abundance
Stan R. Carlson, Lewis G. Coggins Jr., and Charles O. Swanton - Vol. 5(2):88-102. 1998.

We describe a mark-recapture (M-R) technique in which a stratified design and sampling at 1 or 2 stream locations are used to estimate the abundance of a migrating salmon smolt population. The method consists of counting smolts captured at a designated downstream site and releasing marked smolts back into the population at an upstream site. Marked smolts subsequently recovered at the downstream site are counted to estimate capture probability (trap efficiency), which is used to estimate smolt abundance for a segment of the population. This procedure is temporally stratified such that each trap efficiency trial is discretely paired with one capture period; this can typically be accomplished by releasing marked smolts at relatively short intervals (a few days) with little chance of recaptured fish occurring in later strata. This approach accounts for potential temporal changes in capture probability under a fairly modest assumption of stratum consistency. The method simplifies the generalized 2-sample stratified design and provides some important advantages: (1) because marking occurs in discrete intervals, personnel costs are substantially reduced; (2) because each release of marked smolts corresponds to one capture period, only one type of mark is needed, which greatly simplifies marking procedures and recapture tallying; and (3) when only one capture site is used, material costs are reduced by about half. We present approximately unbiased abundance and variance estimators of the total smolt population and develop a method of estimating the number of smolts to be marked. A parametric bootstrap technique for quantifying precision is also developed. An example of the method is given using the 1997 sockeye salmon Oncorhynchus nerka smolts migrating from Akalura Lake, Kodiak Island, Alaska. The Akalura Lake study included a weir count of smolts, which we used to evaluate the accuracy of the M-R estimate.


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Deep-Water Bark Accumulation and Benthos Richness at Log Transfer and Storage Facilities
Ben Kirkpatrick, Thomas C. Shirley, and Charles E. O'Clair - Vol. 5(2):103-115. 1998.

A small, manned submersible was used to determine the extent of bark accumulation and its effects on the epifaunal macrobenthos at depths from 20-130 m at log transfer facilities (LTFs) and log rafting facilities (LRFs) in Dora Bay, Prince of Wales Island, Alaska. Continuous videotaping from an external fixed camera was conducted along 6 transects located near LTFs and LRFs and along 3 transects in a similar, adjacent area not used as an LTF or LRF. Bark and woody debris accumulations and kinds and numbers of organisms were recorded by depth for 3 general habitat types (steep, rocky; moderate incline, cobble; flat, silty) with and without bark. Bark accumulation was found to 40-m depth on 6 dives, and to 70-m depth on 3 dives. Of 91 taxa observed during the study, most (69 species) were found on rocky, bark-free habitat; significantly reduced species richness was found in all bark-dominated habitats. Bark and debris from LTFs appeared to be displaced down slope into adjacent, deeper areas; this is the first published account of bark and woody debris accumulation below 20-m depth. In suitable habitats, manned submersibles or remotely operated vehicles appear to be useful tools for monitoring bark accumulation and investigating the effects of logging facilities.


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Stock-Recruitment Relationship for Bristol Bay Tanner Crab
Jie Zheng and Gordon H. Kruse - Vol. 5(2):116-130. 1998.

We developed a method to estimate male reproductive potential and effective spawning biomass and used the results from a length-based model to develop a stock-recruitment relationship for Bristol Bay Tanner crab Chionoecetes bairdi. Weak and strong recruitment occurred with both low and high effective spawning biomass; however, recruits are not strongly associated with effective spawning biomass. Recruitment is highly autocorrelated. The strongest recruitment is almost 100 times as large as the weakest recruitment, and the largest effective spawning biomass is more than 10 times as large as the lowest. An autocorrelated Ricker curve is flatter and fits the observations better than an ordinary Ricker curve. Much of the recruitment variation can be explained by autocorrelation or cycle; thus, environmental factors are likely to play a very important role in recruitment success.


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Spring and Summer Whole-Body Energy Content of Alaskan Juvenile Pacific Herring
A. J. Paul and J. M. Paul - Vol. 5(2):131-136. 1998.

During the spring and summer of 1996 and 1997, we examined the whole-body energy content (WBEC) of Pacific herring Clupea pallasi less than or equal than 165 mm standard length (SL) from Prince William Sound, Alaska. From May to October, somatic energy (kJ·g^-1 wet weight) exhibited a wide range of values relative to length. Young-of-year recruits, which appeared in July of both years, typically had WBEC of 2-3 kJ·g^-1 wet weight after metamorphosis, and older fish had WBEC of 4-6 kJ·g^-1 wet weight. By October the WBEC of juvenile herring was typically 4-6 kJ·g^-1 wet weight. The consequences of the large seasonal and size-related variability in WBEC in juvenile herring are discussed relative to the transfer of energy to predators.


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An Egg-Loss Correction for Estimating Spawning Biomass of Pacific Herring in Prince William Sound, Alaska
Christopher N. Rooper, Lewis J. Haldorson, and Terrance J. Quinn II - Vol. 5(2):137-142. 1998.

Spawning biomass of Pacific herring Clupea pallasi populations is commonly estimated from surveys that quantify their egg deposition. Because surveys occur after spawning, a correction for egg loss is required. We estimated this correction factor for the 1995 herring stock in Prince William Sound, Alaska, using an egg-loss model. The model was based on the cumulative time of exposure to air during egg incubation. The correction factor for the percentage of eggs lost between spawning and spawn-deposition surveys was estimated at 31% (SE = 2.2%). This value is much higher than the value previously assumed for Alaska stocks. Because interannual variability in the egg-loss correction may occur, we suggest that future spawn surveys be accompanied by egg-loss studies.


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Age and Marine Survival of Ocean-Type Chinook Salmon Oncorhynchus tshawytscha from the Situk River, Alaska
John F. Thedinga, Scott W. Johnson, and K V. Koski - Vol. 5(2):143-148. 1998.

Chinook salmon Oncorhynchus tshawytscha smolts were sampled for scales, coded-wire-tagged, and released in the Situk River, Alaska. As returning adults, they were then sampled for scales to compare freshwater age composition at release and recovery and to estimate marine survival. Of 10,191 chinook salmon smolts tagged (July 1989), 98% were age 0. From 1991 through 1993, 23 of 35 tagged chinook salmon adults recovered in the commercial fishery and spawning-ground surveys had readable scales that identified 87% of the fish as age 0. (ocean-type). Estimated marine survival was 2.9%, excluding returning age-0.1 jacks. We concluded that ocean-type chinook salmon are the predominate life history type for the Situk River. Situk River chinook salmon are unique because they are the only known stock in Alaska that migrates to sea primarily at age 0.


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VOLUME 6(1) - Summer 1999

Assessment of Red King Crabs Following Offshore Placer Gold Mining in Norton Sound
Stephen C. Jewett - Vol. 6(1):1-18. 1999.

In a 4-year study I assessed impacts of offshore placer gold mining on adult red king crabs Paralithodes camtschaticus in the northeastern Bering Sea near Nome, Alaska. From June to October 1986-1990, nearshore mining with a bucket-line dredge to depths of 9 to 20 m removed 1.5 km² and about 5.5 X 10⁶ m³ of substrate. Crabs were offshore of the study area when mining occurred but were in the mining vicinity during the ice-covered months of March and April, which was the primary time data on crab abundance and prey were obtained. Comparisons between mined and unmined stations revealed that mining had a negligible effect on crabs. Crab catches, size, sex, quantity, and contribution of most prey groups in stomachs were similar between mined and unmined areas. However, a few ROV observations indicated that crab abundance was lower in mined areas. Also, plants (mainly eelgrass Zostera marina) and hydroids, which accumulated in mining depressions, were more common in crab stomachs from mined areas. The preponderance of food consumed by crabs throughout the mined and unmined regions was unidentified fishes. Mining effects were analyzed in the context of the small size of the area disturbed, the dynamic nature of the benthic habitat in the region, and the opportunistic feeding habits of the crabs.


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Mass Molting of Tanner Crabs Chionoecetes bairdi in a Southeast Alaska Estuary
Robert P. Stone - Vol. 6(1):19-28. 1999.

A spring migration of Tanner crabs Chionoecetes bairdi into a shallow, glacially-influenced cove to molt en masse was studied in 1992 and 1993. An estimated 11,500 crabs molted in a 0.034 km² area of shallow (+0.6 m to -17.4 m) water in 1992. Over 2,400 carapaces from intact exuviae were collected by scuba divers in a 100 X 70 m section of the molting area. Molting in both years was restricted to a small area of the cove even though oceanographic conditions and habitat were similar throughout the cove. Crabs were 97% males and had probably molted within the previous year. Approximately 30% of the crabs would have recruited to the commercial fishery after this molt. Chelae measured from exuviae in spring 1993 indicated the migration consisted almost entirely of small-clawed crabs.


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Energy Contents of Whole Body, Ovaries, and Ova from Pre-Spawning Pacific Herring
A. J. Paul and J. M. Paul - Vol. 6(1):29-34. 1999.

The energy content of whole bodies (WBEC), ovaries (OEC), and ova taken from ripe Pacific herring Clupea pallasi collected from one site in Prince William Sound, Alaska was measured to determine how female nutritional status influenced ova energy content and OEC. The average female WBEC was 23.86 kJ·g^-1 dry weight (SD = ±1.19), and the average energy content of one ovum was 8.1 J (SD = ±0.9). The WBEC of spawning females varied considerably. No clear relationship was found between either female body weight or WBEC and the mean energy content of ova or OEC·g^-1. Well-fed females, those identified by high WBEC, did not have a higher average energy content in their ova. Apparently Pacific herring allocate energy to somatic growth rather than enriching OEC·g^-1. This strategy would improve their chances to successfully propagate because bigger females spawn more eggs.


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Growth of Juvenile Arrowtooth Flounders from Kachemak Bay, Alaska
Kenneth A. Bouwens, A. J. Paul, and Ronald L. Smith - Vol. 6(1):35-40. 1999.

Growth rates, morphometric conversions, and otolith surface-pattern formation are reported and discussed for age 0-2 arrowtooth flounders Atheresthes stomias from Kachemak Bay, Alaska. Absolute growth rates averaged 0.20-0.24 mm/d or 0.17 g/d. Instantaneous growth rates averaged 0.17%/d in length and 0.49%/d in weight. The mean standard lengths for age-0, -1, and -2 flounders were 67, 108, and 211 mm. Annuli form sometime between February and May; the first annulus on the otolith was often indistinct.


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Length at and Timing of Hatching and Settlement for Arrowtooth Flounders in the Gulf of Alaska
Kenneth A. Bouwens, Ronald L. Smith, A. J. Paul, and William Rugen - Vol. 6(1):41-48. 1999.

Structures on the otoliths of arrowtooth flounders Atheresthes stomias have been identified that correspond with hatching and settlement. Analysis of length frequency profiles and back-calculation of otolith dimensions suggested that arrowtooth flounders hatch at a mean standard length (SL) of 8-9 mm. They are planktonic for 145 d, and become benthic at 40-43 mm SL. Averaged over 14 years, the mean dates for hatching and settlement were April 15 and September 8, respectively. The hatch and settlement periods were protracted, with a 95% prediction interval (PI) of 37 days for each period. This wide 95% PI in hatch and settlement dates is a function of a long hatching period, not year-to-year fluctuations in hatch date.


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A Pelagic Basslet Howella sherborni (Family Acropomatidae) off of the Aleutian Islands
Morgan S. Busby and James Wilder Orr - Vol. 6(1):49-53. 1999.

An adult male pelagic basslet Howella sherborni was collected in a bottom trawl during a research survey in June 1993, south of Unimak Island, Alaska. This represents a northwestward extension of the known range by approximately 2,656 km (1,415 km north in latitude). We provide information on the size, morphology, and diagnostic features of this and other specimens of Howella collected in the equatorial and north Pacific. The taxonomic status and systematics of the genus Howella are discussed.


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Milestones for the Alaska Fishery Research Bulletin
Susan M. Shirley - Vol. 6(1):54. 1999.
(No Abstract) Full Editorial:

This year as we enter a new era, we naturally reflect on past accomplishments, gauge progress, and set future goals. This is also the time to commemorate two milestones for the Alaska Fishery Research Bulletin. The 1999 volume marks its 5th year of publication. Congratulations to the authors, reviewers, editorial board, and staff of the Alaska Department of Fish and Game who helped to make the journal a success.

With the new millennium also comes change for the Alaska Fishery Research Bulletin. The founding editor, Robert L. Wilbur, retired from the Alaska Department of Fish and Game in December 1998. Before becoming Scientific Publications Editor in 1986, Bob served as Statewide Enhancement Harvest Coordinator from 1976 through 1984, and Statewide Herring and Shellfish Management Coordinator until 1986. His long tenure with the Alaska Department of Fish and Game, and his commitment to producing high-quality scientific publications are laudable. We wish Bob continued success and enjoyment in his future endeavors.

As the new editor of the Alaska Fishery Research Bulletin, I would like to take this opportunity to introduce myself. My biological research experience and knowledge of Alaska fisheries will serve as a good foundation for the challenges of editing the Alaska Fishery Research Bulletin. I have B.S. and M.S. degrees in zoology and physiology, with an emphasis on physiology of aquatic organisms. When I came to Alaska in 1982, I worked at the University of Alaska Juneau on salmon genetics and biochemistry projects as a research technician. Later, I became a research associate at the University of Alaska Fairbanks, Juneau Center for Fisheries and Ocean Sciences, studying and publishing on early life history and larval biology of king crabs and Dungeness crabs in Southeast Alaska. I was a research analyst for 9 years with the Alaska Commercial Fisheries Entry Commission before joining the Alaska Department of Fish and Game in October 1999.

Alaska's fisheries continue to provide important recreational, subsistence, and commercial opportunities in the state. State-of-the-art scientific methods and analyses are crucial for responsible management, development, enhancement, rehabilitation, conservation, and wise use of our natural resources. Alaska is fortunate to have many internationally recognized scientists and managers who make significant contributions to fisheries research and management. We also benefit from fisheries research conducted in Alaska by scientists from other places. Effective communication is paramount for exchange of their techniques, conclusions, and data, and the Alaska Fishery Research Bulletin is a valuable forum for disseminating this information.

As we enter a new phase for the Alaska Fishery Research Bulletin, we are committed to supporting the journal. We will continue to produce a professional and informative journal with regional as well as universal perspectives. We will strive to make this and other publications of the Alaska Department of Fish and Game more visible and accessible online and through the use of electronic media. I look forward to receiving your manuscripts, and working with you to maintain the high standards of this important fishery journal.


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VOLUME 6(2) - Winter 1999

The Economic Value of Alaska's Copper River Personal Use and Subsistence Fisheries
Michelle M. Henderson, Keith R. Criddle, and S. Todd Lee - Vol. 6(2):63-69. 2000.

Commercial, sport, personal use, and subsistence fishers share the salmon harvest on the Copper River, Alaska. The allocation of salmon among these user groups is a contentious and recurring issue. Economic analyses, along with biological, legal, social, and cultural considerations, have the potential to help policy makers appreciate the consequences of alternative allocations. The zonal travel cost method is used in this study to estimate the net economic value (consumer surplus) of the Copper River basin personal use and subsistence fisheries. The nature of the fishery and the data set are especially well suited for this purpose.


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Changes in Chela Heights and Carapace Lengths in Male and Female Golden King Crabs Lithodes aequispinus after Molting in the Laboratory
A. J. Paul and J. M. Paul - Vol. 6(2):70-77. 2000.

Golden king crabs Lithodes aequispinus from Prince William Sound, Alaska were measured for changes in carapace length (CL) and chela height (CH) after they molted in the laboratory. The predicted increase in CL for males (95 to 155 mm) was expressed by the equation: New CL (mm) = Initial CL (0.91) + 21.90 (r ² = 0.97). The postmolt CH (Y) was linearly related to premolt values (X) by the equation: Y = 0.90X + 6.79 (r ² = 0.85). Increases in CL and CH for males averaged 10% (SD = 3) and 12% (SD = 10), respectively. After molting CH/CL increased in 42%, decreased in 41%, and stayed the same in the remaining 17% of the 58 males. The predicted increase in CL for females (104 to 157 mm) was expressed by the equation: New CL (mm) = Initial CL (0.97) + 10.21 (r ² = 0.91). Increases in CL and CH averaged 5% (SD = 2) and 16% (SD = 18), respectively, for ovigerous females. Like males claw growth in millimeters in females was weakly dependent on initial CH. After molting CH/CL ratios increased in 48%, decreased in 14%, and stayed the same in 38% of 104 females.


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Northern Range Extensions and Habitat Observations for Blackeye Goby Rhinogobiops nicholsii and Kelp Perch Brachyistius frenatus in Southeastern Alaska
David J. Csepp and Bruce L. Wing - Vol. 6(2):78-84. 2000.

Blackeye goby Rhinogobiops nicholsii (Bean 1882) and kelp perch Brachyistius frenatus (Gill 1862) were caught or observed from April to September 1998 and 1999 with beach seines and a remotely operated vehicle at 20 locations near Sitka, Craig, and Klawock in southeastern Alaska. This is the first verified account of blackeye goby (Gobiidae) and kelp perch (Embiotocidae) in Alaska. We captured blackeye gobies as far north as lat 57°17'26"N, long 135°35'14"W, near Sitka, and kelp perch at lat 55°34'38"N, long 133°05'42"W, near Klawock; these may be the northern range limits for these species. Blackeye gobies were found in greater ranges of temperature (9.5° to 17.0°C) and salinity (13 to 27 on the Practical Salinity Scale) than kelp perch (10.0° to 13.2°C, salinity 22 to 28). Specimens of both species have been deposited and cataloged in the Auke Bay Laboratory fish collection.


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Prevalence of the Sockeye Salmon Brain Parasite Myxobolus arcticus in Selected Alaska Streams
Adam Moles and Kathleen Jensen - Vol. 6(2):85-93. 2000.

Over 10,000 spawning sockeye salmon Oncorhynchus nerka throughout Alaska were examined for the presence of the brain parasite Myxobolus arcticus to evaluate its potential as a natural marker to separate mixed stock fisheries in Alaska. Prevalence of the parasite (proportion of fish infected by the parasite) differed widely among sampling locations. The brain parasite, previously reported as common in southeastern Alaska, infected sockeye salmon primarily in coastal lake systems of eastern Prince William Sound and the Copper River area. Brain parasites were present in >85% of the fish returning to lakes east of Cook Inlet, whereas <20% of fish returning to glacial and riverine habitats in the same region were infected. Sockeye salmon systems west of Prince William Sound, such as Bristol Bay and Cook Inlet, were largely devoid of the parasite. Prevalence of the parasite in southeastern Alaska systems appeared stable over the last decade in lake systems but was more variable in riverine habitat. In the Taku River parasite prevalence varied widely between sites but was similar among years for most locations within the river. The restricted geographic distribution and potential for low interannual variability suggest that M. arcticus could serve, especially when used in conjunction with other techniques, as an effective biological marker for estimating origins of sockeye salmon caught in high seas and coastal fisheries.


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Capture Efficiency and Size Selectivity of Two Types of Pots for Red King Crabs in the Bering Sea
Shijie Zhou and Gordon H. Kruse - Vol. 6(2):94-103. 2000.

We compared the catch efficiency and size selectivity of experimental and standard king crab pots in Bristol Bay in the eastern Bering Sea in 1996. The experimental pot was intended to selectively catch legal-sized (carapace width greater than or equal to 165 mm) male red king crabs and reduce the catch of smaller (< 165 mm) crabs. Mean catch per pot haul (CPUE) for legal male red king crabs was 25.3 (SD = 7.9) for standard pots and 20.5 (SD = 8.5) for experimental pots. Mean CPUE of all crabs combined was 63.3 (SD = 26.0) for standard pots and 55.0 (SD = 28.1) for experimental pots. We found no statistically significant differences in CPUE (P > 0.05) except standard pots caught significantly more crabs greater than or equal to 130 mm carapace length in 3 of 6 fishing locations than experimental pots. When CPUE was standardized by effective pot volume, the experimental pots had significantly higher catch per unit of volume for all crab groups than the standard pots. Female and small male crabs remained in both pots during the 2-d soak time even though they were capable of leaving.


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Food Consumption and Growth of Juvenile Arrowtooth Flounders
A. J. Paul, J. M. Paul, R. L. Smith, and K. A. Bouwens - Vol. 6(2):104-107. 2000.

Food consumption and growth of juvenile arrowtooth flounders Atheresthes stomias were examined in the laboratory. Weight gain, Y (in % BW/d) was related linearly to food consumption, X (in J/g/d): Y = 0.0033X - 0.0564; r ² = 0.75 at 4°C. Fish 30 to 300 g had similar energy conversion efficiencies. When fed Pacific herring Clupea pallasi at 4°C, maintenance ration was estimated to be 17 J/g/d. Minimum estimates for daily ration to achieve growth rates observed in the Gulf of Alaska were approximately 3.0 to 1.0% BW/d for 1- to 4-year-old arrowtooth flounders, respectively, when fed walleye pollock Theragra chalcogramma. When feeding on euphausiids, the corresponding consumption rates were 6.9 and 2.4% BW/d.


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VOLUME 7 - Summer 2000

Rebuilding Probabilities Under Alternative Management Strategies for Eastern Bering Sea Tanner Crabs
Jie Zheng and Gordon H. Kruse - Vol. 7:1-10. 2000.

Because of its depressed status the eastern Bering Sea Tanner crab Chionoecetes bairdi stock was deemed overfished in March 1999. This determination necessitated the development of a rebuilding plan. We estimated rebuilding times and rebuilding probabilities using a length-based model and computer simulations under 3 alternative rebuilding strategies for this stock: (1) a complete closure of the directed Tanner crab fishery and a maximum constraint on other fisheries, (2) no directed fishing mortality other than unavoidable bycatch mortality, and (3) a new harvest strategy for the directed Tanner crab fishery with the same bycatch constraints for other fisheries as strategy 2. Rebuilding times were estimated as 7 years for greater than or equal to 50% probability and 20 years for greater than or equal to 90% probability for strategy 1, 8 and 27 years for strategy 2, and 10 and 30 years for strategy 3. Distributions of total mature biomass were skewed; the mean biomass was much larger than the median value. The recruitment dynamic affected rebuilding time periods, probabilities of fishery closure, and mean annual yields. Estimated rebuilding times with a greater than or equal to 50% probability ranged from 4 to >35 years depending on different assumptions on recruitment. Because the history of stock assessments is short (25 years) relative to the periodicity of recruitment cycles (13-14 years), additional years of data are needed to resolve alternative recruitment models and to determine whether statistical relationships with oceanographic conditions can predict future Tanner crab recruitment success.


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A Comparison of Fish Assemblages in Eelgrass and Adjacent Subtidal Habitats Near Craig, Alaska
Michael L. Murphy, Scott W. Johnson, and David J. Csepp - Vol. 7:11-21. 2000.

Fish assemblages were compared between sites with eelgrass Zostera marina and sites with either kelp (e.g., Laminaria saccharina) or only filamentous algae (e.g., Cladophora and Pilayella). Four pairs of sites near Craig, Alaska, were seined monthly from April to June and in September 1998. Eelgrass in June averaged 1,001 shoots/m² (SE = 57), dry biomass was 145 g/m² (SE = 37), and blade length averaged 49 cm (SE = 5). Overall, more species were caught at sites with either eelgrass or kelp than at sites with only filamentous algae: 41 species in eelgrass, 38 in kelp, and 26 in filamentous algae. Total catch was greater at eelgrass than at non-eelgrass sites, principally because of large catches of bay pipefish Syngnathus leptorhynchus, crescent gunnels Pholis laeta, and shiner perch Cymatogaster aggregata. Juvenile rockfish (age greater than or equal to 1) were caught frequently (94% of sites) in May to September in both eelgrass and kelp, but not at sites with only filamentous algae. Age-0 rockfish were caught only in September, nearly all (97%) in eelgrass. Catch of pink salmon Oncorhynchus gorbuscha fry, chum salmon O. keta fry, and coho salmon O. kisutch smolts was similar at eelgrass and non-eelgrass sites, except for chum salmon in June when catch was significantly lower at eelgrass sites. Gadids (96% Microgadus proximus) were uncommon; only 25 were caught, but most (72%) were in eelgrass. Catch of forage fish (Pacific herring Clupea pallasi and Pacific sand lance Ammodytes hexapterus) was similar at eelgrass and non-eelgrass sites. Eelgrass and kelp vegetation supported high biodiversity and provided important habitat for juvenile rockfish and other species. Because biological communities vary geographically, additional data from other areas are needed to obtain a full perspective of the role of eelgrass and kelp as fish habitat in coastal Alaska.


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Depth and Habitat Distribution of Parastichopus californicus Near Sitka, Alaska
Doug Woodby, Scott Smiley, and Robert Larson - Vol. 7:22-31. 2000.

The depth distribution of sea cucumbers Parastichopus californicus was investigated in the vicinity of Sitka Sound, Alaska, to evaluate the proportion of the emergent population available to commercial dive harvesters. A submersible was used to census 20 transects to 118 m. Observations above 10-m depth were made by scuba on 10 transects. Sea cucumber densities were greatest in shallow waters, with approximately 60% of the sea cucumbers observed above 15 m and 70% above 20 m. Average densities were 0.03·m^-2 on the submersible transects and 0.30·m^-2 on the scuba transects. The deepest sea cucumber observed was at 87 m. Sea cucumber densities were highest on shell debris and gravel (pebbles), and lowest on mud and silt bottoms. Tests for substrate distribution generally indicated a nonrandom affinity for harder substrates, except bedrock and boulders. The mostly shallow distribution of P. californicus near Sitka exposes approximately two-thirds of the surveyed population to exploitation by commercial divers, who commonly descend to 15- or 20-m depth. The large fraction of the population in deeper water is not included in estimating the harvestable surplus, and because this leads to an underestimate of the population size, this approach provides a conservative safeguard against overexploitation.


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Species Composition and Abundance of Juvenile Groundfishes Around Steller Sea Lion Eumetopias jubatus Rookeries in the Gulf of Alaska
Franz J. Mueter and Brenda L. Norcross - Vol. 7:32-43. 2000.

We conducted bottom trawl surveys to determine species composition and abundance of juvenile groundfish communities around 6 Steller sea lion rookeries in the western Gulf of Alaska from 1994 to 1996. Overall, the most abundant species in our collections were rock sole Pleuronectes bilineatus, walleye pollock Theragra chalcogramma, Pacific halibut Hippoglossus stenolepis, northern sculpin Icelinus borealis, Triglops spp., Gymnocanthus spp., Pacific cod Gadus macrocephalus, slim sculpin Radulinus asprellus, and arrowtooth flounder Atheresthes stomias. Our results showed significant differences in species composition among rookeries within each of 3 depth strata and a greater abundance of juvenile groundfishes in the western part of the study area. Gadid and flatfish species were more abundant and had a higher probability of occurrence in the vicinity of sea lion rookeries on Akun, Ugamak, Atkins, and Chowiet Islands, compared to rookeries on Marmot and Sugarloaf Islands. The observed differences in species composition coincided with differences in topography, substrate composition, temperature, and salinity. A potential relationship between the abundance of juvenile groundfishes and sea lion survival is discussed.


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Genetic Variation of Fecundity and Egg Size in Anadromous Pink Salmon Oncorhynchus gorbuscha Walbaum
William W. Smoker, A. J. Gharrett, Michael S. Stekoll, and S. G. Taylor - Vol. 7:44-50. 2000.

We studied genetic variation of fitness traits in a population of salmon that is not captive but spawns naturally and grows to maturity in nature. Additive genetic variation contributed significantly to variation of fecundity, a trait closely related to fitness, but not to variation of egg size (another trait closely related to fitness) in families drawn from an anadromous population of salmon and measured after growing to maturity in the wild. Greater fecundity-at-length in families drawn from the early-spawning component of the population suggests that variation of fecundity is itself adaptive. The families were generated by hierarchical mating of 60 male pink salmon to 120 females randomly chosen from the odd-year population at Auke Creek, Juneau, Alaska, 2 females to each male. Half were from the early (August-spawning) component and half from the late (September-spawning) component. The families were incubated separately, tagged with coded microwires, released during emigration of naturally-spawned fry (~1,000 unfed fry per family), and recovered at maturity when they returned to Auke Creek after 16 months at liberty (119 of the 120 families had surviving female members). Body size (length), egg number, and egg size (weight) were measured in 2 females sampled at random from those members having intact ovaries (i.e., before ovulation and retaining all eggs) in each returning full-sib family. Heritability (estimated from the paternal component of variation) of number of eggs was 0.8 (standard error, SE = 0.3). The estimate of genetic correlation of body length and egg number was imprecise (0.4, SE = 0.5). Mean egg number (adjusted for body size) was greater in families from the early component of the population than in families from the late component (1,501 vs. 1,351, P < 0.01). Egg size did not differ between components. Maternal effects contributed significantly to variation of egg size, suggesting the importance of special maternal environments (e.g., yolk accumulation) or nonadditive genetic effects. Our observations suggest that variations of fitness-related traits can be maintained from generation to generation in fluctuating environments by genetic variation and are important to the adaptability and persistence of salmon populations.


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Longevity of Captive Pinto Abalones Haliotis kamtschatkana
A. J. Paul and J. M. Paul - Vol. 7:51-53. 2000.

Ten pinto abalones Haliotis kamtschatkana were captured in Sitka Sound in 1979 and held in captivity at the Seward Marine Center Laboratory. The first of them died in 1985, and 3 were still alive in 2000 when this note was written. Their shell lengths at capture ranged from 48 to 53 mm. At death 7 individuals had shell lengths ranging from 91 to 102 mm. The 3 live individuals had shell lengths of 81, 96, and 98 mm. These observations indicate pinto abalones have the capacity to live for periods exceeding 20 years in captivity.


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VOLUME 8(1) - Summer 2001

Estimation of Tag-Reporting Rates for Sablefish in the Northeastern Pacific Ocean
Jonathan Heifetz and Nancy E. Maloney - Vol. 8(1):1-11. 2001.

An essential component of any mark and recapture study that seeks to estimate fish population abundance, exploitation rates, or migration rates from tagging data is the tag-reporting rate. We obtained tag-reporting rates for the sablefish Anoplopoma fimbria fishery during 1980-1998 by comparing tag returns in the fishery to tag returns from a scientific survey where all tag recoveries were assumed to be reported. Analytical formulae were derived for the measurement error associated with the estimates. When pooled over geographic areas or years, estimates of reporting rates were reasonably precise with coefficients of variation (CVs) usually less than 25%. Reporting rates were highest in the central (0.385) and eastern (0.315) Gulf of Alaska, intermediate in the western Gulf of Alaska (0.269), and lowest in the Aleutians (0.174) and Bering Sea (0.169). Rates pooled over all areas increased from lows of 0.102-0.248 in 1980-1982 to a peak of 0.465 in 1985 before declining to 0.199 in 1986 and 0.157 in 1987. The reporting rate increased gradually and fluctuated between 0.376 and 0.450 since 1995. The increase in reporting in 1995 was coincidental with the implementation of the Individual Fishing Quota (IFQ) system. The linear increase in reporting rates during 1986-1998 was significant. Factors that may have influenced the reporting rate were the number of tags available for recovery, the length of the commercial fishing season, the presence of scientific observers on commercial vessels, and the tag reward program. Pooled over all years and areas the tag-reporting rate has been 0.276 with a CV of 4.2%.


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Maximum Ages of Groundfishes in Waters off Alaska and British Columbia and Considerations of Age Determination
Kristen M. Munk - Vol. 8(1):12-21. 2001.

The longevity in some groundfish species in the eastern North Pacific Ocean and Bering Sea is remarkable. Maximum ages of some species are relatively young: walleye pollock and lingcod are 28 and 25 years, respectively. Some Sebastes species are frequently aged to be over 100 years old, with some areas producing more than a few specimens aged 120-160 years old. The oldest fish recorded from Alaska, and possibly for all of the North Pacific, is a rougheye rockfish Sebastes aleutianus captured May 2000 in southeastern Alaska, visually aged from a sagittal otolith transverse section to be 205 years old. This paper consolidates and updates the maximum ages achieved by many groundfishes collected primarily during commercial and research harvest operations north of approximately 48°N latitude in the eastern North Pacific Ocean (Aleutians, Gulf of Alaska, nearshore and inshore waters of Alaska and British Columbia) and Bering Sea, and describes typical age-determination process and error which produced these age estimates.


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Fishing Practices Under Maximum Retainable Bycatch Rates in Alaska's Groundfish Fisheries
David R. Ackley and Jonathan Heifetz - Vol. 8(1):22-44. 2001.

Most groundfish species managed by the North Pacific Fishery Management Council are closed to directed fishing for a portion of the fishing year for various reasons, the most common being the attainment of the total allowable catch (TAC) or the seasonal allowance of the TAC. Bycatch of non-targeted groundfish species for which directed fishing is closed may be retained in other fisheries up to a maximum retainable bycatch (MRB) level established by regulation as a percentage of the directed catch retained during a fishing trip. For some species, MRB percentages are generously set at levels that exceed "natural" bycatch rates to maximize the opportunity to retain these non-targeted species while reducing overall harvest rates. When the bycatch species is more economically valuable than the target species an incentive exists to "top off" by targeting the bycatch species until the MRB level is attained. We contrast 2 fisheries in which topping-off behavior was previously anecdotally reported. Because of differing species spatial distributions, some rockfish fisheries, Sebastes and Sebastolobus, in the Gulf of Alaska usually have an observed sablefish Anoplopoma fimbria bycatch rate below the prescribed MRB. These natural bycatch rates were estimated based on National Marine Fisheries Service survey and observer program fishery data. The estimated bycatch rates were reasonably precise with most coefficients of variation less than 50% for species of interest. By examining the observed catch from individual trawl hauls in a geographical information system, we were able to demonstrate topping-off behavior with more valuable sablefish in the rockfish fishery. The temporal and spatial targeting patterns of individual vessels were tracked, and distinctive hauls with sablefish as the dominant catch were identified. Similarly, shortraker Sebastes borealis and rougheye S. aleutianus rockfish are more valuable than Pacific ocean perch S. alutus in the Aleutian Islands, and there were anecdotal reports of topping-off with the shortraker-rougheye management complex of rockfish. However, our analysis did not reveal strong evidence of this practice.


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Juvenile Groundfish Habitat in Kachemak Bay, Alaska, During Late Summer
Alisa A. Abookire, John F. Piatt, and Brenda L. Norcross - Vol. 8(1):45-56. 2001.

We investigated the habitat of juvenile groundfishes in relation to depth, water temperature, and salinity in Kachemak Bay, Alaska. Stations ranging in depth from 10 to 70 m and with sand or mud-sand substrates were sampled with a small-meshed beam trawl in August-September of 1994 to 1999. A total of 8,201 fishes were captured, comprising at least 52 species. Most fishes (91%) had a total length < 150 mm and were in their juvenile stage. Overall, the most abundant fishes were the rock soles Lepidopsetta spp. and Pacific cod Gadus macrocephalus. Other common species (>5% of the total catch) were flathead sole Hippoglossoides elassodon, slim sculpin Radulinus asprellus, Pacific halibut Hippoglossus stenolepis, and arrowtooth flounder Atheresthes stomias. Depth accounted for most of the spatial variability in juvenile groundfish abundance, and neither temperature nor salinity was correlated with fish abundance. Juvenile groundfishes concentrated in either shallow (less than or equal to 20 m) or deep (50-70 m) water, with co-occurrence of some species between 30-40 m. Shallow fishes were the rock soles, Pacific halibut, and great sculpin Myoxocephalus polyacanthocephalus. Deep species were flathead sole, slim sculpin, spinycheek starsnout Bathyagonus infraspinatus, rex sole Glyptocephalus zachirus, tadpole sculpin Psychrolutes paradoxus, and whitebarred prickleback Poroclinus rothrocki. This 6-year study provides baseline data on relative abundance and distribution of juvenile groundfishes in Kachemak Bay and may provide a useful tool for predicting the presence of species in similar habitats in other areas of Alaska.


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Young of the Year Sablefish Abundance, Growth, and Diet in the Gulf of Alaska
M. F. Sigler, T. L. Rutecki, D. L. Courtney, J. F. Karinen, and M.-S.Yang - Vol. 8(1):57-70. 2001.

Abundance is dependent on year class success, which is highly variable from year to year. We studied young of the year sablefish Anoplopoma fimbria to collect basic life history information on their abundance, growth, and diet and to determine whether forecasting year class abundance based on young of the year surveys was practical. Surface gillnet surveys were conducted annually from 1995 to 1999 along the seaward edge of the continental shelf of Alaska. Sablefish made up about one-third of the catch and were caught mostly in the central and eastern Gulf of Alaska. Growth averaged 1.2 mm·d^-1. The mean date the first otolith increment formed, April 30, implied an average spawning date of March 30. Diet was mainly euphausiids. Growth rate tended to be higher in years when gillnet catches were higher, but no relationship was apparent between diet and gillnet catches.


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Rockfish Assessed Acoustically and Compared to Bottom-Trawl Catch Rates
Kenneth Krieger, Jonathan Heifetz, and Daniel Ito - Vol. 8(1):71-77. 2001.

Rockfish Sebastes spp. abundances were assessed acoustically using echo integration and compared to rockfish catch rates using a bottom trawl. Twenty-three sites were assessed acoustically and trawled simultaneously at depths of 177-294 m in the eastern Gulf of Alaska. The acoustics sampled depths from 0.5 to 25.5 m above the seafloor, whereas the bottom trawl sampled depths from the seafloor to 10 m above the seafloor. Rockfish were the primary species caught in the trawls, and 93% of the rockfish consisted of 4 species: Pacific ocean perch S. alutus (53%), redstripe rockfish S. proriger (18%), silvergray rockfish S. brevispinis (12%), and sharpchin rockfish S. zacentrus (10%). Rockfish catch rates were 1,524-17,493 kg/h at 6 sites with rockfish schools and were 10-1,153 kg/h at 17 sites with solitary rockfish and no schools. A significant relationship between rockfish catch rates C and acoustic indices A was best explained by the multiplicative model C = 4.32 A^0.83 (r² = 0.69, P < 0.001), indicating that acoustics can be used to assess rockfish abundance.


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Focus Issue on Groundfish Research
Susan M. Shirley - Vol. 8(1):78. 2001.
(No Abstract) Full Editorial:

This issue of the Alaska Fishery Research Bulletin exclusively features research papers on groundfishes and groundfish fisheries in Alaska. The groundfishes are a speciose group, with vastly differing life histories, habitats, and ranges. Together they make up one of the most abundant and valuable fisheries resources in Alaska and the northeastern Pacific Ocean. The patchy distribution, extensive migrations, complex habitats, and very long life spans for some groundfish species require a different approach to managing sustainable fisheries, conserving the health of the resource, assessing population abundance, predicting year class strength and recruitment, and evaluating the effects of oceanic conditions and climatic change on groundfishes. In this issue the authors present new information on early life history, juvenile growth and diet, maximum groundfish ages, improved or alternate techniques for assessing abundance and identifying year class strength, and identification of fishing patterns that maximize bycatch limits of valuable groundfish species. The research in most of these, and many other, papers was presented at the 11th Western Groundfish Conference held in April 2000 in Sitka, Alaska. The AFRB is pleased to serve as a forum for publication of groundfish research as well as other fisheries research in Alaska.


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VOLUME 8(2) - Winter 2001

Trawl Comparisons of Fishing Power Differences and Their Applicability to National Marine Fisheries Service and Alaska Department of Fish and Game Trawl Survey Gear
Paul G. von Szalay and Eric Brown- Vol. 8(2):85-95. 2001.

We analyzed catch per unit effort data collected near Kodiak Island during a side-by-side trawl comparison experiment between the National Marine Fisheries Service (NMFS) and the Alaska Department of Fish and Game (ADF&G) conducted in 1997. Using Kappenman’s estimator, fishing power correction factors (FPCs) were estimated for 4 common species, and a mean squared error-based decision rule to determine whether the use of fishing power correction factors is warranted was applied in each case. The NMFS vessel–gear unit was considerably more efficient at catching walleye pollock Theragra chalcogramma (FPC = 3.84) and Pacific cod Gadus macrocephalus (FPC = 1.72) than its ADF&G counterpart, but the ADF&G vessel–gear unit was somewhat more efficient at catching arrowtooth flounders Atheresthes stomias (FPC = 0.73) and flathead sole Hippoglossoides elassodon (FPC = 0.75). The outcome of the decision rule suggests that fishing power correction factors should be applied for all 4 species when integrating the 2 agencies’ survey data. Length-based FPCs, designed to fine-tune fishing power corrections to individual size categories, were not significantly different for Pacific cod (P = 0.91), arrowtooth flounder (P = 0.096), or flathead sole (P = 0.15). However, 3 significantly different length-based FPCs were obtained for walleye pollock (0–14 cm, 15–62 cm, and > 62 cm).


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Summer Zooplankton Abundance and Composition Estimates from 20-m Vertical Hauls in Prince William Sound, Alaska, Using Three Net Meshes
Molly V. Sturdevant- Vol. 8(2):96-106. 2001.

The abundance and composition of mesozooplankton in the top 20 m of the water column were compared between NORPAC nets having 105-, 243- and 303-µm meshes to evaluate net retention and gear suitability for sampling prey fields of age-0 and age-1 forage fish. Single, consecutive vertical hauls were made with each net in daylight at 3 stations in northeastern Prince William Sound, Alaska, on August 5–6, 1995. Individual samples were examined microscopically, and data were pooled by mesh size for analysis. Total zooplankton abundance differed by an order of magnitude between 105- and 303-µm mesh nets (41,000 and 1,400 organisms·m^-3). Small calanoid copepods comprised equal to or less than 86% of the composition in all the net mesh sizes. Net retention in the smallest meshes was significantly higher for the small species and stages of calanoids and for several other small taxa (bivalve larvae, invertebrate eggs, barnacle larvae) compared to the largest mesh; conversely, retention for chaetognaths was significantly higher in the largest mesh. The 105-µm mesh net best represented abundances and composition of mesozooplankton consumed by forage fish in summer, predominantly small calanoids, because the others undersampled taxa present in the diets of Pacific herring Clupea pallasi, pink salmon Oncorhynchus gorbuscha, walleye pollock Theragra chalcogramma, Pacific tomcod Microgadus proximus, capelin Mallotus villosus, and Pacific sand lance Ammodytes hexapterus. Although sampling gear bias has long been recognized as critical to estimates of zooplankton production and community structure, this study demonstrates the importance of selecting the appropriate sampling net mesh to characterize prey selection and consumption by planktivorous fish.


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A Survey of Participants in the Lower and Central Cook Inlet Halibut and Salmon Sport Fisheries
Mark Herrmann, S. Todd Lee, Keith R. Criddle, and Charles Hamel- Vol. 8(2):107-117. 2001.

Results of a postal survey of participants in the 1997 central and lower Cook Inlet saltwater halibut and salmon sport fisheries are reported and compared with the results of the 1997 Alaska Department of Fish and Game (ADF&G) statewide sportfishing harvest survey and the 1998 ADF&G saltwater charter vessel logbook census. Despite the use of different survey methods and instruments, responses to related questions correspond closely across all 3 surveys. Nonresident sportfishing accounted for 44% of the 197,556 angler-days of effort in the lower and central Cook Inlet halibut and salmon saltwater sport fisheries during 1997. Effort levels by Kenai Peninsula Borough residents and other Alaskans were 25% and 31% of the total, respectively. Local residents, other Alaskans, and nonresidents exhibited differing demographic and economic characteristics and different catch rates, selected different fishing modes, and incurred different trip expenditures. Alaskan respondents were younger, lived with larger families, and had a lower average income than the average nonresident angler. Women comprised over a third of the Alaskan anglers, but scarcely more than a fifth of the nonresidents. Nonresidents, local residents, and other Alaskans accounted for 65%, 10%, and 25% of the charter client-days, respectively. Nonresidents incurred higher average fishing trip-specific costs than residents for similar trips. Likewise, fishing trip-specific expenditures were higher for charter clients than for private-vessel or shorebased fishers. Although 88% of the Alaskan respondents identified saltwater fishing as the primary purpose of their trip to the Kenai Peninsula, 57% of the nonresident respondents indicated their participation was incidental to their primary trip purpose. After adjusting for spending that would have occurred in the absence of sportfishing, we estimate that $34.1 million in expenditures can be uniquely attributed to the 1997 central and lower Cook Inlet halibut and salmon sport fisheries. These expenditures include $24.9 million in “new” money, money released into the Kenai Peninsula economy by individuals who reside outside the borough. These same fisheries contributed $22.3 million and $23.5 million in new money in 1998 and 1999, respectively.


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Macrocystis Biomass, Quality, and Harvesting Effects in Relation to the Herring Spawn-On-Kelp Fishery in Alaska
Peter G. van Tamelen and Doug Woodby- Vol. 8(2):118-131. 2001.

Giant kelp Macrocystis spp. is harvested for use in herring spawn-on-kelp, also called roe-on-kelp, fisheries, but information on the biology and ecology of kelp is limited for Southeast Alaska. A successful management plan must evaluate both the amount of kelp available for harvest and the recovery rates of kelp from harvest. In this study, estimating the amount of kelp available consisted of first estimating the total abundance of kelp in a survey area and second estimating the biomass of available and desirable kelp. The total biomass was estimated by surveying the surface area of kelp beds in selected regions on the west coast of Prince of Wales Island. Randomly selected “index beds” were surveyed to determine kelp density, and samples were measured and weighed to estimate the average weight of kelp fronds. About 2.04 x 105 t of kelp were identified in the survey. The harvest of kelp for spawn on kelp is highly selective. We found that blades at least 14 cm wide and fronds with a high proportion of desirable blades were selected. The proportion of blades and fronds meeting these selection criteria were determined for the index beds, and the biomass of desirable kelp was estimated to be about 14% of the total kelp biomass in April. The growth in kelp canopy was rapid from March to April, with April canopies about 82% larger than March canopies. Even if kelp harvests increase 10 times over present levels, the harvest will represent only about 4.5% of the total estimated amount of kelp. Experimentally harvesting kelp canopies in March, April, or at both times had few significant effects. Kelp beds that were experimentally harvested at both times or only in April had shorter fronds and possibly fewer large fronds and fronds per plant. This experiment was monitored only one month after the last harvest, so there may not have been sufficient time for the cut kelp to recover.


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Effects of Temperature on Length of Intermolt Periods in Juvenile Male Chionoecetes bairdi
A. J. Paul and J. M. Paul - Vol. 8(2):132-134. 2001.

The purpose of this study was to examine the effect of temperature on the intermolt duration of juvenile Tanner crabs Chionoecetes bairdi Rathbun. The average length of the intermolt period for Gulf of Alaska male Tanner crabs, with carapace widths (CW) of 24–26 mm, was ascertained for captives held at 3°, 6°, and 9°C. No test specimens died, and regardless of rearing temperature they fed avidly during captivity. Molting intervals were summarized in units of days and degree days. Increasing the rearing temperature from 3° to 6°C reduced the number of days between molts, but raising it to 9°C did not result in a similar reduction. The intermolt periods were 154 (SD =24), 78 (SD = 14), and 74 (SD = 8) days for juveniles held at 3°, 6°, and 9°C, respectively. The number of days between molts for the 3°C test group was significantly longer than the intermolt duration of juveniles reared at 6° and 9°C. There was no significant difference in the number of days between molts for the 6° and 9°C groups. In units of degree days, the mean intermolt periods at 3° and 6°C were nearly identical: 462 (SD = 74) and 467 (SD = 87) days, respectively. At 9°C molting occurred after an average of 665 (SD = 73) degree days. At 3° and 6°C, degree-day intermolt durations were not significantly different, but at 9°C the intermolt duration was significantly longer than those observed at 3° and 6°C. Thus, at 9°C, a temperature commonly encountered by Gulf of Alaska Tanner crabs during fall, a prolonging of the degree-day intermolt duration occurred. The degree-day method of describing intermolt durations worked adequately at 3° and 6°C, but above 6°C additional experiments are needed to better comprehend the influence of temperature on molting frequency. There was no obvious relationship between rearing temperature and growth. The average increase in carapace width for males held at 3°, 6°, and 9°C was 33% (SD = 4), 32% (SD = 6), and 32% (SD = 8) with no significant differences detected in growth per molt relative to rearing temperature.


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Growth of Juvenile Golden King Crabs Lithodes aequispinus in the Laboratory
A. J. Paul and J. M. Paul - Vol. 8(2):135-138. 2001.

Growth observations were made for juvenile male golden king crabs Lithodes aequispinus with carapace lengths (CL) of 2 to 35 mm to improve our understanding of the recruitment process. Gravid females were captured in Prince William Sound, Alaska, and juveniles were reared in the laboratory at 3°–10°C to obtain information on growth per molt and intermolt duration. The equation describing the increase in CL for crabs 2 to 35 mm CL was: New CL mm = Initial CL (1.25) + 0.14; r² = 0.99, n = 76. The average increase in CL after molting was 28% (SD = 8%), and the corresponding value for chela height (CH) was 33% (SD = 17%). The intermolt duration, in units of degree days, of crabs 2 to 35 mm CL was described by the equation: Intermolt Duration = Initial CL mm (16.32) + 259; r² = 0.76. The results from this study provide new insight into the growth patterns of this commercially important species.


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VOLUME 9(1) - Summer 2002

Preseason Forecasts of Pink Salmon Harvests in Southeast Alaska Using Bayesian Model Averaging
Milo D. Adkison - Vol. 9(1):1-8. 2002.

Competing models for generating a forecast of salmon returns may give differing predictions yet have similar credibility. Within a single model, a wide range of alternative parameter values may also have similar credibility. Bayesian methods allow us to incorporate a wide range of models, weighting their forecasts by the posterior probability of each model and parameter combination. I illustrate this procedure by forecasting pink salmon harvests for the year 2002 for northern and southern Southeast Alaska.


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A Statistical Approach to Estimating Fish Passage Using a Form of Echo Integration
Pham X. Quang and Harold J. Geiger - Vol. 9(1):9-15. 2002.

Sonar echo integration is widely used to assess fish density when individual targets cannot be tracked or counted. We propose an echo-integration estimator of fish density, which is proportional to the ratio of the echo integral to an estimate of the average, squared echo-voltage amplitude. Our argument is based on the fact, pointed out by Ehrenberg, that amplitudes of returning echoes constitute an inhomogeneous filtered Poisson process. Our estimator, unlike the classical echo integrator, is not based on the thin-shell approximation. It uses thresholded echoes and accommodates background noises, and thus could be more appropriate in riverine environments.


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A Review of the Net Selectivity Problem and a Model for Apportioning Species Based on Size-Selective Sampling
Pham X. Quang and Harold J. Geiger - Vol. 9(1):16-26. 2002.

The theory of inference of a size distribution for fish captured with size-biased fishing gears is called the “net selectivity problem.” This family of problems arises because of questions about the underlying distribution of the sampled fish, questions about the nature of the size bias, or perhaps questions about the mixtures of species of different sizes. We discuss these problems in the context of size-biased gillnets, although generalization to other kinds of fishing gear is straightforward. We estimate the length distribution of the captured fish, the size distribution of the fish population, and the parameters of the selectivity curves parametrically, using maximum likelihood. To avoid overparametrization we make strong assumptions about the relationship among the selectivity curves, so that fishing power cannot be estimated in this setup. This assumption is called “geometric similarity.” The normal-normal and gamma-gamma combination models are considered, so called because of the shape of the fish-length distribution and the shape of the selectivity curves. The method is demonstrated with a worked simulation example and the American plaice Hippoglossoides platessoides data of Holst and Moth-Poulsen.


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German Participation in Alaska Sport Fisheries in 1998
Mark Herrmann, Laura M. Milner, Kelly L. Giraud, Michelle Skogen Baker, and Rod F. Hiser - Vol. 9(1):27-43. 2002.

This study is the first characterization of German sport fishing anglers in Alaska. A survey was taken of 601 residents of Germany who had purchased a 1998 Alaska fishing license. Of the 601 individuals surveyed, 363 responded, and after eliminating the undeliverable surveys, a response rate of 61.7% was achieved. The German anglers who participated in the Alaska sport fishery are predominantly male, employed, married, and have children. The average age is approximately 45 years old. Fully one-quarter of the surveyed anglers came from the German state of Bavaria. More than half of the German anglers fishing Alaska have visited Alaska multiple times. Reasons for return trips include the Alaska wilderness, abundance of salmon and halibut, beautiful countryside, friendly people, remoteness, solitude, nature, and scenery. Salmon were the most popular targeted species by German anglers, with sockeye Oncorhynchus nerka, coho O. kisutch, and chinook salmon O. tshawytscha leading the way. The results of this study show a high level of satisfaction among German anglers who fish in Alaska. The level of satisfaction was modeled and the parameters were estimated using an ordered probit model. The results of the German angler satisfaction estimation indicate that trip satisfaction was likely to be increased for those fishermen who exceeded their expectations in regard to the number and size of fish caught, were dedicated to fly-fishing, who exhibited pre-trip preferences towards a favorable fishing environment, and who encountered less crowding conditions than expected.


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Estimated Mortality of Snow Crabs Chionoecetes opilio Discarded During the Bering Sea Fishery in 1998
Jonathan J. Warrenchuk and Thomas C. Shirley - Vol. 9(1):44-52. 2002.

The mortality of discarded snow crabs Chionoecetes opilio was estimated for the 1998 fishery for snow crabs in the Bering Sea. Estimates of discard mortality were calculated from deadloss of retained crabs, a windchill model of mortality was developed from the results of a laboratory study, and a model that predicts mortality from temperature and windspeed was developed. The 1998 season was used because it had the most complete set of data. No relationship existed between the deadloss reported in the catch delivered to processors and the windchill conditions when the crabs were caught. Mortality of discarded snow crabs was estimated at 3.9% by the windchill model and 19.6% by the temperature and windspeed model.


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An Overview of Salmon Bycatch in Alaska Groundfish Fisheries
David Witherell, David Ackley, and Cathy Coon - Vol. 9(1):53-64. 2002.

Chinook salmon Oncorhynchus tshawytscha and chum salmon O. keta are caught incidentally in Alaska groundfish fisheries, primarily in the walleye pollock Theragra chalcogramma trawl fishery. From 1990-2001, an average of 37,819 chinook salmon and 69,332 other salmon species (> 95% are chum salmon) were incidentally caught annually in the Bering Sea and Aleutian Islands groundfish trawl fisheries, and 20,799 chinook salmon and 20,496 other salmon were incidentally caught annually in the Gulf of Alaska trawl fisheries. In 1999 and 2000, chinook salmon bycatch was reduced in the Bering Sea, but increased in the Gulf of Alaska. Chum salmon bycatch has remained relatively stable in recent years. Bycatch is primarily juvenile salmon that are one or two years away from returning to the river of origin as adults. The origin of salmon taken as bycatch includes rivers in western Alaska, Southcentral and Southeast Alaska, Asia, British Columbia, and Washington. Analysis indicates that an incidental catch of 30,000 chinook salmon in Bering Sea and Aleutian Islands groundfish trawl fisheries equates to about 14,581 adult chinook salmon from western Alaska. Similarly, a bycatch of 60,000 chum salmon in Bering Sea and Aleutian Islands groundfish trawl fisheries equates to about 13,120 adult chum salmon from western Alaska. We estimated that, on average, salmon bycatch in Bering Sea and Aleutian Islands groundfish trawl fisheries reduced the western Alaska chum salmon run by less than 0.2%, and reduced the western Alaska chinook salmon run by less than 2.7%. Impacts of salmon bycatch from the Gulf of Alaska groundfish trawl fisheries cannot be estimated at this time.


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New Records of the Slender Codling Halargyreus johnsonii Günther, 1862 from the Eastern Bering Sea, Alaska
Gerald R. Hoff - Vol. 9(1):65-67. 2002.

Two specimens of the slender codling Halargyreus johnsonii Günther, 1862 were collected from the eastern Bering Sea, the most northerly records from the eastern North Pacific. The two immature specimens were collected in June of 2000 by bottom trawl during the Alaska Fisheries Science Center’s groundfish survey of the eastern Bering Sea upper continental slope. These two individuals appear similar to all previously reported specimens from the Pacific and extend the range for the species to Alaska. Also reported herein are 5 previously unreported records of H. Johnsonii collected just south of the Gulf of Alaska in the eastern North Pacific.


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VOLUME 9(2) - Winter 2002

Ecology of Herring and Other Forage Fish as Recorded by Resource Users of Prince William Sound and the Outer Kenai Peninsula, Alaska
Evelyn D. Brown, Jody Seitz, Brenda L. Norcross, and Henry P. Huntington - Vol. 9(2):75-101. 2002.

We documented qualitative ecological information about non-harvested fish age classes and species from resource users and area residents. Our primary objective was to compile local and traditional ecological knowledge about the distribution, abundance, ecology, and associated changes over time of Pacific herring Clupea pallasi and other forage fish species in Prince William Sound (PWS) and the Outer Kenai Peninsula (OK) in Southcentral Alaska. A secondary objective was to provide ecological information to aid in developing study or management plans concerning herring and other forage fish. Both objectives were met by developing an oral interview protocol, selecting and interviewing key informants in 5 Alaskan communities, and developing a geographic database. Researchers tape-recorded and mapped respondents' observations. Survey questions fell into 6 categories: 1) life history stage and species of the fish observed, 2) fish behavior and school characteristics, 3) presence and behavior of co-occurring predators, 4) seasonal spatial distributions observed, 5) decadal shifts observed, and 6) observation and method activity. Forty-eight interviews were conducted. The earliest observation was from 1934. Thirty-seven respondents were commercial fishermen and 17 were pilots. Respondents made most observations of juvenile herring schools from planes. Other observations came from net catches, visual sightings, and sonar output. Most observations were made during summer (June through August), probably due to both shallow distribution of schools and an increase in human activity during this season. In PWS the spring spatial distribution of herring was significantly different from summer and fall-winter, but the latter 2 were not significantly different. Spatial distributions of herring in the OK were significantly different from one another in all 3 seasons, and the differences were more highly significant than in PWS. Most observations concerned juvenile herring, but locations of herring spawning overlap with adult herring, Pacific sand lance Ammodytes hexapterus, capelin Mallotus villosus, capelin spawning, and eulachon Thaleichthys pacificus were also documented. Most respondents were able to distinguish herring from other species by their school shape, school color, behavior, and location within a bay. Some pilots believed sunny days were better than overcast days for distinguishing herring from forage fish schools because herring schools "flash silver" and forage fish (mainly sand lance), also called "feed fish" or "bait fish," look brown or gold. Pilots said that they did not see schools of salmon fry from the air. Juvenile herring were reported as broadly distributed, mainly in bays in PWS and the OK, and easily observed in the summer. Juvenile herring were found at the heads of bays during the winter. They were seen in winter with adult herring in a very limited number of sites. Decadal shifts were observed with an increase in juvenile herring from the 1970s to the 1980s and a much more restricted distribution in the 1990s. In PWS the 1970s distribution was not significantly different from the 1980s, but was highly significantly different from the 1990s. The 1980s and 1990s were also highly significantly different from one another. In the OK all 3 decades were significantly different from one another, and the level of significance was higher than for the PWS pairwise tests. Decadal shifts in the reported extent of juvenile herring distribution matched decadal trends in catches of the PWS adult herring population indicating that traditional ecological knowledge is a potentially valuable source of information for indicators of recruitment and population trends. Juvenile herring overlapped sand lance distribution to a large degree, and capelin and eulachon to a small degree. Herring spawning locations prior to the 1970s not previously reported by the Alaska Department of Fish and Game were documented. Our study preserves knowledge of the historical changes in distribution of Pacific herring in PWS and the OK that predates scientific data collection.


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A Description of Escaped Farmed Atlantic Salmon Salmo salar Captures and Their Characteristics in One Pacific Salmon Fishery Area in British Columbia, Canada, in 2000
Alexandra Morton and John Volpe - Vol. 9(2):102-110. 2002.

Since 1995, the Canadian salmon farming industry as a whole has reported losing an average of 46,255 Atlantic salmon Salmo salar annually into the coastal waters of British Columbia. While the number of fish lost is arguably much higher, it is unarguable that the fate of these fish is largely unknown. This study was conducted on the fishing grounds of British Columbia by contacting commercial fishers frequently via VHF radio and boat visits. Atlantic salmon were collected directly from fishers, packers, and a processing plant. The goal of this project was to enumerate the number of Atlantic salmon caught by commercial fishers in Pacific Management Area 12, a region of intense salmon farm activity. Further, we wished to examine the condition of these escaped farm salmon to aid managers in determining their ability to survive in the wild. A total of 10,826 Atlantic salmon were caught in the 17 days of open fishing periods during this study, August 2, 2000 through September 22, 2000, by troll, seine, and gillnet gear. The mean fork length and weight of the sampled Atlantic salmon were 75.0 cm (±5.1 cm) and 4.8 kg (±1.3 kg), respectively. Autopsies on 775 whole or partial Atlantic salmon found identifiable stomach contents in 3.9% of the sample overall, and up to 24.4% at some sampling locations. Eighteen fish (2.3%) showed signs of sexual maturity. One group of escaped Atlantic salmon was sampled weekly over a fourteen-day interval, days 1, 8, 14, and an increase in foraging success was recorded. Gillnets were the most successful gear type in recovering escaped farm salmon. The present passive reporting system of Fisheries and Oceans Canada underestimates Atlantic salmon escapes. This study recorded 40.8% more Atlantic salmon caught in the 8 week study period in Pacific Management Area 12 by commercial fishers than the federal Fisheries and Oceans Canada's passive monitoring program.


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A Bioenergetics Approach to Estimating Consumption of Zooplankton by Juvenile Pink Salmon in Prince William Sound, Alaska
Jennifer L. Boldt and Lewis J. Haldorson - Vol. 9(2):111-127. 2002.

Juvenile pink salmon Oncorhynchus gorbuscha were sampled through the summer and fall of 1998 in Prince William Sound, Alaska. Samples collected in the field and a bioenergetics model were used to estimate consumption of zooplankton by juvenile pink salmon during their first three months at sea. Based on an initial weight of 0.26 g and a growth rate of 4% body weight per day, a pink salmon would consume 27.9 g of wet weight in a 93 d residence time in Prince William Sound. A cohort of juvenile pink salmon would consume 5.53×10⁹ g wet weight or 0.05 g Carbon/m²/year (g C/m²/year) in PWS. Sensitivity analyses indicate that residence time, mortality, and diet strongly influence consumption estimates. Assuming a primary production of 100 to 300 g C/m²/year, a transfer efficiency of 20%, and secondary production of 20 to 60 g C/m²/year, consumption by juvenile pink salmon was about 0.06-0.45% of annual secondary production. This estimate would be higher (up to 8.28%) if only nearshore areas of Prince William Sound are considered. The average daily consumption of large calanoid copepods was 2.2×10^-4 g C/m² or 1.5% of the large calanoid copepods available. If standing stocks were fixed over a 10-day period, pink salmon consumption would represent a large proportion of large calanoid copepods (15%) and amphipods (19%). Consumption by pink salmon and other planktivores needs to be considered along with geographic and interannual variability in zooplankton biomass and productivity when examining the carrying capacity of the Prince William Sound ecosystem.


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A Simple Procedure to Evaluate Salmon Escapement Trends that Emphasizes Biological Meaning Over Statistical Significance
Harold J. Geiger and Xinxian Zhang - Vol. 9(2):128-134. 2002.

Statistical hypothesis testing for a "significant" decline is poorly suited for the analysis of salmon stock trends. Unfortunately, when statistical hypothesis-test machinery is applied to an escapement series, biologically unimportant, small downward fluctuations can be considered "significant," especially in long series. Alternatively, often very steep declines in escapement levels are found to be "not significant," especially in short series. The hypothesis test may tell more about the length of the series than the magnitude of the decline or the stock dynamics. We propose a simple and robust method of estimating the magnitude of stock decline (or increase), and propose a way to reference stock decline in terms of an underlying escapement level at the beginning of the series, so the decline can be judged in some kind of context. We regressed escapement on time using a resistant regression line. We propose using the back-cast estimate of what the escapement was in year zero of the series as a nonparametric escapement benchmark, and we call this benchmark the year-zero reference point. This back-cast estimate is just the estimated y-intercept of the regression line. In several 15-year series that we examined, we concluded that an escapement decline was biologically meaningful when the estimated underlying annual decline was more than 5% of the year-zero reference point, as that decline will result in the underlying escapement level dropping by half over a 10-year period.


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VOLUME 10(1) - Summer 2003

The Feasibility of Reducing the Variance of Fish Relative Abundance Estimates by Integrating CPUE Data from Two Demersal Trawl Surveys in
the Gulf of Alaska
Paul G. von Szalay - Vol. 10(1):1-13. 2003.

Catch per unit effort data of walleye pollock Theragra chalcogramma, Pacific cod Gadus macrocephalus, arrowtooth flounder Atheresthes stomias, and flathead sole Hippoglossoides elassodon from the National Marine Fisheries Service and Alaska Department of Fish and Game 1999 and 2001 Gulf of Alaska bottom trawl surveys were integrated to evaluate the feasibility of reducing the variance of the National Marine Fisheries Service biomass estimates for these species. Because of differences in the spatial design and areas covered by the 2 surveys, 2 new strata, recognizing bays as a separate stratification element and made up of portions of some of the original National Marine Fisheries Service strata, were introduced. Variance estimates based on the combined surveys were similar (<10% difference) to those based exclusively on the National Marine Fisheries Service survey data for all species and both years except for walleye pollock in 2001 (84% higher for the integrated surveys). Biomass estimates were also similar (<10% difference) between the integrated and nonintegrated data for all species and both years except for walleye pollock in both 1999 and 2001 (22% and 82% higher estimates for the integrated surveys in 1999 and 2001, respectively). A potential reason for the unexpected increase in the biomass and variance estimates for walleye pollock is a significant time-dependence of the fishing power correction factor due to vertical migration of these fish. The appropriateness of integrating the data from these surveys is discussed.


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Sex, Age, and Growth of Black Rockfish Sebastes melanops from a newly exploited population in the Gulf of Alaska, 1993–1999
Carrie L. Worton and Gregg E. Rosenkranz - Vol. 10(1):14-27. 2003.

A newly exploited population of black rockfish Sebastes melanops were sampled from commercial landings in the Gulf of Alaska from 1993–1999 to identify issues in future management of this resource. Fish were measured, sexed, and sagittal otoliths were removed and aged. Males dominated the catches, comprising 71% of the samples. The majority of the catch was between 38 and 53 cm fork length, with a distinct mode at 39 cm fork length in 1997 in both the Kodiak and Alaska Peninsula Areas. Length-at-age for each year revealed differences in growth between sexes, with females larger than males. Growth differences between areas were observed but were significant for only males. The oldest fish aged was 48 years old, with the majority of the catch between 8 and 20 years old. Variations in year class strength were large and apparent in all areas. Strong recruitment events in 1979 and 1990 were tracked throughout the entire range of collection years and throughout the Gulf of Alaska. Research priorities for black rockfish in the Gulf of Alaska should focus on determining the relationship between sex-specific depth distributions, changes in sex compositions with respect to reproductive timing, age of maturity, and the affects of local and large scale environmental conditions on recruitment. Maintenance of a time series of biological data such as age and growth and monitoring specific fishing practices may offer indicators of long-term fishing effects on successful recruitment.


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Coherence of Observed Adult Sockeye Salmon Abundance Within and Among Spawning Habitats in the Kvichak River Watershed
Ian J. Stewart, Ray Hilborn, and Thomas P. Quinn - Vol. 10(1):28-41. 2003.

Despite coherent trends in aggregate abundance of Pacific salmon Oncorhynchus species at ocean-basin scales, individual populations often fluctuate out of phase with one another. However, spatial covariation in shared environmental conditions may lead to correlation among proximate populations in survival, recruitment, and subsequent adult abundance. We found strong covariation in 45 years of aerial abundance estimates of adult sockeye salmon Oncorhynchus nerka in 93 spawning populations in the Kvichak River system, Bristol Bay, Alaska. A significant negative relationship with geographic distance (P<0.01) accounted for just 2.96% of the variability in both correlation
of abundance between populations, and a related similarity coefficient. There was no evidence for a threshold of rapid decay in this relationship, despite distances of up to 175 km between populations. Island beaches showed significantly higher covariation (P<0.05) than other types of spawning habitat, even after removing the effect of distance. We conclude that these patterns are likely a result of the commercial fishery, broad environmental patterns experienced by populations throughout the drainage, and differences in population-specific early life history survival rates among habitats. A better understanding of the degree to which spawning sites show covariation in abundance, as well as of patterns present within a single river system, could assist researchers in locating suitable control sites for experiments and may allow for more accurate interpolation of missing historical data.


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Change in the Performance of a Bering Sea Survey Trawl Due to Varied Trawl Speed
Kenneth L. Weinberg - Vol. 10(1):42-49. 2003.

An experiment was conducted by the Alaska Fisheries Science Center to study the effect of trawl speed through the water on the footrope bottom-tending performance, and other measures of trawl geometry, of the 83/112 Eastern flatfish trawl used annually in surveys of commercially important eastern Bering Sea crab and groundfish resources. A series of tows was made in one eastern Bering Sea location at vessel speeds (speed over ground) ranging from 2.0 to 5.0 knots at 0.5 knot intervals while simultaneously measuring the speed of the trawl moving through the water. The distance of the center of the footrope above the bottom was measured using an electronic bottom contact sensor. The flatfish trawl gear remained relatively stable as evidenced by only minor increases in measured footrope distances off the bottom with increasing trawl speed. Predicted heights were 1.1 cm at 3 knots, 2.5 cm at 4 knots, and 4.9 cm at 5 knots speed through the water. Footrope distances off the bottom were relatively minor at trawl speeds through waters typically encountered during a Bering Sea survey and likely would have a nominal effect on the capture rates of most commercially targeted semi-benthic fish species. However, variable footrope contact caused by variable trawl speed through the water could potentially introduce unwanted variability in estimates of catch per unit of effort for bottom dwelling fauna such as sculpins, skates, flatfish, red king crab Paralithodes camtschaticus, snow crab Chionoecetes opilio, and Tanner
crab C. bairdi. Survey scientists might better control the variability in catch per unit of effort estimates caused by varying trawl efficiency by lending attention to local current conditions. One improvement to surveys may well be standardizing towing speed to trawl speed through the water.


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Identifying the Spatial Distribution of Stocks of Migrating Adult Sockeye Salmon Using Age Composition Data
Lucy Flynn, Ray Hilborn, and André E. Punt - Vol. 10(1):50-60. 2003.

We present a model for identification of the spatial distributions of component stocks of sockeye salmon Oncorhynchus nerka in the Port Moller test fishery, which are migrating to Bristol Bay, Alaska, using the differential age composition of those stocks. We model the spatial distribution of each stock as a normal density with parameters of mean and standard deviation of distance along the sampling transect. The model predicts the number and age composition of sockeye salmon at different sampling stations, and compares them to the observed abundance and age composition at these sampling stations. Some level of stock separation is apparent at Port Moller, but the ability to discriminate a component stock depends on both its uniqueness of age composition and its relative magnitude. We believe these methods may provide additional information that can be integrated with other sources currently used for inseason projections of sockeye salmon runs in Bristol Bay.


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Interactions Between Commercial Fishing and Walleye Pollock
Christopher D. Wilson, Anne B. Hollowed, Michiyo Shima, Paul Walline, and Sarah Stienessen - Vol. 10(1):61-77. 2003.

Results from the first two years of a multiyear fishery interaction study near Kodiak Island in the Gulf of Alaska are presented. Findings from acoustic surveys, which were conducted in August 2000 and 2001, provide important information that begins to address the question of whether the abundance and spatial patterns of various species, including walleye pollock Theragra chalcogramma are impacted by commercial fishing activities over short spatio-temporal scales. The biomass and distribution of walleye pollock were stable over periods of days to weeks although during the second year an unusual, extremely dense, small-scale walleye pollock aggregation was detected during one of several survey passes. Several morphological descriptors of the walleye pollock echosign layers were evaluated to better understand whether differences at the scale of the fish aggregations occurred in response to fishing. Variography was also used to quantify walleye pollock spatial patterns. Results from the second year, when the
commercial fishery took place within the study area, do not suggest a significant link between fishing activities and changes in estimates of juvenile and adult walleye pollock geographical distribution, biomass, or vertical distribution. It will be important, however, to evaluate whether these trends persist during subsequent years.


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VOLUME 10(2) - Winter 2003

The Long-Term Outlook for Salmon Returns to Alaska
Milo D. Adkison and Bruce P. Finney - Vol. 10(2):83-94. 2003.

With the exception of some western Alaska stocks, Alaska's salmon populations are numerically healthy. However, even fisheries on abundant stocks are suffering economically due to sharp declines in the value of the catch. The abundance of Alaskan salmon stocks has fluctuated greatly, both in modern times and prehistorically. These fluctuations are thought to be caused by multi-decadal changes in environmental conditions over large areas that affect many other species as well as salmon. Forecasts of salmon returns are not very reliable, and the potential for significant improvement in their accuracy is low in the short term. A viable fishing industry must be able to adapt to dramatic, persistent, and unanticipated changes in harvest levels. Nonetheless, Alaska's salmon stocks should continue to produce healthy harvests for the foreseeable future, barring significant damage to their habitat either via local activities or global warming.


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Critical Elements of Kvichak River Sockeye Salmon Management
Lowell F. Fair - Vol. 10(2):95-103. 2003.

The Kvichak River of Bristol Bay, Alaska, is one of the world's largest sockeye salmon producing systems. This paper reviews and documents past management practices for the Kvichak River sockeye salmon. Fishery harvests are managed to meet a biological spawning escapement goal set by the State of Alaska and regulated using management plans adopted by the Alaska Board of Fisheries. Several measures of inseason run abundance are used to determine time and area of fishery openings that allow the escapement goal to be met and ensure that escapement is obtained throughout the run. Returns to the Kvichak River have been relatively small for seven of the past eight years. To hasten rebuilding of this run, the Alaska Board of Fisheries implemented additional management plans in 2001 that limit incidental harvests of Kvichak River sockeye salmon. These restrictions were effective in decreasing the catch of Kvichak River sockeye salmon, but total escapements achieved in 2002 and 2003 were still below the lower end of the escapement goals thought to produce the greatest catches in the future. While small runs and resulting low escapement levels have restricted commercial and sport fishery harvests, sustainability of this sockeye salmon run does not appear threatened at this time. The escapement goal for the Kvichak River is set at a level that provides the greatest potential for obtaining maximum sustained yield. While it is unlikely that escapements below the goal will provide high yields, past performance of low escapements has demonstrated that the Kvichak River run is still sustainable and has the capacity to produce large returns when conditions are favorable.


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Biological and Spatial Characteristics of the Weathervane Scallop Patinopecten Caurinus at Chiniak Gully in the Central Gulf of Alaska
Michele M. Masuda and Robert P. Stone - Vol. 10(2):104-118. 2003.

A manned submersible was used to collect biological and behavioral information on a deepwater population of weathervane scallops Patinopecten caurinus near Kodiak Island in the central Gulf of Alaska. Counts and positions of weathervane scallops and 3 additional species groups (anemones [Cribrinopsis fernaldi and Metridium senile], sunflower sea stars Pycnopodia helianthoides, and sea whips [Protoptilum sp. and Halipteris willemoesi]) along 20 fixed transects were compiled from video footage of the seafloor. The study site encompassed areas open to bottom trawling and scallop dredging and areas closed for 11 and 12 years. Statistical methods of circular tests, neighbor K analysis for one-dimensional data, analysis of variance, and Spearman rank correlation coefficient were used to assess weathervane scallop orientation, spatial characteristics, differences in abundance and size distributions between open and closed areas, and faunal associations. Orientation of weathervane scallops was directed with most oriented towards the strongest, prevailing bottom currents or the reciprocal, weaker currents. Adult weathervane scallops were aggregated in patch lengths ranging from less than 10 m to over 700 m. In 1999 only, the open area had higher prerecruit abundance relative to recruit abundance than the closed area. Weathervane scallop density (number of scallops m^-2) was not significantly lower in the open than in the closed area. There was some evidence of positive spatial associations between adult weathervane scallops and both large sea whips and anemones, and negative spatial association between adult weathervane scallops and sunflower sea stars. Juvenile weathervane scallops exhibited positive spatial association with anemones. Weathervane scallop density tended to be high in areas of high sea whip density and low in areas of high sunflower sea star density.


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Effect of Parasitism by Philonema agubernaculum (Nematoda: Philometridae) on the Ability of Dolly Varden to Capture Prey in Fresh and Salt Water
Adam Moles - Vol. 10(2):119-123. 2003.

Dolly Varden Salvelinus malma parasitized by a single nematode Philonema agubernaculum had significantly reduced ability to capture pink salmon fry Oncorhynchus gorbuscha in laboratory tests. Predator-prey trials, in which half the Dolly Varden were parasitized, were conducted in fresh water and salt water. Unparasitized Dolly Varden in fresh water captured a mean of 64% of the pink salmon during the test period and unparasitized Dolly Varden in salt water captured 61% of their available prey in the time allotted. In contrast, parasitized Dolly Varden in fresh water captured 32% of their prey as opposed to 29% in salt water. Nematode parasitism has the potential to reduce the foraging ability of Dolly Varden in the laboratory under conditions of abundant food, but the broader ecological consequences remain unclear.


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Pop-up Archival Transmitting (PAT) Tags: A Method to Investigate the Migration and Behavior of Pacific Halibut Hippoglossus stenolepis in the Gulf of Alaska
Andrew C. Seitz, Derek Wilson, Brenda L. Norcross and Jennifer L. Nielsen - Vol. 10(2):124-136. 2003.

Pop-up archival transmitting (PAT) tags provide a fisheries-independent method of collecting environmental preference data (depth and ambient water temperature) and migration distance. In this study, we evaluate the use of pop-up archival transmitting tags as a method to investigate demersal fish. We report the results from eight pop-up archival transmitting tagged Pacific halibut Hippoglossus stenolepis (from 107 to 165 cm FL) that were released in and around Resurrection Bay, Alaska. Commercial fishermen recovered three tags, while five tags transmitted data to Argos satellites. Horizontal migration was not consistent among fish as four Pacific halibut remained in the vicinity of release while the other four traveled up to 358 km from the release site. Vertical movement was not consistent among fish or over time; however, they spent most of their time at depths of 150 to 350 m. The minimum and maximum depths reached by any of the Pacific halibut were 2 m and 502 m, respectively. The fish preferred water temperatures of approximately 6°C, but experienced temperatures between 4.3 and 12.2°C. Light attenuation with depth prevented geolocation software and light sensing hardware from accurately estimating geoposition for the majority of days. The methods, adapted from investigations on large pelagic fish, proved to be effective for studying Pacific halibut in the northern Gulf of Alaska. PAT tags allowed us to obtain high accuracy locations of the fish at the end of the tag deployments as well as preliminary data to identify approximate seasonal locations and to characterize their depth and temperature characteristics. By using PAT tags, we will be able to ensure tag returns during the winter season (which is closed to fishing) and gain valuable biological information even if fish migrate large distances or to unexpected locations.


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Growth of Male Tanner Crabs Chionoecetes bairdi in a Southeast Alaska Estuary
Robert P. Stone, Michele M. Masuda, and John E. Clark - Vol. 10(2):137-148. 2003.

Growth of male Tanner crabs Chionoecetes bairdi from a glacial Southeast Alaska estuarine population was studied during 1999 and 2000. Premolt crabs were collected in situ by scuba divers and held in the laboratory until molting occurred (less than or equal to 33 d). An interannual difference in growth was not found, but growth was significantly greater (2.3% to 6.2%) than that observed for Kodiak Island area crabs during the 1970s. Current management of Tanner crabs throughout Alaska is based on growth estimated for Kodiak Island crabs in the 1970s. A significant change in allometric growth occurred at 96.5 mm carapace width. Growth was reduced for crabs held in the laboratory >13 d, crabs missing three or more premolt limbs, and crabs missing two or more postmolt limbs. Crabs attained large-claw status over a wide size range (approximately 125.0 to 178.9 mm postmolt carapace width) and among large-clawed crabs a percent increase in chela height was not associated with a percent decrease in growth. Growth data indicated that the majority (53% to 70%) of Tanner crabs harvested in the Southeast Alaska commercial fishery during most years were newly recruited to the fishery.


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VOLUME 11(1) - Summer 2005

Catch Estimation Algorithm for the Walleye Pollock Theragra chalcogramma Fishery and Comparison to Similar National Marine Fisheries Service Databases
Brian Battaile, Terrance J. Quinn II, David Ackley, and Galen Tromble - Vol. 11(1):1-14. 2005.

As fisheries management entertains more complex objectives to ensure sustainable fisheries and ecosystems, reexamination of all aspects of data collection, data analysis, and management actions is needed. In particular, focus on fine spatial and temporal scales is becoming more common. A new spatially and temporally explicit database was constructed with this focus for the total walleye pollock (Theragra chalcogramma) catch in the waters off Alaska. Three sources provide information about pollock catches: the National Marine Fisheries Service observer program data, weekly processor reports to the National Marine Fisheries Service, and Alaska Department of Fish and Game fish tickets. The observer program database contains exact locations by longitude and latitude and dates. Fish tickets and weekly processor reports are much coarser in time (by cruise and week, respectively) and space (by Alaska Department of Fish and Game and federal reporting areas, respectively). Hence, obtaining spatiotemporal
data at the finest scale requires maximum use of observer data. However, a significant portion of pollock catch is unobserved, so that it was necessary to combine the three data sources to provide a full accounting of catch. Comparisons were made to two National Marine Fisheries Service algorithms, the Catch By Vessel and Blend, presently used for fisheries management and analysis purposes. Estimated total catch was similar among the three systems, but the new database makes best use of the observer data and consequently is preferred for addressing fine-scale questions about pollock management.


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Distribution, Migration Pathways, and Size of Western Alaska Juvenile Salmon Along the Eastern Bering Sea Shelf
Edward V. Farley, Jr., James M. Murphy, Bruce W. Wing, Jamal H. Moss, and Angela Middleton - Vol. 11(1):15-26. 2005.

The size, condition, distribution, and migration pathways of juvenile Pacific salmon (pink, chum, sockeye, coho, and Chinook salmon) were examined along the eastern Bering Sea shelf during August through October 2002. Juvenile salmon were widely distributed across the eastern Bering Sea shelf, but species-specific distributional patterns were found. Juvenile sockeye and chum salmon were large during 2002, suggesting that growth rates were high during their first summer at sea. Seaward migratory pathways for juvenile salmon from Bristol Bay and the Kuskokwim and Yukon rivers were inferred from their size distributions along the eastern Bering Sea shelf, and differ from earlier migration models.


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Faunal Assemblage Structure on the Patton Seamount (Gulf of Alaska, USA)
Gerald R. Hoff and Bradley Stevens- Vol. 11(1):27-36. 2005.

Epibenthic and demersal assemblages of fish and invertebrates on the Patton Seamount in the Gulf of Alaska, U.S.A., were studied in July 1999 using the Deep Sea Research Vehicle Alvin. Faunal associations with depth were described using video analysis of 8 dives from 151 to 3,375 m. A cluster analysis applied to the observations suggests three benthic faunal communities based on depth: 1) a shallow-water community (151–950 m) consisting mainly of rockfishes, flatfishes, sea stars, and attached suspension feeders, 2) a mid-depth community (400–1500 m) also consisting of numerous attached suspension-feeding organisms such as corals, sponges, crinoids, sea anemones, and sea cucumbers and fish such as the sablefish Anoplopoma fimbria and the giant grenadier Albatrossia pectoralis both of which were aggregated over a relatively narrow depth range, and 3) a deep-water community (500–3,375 m) consisting of fewer attached suspension feeders and more highly mobile species such as the Pacific grenadier Coryphaenoides acrolepis, popeye grenadier C. cinereus, Pacific flatnose Antimora microlepis, and large mobile crabs Macroregonia macrochira and Chionoecetes spp. that were less aggregated and covered a much greater depth range. Bottom depth was highly correlated with temperature and bottom substratum type where the upper 1,300 m was primarily a mixed habitat of boulders and large cobbles. The bottom substratum types were less diverse from 1,300 m to 3,300 m, which was composed of gravels and smaller sized particles. The absence of many near shore species on the Patton Seamount suggests this seamount is a unique subset of the near shore fauna but maintains distinct assemblage characteristics.


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Resistance of Naturally Spawned Pink Salmon Eggs to Mechanical Shock
John F. Thedinga, Mark G. Carls, Jacek M. Maselko, Ronald A. Heintz, and Stanley D. Rice - Vol. 11(1):37-43. 2005.

Routine hydraulic sampling of pink salmon eggs Oncorhynchus gorbuscha is the subject of a longrunning dispute over impacts of the Exxon Valdez oil spill on embryo survival in Prince William Sound, Alaska, because relationships between the time of spawning, sensitivity of eggs to mechanical damage, and sample timing were unclear. Previous laboratory and hatchery studies demonstrate that resistance of eggs to mechanical damage increases with maturity, but natural populations require estimates of embryo age distributions and the ability to discriminate between sampler-induced and natural egg mortality. Resistance of naturally-spawned eggs to hydraulic shock, determined 6 times between late September and mid-November in a southeastern Alaska stream, increased sigmoidally from < 2% to 98%. In contrast, the number of eggs that died from natural causes was unrelated to sample time. Rapid removal of all eggs from the water allowed accurate discrimination between eggs shocked and killed by sampling and eggs dead prior to sampling. We caution that combining shocked and dead eggs into a single “dead” category does not accurately describe natural mortality, and recommend use of our method for future studies. Our study showed the rate of mortality resistance to the same hydraulic shock was slower in populations of naturally spawned, mixed-age eggs than in artificially cultured uniform-age eggs.


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United States and Canadian Chinook Salmon Populations in the Yukon River Can Be Segregated Based on Genetic Characteristics
William D. Templin, Richard L. Wilmot, Charles M. Guthrie III, and Lisa W. Seeb - Vol. 11(1):44-60. 2005.

Chinook salmon (Oncorhynchus tshawytscha) spawn throughout the Yukon River drainage, supporting fisheries in both the United States and Canada. To achieve management goals set under international agreements, it is vital to know the proportion of Canadian-origin Chinook salmon harvested in United States fisheries. Currently this proportion is estimated using scale pattern analysis, but this method has several weaknesses, including limited resolution and the necessity for annual sampling. We analyzed samples collected from representative spawning populations throughout the drainage and mixtures from inriver fisheries to investigate the utility of genetic stock identification for applications based on allozyme loci in the Yukon River. Populations demonstrated a strong association between genetic differences and geographic location and could be combined into 6 regional groups. Simulations showed that these regions could be identified in mixtures with a high degree of accuracy and precision.


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Quillfish Ptilichthys goodei, Filiform Prey for Small Coho and Chinook Salmon
Laurie A. Weitkamp - Vol. 11(1):61-65. 2005.

Juvenile quillfish Ptilichthys goodei were identified in the stomachs of nine juvenile coho Oncorhynchus kisutch and two juvenile Chinook O. tshawytscha salmon captured in marine waters of Southeast Alaska in June and July of 1999 and 2000. These extremely elongate prey were nearly as long (maximum 82.3%, mean 65.2%) as their salmon predators, providing the highest prey-predator length ratio reported for juvenile Pacific salmon. Despite this disproportionately high length ratio, however, the mean weight of quillfish consumed per salmon (0.287 g) represented only 35.4% of the total stomach content weight, or 0.5% (range .02–1.76%) of the salmon’s total body weight. While prey length is clearly an important metric for determining which prey a predator will potentially consume, this study emphasizes that it is not the only determinant.


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VOLUME 11(2) — Winter 2005

Effects of Inbreeding and Family Origin on Variation of Size of Chinook Salmon
Oncorhynchus tshawytscha Fry
Cara J. Rodgveller, William W. Smoker, Andrew K. Gray, John E. Joyce, and Anthony J. Gharrett — Vol. 11(2):73–81. 2005.

We cultured separate lines of Chinook salmon fry Oncorhynchus tshawytscha of Chickamin River, Southeast Alaska ancestry in 7 common garden enclosures. A parentage analysis based on variation of microsatellite alleles showed that within these lines, 7 brother-sister matings ( F satellite F = 0.25) had created 35 inbred fish in 7 = 0.25) had created 35 inbred fish in 7 families [bred from 6 females (dams) and 6 related males (sires)], and other matings of unrelated fish had created 37 outbred fish in 10 familes (bred from 7 females and 6 males.) There was no measurable effect of inbreeding on growth of Chinook salmon fry through 114 days post swim-up. A general linear model showing the effects of dam, sire, and the interaction of dam and sire explained a significant amount of the variation of length and weight, but not of condition factor. However, analysis of a mixed model showed that only the interaction between dam and sire explained a significant amount of the variation of lengths and weights. Because variation among individuals from different families can be large, effects of individuals can potentially be confounded with the effects for which a study is designed. To avoid drawing improper conclusions, studies should estimate the amount of variation that can be attributed to family origin, or be certain that many families are sampled.


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Evaluation of Biological Sampling Protocols for At-Sea Groundfish Observers in Alaska
Steven J. Barbeaux, Sarah Gaichas, James N. Ianelli, and Martin W. Dorn — Vol. 11(2):82–101. 2005.

In 1999 the North Pacific Groundfish Observer Program (NPGOP) changed sampling protocols in order to optimize available observer resources. As the NPGOP modifies their program to meet an increasing number of objectives, it is important to ensure that new protocols continue to meet previously defined objectives. In this study, we evaluate how the changes in sampling protocols have affected data critical to stock assessments. We explore how changes to the length and otolith sampling protocols effect estimates of length distributions, mean length, and catch-at-age distributions in the eastern Bering Sea walleye pollock Theragra chalcogramma fishery. We also investigate the spatial distribution of observer length and otoliths samples in relation to total catch. We found that the modified protocols employed by NPGOP in 1999 did not significantly reduce the precision of estimates based on collected data, but did improve the spatial distribution of length and otolith sampling in this fishery. Given these results, coupled with an overall reduction in the time necessary to complete these sampling tasks, we conclude that the modification to observer sampling protocols in 1999 improved data collection in the NPGOP.


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Distribution of Juvenile Pacific Ocean Perch Sebastes alutus in the Aleutian Islands in Relation to Benthic Habitat
Christopher N. Rooper and Jennifer L. Boldt — Vol. 11(2):102–112. 2005.

The habitat of juvenile Pacific ocean perch (POP) Sebastes alutus was identified using data from trawl surveys conducted by the National Marine Fisheries Service and linear modeling techniques. Analyses were carried out to evaluate the POP catch per unit effort (CPUE) data in relationship to depth, temperature, and sponge and coral CPUE. Sponge and coral CPUE were positively correlated, while depth and temperature were negatively correlated. Over 96% of the juvenile POP catch was from depths of 76 to 225 m and their CPUE increased with depth, and decreased with increasing temperature. The most important finding of this analysis was that juvenile POP CPUE increased significantly with increasing sponge and coral CPUE. Multiple regression analysis predicting juvenile POP CPUE explained 16% -17% of the CPUE variability using sponge and coral CPUE and either bottom temperature or depth. Juvenile POP were most abundant at sites in the western Aleutian Islands (beyond 170º W longitude), on large underwater banks (Stalemate and Petrel banks), and in passes between islands where currents are strong and prey availability may be higher than surrounding areas. These results suggest sponge and coral have an important role in the early life history of juvenile POP.


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Co-occurrence of Pacific Sleeper Sharks Somniosus pacificus and Harbor Seals Phoca vitulina in Glacier Bay
S. James Taggart, Alexander G. Andrews, Jennifer Mondragon, and Elizabeth A. Mathews — Vol. 11(2):113–117. 2005.

We present evidence that Pacific sleeper sharks Somniosus pacificus co-occur with harbor seals Phoca vitulina in Glacier Bay, Alaska, and that these sharks scavenge or prey on marine mammals. In 2002, 415 stations were fished throughout Glacier Bay on a systematic sampling grid. Pacific sleeper sharks were caught at 3 of the 415 stations, and at one station a Pacific halibut Hippoglossus stenolepis was caught with a fresh bite, identified as the bite of a sleeper shark. All 3 sharks and the shark-bitten halibut were caught at stations near the mouth of Johns Hopkins Inlet, a glacial fjord with the highest concentration of seals in Glacier Bay. Using a bootstrap technique, we estimated the probability of sampling the sharks (and the shark-bitten halibut) in the vicinity of Johns Hopkins Inlet. If sharks were randomly distributed in Glacier Bay, the probability of sampling all 4 pots at the mouth of Johns Hopkins Inlet was very low (P = 0.00002). The highly non-random distribution of the sleeper sharks located near the largest harbor seal pupping and breeding colony in Glacier Bay suggests that these 2 species co-occur and may interact ecologically in or near Johns Hopkins Inlet.


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Development of a Long-term Monitoring Project to Estimate Abundance of Chinook Salmon in the Copper River, Alaska, 2001-2004
Jason J. Smith, Michael R. Link, and Bruce D. Cain — Vol. 11(2):118–134. 2005.

We used fishwheels and 2-event mark-recapture methods to estimate the annual drainage-wide abundance of adult Chinook salmon Oncorhynchus tshawytscha returning to the Copper River in Southcentral Alaska. In the first event, fish were captured from May through July using 2 fishwheels operated in Baird Canyon (river km 66) in the lower Copper River. All marked fish received a back-sewn spaghetti tag during each year of study, and up to 500 fish in each of 2002, 2003 and 2004 were also fitted with radio tags. In the second event, marked fish were recaptured in one or 2 additional fishwheels operated on the Copper River near Canyon Creek (river km 157). The Baird Canyon fishwheels were operated from 2001 to 2004, and the Canyon Creek fishwheels were operated from 2002 to 2004. Unbiased system-wide abundance estimates were made in 2003 and 2004. An estimated 44,764 (SE=12,506) Chinook salmon measuring 810 to 1,070 mm fork length (FL) passed through Baird Canyon from 17 May to 1 July 2003. From 22 May to 22 June 2004, an estimated 40,564 (SE= 4,650) Chinook salmon (equal to or greater than 600 mm FL) passed through Baird Canyon. Capture probabilities during both events varied over the season in 2003 and 2004 and appeared to be influenced by flow-related changes in fishwheel catchability. We developed vertical-slot "escape panels" to place in the fishwheel live tanks, which allowed the much more abundant sockeye salmon O. nerka to easily escape from the live tanks back into the river while retaining Chinook salmon. The project has evolved into a successful long-term monitoring program and has demonstrated that Federal, State and Tribal agencies can work cooperatively to collect valuable data on Copper River salmon stocks.


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Estimating Capture Probability of a Survey Bottom Trawl for Bering Sea Skates (Bathyraja spp.) and Other Fish
Stan Kotwicki and Kenneth L. Weinberg — Vol. 11(2):135–145. 2005.

Capture probabilities for skates (Bathyraja spp.), 3 species of flatfish, and 7 other fish species were estimated for the standard survey trawl (83-112 Eastern bottom trawl) used to conduct the National Marine Fisheries Service annual eastern Bering Sea bottom trawl survey. Capture probability data were collected by an experimental trawl consisting of a standard survey trawl with an auxiliary net attached beneath the footrope. Capture probability was estimated for each 1-cm length interval by calculating the ratio of fish caught in the standard survey trawl to the sum of fish caught in both standard survey trawl and auxiliary net. Four competing models describing different capture processes were fitted to the data using a maximum likelihood method, and the best model was chosen by likelihood ratio test. Capture probability for skates increased monotonically with length from approximately 0.65 for 30 cm skates to approximately 0.8 for skates >100 cm. Capture probability for flatfish (arrowtooth flounder, Atheresthes stomias; rex sole, Glyptocephalus zachirus; and Pacific halibut, Hippoglossus stenolepis); sturgeon poacher, Podothecus accipenserinus; wattled eelpout, Lycodes palearis; and great sculpin, Myoxocephalus polyacanthocephalus, was constant across lengths and close to unity (> 0.97). Capture probability was constant, but significantly lower than 1.0 for sawback poacher Leptagonus frenatus (0.89), searcher Bathymaster signatus (0.94), and spinyhead sculpin Dasycottus setiger (0.69). For spectacled sculpin Triglops scepticus capture probability was 1.0 for fish smaller than 15 cm but decreased for larger fish.


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Mortality Rates for Juvenile Pink Oncorhynchus gorbuscha and Chum O. keta Salmon Infested with Sea Lice Lepeophtheirus salmonis in the Broughton Archipelago
Alexandra Morton and Rick Routledge — Vol. 11(2):146–152. 2005.

Wild juvenile pink Oncorhynchus gorbuscha and chum salmon O. keta were captured and sorted by the number of sea lice Lepeophtheirus salmonis infecting each fish. These fish were placed in groups of 60 in flowthrough containers immersed in seawater near the site of capture. There were 3-4 replicates for each infection category and 3 consecutive trials or Series run to assess the impact of sea lice on short-term fish mortality. Control groups of lice-free fish were included to measure handling and containment effects. In each trial or Series, significantly more fish died in the categories with sea lice than in the lice-free category. The majority of fish infected with motile-stage sea lice died. These observations indicate that short-term mortality of wild juvenile pink and chum salmon is increased by infestations of 1-3 sea lice.


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VOLUME 12(1) — Summer 2006

The Commercial Salmon Fishery in Alaska
John H. Clark, Robert D. Mecum, Andrew McGregor, Paul Krasnowski and Amy Carroll — Vol. 12(1):1–146. 2006.

Alaska’s commercial salmon fisheries have harvested an average of 172 million salmon annually since 1990, ranging from 123 million to 221 million fish per year. This stands in stark contrast to the average annual harvest of 41 million fish during the 1950s — the final decade under federal management of the state’s commercial salmon fisheries. When Alaska assumed management authority of its salmon fisheries in 1960, one year after statehood, many of the state’s salmon runs were depressed and its salmon fisheries were in desperate shape. In this paper we describe how these once depleted salmon fisheries have been rebuilt over the last 45 years into one of the strongest and most sustainable fishery resources in the world. We review state policies and regulatory structure, describe how the resource is managed, and provide outputs from the management program including harvest levels and values, the number of fishermen involved, and the current status of Alaska’s salmon stocks. Detailed information is provided for each of 11 commercial fishing areas in the state. We also provide information on funding levels and sources that the Alaska Department of Fish and Game has used to support its salmon management and assessment programs. Challenges faced by the state in maintaining and improving resource management and by the state and industry in improving fishery profitability are discussed.


FULL ARTICLE ( LARGE PDF file * — 5,441 KB ) Also available in smaller pieces: Introduction (1,506 KB) \| SE Alaska/Yakutat, Prince William Sound, and Cook Inlet salmon fisheries (1,955 KB) \| Kodiak, Chignik, Peninsula-Aleutians, and Bristol Bay salmon fisheries (1,781 KBK) \| Kuskokwim, Yukon, Norton Sound, Kotzebue salmon fisheries and Literature Cited (1,517 KB)		Top of Page

Using Otolith Morphometrics to Separate Small Walleye Pollock Theragra chalcogramma from Arctic Cod Boreogadus saida in Mixed Samples
Jonathan A. Short, Christopher M. Gburski, and Daniel K. Kimura — Vol. 12(1):147–152. 2006.

Species identification errors occasionally occur when collecting biological information and ageing
structures. Therefore, it is useful to have the ability to distinguish between species using only otoliths. Otolith
morphometrics (area, perimeter, length, width, and number of scallops) and fish fork length were used to distinguish
between walleye pollock Theragra chalcogramma and Arctic cod Boreogadus saida measuring between 8 and
20 cm caught in the eastern Bering Sea. Discriminant analysis of otolith morphometrics and fork length correctly
classified verified walleye pollock and Arctic cod with 99% accuracy. The number of scallops and otolith area were
the most effective individual otolith characteristics for distinguishing between species. Otolith shape analysis using
Fourier methods with fork length was also attempted and was found to be less effective (94% accuracy) than otolith
morphometrics and fork length combined. The discriminant functions were applied to an unverified productionaged
juvenile walleye pollock sample from the eastern Bering Sea. Based on length-at-age of some specimens,
it was thought that this sample might be contaminated with Arctic cod. Twelve of the 154 (8%) production-aged
specimens were classified as Arctic cod by the best of these discriminant functions; however, none of the aged
specimens displayed strong Arctic cod characteristics.


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Assessing the Potential for Remote Delivery of Persistent Organic Pollutants to the Kenai River in Alaska
Stanley Rice and Adam Moles — Vol. 12(1):153–157. 2006.

Contaminants such as polychlorinated biphenyls and organochlorine pesticides are among the most
environmentally persistent pollutants. Although the more problematic of these chemicals are not produced in the
United States, the compounds can be transported to Alaskan watersheds from remote locations via winds, currents,
and through carcasses of returning salmon. Concentrations of total polychlorinated biphenyls and 23 pesticides
eluted from passive samplers deployed for 30 days in the Kenai River were near or below 10 ppb, despite 30-day
deployments of the strips. Concentrations of these compounds in both eggs and muscle tissue from returning Chinook
salmon were also below 10 ppb and did not differ with respect to ocean residence time. There was no evidence of
remote delivery of polychlorinated biphenyls or pesticides in this major salmon producing river.


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VOLUME 12(2) — Winter 2007

Geographic Distribution, Depth Range, and Description of Atka Mackerel Pleurogrammus monopterygius Nesting Habitat in Alaska
Robert R. Lauth, Scott W. McEntire, and Harold H. Zenger Jr. — Vol. 12(2):165–186. 2007.

Understanding the spatial and bathymetric extent of the reproductive habitat of Atka mackerel Pleurogrammus monopterygius is basic and fundamental information for managing and conserving the species. From 1998 to 2004, scuba diving and in situ and towed underwater cameras were used to document reproductive behavior of Atka mackerel and to map the geographic and depth ranges of their spawning and nesting habitat in Alaska. This study extended the geographic range of nesting sites from the Kamchatka Peninsula to the Gulf of Alaska, and extended the lower depth limit from 32 to 144 m. Male Atka mackerel guarding egg masses were observed during October—indicating that the duration of the nesting period in Alaska is more protracted than in the western Pacific. Results from this study also suggest that nearshore nesting sites constitute only a fraction of the nesting habitat and that there is no concerted nearshore spawning migration for Atka mackerel in Alaska. Nesting sites were widespread across the continental shelf and found over a much broader depth range than in the western Pacific. Nesting habitat was invariably associated with rocky substrates and water currents; however, smaller-scale geomorphic and oceanographic features as well as physical properties of the rocky substrate were variable between different island groups and nesting sites. Water temperatures for nesting sites ranged from 3.9°C to 10.5°C. Water temperatures within nesting sites varied little and did not appear to be limiting the upper or lower depth boundaries of nesting. Results from dive transects showed significantly fewer egg masses above 20 m water depth. Other possible factors limiting the upper or lower depth limit of nesting sites are discussed.


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A Feeding Aggregation of Humpback Whales Megaptera Novaeangliae near Kodiak Island, Alaska: Historical and Current Abundance Estimation
Briana H. Witteveen, Kate M. Wynne, and Terrance J. Quinn II — Vol. 12(2):187–196. 2007.

A photo-identification, mark–recapture study was conducted on a feeding aggregation of humpback whales Megaptera novaeangliae in the waters of eastern Kodiak Island between June and September 2002. Historically, a portion of this population was targeted in a local commercial whale fishery. The fishery was conducted in eastern Kodiak Island out of Port Hobron, Alaska, between 1926 and 1937 and resulted in the removal of nearly 1,600 humpback whales. An estimated 157 (95% confidence interval: 114, 241) whales were in the study area in 2002 based on the Schnabel maximum likelihood estimator (MLE) for closed populations. The Schnabel MLE of abundance in 2002 and historic catch values were used to back-calculate the historical abundance trend in the study area between 1925 and 2002 using a delay-difference model with a density dependent recruitment function. Historical abundances were calculated both prior to commercial whaling in 1925 and immediately post-whaling in 1938. Estimated abundance within the study area just prior to commercial whaling was 343 (331, 376). Immediately following the cessation of whaling in 1938, estimated abundance within the study area was 27 (14, 61). Results from this study show the Port Hobron whale fishery likely had a significant impact on the local humpback whale population.


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Parasites of the Fishes of Alaska and Surrounding Waters
Adam Moles — Vol. 12(2):197–226. 2007.

The published records of parasites of freshwater and marine fishes of Alaska and the surrounding seas through 2006 are summarized. Fish hosts are listed alphabetically, providing a single, convenient source of information on the known parasites of Alaskan fishes. Of the 601 species of fish believed to inhabit the waters of Alaska, parasites are herein listed for 89 species. Information from 135 published studies spanning over a century of work are consolidated to assist both biologists and future investigators in parasite identification.


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Estimating Southeast Alaska Tanner Crab Abundance Using Pot Survey and Commercial Catch Data
Jie Zheng, Janet M. Rumble, and Gretchen H. Bishop — Vol. 12(2):227–242. 2007.

A catch–survey analysis was developed for 11 Tanner crab stocks in Southeast Alaska. The models were applied to pot survey and commercial catch data time series ranging from 1999–2005 to 1978–2005, depending on the availability of data for each stock. The models fit the pot survey data very well for 9 out of 11 stocks. The models estimated absolute abundance for mature and legal males and relative abundance for mature females. The trends of absolute male abundance estimates differed among some stocks, and there was no a consistent pattern of male recruitment to the model for all 11 Tanner crab stocks. Mature male abundance and recruitment to the model declined during recent years for several stocks. Although legal harvest rates have been lower during the recent 10 years than for the previous period, overall harvest rates are still very high for some stocks.


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Seasonal Marginal Growth on Otoliths of Seven Alaska Groundfish Species Support the Existence of Annual Patterns
Daniel K. Kimura, Delsa M. Anderl, and Betty J. Goetz — Vol. 12(2):243–251. 2007.

The Alaska Fisheries Science Center’s Age and Growth Program has been collecting qualitative otolith edge growth data for many of the principal species that it ages. The edge-type data collected are coded on a scale from 0 to 5, in an attempt to categorize the characteristics of the outermost growth zone of the otolith for the month of capture. Edge growth classification data can be subject to biases when age readers are looking for a particular pattern of growth. However, analysis of edge-type data can be used to determine the apparent strength and timing of seasonal growth patterns, and thus provides a weak form of age validation. We develop a simple model that allows us to estimate the signal strength and timing of otolith edge growth using standard nonlinear least squares. We do this by combining edge codes so that they are concentrated into two distinct categories: category 1 which represents an otolith with a full increment of opaque growth or a translucent zone on the edge (with perhaps a hint of new opaque growth), or category 3 which represents an otolith which has substantial growth, ¼ to ½ of the previous year’s otolith growth, on its edge. Because the remaining categories (2 and 4) contained relatively few observations, categories 1 and 3 can be treated using a logit-like transformation, and then modeled with a cosine function. This model appeared to capture a strong seasonal trend in edge-type growth in 7 species for which reasonable amounts of data were available. These results support that the growth rings found in many Alaska groundfish are generally annual marks, but do not validate that conventional ages from otolith ring counts for any of these species are accurate.


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Evaluation of the Macroscopic Staging Method for Determining Maturity of Female Walleye Pollock Theragra chalcogramma in Shelikof Strait, Alaska
Kresimir Williams — Vol. 12(2):252–263. 2007.

Macroscopic or visual staging is the primary method for determining maturity status of walleye pollock Theragra chalcogramma stocks in the Gulf of Alaska and the Bering Sea, although its accuracy has not been established. To address this, maturity data and samples were taken during several annual spawning surveys of pollock conducted in Shelikof Strait, Gulf of Alaska. Comparison of histological and macroscopic staging methods on 126 ovary samples resulted in a 25% misclassification rate, with 75% of these misclassifications reclassified into the adjacent stages. Misclassifications were most common among developing stages 2 and 3, and the prespawning stage 4. Paired readings of female pollock maturities were made at sea during the surveys, with readers disagreeing on classification stage in 36% of 411 observations. Reader disagreements were most common between stages 3 and 4 (11.4%), stages 4 and 5 (5.8%) and stages 7 and 8 (4.8%). Errors made across the boundaries of stages 3 and 4 as well as stages 2 and 8 can impact the estimates of length at 50% maturity and consequently the spawning stock biomass. These types of errors were observed in the histological validation process, but due to the very low incidence of stages 3 and 8 in the survey population (1.8% and 0.4%, respectively), the contribution of these potential errors to maturity assessments can be considered small.


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Maturity of Female Northern Rockfish Sebastes polyspinis in the Central Gulf of Alaska
Elizabeth Chilton — Vol. 12(2):264–269. 2007.

The northern rockfish Sebastes polyspinis (Taranetz and Moiseev in Taranetz, 1933) is the second most important commercial rockfish species caught in the Gulf of Alaska. Current estimates of northern rockfish age and length at 50% maturity from the annual Gulf of Alaska stock assessment are based on macroscopic evaluations of a relatively small sample size collected in 1996. This study determined the maturity stage of female northern rockfish using histological techniques from 157 samples over a 2-year period. Estimated age at 50% maturity for female northern rockfish in the central Gulf of Alaska is 8 years and estimated length at 50% maturity is 310 mm. The maturity estimates presented in this study indicate that female northern rockfish mature at a younger age and smaller size than previously reported.


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Growth of Female Red King Crabs Paralithodes camtshaticus from Kodiak, Alaska, during Pubertal, Primiparous, and Multiparous Molts
Bradley G. Stevens and Katherine M. Swiney - Vol. 12(2):270–277. 2007.

Growth models for red king crabs Paralithodes camtschaticus typically apply increments based strictly on size and sex, but growth of female red king crabs depends on their specific life history stage and previous reproductive history. Over a period of 5 years, we held female red king crabs in the laboratory for periods up to 4 years, during which we recorded growth for 77 crabs that molted at least once, and some that molted 2 or 3 times, for a total of 121 different molting events. Molts (and data) were classified as being pubertal (i.e., the molt to maturity), primiparous, or multiparous. During their pubertal molt, female red king crabs grew an average of 18.2%, primiparous crabs grew an average of 6.7% and multiparous crabs grew an average of 3.6%. Relationships between premolt and postmolt size differed significantly between molting types. As a result, female crabs of a given size would have different molt increments depending on their reproductive history. Length of captivity did not affect the molt increment at a specific life history stage, i.e. during the primiparous molt; molt increments for females that molted within 6 months of capture were similar to those that molted after an additional year in captivity. Molt increments for multiparous crabs were essentially identical to those reported previously for tagged females. Models of red king crab growth, recruitment, and reproductive output could be significantly improved by considering both the size of female crabs and their reproductive history.


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A Workshop on Mechanisms Affecting Year-Class Strength Formation in Snow Crabs Chionoecetes opilio in the Eastern Bering Sea
Gordon H. Kruse, Albert V. Tyler, Bernard Sainte-Marie, and Douglas Pengilly - Vol. 12(2):270-277. 2007.

A group of specialists on subarctic crab biology and fisheries participated in a workshop to discuss
stage-specific recruitment processes of snow crab Chionoecetes opilio populations. The goal was to develop from
experience with North Pacific and North Atlantic stocks a comprehensive set of hypotheses on the physical and biotic
factors that may contribute to the variation in year-class success of the snow crab stock in the eastern Bering Sea.
Participants identified 15 life history stages and associated survival and productivity processes. Some of the processes
deemed to be most critical include match of hatching larvae with adequate densities of suitable prey, advection (or
retention) of larvae to nursery areas suitable for settlement, predation by Pacific cod Gadus macrocephalus and
other predators, and cannibalism of newly settled juveniles by older, larger snow crab juveniles. A comprehensive
set of hypotheses is intended to serve as a vehicle by which to direct future field and laboratory research programs
to better understand snow crab population and fishery dynamics.


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Trends in Area-Weighted CPUE of Pacific Sleeper Sharks Somniosus pacificus in the Northeast Pacific Ocean Determined from Sablefish Longline Surveys
Dean L. Courtney and Michael F. Sigler — Vol. 12(2):292–316. 2007.

The deepwater Pacific sleeper shark Somniosus pacificus is an opportunistic predator in the northeast Pacific Ocean. Their life history and distribution are poorly understood, and changes in their relative abundance or distribution could have direct and indirect effects on the ecosystem. There are no directed fisheries or surveys for Pacific sleeper sharks in Alaskan marine waters; consequently, abundance estimation is limited to indirect methods. We analyzed Pacific sleeper shark incidental catch (bycatch) from sablefish longline surveys conducted on the upper continental slope of the eastern Bering Sea, Aleutian Islands, and Gulf of Alaska between the years 1979 and 2003. Our objectives were to estimate trends in Pacific sleeper shark relative abundance and their statistical significance. A total of 1,565 Pacific sleeper sharks were captured by sablefish longline surveys between the years 1979 and 2003 with a sample effort of 19.7 million hooks. Area (km²) weighted catch per unit effort (CPUE) of Pacific sleeper sharks was analyzed from standardized sablefish longline surveys between the years 1982 and 2003 with bootstrap 95% confidence intervals as an index of relative abundance in numbers. Within the limited time series available for hypothesis testing, area-weighted CPUE of Pacific sleeper sharks increased significantly in the eastern Bering Sea between the years 1988 and 1994 and in the Gulf of Alaska between the years 1989 and 2003, but also decreased significantly in the Gulf of Alaska in 1997. The increasing trend in the Gulf of Alaska was driven entirely by one region, Shelikof Trough, where most (54%) Pacific sleeper sharks were captured. Increasing trends in area-weighted CPUE of Pacific sleeper sharks in the eastern Bering Sea and Shelikof Trough are consistent with previous analyses of fishery-dependent and fishery-independent data from the northeast Pacific Ocean and with evidence of a climatic regime shift that began in 1976 and 1977. Whether increasing trends in area-weighted CPUE of Pacific sleeper sharks from sablefish longline surveys represent an increase in the relative abundance of Pacific sleeper sharks at the population level or just reflect changes in local densities is unknown because of caveats associated with computing area-weighted CPUE of Pacific sleeper sharks from sablefish longline surveys and because of a lack of information on the life history and distribution of Pacific sleeper sharks.


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AFRB: Editor's Note
Doug Eggers - Vol. 12(2):323. 2007.
(No Abstract) Full Editorial:

Readers,

After a run of 13 years, the Alaska Department of Fish and Game, Division of Commercial Fisheries is ceasing publication of the Alaska Fishery Research Bulletin. This is the final issue. In 1994, the AFRB evolved from the Fishery Research Bulletin monograph series into the current peer-reviewed journal, publishing articles, issues and perspectives, notes and letters on fisheries research by state, federal and university scientists. Regretfully, current budget and staffing issues make it impossible to continue publishing the AFRB. All issues of the AFRB will continue to be available online at http://www.adfg.state.ak.us/pubs/afrb/afrbabst.php.

Doug Eggers,
Editor

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