Impact of the California sea lion (Zalophus californianus) on salmon fisheries in Monterey Bay, California

To assess the impact of California sea lions (Zalophus californianus) on salmon fisheries in the Monterey Bay region of California, the percentages of hooked fish taken by sea lions in commercial and recreational salmon fisheries were estimated from 1997 to 1999. Onboard surveys of sea lion interactions with the commercial and recreational f isheries and dockside interviews with fishermen after their return to port were conducted in the ports of Santa Cruz, Moss Landing, and Monterey. Approximately 1745 hours of onboard and dockside surveys were conducted—924 hours in the commercial fishery and 821 hours in the recreational fishery (commercial passenger fishing vessels [CPFVs] and personal skiffs combined). Adult male California sea lions were responsible for 98.4% of the observed depredations of hooked salmon in the commercial and recreational fisheries in Monterey Bay. Mean annual percentages of hooked salmon taken by sea lions ranged from 8.5% to 28.6% in the commercial fishery, 2.2% to 18.36% in the CPFVs, and 4.0% to 17.5% in the personal skiff fishery. Depredation levels in the commercial and recreational salmon fisheries were greatest in 1998—likely a result of the large El Niño Southern Oscillation (ENSO) event that occurred from 1997 to 1998 that reduced natural prey resources. Commercial fishermen lost an estimated $18,031−$60,570 of gear and $225,833−$498,076 worth of salmon as a result of interactions with sea lions. Approximately 1.4−6.2% of the available salmon population was removed from the system as a result of sea lion interactions with the fishery. Assessing the impact of a growing sea lion population on fisheries stocks is difficult, but may be necessary for effective fisheries management.

Use of Electroshock for Euthanizing and Immobilizing Adult Spring Chinook Salmon in a Hatchery

This study evaluated the use of electroshock as in alternative to traditional techniques for immobilizing and euthanizing hatchery fish. We used a commercially available electroanesthesia unit at the U.S. Fish and Wildlife Service's Carson National Fish Hatchery (Carson, Washington) to euthanize adult spring Chinook salmon Oncorhynchus tshawytscha and to son and collect gametes of fish at maturation. During euthanization by electroshock, the response of each fish was observed, Muscular and vertebral hemorrhaging wits quantified, and electrical settings were optimized accordingly. During gamete collection, fish were either electroshocked or exposed to tricaine methanesulfortate (MS-222); hemorrhaging, egg viability. egg size and quantity, and resultant fry quality were examined for each treatment group. Electroshocked fish had a higher likelihood Of injury during gamete collection than did fish exposed to MS-222. On average, each electroshocked fish had less than two hemorrhages oil both fillets examined. The size of each hemorrhage was less than 0.10% of the fillet surface. Fecundity and egg and fry quality were not affected by either immobilization method. Electroshock was a viable and efficient means of euthanizing adult spring Chinook salmon or sorting the fish and collecting their gametes. However, equipment settings must be optimized based on site-specific (e.g., water conductivity) and species-specific (e.g., fish size and seasonal state of maturation) factors.

Seal and salmon fisheries and general resources of Alaska.

2

Program for the rehabilitation of the Alaska salmon fisheries.

At head of title: Committee print. 84th Cong., 2d sess. Senate.

Proposed plan for managing the 1980 salmon fisheries off the coast of California, Oregon, and Washington : [final] : an amendment to the "Fishery management plan for commercial and recreational salmon fisheries off the coast of Washington, Oregon, and California commencing in 1978" /

Mode of access: Internet.

On the natural history of the salmon, and on the salmon-fisheries [as stated in the Report from the Select committee on salmon-fisheries of the United Kingdom,

Cover-title.

An inquiry into the present state and means of improving the salmon fisheries; including a digest of the evidence taken by the a select committee of the House of commons.

Mode of access: Internet.

An act for the preservation of the salmon fisheries in Scotland. 1828.

Mode of access: Internet.

Report from the Select committee on salmon fisheries, Scotland; together with the minutes of evidence, appendix and index. Ordered, by the House of commons, to be printed, 30 June 1836.

Mode of access: Internet.

Seal and salmon fisheries and general resources of Alaska.

Mode of access: Internet.

Constraints on community participation in salmon fisheries management in Northwest Russia

Acknowledgements Many parties contributed to making this paper a reality. This research was supported by the European Social and Research Council, grant ESRC ES/K006428/1. The author is particularly grateful to the grant’s holder, Professor David Anderson from the Department of Anthropology, University of Aberdeen, for his various support throughout this research. The Barents Center of the Humanities at Kola Science Center of the Russian Academy of Sciences in Apatity provided important institutional support. Officials from several fisheries management institutions of Arkhangelsk oblast, including Shiriaev Igor Alekseevich from Dvinsko-Pechorskoe Territorial Management Board, Skovorod’ko Artem Aleksandrovich from the Northern Basin Directorate of Fisheries and Water Biological Resources Conservation (Sevrybvod) and Korotenkov Aleksei Anatol’evich from the Fishing Industry Agency of Arkhangelsk oblast were very supportive and shared their knowledge wherever possible. Scholars Studenov Igor Ivanovich and Stasenkov Vladimir Aleksandrovich at Northern branch of the Knipovich Polar Research Institute of Marine Fisheries and Oceanography (SevPINRO) in Arkhangelsk provided their invaluable expertise on marine fisheries. Chairmen of several fishing collective farms – Tuchin Sergei Viktorovich, Samoilov Sergei Nikolaevich and Seliverstova Marina Nikolaevna – offered a great administrative support. Local residents of several villages in Mezen region were extremely generous and hospitable, providing places to stay, warm clothes, food, endless cups of tea, and most valuably, sparing their time. Finally, Natalie Wahnsiedler was a regular companion during fieldwork and a great source of inspiration for this research.

Constraints on community participation in salmon fisheries management in Northwest Russia

Acknowledgements Many parties contributed to making this paper a reality. This research was supported by the European Social and Research Council, grant ESRC ES/K006428/1. The author is particularly grateful to the grant’s holder, Professor David Anderson from the Department of Anthropology, University of Aberdeen, for his various support throughout this research. The Barents Center of the Humanities at Kola Science Center of the Russian Academy of Sciences in Apatity provided important institutional support. Officials from several fisheries management institutions of Arkhangelsk oblast, including Shiriaev Igor Alekseevich from Dvinsko-Pechorskoe Territorial Management Board, Skovorod’ko Artem Aleksandrovich from the Northern Basin Directorate of Fisheries and Water Biological Resources Conservation (Sevrybvod) and Korotenkov Aleksei Anatol’evich from the Fishing Industry Agency of Arkhangelsk oblast were very supportive and shared their knowledge wherever possible. Scholars Studenov Igor Ivanovich and Stasenkov Vladimir Aleksandrovich at Northern branch of the Knipovich Polar Research Institute of Marine Fisheries and Oceanography (SevPINRO) in Arkhangelsk provided their invaluable expertise on marine fisheries. Chairmen of several fishing collective farms – Tuchin Sergei Viktorovich, Samoilov Sergei Nikolaevich and Seliverstova Marina Nikolaevna – offered a great administrative support. Local residents of several villages in Mezen region were extremely generous and hospitable, providing places to stay, warm clothes, food, endless cups of tea, and most valuably, sparing their time. Finally, Natalie Wahnsiedler was a regular companion during fieldwork and a great source of inspiration for this research.

Age and length composition of Columbia Basin chinook, sockeye, and coho salmon at Bonneville Dam in 2001

In 2001, representative samples of adult Columbia Basin chinook (Oncorhynchus tshawytscha), sockeye (O. nerka), and coho salmon (O. kisutch) populations at Bonneville Dam were collected. Fish were trapped, anesthetized, sampled for scales and biological data, revived, and then released adult migrating salmonids. Scales were examined to estimate age composition; the results contributed to an ongoing database for age class structure of Columbia Basin salmon populations. Based on scale analysis of chinook salmon, four-year-old fish (from brood year [BY] 1997) comprised 88% of the spring chinook, 67% of the summer chinook, and 42% of the Bright fall chinook salmon population. Five-year-old fish (BY 1996) comprised 9% of the spring chinook, 14% of the summer chinook, and 9% of the fall chinook salmon population. The sockeye salmon population at Bonneville was predominantly four-year-old fish (81%), with 18% returning as five-year-olds in 2001. The coho salmon population was 96% three-year-old fish (Age 1.1). Length analysis of the 2001 returns indicated that chinook salmon with a stream-type life history are larger (mean length) than the chinook salmon with an ocean-type life history. Trends in mean length over the sampling period for returning 2001 chinook salmon were analyzed. Chinook salmon of age classes 0.2 and 1.3 show a significant increase in mean length over time. Age classes 0.1, 0.3, 0.4, 1.1, 1.2, and 1.4 show no significant change over time. A year class regression over the past 12 years of data was used to predict spring, summer, and Bright fall chinook salmon population sizes for 2002. Based on three-year-old returns, the relationship predicts four-year-old returns of 132,600 (± 46,300, 90% predictive interval [PI]) spring chinook and 44,200 (± 11,700, 90% PI) summer chinook salmon for the 2002 runs. Based on four-year-old returns, the relationship predicts five-year-old returns of 87,800 (± 54,500, 90% PI) spring, 33,500 (± 11,500, 90% PI) summer, and 77,100 (± 25,800, 90% PI) Bright fall chinook salmon for the 2002 runs. The 2002 run size predictions should be used with caution; some of these predictions are well beyond the range of previously observed data.

Age and length composition of Columbia Basin chinook, sockeye, and coho salmon at Bonneville Dam in 2000

In 2000, representative samples of adult Columbia Basin chinook (Oncorhynchus tshawytscha), sockeye (O. nerka), and coho salmon (O. kisutch), populations were collected at Bonneville Dam. Fish were trapped, anesthetized, sampled for scales and biological data, allowed to revive, and then released. Scales were examined to estimate age composition and the results contribute to an ongoing database for age class structure of Columbia Basin salmon populations. Based on scale analysis, four-year-old fish (from brood year (BY) 1996) were estimated to comprise 83% of the spring chinook, 31% of the summer chinook, and 32% of the upriver bright fall chinook salmon population. Five-year-old fish (BY 1995) were estimated to comprise 2% of the spring chinook, 26% of the summer chinook, and 40% of the fall chinook salmon population. Three-year-old fish (BY 1997) were estimated to comprise 14% of the spring chinook, 42% of the summer chinook, and 17% of the fall chinook salmon population. Two-year-olds accounted for approximately 11% of the fall chinook population. The sockeye salmon population sampled at Bonneville was predominantly four-year-old fish (95%), and the coho salmon population was 99.9% three-year-old fish (Age 1.1). Length analysis of the 2000 returns indicated that chinook salmon with a stream-type life history are larger (mean length) than the chinook salmon with an ocean-type life history. Trends in mean length over the sampling period were also analysis for returning 2000 chinook salmon. Fish of age classes 0.2, 1.1, 1.2, and 1.3 have a significant increase in mean length over time. Age classes 0.3 and 0.4 have no significant change over time and age 0.1 chinook salmon had a significant decrease in mean length over time. A year class regression over the past 11 years of data was used to predict spring and summer chinook salmon population sizes for 2001. Based on three-year-old returns, the relationship predicts four-year-old returns of 325,000 (± 111,600, 90% Predictive Interval [PI]) spring chinook and 27,800 (± 29,750, 90% PI) summer chinook salmon. Based on four-year-old returns, the relationship predicts five-year-old returns of 54,300 (± 40,600, 90% PI) spring chinook and 11,000 (± 3,250, 90% PI) summer chinook salmon. The 2001 run size predictions used in this report should be used with caution, these predictions are well beyond the range of previously observed data.