Chilkoot Lake Sockeye Salmon Stock Status and Escapement Goal Review PDF Download

Author: Rich Brenner
Publisher:
ISBN:
Category : Escapement (Fisheries)
Languages : en
Pages : 34

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Book Description
Chilkoot Lake, located in upper Lynn Canal near the city of Haines, supports one of the largest runs of sockeye salmon (Oncorhynchus nerka) in southeast Alaska. This stock is currently managed as a sustainable escapement goal range with a lower bound of 38,000 and an upper bound of 86,000 spawners. Escapement is monitored by the Alaska Department of Fish and Game with a weir on the Chilkoot River, and stock of origin from the District 15 commercial drift gillnet fishery harvest is determined using scale pattern analysis. We used Ricker spawner-recuit models in a Bayesian framework to fit data from brood years 1976-2010. Given significant autocorrelation at lag-1, we chose an autoregressive Ricker model for this assessment. Based on model results, maximum sustainable yield would be achieved with an escapement of approximately 52,900 sockeye salmon (median of spawning abundance at maximum sustained yield), and a range of 45,000-60,000 spawners would result in a greater than 80% probability of achieving at least 90% of maximum sustainable yield. This range of escapements fits within the current escapement goal range and, given considerable uncertainty in parameter estimates, we do not recommend changes to the goal at this time. However, some large escapements since 2012 will provide contrast to the existing data once the resulting recruits can be enumerated; thus, we recommend reassessing this escapement goal prior to the Alaska Board of Fisheries meeting in 2021.

Author: Nicole L. Zeiser
Publisher:
ISBN:
Category : Escapement (Fisheries)
Languages : en
Pages : 48

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Book Description
The Chilkoot Lake sockeye salmon (Oncorhynchus nerka) run, which spawns near Haines, is one of the largest in Southeast Alaska and contributes substantially to harvests in the District 15 commercial drift gillnet fishery in Lynn Canal. This operational plan outlines objectives, methods, and timelines for conducting sockeye salmon stock assessment designed to (1) estimate annual escapement and harvest, (2) provide information for inseason fishery management, and (3) reconstruct runs and assess stock status. The Chilkoot Lake run is managed for a biological escapement goal of 38,000–86,000 fish, which is enumerated through a standard picket weir located just downstream of the lake outlet. Weir counts of sockeye salmon are compared to weekly escapement targets to determine inseason run strength. Genetic mixed stock analysis of weekly sockeye salmon harvests in the District 15 commercial drift gillnet fishery provides stock composition estimates that also guide inseason management of the fishery. Biological sampling, along with escapement enumeration and stock-specific harvest data, allows for total run reconstruction required for escapement goal review.

Author: Steven C. Heinl
Publisher:
ISBN:
Category : Escapement (Fisheries)
Languages : en
Pages : 93

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Book Description
The Alaska Department of Fish and Game interdivisional escapement goal review committee reviewed Pacific salmon Oncorhynchus spp. escapement goals for Southeast Alaska in August of 2019 and again early in 2020. Escapement goals were reviewed based on the Policy for the Management of Sustainable Salmon Fisheries (5 AAC 39.222) and the Policy for Statewide Escapement Goals (5 AAC 39.223) adopted by the Alaska Board of Fisheries into regulation in 2001. There is a total of 47 escapement goals in Southeast Alaska for 11 Chinook, 12 sockeye, 13 coho, 3 pink, and 8 chum salmon stocks. The Southeast escapement goal review committee recommended changes to these goals to the directors of the Divisions of Commercial Fisheries and Sport Fish as follows: (1) change the Taku River sockeye salmon sustainable escapement goal range of 71,000–80,000 fish (based on a historical dataset) to a biological escapement goal range of 40,000–75,000 fish based on a revised dataset; and (2) change the Situk River coho salmon biological escapement goal range of 3,300–9,800 fish to a sustainable escapement goal range of 3,800–9,600 fish based on percentiles of historical survey counts. Detailed analyses of Chilkoot, Speel, and Redoubt Lakes sockeye salmon escapement goals are also documented here, although the committee did not recommend changes to those goals.

Author: Shane R. Ransbury
Publisher:
ISBN:
Category : Escapement (Fisheries)
Languages : en
Pages : 0

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Book Description
From 2016 to 2019, the Alaska Department of Fish and Game, Division of Commercial Fisheries, continued a stock assessment program that began in 1976 to estimate escapements and harvests of Chilkoot Lake sockeye salmon (Oncorhynchus nerka). Sockeye salmon were counted through a weir near the outlet of Chilkoot Lake, and age, length, and sex data were collected and analyzed each year. Sockeye salmon escapements at the weir were 86,721 fish in 2016, 43,098 fish in 2017, 85,463 fish in 2018, and 140,378 fish in 2019, all of which fell within or exceeded the sustainable escapement goal range of 38,000–86,000 fish. Ocean-age-3 sockeye salmon (ages 1.3 and 2.3 combined) of both sexes were the shortest in length since scale sampling began in 1982. The stock compositions of sockeye salmon harvested annually in the District 15 commercial drift gillnet fishery were estimated through scale pattern analysis (2016) and genetic stock identification (2017–2019). Estimated commercial harvests of Chilkoot Lake sockeye salmon were 119,843 fish in 2016, 1,933 fish in 2017, 33,969 fish in 2018, and 149,586 fish in 2019. Estimated harvest rates (including subsistence and sport harvests) were 59% in 2016, 9% in 2017, 31% in 2018, and 52% in 2019. Estimated fall sockeye salmon fry populations at Chilkoot Lake were 42% above average in 2016, 45% below average in 2017, and at or slightly below average in 2018 and 2019, respectively. Average May–September zooplankton density and biomass at Chilkoot Lake were nearly double the long-term average, and zooplankton density in 2019 and biomass in 2016 were the highest recorded since sampling began in 1987.

Author: Douglas Murrell Eggers
Publisher:
ISBN:
Category : Escapement (Fisheries)
Languages : en
Pages : 46

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Book Description
This work represents a review of escapement goals for sockeye salmon stocks (Oncorhynchus nerka) in the Southeast Alaska and Yakutat area.

Author: Douglas Murrell Eggers
Publisher:
ISBN:
Category : Escapement (Fisheries)
Languages : en
Pages : 48

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Author: Steven C. Heinl
Publisher:
ISBN:
Category : Escapement (Fisheries)
Languages : en
Pages : 77

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Book Description
The Alaska Department of Fish and Game interdivisional escapement goal review committee reviewed Pacific salmon Oncorhynchus spp. escapement goals for Southeast Alaska in 2014. As specified in the Pacific Salmon Treaty, escapement goal recommendations for transboundary Alsek and Klukshu river Chinook and sockeye salmon runs underwent bilateral U.S./Canada review, and recommended changes were adopted by the Transboundary River Panel of the Pacific Salmon Commission in 2013. Thus, as of 2013, escapement goals were established for 12 Chinook, 14 sockeye, 14 coho, 4 pink, and 8 chum salmon stocks. The Southeast escapement goal review committee recommended to the directors of the divisions of Commercial Fisheries and Sport Fish that all but 5 of those escapement goals remain unchanged. The committee recommended (1) changing the Speel Lake sockeye salmon goal from a biological escapement goal range of 4,00-13,000 fish to a sustainable escapement goal range of 4,000-9,000 fish; (2) changing the Lost River coho salmon goal from a lower-bound sustainable escapement goal of 2,200 fish to a sustainable escapement goal range of 1,400-4,200 fish, and changing the name of the goal to Tawah Creek (Lost River); (3-4) increasing aggregate lower-bound sustainable escapement goals for summer-run chum salmon in the Southern Southeast and Northern Southeast Outside subregions to account for the addition of new index streams to those stock groups; and, finally, (5) changing the Chilkat River fall-run chum salmon sustainable escapement goal range of 75,000-170,000 fish to a range of 75,000-250,000 fish.

Author: Julie Bednarski
Publisher:
ISBN:
Category : Fish populations
Languages : en
Pages : 64

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Since 1967 the Alaska Department of Fish and Game, Division of Commercial Fisheries, has operated a stock assessment program to estimate escapements and harvests of Chilkat sockeye salmon (Oncorhynchus nerka). Sockeye salmon were counted through a weir near the outlet of Chilkat Lake, and age, length, and sex data were collected and analyzed each year. Since 1994, mark-recapture studies were conducted to estimate Chilkat sockeye salmon escapements. Since the start of the 2008 season, DIDSON sonar has been used at the weir site to directly enumerate adult sockeye salmon escapement into Chilkat Lake. Visual scale pattern analysis was conducted to determine the proportion of Chilkat sockeye salmon harvested annually in the District 15 commercial drift gillnet fishery. In addition, limnological sampling was conducted in Chilkat Lake and analyzed each year. The intent of this report was to review Chilkat sockeye salmon stock assessment data from 1971 to 2016. The visual and DIDSON weir counts provide an index of escapement; however concerns regarding mark-recapture as a reliable index of abundance lead us to recommend eliminating mark-recapture studies in 2017 and, instead, maintain the DIDSON to estimate escapement into Chilkat Lake. We also recommend reviewing the current Chilkat Lake biological escapement goal to ensure that the goal and escapement estimates are in the same units, which is currently based on mark-recapture units. An average of 77,800 Chilkat Lake sockeye salmon were harvested annually in the District 15 commercial drift gillnet fishery (1976-2016). A comparison of historical fish wheel counts to Chilkat Lake escapement estimates demonstrates that the fish wheel project provides a rough indication of Chilkat Lake run strength. Zooplankton samples from Chilkat Lake were composed primarily of one species of copepod (Cyclops columbianus) and three species of cladocerans (Bosmina longerostris, Daphnia longiremus, and Daphnia rosea).

Author: Shelby M. Flemming
Publisher:
ISBN:
Category : Escapement (Fisheries)
Languages : en
Pages : 0

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Book Description
In 2020 and 2021, the Alaska Department of Fish and Game, Division of Commercial Fisheries, continued a stock assessment program that began in 1976 to estimate escapements and harvests of Chilkoot Lake sockeye salmon (Oncorhynchus nerka). Sockeye salmon were counted through a weir near the outlet of Chilkoot Lake, and age, length, and sex data were collected and analyzed each year. Sockeye salmon escapements at the weir were 60,218 fish in 2020 and 98,672 fish in 2021, which fell within or exceeded the sustainable escapement goal range of 38,000–86,000 fish. Age-1.2 male sockeye salmon in 2020 were larger than the 1982–2019 average, whereas both male and female fish of other ages fell below this average. Genetic stock identification was conducted to determine the stock composition of sockeye salmon harvested annually in the District 15 commercial drift gillnet fishery. Estimated commercial harvests of Chilkoot Lake sockeye salmon were 24,878 fish in 2020, and 50,219 fish in 2021. Estimated harvest rates (including subsistence and excluding sport harvests) were 32% in 2020 and 35% in 2021, and Chilkoot Lake sockeye salmon accounted for an estimated 50% (2020) and 59% (2021) of the annual commercial sockeye salmon harvest in District 15. The estimated fall sockeye salmon fry population at Chilkoot Lake was 66% below average in 2020 (no surveys were conducted in 2021). Average May–September zooplankton density and biomass at Chilkoot Lake were above average in 2020 and below average in 2021.

Author: Edward O. Otis
Publisher:
ISBN:
Category : Escapement (Fisheries)
Languages : en
Pages : 0

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The Alaska Department of Fish and Game (ADF&G) interdivisional escapement goal review committee (committee) reviewed 41 escapement goals for Pacific salmon Oncorhynchus spp. stocks in Lower Cook Inlet (LCI). Escapement goals were reviewed based on the Policy for the Management of Sustainable Salmon Fisheries (5 AAC 39.222) and the Policy for Statewide Salmon Escapement Goals (5 AAC 39.223) adopted by the Alaska Board of Fisheries into regulation in 2001. All of the existing goals were adopted in 2017, except for 1 chum salmon O. keta stock (McNeil River, adopted 2007) and 2 sockeye salmon O. nerka stocks (Bear and English Bay Lakes, adopted 2001). Except for 2 Chinook salmon O. tshawytscha stocks (Anchor and Ninilchik Rivers) and 4 sockeye salmon stocks (English Bay, Bear, Mikfik, and Chenik Lakes), salmon escapements in LCI are primarily monitored by single or multiple aerial and/or foot surveys of appropriate stream reaches. The resulting escapement indices do not provide absolute abundance estimates suitable for estimating biological escapement goals (BEG). Consequently, all LCI goals are sustainable escapement goals (SEG). There are no escapement goals for coho salmon O. kisutch in LCI. To improve management flexibility and consistency between management areas in Alaska, the committee supported LCI transitioning from stock-specific SEGs for pink (O. gorbuscha, 18 stocks) and chum (12 stocks) salmon to aggregate escapement goals for each of the 3 LCI districts with commercial fisheries targeting these species (Southern, Outer, and Kamishak). ADF&G will continue managing LCI Chinook (3 stocks) and sockeye (8 stocks) salmon using stock-specific SEGs, with 2 Chinook (Anchor and Ninilchik Rivers) and 2 sockeye salmon (Bear and English Bay Lakes) goals changing during this review period.