Spawner-recruit Analysis and Escapement Goal Recommendation for Kenai River Late-run Sockeye Salmon

Spawner-recruit Analysis and Escapement Goal Recommendation for Kenai River Late-run Sockeye Salmon PDF Author: James J. Hasbrouck
Publisher:
ISBN:
Category : Escapement (Fisheries)
Languages : en
Pages : 0

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Book Description
The current sustainable escapement goal (700,000–1,200,000) for Kenai River late-run sockeye salmon was established in 2011. For this escapement goal review, the escapement time series and production data were updated through 2018. The fit of 6 spawner–recruit models to data from brood years 1968–2012 and brood years 1979–2012 was examined. Although the classic Ricker model was determined the most appropriate to use given the data, all brood years were estimated to have replaced themselves, which compromised obtaining accurate and precise estimates of most model parameter estimates and biological reference points, including a scientifically defensible estimate of maximum sustained yield. Markov-type yield tables were constructed to evaluate yields at different levels of escapement. We recommend the sustainable escapement goal for Kenai River late-run sockeye salmon be revised to 750,000–1,300,000 fish because the analyses indicated escapements in this range will likely provide better yields.

Spawner-recruit Analysis and Escapement Goal Recommendation for Kenai River Late-run Sockeye Salmon

Spawner-recruit Analysis and Escapement Goal Recommendation for Kenai River Late-run Sockeye Salmon PDF Author: James J. Hasbrouck
Publisher:
ISBN:
Category : Escapement (Fisheries)
Languages : en
Pages : 0

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Book Description
The current sustainable escapement goal (700,000–1,200,000) for Kenai River late-run sockeye salmon was established in 2011. For this escapement goal review, the escapement time series and production data were updated through 2018. The fit of 6 spawner–recruit models to data from brood years 1968–2012 and brood years 1979–2012 was examined. Although the classic Ricker model was determined the most appropriate to use given the data, all brood years were estimated to have replaced themselves, which compromised obtaining accurate and precise estimates of most model parameter estimates and biological reference points, including a scientifically defensible estimate of maximum sustained yield. Markov-type yield tables were constructed to evaluate yields at different levels of escapement. We recommend the sustainable escapement goal for Kenai River late-run sockeye salmon be revised to 750,000–1,300,000 fish because the analyses indicated escapements in this range will likely provide better yields.

Run Reconstruction, Spawner-recruit Analysis, and Escapement Goal Recommendation for Late-run Chinook Salmon in the Kenai River

Run Reconstruction, Spawner-recruit Analysis, and Escapement Goal Recommendation for Late-run Chinook Salmon in the Kenai River PDF Author: Steven J. Fleischman
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 69

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Spawner-recruit Analyses and Escapement Goal Recommendations for Kenai River Chinook Salmon

Spawner-recruit Analyses and Escapement Goal Recommendations for Kenai River Chinook Salmon PDF Author: Steven J. Fleischman
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 68

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Book Description
Age-structured state-space spawner-recruit models were fit to 1986-2015 data on abundance, harvest, and age composition for early and late runs of Kenai River Chinook salmon (Oncorhynchus tshawytscha), 75 cm mid eye to tail fork (METF) and longer. Historical annual run abundance, stock recruitment parameters, and fishery management reference points were estimated from these models. Sustainable Escapement Goals of 2,800-5,600 (early run) and 13,500-27,000 (late run) Chinook salmon 75 cm METF and longer are recommended, and their attributes and limitations discussed. Fish 75 cm METF (approximately 33.3 in total length) and longer can be assessed directly by imaging sonar in the Kenai River at river mile 13.7.

Run Reconstruction, Spawner-recruit Analysis, and Escapement Goal Recommendation for Early-run Chinook Salmon in the Kenai River

Run Reconstruction, Spawner-recruit Analysis, and Escapement Goal Recommendation for Early-run Chinook Salmon in the Kenai River PDF Author: Timothy R. McKinley
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 71

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Escapement Goal Review for Kenai River Late-run Sockeye Salmon

Escapement Goal Review for Kenai River Late-run Sockeye Salmon PDF Author: John H. Clark
Publisher:
ISBN:
Category : Escapement (Fisheries)
Languages : en
Pages : 30

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Run Reconstruction, Spawner-recruit Analysis, and Escapement Goal Recommendation for Chinook Salmon in the Copper River

Run Reconstruction, Spawner-recruit Analysis, and Escapement Goal Recommendation for Chinook Salmon in the Copper River PDF Author: James William Savereide
Publisher:
ISBN:
Category : Chinook salmon fisheries
Languages : en
Pages : 46

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Book Description
An age-structured state-space spawner–recruit model was fit to estimates of relative and absolute abundance, harvest, and age composition for Copper River Chinook salmon (Oncorhynchus tshawytscha) from 1980 to 2016. Bayesian statistical methods were employed to assess uncertainty in the presence of measurement error, serial correlation, and missing data. Ricker stock-recruit parameters and management reference points were estimated, including the escapement that provides for maximum sustained yield (SMSY). It is recommended that a sustainable escapement goal range of 18,500 to 33,000 fish be adopted for Copper River Chinook salmon. Escapement is evaluated by subtracting estimates of inriver harvest from estimates of inriver abundance. Escapements within this range have a high probability of producing sustainable yields.

Spawner-recruit Analysis and Escapement Goal Recommendation for Chinook Salmon in the Kuskokwim River Drainage

Spawner-recruit Analysis and Escapement Goal Recommendation for Chinook Salmon in the Kuskokwim River Drainage PDF Author: Toshihide Hamazaki
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 62

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Book Description
The objectives of this report are to: 1) describe the productivity and capacity of the Kuskokwim River Chinook salmon stock, as quantified from stock-recruit analyses, 2) recommend a drainage-wide escapement goal based on this information, and 3) revise escapement goals for selected tributaries.

Report to the Alaska Board of Fisheries on Spawning Escapement Goal Evaluations for Bristol Bay Salmon

Report to the Alaska Board of Fisheries on Spawning Escapement Goal Evaluations for Bristol Bay Salmon PDF Author: Beverly A. Cross
Publisher:
ISBN:
Category : Fishery management
Languages : en
Pages : 96

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Book Description
A workshop was held on September 16-18, 1997 in Anchorage by the Alaska Department of Fish and Game to review Pacific salmon Oncorhynchus escapement goals for major rivers in Bristol Bay. Spawner-return data were analyzed for Kvichak, Naknek, Egegik, Ugashik, Wood, Igushik, Nushagak, and Togiak Rivers sockeye salmon 0. nerka. Sockeye smolt information was reviewed for Kvichak, Egegk, and Ugashik Rivers. Available limnological and juvenile information were analyzed fiom Lake Iliarnna. In addition, spawner-return data for Nushagak River chinook salmon O. tshawytscha were also reviewed. With a few exceptions available data supported current escapement goals in Bristol Bay. Based on this most recent escapement goal evaluation, workshop participants recommended the following changes. They recommended restructuring the escapement goal policy for Kvichak River sockeye salmon to a more robust variable escapement goal. Analyses of available data were inconclusive as to whether the underlying cause of cycles in Kvichak River sockeye production were due to inherent depensatory factors or lack of spawners. The recommended policy included an off-cycle escapement range of 2-10 million sockeye salmon with a minimum goal of 2 million and an exploitation rate of 50% on runs of 4 - 20 million. The point goal for a given off-cycle year would be 50% of the inshore Kvichak run but never less than 2 million or greater than 10 million. A 6 -10 million escapement range was proposed for pre-peak and peak cycle years with a minimum of 6 million and an exploitation rate of 50% on runs of 12 - 20 million. The point goal for a given prepeak or peak cycle year would be 50% of the inshore Kvichak run but never less than 6 million or greater than 10 million. Workshop participants also recommended managing for escapements within the middle of the current escapement goal ranges for Naknek, Egegik, and Ugashik Rivers. The current management objectives or point goals for those rivers are artifacts of past Ricker stock-recruitment models and are no longer supported by the data. Therefore, it was recommended that the management objectives be changed to 1.1 million sockeye salmon for Naknek River, 1.1 million sockeye salmon for Egegik River, and 0.85 million sockeye salmon for Ugashik River. The final recommendation coming out of the workshop was that the sockeye escapement goal range for Togiak River be changed to 100 - 200 thousand sockeye salmon. Available data supported the current management objective of 150 thousand sockeye salmon for Togiak River, but indicated an escapement range of 100 - 200 thousand would on average produce higher yields.

Review of Salmon Escapement Goals in Upper Cook Inlet, Alaska, 2019

Review of Salmon Escapement Goals in Upper Cook Inlet, Alaska, 2019 PDF Author: Timothy R. McKinley
Publisher:
ISBN:
Category : Escapement (Fisheries)
Languages : en
Pages : 99

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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 the major river systems in Upper Cook Inlet. Escapement goals were reviewed for 21 Chinook salmon, 1 chum salmon, 4 coho salmon, and 9 sockeye salmon stocks. The committee recommended to the Commercial Fisheries and Sport Fish division directors updates to 7 Chinook salmon goals (Deshka River, Alexander Creek, Chulitna River, Chuitna River, Theodore River, Little Susitna River, and Crooked Creek), consolidation of 10 Chinook salmon goals into 3 goals (Eastside Susitna, Talkeetna River, and Yentna River), a discontinuation of 11 Chinook salmon goals (Goose Creek, Little Willow Creek, Montana Creek, Sheep Creek, Willow Creek, Clear [Chunilna] Creek, Prairie Creek, Talachulitna River, Lake Creek, Peters Creek, and Lewis River), updates to 3 coho salmon goals (Fish Creek, Jim Creek, and Little Susitna River), and updates to 3 sockeye salmon goals (Kasilof River, Kenai River, and late-run Russian River).

Chilkat Lake Sockeye Salmon Escapement Goal Review

Chilkat Lake Sockeye Salmon Escapement Goal Review PDF Author: Sara E. Miller
Publisher:
ISBN:
Category : Escapement (Fisheries)
Languages : en
Pages : 61

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Book Description
We reviewed the escapement goal for the Chilkat Lake sockeye salmon (Oncorhynchus nerka) run, which is intensely harvested in the District 15 commercial drift gillnet fishery in Lynn Canal, Southeast Alaska. The current biological escapement goal of 70,000 to 150,000 sockeye salmon was established in 2009, based on a spawner-recruit analysis with weir counts converted to mark-recapture units. We fit age-structured state-space spawner-recruit models to updated 1976-2016 data on abundance, harvest, age composition, and coefficients of variation to examine the effect of autocorrelation and fry plants on recruits and to recommend a new biological escapement goal in Dual-frequency Identification Sonar (DIDSON) units. Historical mark-recapture and weir counts were considered indices of escapement, while the DIDSON counts (2008-2016) were considered 'true' counts of escapement. Fishery management reference points as well as optimal yield, optimal recruitment, and overfishing profiles were estimated from the final state-space Ricker model. Estimates derived from the state-space Ricker model suggest that the probability of achieving yields greater than 90% of maximum sustained yield from escapements at the current upper and lower bounds is 62% and 34%, respectively, and an average 65% over the entire escapement goal range. Therefore, we recommend maintaining the current biological escapement goal of 70,000 to 150,000 sockeye salmon counted at the Chilkat Lake weir site with the DIDSON sonar.