2019 Kuskokwim River Chinook Salmon Run Reconstruction and 2020 Forecast PDF Download

Author: Sean D. Larson
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 46

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Book Description
A maximum likelihood model was used to estimate the 2019 drainagewide run size and escapement of Kuskokwim River Chinook salmon (Oncorhynchus tshawytscha). Total run and escapement were estimated to be 226,987 (95% CI: 182,811–281,839) and 188,483 (95% CI: 144,307–243,335) fish, respectively. Model estimates were informed by direct observations of the 2019 escapement at 16 locations (4 weirs and 12 aerial surveys) and harvest, combined with historical observations of escapement (up to 6 weirs and 14 aerial surveys), harvest, test fishery, and mark–recapture data dating back to 1976. Model results are adequate to draw broad conclusions about the 2019 run and escapement. The 2019 total run of Chinook salmon was the largest since 2007 and was probably above the 1976–2018 average of 215,529 fish. The drainagewide sustainable escapement goal of 65,000–120,000 was exceeded in 2019. The 2020 Kuskokwim River Chinook salmon forecast is for a range of 193,000–261,000 fish.

Author: Sean D. Larson
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 46

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Book Description
A maximum likelihood model was used to estimate the 2020 drainagewide run size and escapement of Kuskokwim River Chinook salmon (Oncorhynchus tshawytscha). The total run was estimated to be 124,486 fish (95% CI: 102,661–150,952) and escapement was estimated to be 88,285 fish (95% CI: 66,460–114,751). Model estimates were informed by direct observations of the 2020 escapement at 15 locations (3 weirs and 12 aerial surveys) and harvest, combined with historical observations of escapement (up to 6 weirs and 14 aerial surveys), harvest, test fishery, and mark–recapture data dating back to 1976. Model results are adequate to draw broad conclusions about the 2020 run and escapement. The 2020 total run of Chinook salmon was below the 1976–2019 average of 215,870 fish. The drainagewide sustainable escapement goal of 65,000–120,000 was met in 2020. The 2021 Kuskokwim River Chinook salmon forecast is for a range of 94,000–155,000 fish.

Author: Sean D. Larson
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 46

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Book Description
A maximum likelihood model was used to estimate the 2021 drainagewide run size and escapement of Kuskokwim River Chinook salmon (Oncorhynchus tshawytscha). The total run was estimated to be 129,751 (95% CI: 94,489–178,171) fish and escapement was estimated to be 101,000 (95% CI: 65,738–149,420) fish. Model estimates were informed by direct observations of the 2021 escapement at 3 weirs and 2021 harvest, combined with historical observations of escapement (up to 6 weirs and 14 aerial surveys), harvest, test fishery, and mark–recapture data dating back to 1976. Model results are adequate to draw broad conclusions about the 2021 run and escapement. The 2021 total run of Chinook salmon was below the 1976–2020 average of 214,475 fish. The drainagewide sustainable escapement goal of 65,000–120,000 was met in 2021. The 2022 Kuskokwim River Chinook salmon forecast is for a range of 99,000–161,000 fish.

Author: Sean D. Larson
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 0

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Book Description
A maximum likelihood model was used to estimate the 2022 drainagewide run size and escapement of Kuskokwim River Chinook salmon (Oncorhynchus tshawytscha). The total run was estimated to be 142,495 (95% CI: 107,579–188,743) fish, and escapement was estimated to be 107,980 (95% CI: 73,064–154,228) fish. Model estimates were informed by direct observations of the 2022 escapement at 3 weirs and 2022 harvest, combined with historical observations of escapement (up to 6 weirs and 14 aerial surveys), harvest, test fishery, and mark–recapture data dating back to 1976. Model results are adequate to draw broad conclusions about the 2022 run and escapement. The 2022 total run of Chinook salmon was below the 1976–2021 average of 211,081 fish. The drainagewide sustainable escapement goal of 65,000–120,000 was met in 2022. The 2022 Kuskokwim River Chinook salmon forecast is for a range of 115,000–170,000 fish.

Author: Yukon River Joint Technical Committee
Publisher:
ISBN:
Category : Fish populations
Languages : en
Pages : 169

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Book Description
The Yukon River Joint Technical Committee (JTC) of the United States and Canada meets twice a year to analyze and discuss harvest and escapement goals, management trends, postseason reviews, preseason outlooks, and results of cooperative research projects for Canadian-origin Yukon River salmon. This report summarizes the status of Chinook Oncorhynchus tshawytscha, coho O. kisutch, and summer and fall chum salmon O. keta stocks in 2019, presents a 2020 season outlook, and provides data about salmon harvests in commercial, subsistence, aboriginal, personal use, domestic, and sport or recreational fisheries. Summaries of Yukon River research projects are also included. For 2019, the preliminary estimate of Chinook salmon (mainstem) spawning escapement into Canada was 42,052 fish, just below the lower end of the interim management escapement goal (IMEG) range of 42,500-55,000 fish. A preliminary estimate of the total Canadian-origin Chinook salmon run was 72,620 fish. The preliminary estimate of fall chum salmon spawning escapement in the Canadian mainstem Yukon River was approximately 99,738 fish, near the upper end of the IMEG range of 70,000-104,000 fish. The preliminary estimate of fall chum salmon spawning escapement in the Fishing Branch River (Porcupine River), obtained from a weir count, was 18,171 fish and below the IMEG range of 22,000-49,000 fish. Recommended interim management escapement goals for Canadian-origin mainstem Yukon River Chinook and fall chum salmon and Fishing Branch (Porcupine River) fall chum salmon in 2020 remain the same as for 2019.

Author: Kathrine G. Howard
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 53

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Book Description
Monitoring of juvenile Yukon River Chinook salmon Oncorhynchus tshawytscha stocks rearing in the Northeastern Bering Sea (NBS) was initiated by the National Oceanic and Atmospheric Administration (NOAA) in 2002 using a pelagic trawl survey program. Juvenile salmon were caught after their first summer at sea, and prior work has demonstrated a clear relationship between juvenile abundance and future adult returns, enabling the use of juvenile data in adult run size forecasts. The estimated abundance of juvenile Chinook salmon in the NBS was approximately 2,480,000 (SD 439,000) in 2017, below the 2003-2016 average. The mean proportion of 2017 NBS juvenile Chinook salmon originating in the total Yukon River and Canadian-origin Yukon River was 72% (SD 5%) and 42% (SD 4%), respectively. Abundance of total Yukon and Canadian-origin stocks were estimated as 1,774,000 (SD 338,000) and 1,049,000 (SD 207,000), respectively. Previously established and new adult Yukon River run reconstructions were used to evaluate relationships between juvenile abundance and adult abundance of spawners, runs, and returns. A marked decrease in juvenile production (juveniles per spawner) for total Yukon River and Canadian-origin stocks was below their 2003-2016 averages. These data were incorporated into forecast models to predict total adult run size. Forecasted total Yukon River Chinook salmon run sizes for 2018-2020 were 179,000-301,000, 170,000-297,000 and 114,000-230,000, respectively; forecasted Canadian-origin Chinook salmon run sizes for 2018-2020 were 65,000-102,000, 74,000-116,000 and 62,000-105,000, respectively. The date-adjusted length (FL) of juvenile Chinook salmon in the NBS was 204 mm in 2017, below the 2003-2016 average of 212 mm. Marine data on juvenile Chinook salmon clearly demonstrate that Yukon River Chinook salmon should be expected to remain in a relatively low productivity regime in the near future, but record-low run abundance is unlikely through 2020.

Author: Jordan Head
Publisher:
ISBN:
Category : Chinook salmon fisheries
Languages : en
Pages : 0

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A maximum likelihood model was developed to estimate the 1968–2020 drainagewide run size and escapement of Nushagak River Chinook salmon (Oncorhynchus tshawytscha). The model simultaneously combined information by direct observations of escapement at 8 locations (1 tower and 7 aerial surveys); harvest of fish from commercial, subsistence, and sport fisheries; inriver abundance indices from the Nushagak River sonar project; and inriver abundance estimates from acoustic tag and mark–recapture studies. Results showed that reconstructed total run size ranged from 74,000 to 629,000 Chinook salmon with an average run size of 282,000 fish, and escapement ranged from 49,000 to 476,000 fish with an average of 210,000 fish. The model estimated total run and escapement appeared to be reasonable and tracked well with previous estimates. The major deficiency of this model is the absence of overlapping, long-term escapement and run monitoring data.

Author: Tracy R. Hansen
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 0

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Counting tower techniques were used to estimate Chinook salmon Oncorhynchus tshawytscha escapement in the Gulkana River during 2019, 2020, and 2021. The counting tower was located on the mainstem Gulkana River about 3.25 river kilometers upstream of the West Fork Gulkana River confluence. The estimated escapement of Chinook salmon was 8,400 (SE = 436; 95% CI = 7,546–9,254) in 2019, 2,504 (SE = 216; 95% CI = 2,080–2,928) in 2020, and 3,402 (SE = 273; 95% CI = 2,867–3,937) in 2021. These numbers do not represent total inriver escapement, just escapement above the counting tower site. The 2019 estimated escapement of Chinook salmon was the highest on record since the inception of the project in 2002, whereas the 2020 and 2021 estimated escapements were below the average for the years 2002–2018. The dates of the 25th, 50th, and 75th percentile of cumulative passage of Chinook salmon past the Gulkana River counting tower have been getting later since the project’s inception in 2002. The estimated escapement of sockeye salmon O. nerka during the counting tower’s operational period was 20,850 (SE = 661; 95% CI = 19,555–22,145) in 2019, 13,500 (SE = 574; 95% CI = 12,375–14,625) in 2020, and 13,924 (SE = 711; 95% CI = 12,531–15,317) in 2021. Counting tower operations were extended during 2019–2021 to enumerate more of the sockeye salmon return.

Author: James D. Miller
Publisher:
ISBN:
Category : Chinook salmon fisheries
Languages : en
Pages : 0

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Book Description
Adaptive resolution imaging sonar (ARIS) was used for the first time in 2018 to estimate the abundance of late-run Chinook salmon (Oncorhynchus tshawytscha) at river mile (RM) 8 of the Kasilof River. The same methods were used to estimate late-run Chinook salmon abundance in 2019 and 2020. In 2019, the sonar was operated from 15 June through 31 August. In 2020, the sonar was operated from 15 June through 22 August. Net upstream passage of late-run Chinook salmon greater than or equal to 75 cm mid eye to tail fork length (METF) as measured by ARIS was estimated to be 4,507 (SE = 184) in 2019 and 3,388 (SE = 165) in 2020. The 2019 cumulative late-run Chinook salmon abundance estimate of fish greater than or equal to 75 cm METF was higher than the 2018 and 2020 estimates. Run timing in 2019 and 2020 was earlier than in 2018.

Author: Nathan Frost
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 0

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This plan describes the coded-wire tagging of juvenile Chinook salmon Oncorhynchus tshawytscha on the Unuk River for the 2019 and 2020 brood years, which covers the coded-wire tagging of parr in fall of 2020 and 2021 and smolt in spring of 2021 and 2022, and sampling returning adults for age, sex, length, and coded-wire tags in escapement from the 2022 through 2027 return years. This study provides estimates of smolt and parr abundance, overwinter (freshwater) survival, mean lengths of juveniles, and harvest information of Chinook salmon originating from the Unuk River in Southeast Alaska. A separate project will be conducted on the Unuk River that employs aerial and foot survey peak counts to estimate large (≥660 mm mid eye to fork of tail length) adult Chinook salmon returning to the river in 2020 and 2021. The primary goals of this and the companion study are to estimate inriver run size, total run size, marine harvest-exploitation rate and harvest distribution, smolt and parr abundance, marine survival (smolt to adult) and overwinter survival (parr to smolt). The Alaska Department of Fish and Game uses this information to make local and regional management decisions, and the Pacific Salmon Commission uses the data for coastwide management and stock assessment through the Chinook Technical Committee.