Hatchery‐Origin Stray Rates and Total Run Characteristics for Pink Salmon and Chum Salmon Returning to Prince William Sound, Alaska, in 2013–2015

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The Alaska salmon hatchery program is intended to supplement salmon fisheries without supplanting wild stocks. Hatchery‐origin Chum Salmon Oncorhynchus keta spend most of their lives interacting with wild salmon, including some degree of straying to spawning streams. Our study was designed and implemented to measure the extent and annual variability of straying by hatchery‐produced, summer‐run Chum Salmon in Southeast Alaska from 2013 to 2015 by sampling in individual streams to estimate the proportion of hatchery strays. In the sampled index streams, the proportion ranged from 0.000 to 0.854 over the 3 years. Unbiased estimates of the proportions of hatchery‐origin fish spawning in each of the three management units ranged from 0.016 to 0.081, and the estimated hatchery proportions spawning across Southeast Alaska ranged from 0.032 to 0.060. The proportion of hatchery strays decreased as the distance from hatchery release sites increased; proportions were highest at streams located within 50 km of the nearest release site. The proportion of hatchery‐origin spawners was negatively related to the index of spawning escapement in a stream. A hatchery donor stray rate of 0.8–4.8% was estimated. Hatchery‐origin Chum Salmon occur at low levels in most Chum Salmon systems in Southeast Alaska and at higher levels in systems close to hatchery release sites.

Section: Discussionmentioning

confidence: 73%

Section: Discussionmentioning

confidence: 77%

Section: Discussionmentioning

confidence: 98%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

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Proportions of Hatchery Fish in Escapements of Summer‐Run Chum Salmon in Southeast Alaska, 2013–2015

Josephson

Wertheimer

Gaudet³

et al. 2021

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Big Catch, Undecided Risks: Perspectives of Risk, Reward, and Trade‐Offs in Alaska's Salmon Enhancement Program

Harrison

Gould

2022

Alaska's salmon enhancement program plays an important and substantial role in commercial fishing harvests situated around the Gulf of Alaska, Prince William Sound, and Southeast Alaska. In recent years, discussions about the ecological impacts of the enhancement program have emerged in the media, the Alaska Board of Fisheries, and other public discourses. These discussions have illuminated tension within Alaskan society about the role and impacts of hatcheries in fisheries and coastal communities. This study uses qualitative methods to identify key themes that underlie those tensions within Alaska Board of Fisheries public comments and private discourses. We found that issues raised in public comment formats were limited to four key themes, whereas interviews revealed those same themes as well as a broader and more nuanced cross section of themes, both critical and complimentary of the enhancement program. We discuss these themes within the context of enhancement policy and ongoing research into wild–hatchery salmon interactions, both of which pose certain constraints about how trade‐offs between social, ecological, and economic valuation of the enhancement program can be made. We suggest a road map of four steps for action to help avoid potential societal conflict in the future: (1) establish a process to incorporate socio‐cultural dimensions of hatcheries and stocking into enhancement program decision making; (2) better define “adverse impacts” within enhancement policy; (3) link current and future research findings to decision‐making processes and policy implications; and (4) plan for the future(s) through scenario development work aimed at identifying the ecological and societal impacts of different enhancement policy changes, such as drawing down, scaling up, or otherwise altering existing stocking practices.

The Genetic Composition of Wild Steelhead Based on Spatial Proximity to a Hatchery

Bowersox

Hargrove

Copeland

et al. 2023

Management of hatchery and wild stocks of steelhead Oncorhynchus mykiss within the same watershed requires careful consideration when management objectives include the use of the hatchery stock to meet fishery objectives while maintaining the genetic integrity of coexisting wild stocks. This scenario can be further complicated when management objectives for the hatchery stock include supplementation of natural production. The lower Clearwater River in Idaho provided an ideal location to evaluate hatchery steelhead genetic influence within a drainage with separate wild steelhead and supplementation management emphasis areas. We collected 813 genetic samples from wild juvenile steelhead from two sample years in 10 tributaries to the lower Clearwater River to explore genetic structure and assess hatchery influence. Overall, levels of genetic diversity of wild groups were comparable with those observed elsewhere in the Snake River basin. Estimates of effective population size of sample tributaries ranged from 22 to 198 spawners, with a median of 84. All but two tributaries had >50 spawners, and evidence of natural gene flow from other stocks was observed. Results of the study display three zones of hatchery influence in the lower Clearwater River: (1) no influence in lower tributaries with wild steelhead emphasis, (2) moderate influence in wild steelhead tributaries in close proximity to the hatchery facility, and (3) significant influence in hatchery-supplementation tributaries. Interestingly, a number of wild steelhead reporting groups from elsewhere in the Snake River basin were observed in the assignments of study fish, suggesting movement of wild steelhead among larger drainage areas. Techniques outlined in this study can be used to monitor future hatchery influence in the Clearwater River drainage, track historic versus contemporary genetic influence in the drainage, and apply to other watersheds with hatchery and wild steelhead management objectives.