Record Details

Relationship between Juvenile Fish Condition and Survival to Adulthood in Steelhead

ScholarsArchive at Oregon State University

Field Value
Title Relationship between Juvenile Fish Condition and Survival to Adulthood in Steelhead
Names Evans, A. F. (creator)
Hostetter, N. J. (creator)
Collis, K. (creator)
Roby, D. D. (creator)
Loge, F. J. (creator)
Date Issued 2014-07-10 (iso8601)
Note To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the American Fisheries Society and published by Taylor & Francis. It can be found at: http://www.tandfonline.com/toc/utaf20/current#.U-jq2mPhz5w.
Abstract Understanding how individual characteristics are associated with survival is important to programs aimed at recovering
fish populations of conservation concern. To evaluate whether individual fish characteristics observed during
the juvenile life stage were associated with the probability of returning as an adult, juvenile steelhead Oncorhynchus
mykiss from two distinct population segments (DPSs; Snake River and upper Columbia River) were captured, photographed
to determine external condition (body injuries, descaling, signs of disease, fin damage, and ectoparasites),
measured, classified by rearing type (hatchery, wild), marked with a PIT tag, and released to continue out-migration
to the Pacific Ocean during 2007–2010. The PIT tags of returning adults were interrogated in fishways at hydroelectric
dams on the lower Columbia River 1–3 years following release as juveniles. Juvenile-to-adult survival models were
investigated independently for each DPS and indicated that similar individual fish characteristics were important
predictors of survival to adulthood for both steelhead populations. The data analysis provided strong support for
survival models that included explanatory variables for fish length, rearing type, and external condition, in addition
to out-migration year and timing. The probability of a juvenile surviving to adulthood was positively related to length
and was higher for wild fish compared with hatchery fish. Survival was lower for juveniles with body injuries, fin
damage, and external signs of disease. Models that included variables for descaling and ectoparasite infestation,
however, had less support than those that incorporated measures of body injuries, fin damage, and disease. Overall,
results indicated that individual fish characteristics recorded during the juvenile life stage can be used to predict
adult survivorship in multiple steelhead populations.
Genre Article
Identifier Evans, A. F., Hostetter, N. J., Collis, K., Roby, D. D., & Loge, F. J. (2014). Relationship between Juvenile Fish Condition and Survival to Adulthood in Steelhead. Transactions of the American Fisheries Society, 143(4), 899-909. doi:10.1080/00028487.2014.901248

© Western Waters Digital Library - GWLA member projects - Designed by the J. Willard Marriott Library - Hosted by Oregon State University Libraries and Press