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Sensitivity of salmonid freshwater life history in western US streams to future climate conditions
Author(s) -
Beer W. Nicholas,
Anderson James J.
Publication year - 2013
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/gcb.12242
Subject(s) - streams , oncorhynchus , chinook wind , snowpack , environmental science , climate change , habitat , juvenile , drainage basin , fishery , fish <actinopterygii> , ecology , snow , physical geography , geography , biology , meteorology , computer network , computer science , cartography
We projected effects of mid‐21st century climate on the early life growth of C hinook salmon ( O ncorhynchus tshawytscha ) and steelhead ( O . mykiss ) in western U nited S tates streams. Air temperature and snowpack trends projected from observed 20th century trends were used to predict future seasonal stream temperatures. Fish growth from winter to summer was projected with temperature‐dependent models of egg development and juvenile growth. Based on temperature data from 115 sites, by mid‐21st century, the effects of climate change are projected to be mixed. Fish in warm‐region streams that are currently cooled by snow melt will grow less, and fish in suboptimally cool streams will grow more. Relative to 20th century conditions, by mid‐21st century juvenile salmonids' weights are expected to be lower in the C olumbia B asin and C alifornia C entral V alley, but unchanged or greater in coastal and mountain streams. Because fish weight affects fish survival, the predicted changes in weight could impact population fitness depending on other factors such as density effects, food quality and quantity changes, habitat alterations, etc. The level of year‐to‐year variability in stream temperatures is high and our analysis suggests that identifying effects of climate change over the natural variability will be difficult except in a few streams.