US - Scientists are already seeing a variety of changes in how inland fish reproduce, grow and where they can live, according to four new climate change studies.
Fish that have the most documented risk include those living in arid environments and coldwater species such as sockeye salmon, lake trout, walleye, and prey fish that larger species depend on for food.
Climate change can cause suboptimal habitat for some fish; warmer water, for example, can stress coldwater fish. When stressed, fish tend to eat less and grow less. For other fish, climate change is creating more suitable habitat; smallmouth bass populations, for example, are expanding.
"The US Geological Survey and partners are working to provide a fuller and more comprehensive picture of climate change impacts on North American fish for managers, scientists, and the public alike," said Abigail Lynch, a lead author and fisheries biologist with the USGS National Climate Change and Wildlife Science Center.
The authors reviewed 31 studies across North America and Canada that document fish responses to climate change. The manuscripts describe the impacts of climate change to individual fish, populations, recreational fishers, and fisheries managers.
One of the takeaway messages is that climate change effects on fish are rarely straightforward, and they affect warmwater and coldwater fish differently.
"Thanks to this synthesis, we can see the effects of climate change on inland fish are no longer just future speculation, but today's facts, with real economic, social, and ecological impacts," said Doug Austen, Executive Director of the American Fisheries Society and publisher of Fisheries magazine.
"Now that trends are being revealed, we can start to tease apart the various stressors on inland fish and invest in conservation and research where these programs will really make a difference in both the short and long term."
The studies are available in a special issue of Fisheries magazine, published by the American Fisheries Society.
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