Cold-water fish such as salmon thrives in temperatures of 50 to 65 degrees Fahrenheit. According to a new study by NRDC and Defenders of Wildlife, global warming is likely to spur the disappearance of trout and salmon from as much as 18 to 38 percent of their current habitat by the year 2090. The study also found that habitat loss for individual species could be as high as 17 percent by 2030, 34 percent by 2060 and 42 percent by 2090 -- if emissions of heat-trapping pollution such as carbon dioxide are not reduced.
Canadian scientists have identified broad genetic signatures that can predict which fish will live or die before spawning a new generation. The study combined radio tracking of fish caught in the ocean and river with a genomic signature based on 32,000 genes in individual fish. Fish captured on the spawning grounds were tracked with tags. Researchers found that 60 per cent of the fish they tracked had genomic signatures predicting their fate. Genomic signatures are essentially responses of the fish's genome — the full array of genes — to a threat, with genes "turned on to guide the physiological and behavioural responses to the threat." The techniques used in the study have major promise as a new tool to guide fish restoration efforts.
This work represents a breakthrough in tracking how salmon are surviving new stresses from global warming. The study published in the January, 2011 edition of the journal Science.
http://www.sciencemag.org/content/331/6014/214.abstract?sid=2a274bc4-b33a-41e8-80e5-17c675485f80
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