September 10, 2013 — The human species has adapted to all sorts of climates and habitats, populating the far reaches of the globe. Humans, of course, can get up and move to avoid the consequences of rising temperatures, or apply and shed layers of clothing as the weather demands. Fish — a species humans are intensely reliant on as a food source — aren’t quite as nimble.
According to a recent study in Nature, scientists say many species of cold-water fish have already been affected by rising global ocean temperatures and may be among the first major casualties of climate change.
Global fisheries have been reacting to the earth's rising temperatures over the last four decades, with warming waters attracting new temperate and tropical species, while cold-water species are forced to search for chillier locales. This may be good for fishermen in Nova Scotia hoping to catch Spanish mackerel, but it’s bad for lox lovers. “For salmon and many other species, there is a narrow temperature range that they can live in due to limitations in body function,” William Cheung, co-author of the study and researcher on the University of British Columbia, recently told the Vancouver Sun. “Warm water causes them to suffer poor growth and reproduction and they may die from the heat stress.”
Scientists in the U.K. say sea bass and red mullet are showing up in unusually large numbers in British waters, while more traditional species of the North Sea, like cod, are migrating northward as temperatures rise.
Pacific salmon are for the first time being caught in Beaufort Sea, the body of water off the northern coast of Alaska. The Inuit there, who are catching them, apparently have no name for the new species.
But while salt-water fish are more or less free to migrate, chasing ideal temperatures and environmental conditions into new bodies of water and readapting to new sea level depths, fish which have persisted for decades in freshwater streams, rivers, ponds, and lakes may not be so lucky.
Read the full story at The Seattle Times