Global warming may cause fish die offs

FORT LAUDERDALE, FLORIDA–Global warming of the oceans will likely cause the extinction by 2050 of dozens of fish species that cannot migrate to colder waters, according to a study presented here yesterday at the 11th International Coral Reef Symposium. “The loss of biodiversity will be considerable, and replacing them with new species would take millions of years,” says co-author Daniel Pauly of the University of British Columbia (UBC) in Vancouver, Canada.

Fish can tolerate temperature fluctuations of a few degrees in a laboratory aquarium. But in the wild, a difference of even a degree or two can force them to move into a new ecosystem where they will face different foods and different predators. “Some will not be able to handle that and will disappear,” says the study’s lead author, ecosystem modeler William Cheung, also at UBC. Indeed, almost two-thirds of fish in the North Sea now live in different locations or depths because of rising sea temperatures (Science, 13 May 2005, p. 937).

All told, some 50 species of commercial fishes that live at or near the poles will likely die off. Species living farther from the poles will probably migrate toward the Arctic or Southern oceans, where these newcomers may disturb the existing ecosystems, Cheung says. In addition, Pauly notes, past fishing has already reduced genetic diversity and may limit the ability of populations to adapt to new conditions.

Other populations may be trapped. As the Sea of Cortez warms, the giant croaker (Totoaba macdonaldi), an endangered fish that can reach 2 meters in length, won’t be able to escape northward. The same will happen in closed seas such as the Mediterranean Sea, where fish populations, such as the local hake (Merluccius merluccius), will be unable to migrate to colder waters. Vicky Lam, another author, adds that the results come out the same with several different simulation models of predicted temperatures. The model and some of these results were described in detail in January in one of UBC’s Fisheries Centre Research Reports.

So basically cause we are heating up the planet many fish species will die out and others will move to new areas both of which will fuck up the food chain. How does this affect us? Well we eat allot of fish and majority are not farmed so fucking up the food chain could take your favorite fish off the menu. But lets look at the bigger picture, many peoples lively hoods are based on fishing and I’m not just talking about people who work on large fishing boats and sell there catch to super markets and restraints I’m also talking about people who depend on fishing for food, people who’s supermarket is the ocean, people who may loose the main source for food cause of global warming

Source: Warming Spells Trouble for Fish