Warming oceans are changing the mix of species in the world's fisheries, according to a new study. Marine-ecosystem models have indicated that this could be an effect from global warming.
Robert F. Bukaty/AP
Warming oceans are changing the mix of species in the world's fisheries as fish try to remain in waters in their preferred temperature range, according to a new study.
The movement to keep pace with preferred temperatures shows up most starkly in the northeastern Pacific Ocean and the northeastern Atlantic Ocean, as fish migrate out of the subtropics to beat the heat.
The changes have particular implication for people living in the coastal tropics who either subsist on fishing or fish commercially, the research team says. If ocean temperatures continue to warm there, the heat could top a level that even tropical species find intolerable, reducing their abundance, the researchers say.
This raises the urgency of adopting approaches that minimize other stresses on fisheries, such as pollution and overfishing, the team says.
Marine-ecosystem models have indicated that global warming's impact on ocean temperatures would trigger such a migration. And studies of individual regions have documented the arrival of species from warmer aquatic climes.
This latest effort represents the first attempt at documenting the changes for the planet as a whole, says William Cheung, a scientist with the Fisheries Centre at the University of British Columbia in Vancouver, who led the team. The techniques that the team used, along with the results, appear in Thursday's issue of the journal Nature.
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