May 16, 2013 — For the first time, scientists have shown that ocean warming has had a global impact on the mix of species caught by fishermen. Previous studies indicated that some species are shifting location in response to temperature increases, with fish gradually moving away from the equator into cooler waters. However, research published in May 2013 in Nature shows that species from warmer waters have also been replacing those traditionally caught in many fisheries worldwide at least since 1970.
The authors found that, except in the tropics, catch composition in most ecosystems slowly changed to include more warm-water species and fewer cool-water species. In the tropics, the catch followed a similar pattern from 1970 to 1980 and then stabilized, likely because there are no species with high enough temperature preferences to replace those that declined. Statistical models showed that the increase in warm-water species was significantly related to increasing ocean temperatures.
View a summary of the study from the Pew Environment Group