Using a computer model representing 802 fish and invertebrate species, University of British Columbia scientists predict marine animals will migrate away from the equator, leaving behind local extinctions across the middle of the globe.
The scientists coupled data from the Ocean Biogeographic Information System, which tracks the location and dispersal of animals, with forecasts of how the ocean will warm per a recent Intergovernmental Panel on Climate Change report. At the extreme end, in which the sea surface temperatures rise by an average of about 5.4 degrees over the next century, fish will relocate toward the poles at a rate of 16 miles a decade.
"The tropics will be the overall losers," states William Cheung, a marine biologist at the University of British Columbia, who co-authored the study published in ICES Journal of Marine Science. "This area has a high dependence on fish for food, diet and nutrition. We'll see a loss of fish populations that are important to the fisheries and communities in these regions."
Cheung and his colleague, biologist Miranda Jones, acknowledge that if the available "data only reflect a subset of a species' true niche space," for example, the results of the model may not be exact. But the bigger takeaway, bolstered by such evidence as declining sandeel populations linked to hotter U.K. waters, or walruses unable to find floating ice, is that warmer seas will mean big shifts in the way marine animals live.