Trouble looms as warmer oceans push marine life towards the poles

Rising sea temperatures attributed to global climate change could drive many marine creatures away from the equator, but their move towards the poles promises to put them in peril in habitats that are smaller and less hospitable, scientists say. Two studies published in the journal Science illustrate dangers researchers forecast for sea animals as diverse as corals, fish and crustaceans.

University of Washington oceanographer Curtis Deutsch said warmer ocean temperatures increase both the metabolic rates of ocean creatures and their demand for oxygen, but warm water contains less oxygen than cold, necessitating a move towards the poles to find cooler seas. "As habitat shrinks, populations are also likely to shrink. In the extreme, it leads to extinction, as we see with habitat destruction in terrestrial ecosystems," Deutsch said. As species migrate, they may end up in new environments with different ocean conditions, predators and prey, Deutsch added. The study looked at species including: Atlantic rock crab, a coastal crustacean; Atlantic cod, an open-ocean fish; sharp snout seabream, a subtropical Atlantic and Mediterranean fish; and the common eelpout, a bottom-dwelling, shallow-water fish in high northern latitudes.