Warmer Temperatures Cause Aquatic Animals to Shrink

According to a new study, warmer temperatures cause greater reduction in the sizes of adult aquatic animals than in land-dwelling species.

The research conducted by scientists from Queen Mary, University of London and the University of Liverpool shows that the body size of marine and freshwater species are affected disproportionately by warmer temperatures, which could have implications for aquatic food webs and the production of food by aquaculture.

The researchers compared the extent to which the adult size of 169 terrestrial, freshwater, and marine species responded to different non-harmful temperatures. The team discovered that aquatic animals shrink 10 times more than land dwelling species; animals in water decrease in size by 5 percent for every degree of warming.

The research also demonstrates that the most likely cause of this difference in size is due to the much lower availability of oxygen in water than in air. Warming increases the need for oxygen by organisms on land and in water, but aquatic species have a much harder job meeting this increased demand.

"Given that fish and other aquatic organisms provide three billion people with at least 15 percent of their animal protein intake, our work highlights the importance of understanding how warming in the future will affect ocean, lake and river dwelling species," said Dr. Jack Forster, lead researcher of the study.

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