Warm climate causes aqautic animals to shrink

Warmer temperatures cause greater reduction in the adult sizes of aquatic animals than in land-dwellers, according to a new study, Xinhua news agency reported.

Researchers from Queen Mary, University of London and the University of Liverpool found that the body size of marine and freshwater species are affected disproportionately by warmer temperatures, and may have implications for aquatic food webs and the production of food by aquaculture.

In the largest study of its kind, the scientists compared the extent to which the adult size of 169 terrestrial, freshwater and marine species responded to different non-harmful temperatures.

The study co-author Andrew Hirst said: "Aquatic animals shrink 10 times more than land-dwellers in species the size of large insects or small fish. While animals in water decrease in size by five percent for every degree Celsius of warming, same sized species on land shrink, on average, by half a percent."

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.