Global warming likely to make fish smaller, say scientists

PUBLISHED : Tuesday, 02 October, 2012, 12:00am
UPDATED : Tuesday, 02 October, 2012, 3:52am


A hearty fillet of fish, already a rare treat because of over-trawled oceans, will become even more infrequent in the future when global warming starts to reduce fish size, scientists say.

Researchers looked at computer models to see how warmer, and thus less oxygenated, seas would affect more than 600 species of fish. Compared to 2000, the maximum attainable body weight of these fish would decline by between 14 and 24 per cent by 2050.

Fish inhabiting the Indian Ocean were the most affected, reducing by 24 per cent, followed by counterparts in the Atlantic (20 per cent) and then the Pacific (14 per cent).

"It's a constant challenge for fish to get enough oxygen from water to grow, and the situation gets worse as fish get bigger," said Dr Daniel Pauly of the University of British Columbia in Canada.

"A warmer and less-oxygenated ocean, as predicted under climate change, would make it more difficult for bigger fish to get enough oxygen, which means they will stop growing more."

The study appeared in the journal Nature Climate Change.