Warming Water Makes Fish Cranky

September 30, 2009

Release from: ABC News (Australia)

New research shows climate change may result in fish becoming more aggressive and more vulnerable to predators.

Scientists from the University of Technology in Sydney studied the behaviour of damselfish, which are small, brightly coloured fish found on coral reefs.

The scientists caught the damselfish on the Great Barrier Reef and transferred them to laboratories, where they were subjected to changing water temperatures.

The scientists found even small variations in temperature that might occur normally within a day, or from one day to the next, had a major effect on the way the fish behaved.

They found if water temperature rose by as little as 3 degrees Celsius, the fish could be up to six times more active, bold and aggressive.

The research also found that as the fish became more active and aggressive, they ate more and were more likely to be eaten themselves.

The scientists say warmer temperatures due to climate change may mean fish are more vulnerable to predators and population numbers may decrease.