Australia - Fish populations linked to climate change

Published: June 21, 2007

Source : ABC News

A study along the Great Barrier Reef has linked climate fluctuations with changes in fish populations for the first time.

Researchers at the Australian Institute of Marine Science have been examining the effects of climate events such as El Nino on reef fish numbers for 13 years.

Ecologist Alistair Cheal says those events cause huge changes in water temperatures, wind speed and water circulation.

"All these things can actually effect the breeding success of reef fishes and the survival of their larvae," he said.

The study found different populations of fish species - some up to 800 kilometres apart - rose and fell in sync with one another and the climate events.

"It's nice to say, the more El Nino events the better for the fish, since they did well in our particular study," he said.

But Mr Cheal says if water temperatures and storm activity rise as predicted, the opposite could occur.

The patterns weren't found in the reef's far north, near Cooktown.

Scientists say the findings show climate change could have a much wider effect on reef fish numbers than previously thought.

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