Acidification 'to cause species collapse'

Climate change will lead to a complete food chain collapse across the world's oceans, an Adelaide university study has found.

Increased ocean acidification and warming is set to reduce numbers of and diversity in key species underpinning ecosystems across the world, University of Adelaide associate professor Ivan Nagelkerken says.

He also says the warmer water will boost the metabolic rates of animals, increasing competition for less food.

"There will be a species collapse from the top of the food chain down," Prof Nagelkerken said on Tuesday.

He said this "simplification" of ocean ecosystems would have dire consequences for our way of life, particularly regions relying primarily on fishing.