World's Sea Life Is 'Facing Major Shock', Marine Scientists Warn

http://www.sciencedaily.com/releases/2012/08/120821094452.htm

ScienceDaily (Aug. 20, 2012) — Life in the world's oceans faces far greater change and risk of large-scale extinctions than at any previous time in human history, a team of the world's leading marine scientists has warned.

The researchers from Australia, the US, Canada, Germany, Panama, Norway and the UK have compared events which drove massive extinctions of sea life in the past with what is observed to be taking place in the seas and oceans globally today.

Three of the five largest extinctions of the past 500 million years were associated with global warming and acidification of the oceans -- trends which also apply today, the scientists say in a new article in the journal Trends in Ecology and Evolution.

Other extinctions were driven by loss of oxygen from seawaters, pollution, habitat loss and pressure from human hunting and fishing -- or a combination of these factors.

"Currently, the Earth is again in a period of increased extinctions and extinction risks, this time mainly caused by human factors," the scientists stated. While the data is harder to collect at sea than on land, the evidence points strongly to similar pressures now being felt by sea life as for land animals and plants.

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He adds "The situation is not hopeless. If fact we have seen clear evidence both from the past and the present that sea life can bounce back, given a chance to do so.

"For example, in Australia we have clear evidence of that good management of coral reefs can lead to recovery of both corals and fish numbers.

"So, rather, our paper is an appeal to humanity to give the oceans a chance.

"In effect, it says we need to stop releasing the CO2 that drives these massive extinction events, curb the polluted and nutrient-rich runoff from the land that is causing ocean 'dead zones' manage our fisheries more sustainably and protect their habitat better.

"All these things are possible, but people need to understand why they are essential. That is the first step in taking effective action to prevent extinctions."