We’re killing our oceans

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 17 February 2010

“Are we screwed? Yeah, to a considerable extent!”

That’s how Dr Edward L Miles, Professor of Marine and Public Affairs at the University of Washington answered a somewhat rhetorical question during a scientific conference about the effects of rising atmospheric CO2 levels on the world’s oceans. His blunt assessment is just one of several sobering moments in ‘A Sea Change’, one of three recent documentary films addressing the plight of our seas.

Plankton haul near the surface of the sea © 2002 Image Quest 3-D

A Sea Change tackles a phenomenon that threatens marine life as we know it, but which most people haven’t even heard of: ocean acidification. The oceans are a very important “sink” for CO2. As part of the natural carbon cycle which has been in operation since the Earth’s primordial seas were first formed in the distant geological past, CO2 from the air dissolves in sea water, forming carbonic acid.

A 2009 study showed that the oceans have absorbed more CO2 every year since 1765 and currently suck up somewhere between 25 and 40% of all of the CO2 humans generate by burning coal, oil and gas. As a result, the acidity of the world’s oceans has increased by about 30% since the beginning of the industrial revolution.

The sea is essentially becoming increasingly corrosive to many of the tiny algae and planktonic organism which have carbonaceous skeletons or shells and occupy the bottom of the food chain – the main source of food for fish. The changes are happening at a rate that is faster than at any time during the last 50 million years – fast enough, some experts fear, to lead to widespread extinctions and “a world without fish”.

Source: News 24.com Read full article

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