Pollution creating acid oceans

The world's oceans are becoming acidic at a faster rate than at any time in the last 65 million years, threatening marine life and food supplies across the globe, according to a new study.

By Louise Gray, Environment CorrespondentPublished: 7:00AM GMT 15 Feb 2010

Researchers from the University of Bristol looked at how levels of acid in the ocean have changed over history.
They found that as ocean acidification accelerated it caused mass extinctions at the bottom of the food chain that could threaten whole ecosystems in the future.

The rapid acidification today is being caused by the massive amount of carbon dioxide being pumped out by cars and factories every year, which is absorbed by the water. Since the industrial revolution acidity in the seas have increased by 30 per cent.
The last time such a fast change occurred is thought to be 65 million years ago, when some natural event caused ocean acidification and the dinosaurs died out.
The study looked at sediments from around 55 million years ago, when temperature rose by up to 6C and acidification was occurring at a similar rate as today.
It found widespread extinction of tiny organisms that live on the bottom of the ocean. Ocean acidification can dissolve the carbonate shells of marine organisms and cause muscle wastage and dwarfism in other species.
Andy Ridgwell, lead author of the paper published in Nature Geoscience, said it could mean problems for humans in the future.
"Unlike surface plankton dwelling in a variable habitat, organisms living deep down on the ocean floor are adapted to much more stable conditions. A rapid and severe geochemical change in their environment would make their survival precarious.
"The widespread extinction of these ocean floor organisms during the Paleocene-Eocene greenhouse warming and acidification event tells us that similar extinctions in the future are possible," he said.
Dr Ridgwell said acidification is actually occurring much faster today than in the examples they looked at from the past therefore "exceeding the rate plankton can adapt" and theatening the basis of much of marine life. This would mean fish and other creatures further up the food chain that human beings eat may be affected as soon as the end of this century.
"There is lots of concern about major disruption to ecosystems. Certainly coral reefs will be eroded, that has an impact on other species. We could see marine ecosystems affected this century," he said.
:: A separate study published in Geoscience found that the glaciers on Greenland are melting much faster than expected because of ocean currents bringing warm water into the area. If the warming continues it could cause sea levels to rise by 3ft, three times as much as previous estimates, by 2100.