Arctic seas turn to acid, putting vital food chain at risk (Robin McKie)

• Robin McKie, science editor
• The Observer, Sunday 4 October 2009
• Article history

A decision on classifying the polar bear as threatened is overdue. Juniors Bildarchiv/Alamy

Carbon-dioxide emissions are turning the waters of the Arctic Ocean into acid at an unprecedented rate, scientists have discovered. Research carried out in the archipelago of Svalbard has shown in many regions around the north pole seawater is likely to reach corrosive levels within 10 years. The water will then start to dissolve the shells of mussels and other shellfish and cause major disruption to the food chain. By the end of the century, the entire Arctic Ocean will be corrosively acidic.

"This is extremely worrying," Professor Jean-Pierre Gattuso, of France's Centre National de la Recherche Scientifique, told an international oceanography conference last week. "We knew that the seas were getting more acidic and this would disrupt the ability of shellfish – like mussels – to grow their shells. But now we realise the situation is much worse. The water will become so acidic it will actually dissolve the shells of living shellfish."

Just as an acid descaler breaks apart limescale inside a kettle, so the shells that protect molluscs and other creatures will be dissolved. "This will affect the whole food chain, including the North Atlantic salmon, which feeds on molluscs," said Gattuso, speaking at a European commission conference, Oceans of Tomorrow, in Barcelona last week. The oceanographer told delegates that the problem of ocean acidification was worse in high latitudes, in the Arctic and around Antarctica, than it was nearer the equator.

"More carbon dioxide can dissolve in cold water than warm," he said. "Hence the problem of acidification is worse in the Arctic than in the tropics, though we have only recently got round to studying the problem in detail."

http://www.guardian.co.uk/world/2009/oct/04/arctic-seas-turn-to-acid