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Ocean life under threat

Summary21 February 2012

There's heightened concern about the future state of the world's oceans. New research indicates that if seawater continues to acidify at the rate currently seen then the marine¹ environment could lose about 30% of the diverse life forms that exist within it by the end of the century. The research was presented at a major meeting in Vancouver.

Reporter

Jonathan Amos

Report

Much of the carbon dioxide put into the atmosphere through fossil fuel burning is being absorbed by the seas. It's acidifying the waters, corroding² the shells and skeletons of corals, sea urchins³ and similar species. Scientists want to know how conditions might deteriorate⁴ in the future and have been looking at underwater volcanoes, where C02 naturally bubbles through the water.

The level of acidification in these places simulates what the global oceans might look like if we keep on emitting carbon dioxide. And the new data gathered by a Plymouth University team indicates the world's oceans could lose up to 30% of their biodiversity by 2100. Dr Jason-Hall Spencer led the research at volcanic⁵ vents⁶ in Europe, the US and in Asia.

CLIP: "What we notice, unfortunately, is there're very dramatic shifts in the ecosystem⁷. There's a tipping point that occurs at about the levels of ocean acidification we expect to see at the end of this century, but even before that - even within the next few years - the water becomes corrosive⁸ to the shells of organisms, and some corals can't survive."

The scientists warn that the rates of change seen in our oceans are unprecedented⁹ in the recent Earth history, and the damage our seas are on course to sustain could take thousands, even millions, of years to correct.