Last updated at 13:46 GMT, Tuesday, 21 February 2012

Ocean life under threat

Summary

21 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 marine 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

coral reef

The seawater acidification may endanger world's oceans biodiversity

Listen

Click to hear the report

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, corroding the shells and skeletons of corals, sea urchins and similar species. Scientists want to know how conditions might deteriorate 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 volcanic vents in Europe, the US and in Asia.

CLIP: "What we notice, unfortunately, is there're very dramatic shifts in the ecosystem. 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 corrosive to the shells of organisms, and some corals can't survive."

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

Listen

Click to hear the vocabulary

Vocabulary

absorbed

taken in

corroding

gradually destroying

simulates

creates particular conditions that exist in real life using computers, models, etc, for research

deteriorate

become worse

emitting

giving off, releasing

indicates

shows

biodiversity

the existence of many different kinds of animals and plants

dramatic shifts

big changes

a tipping point

the point at which many small changes reach a level where a further small change has a very great effect

unprecedented

has not happened before