Sea acid stops creatures forming shells

Research by Australian scientists has revealed that greater acidification in the Southern Ocean due to carbon emissions is restricting the capability of some marine species to create shells, putting sea life at risk.

Dr Will Howard, one of the research team, said the results were the first natural confirmation of the effect, rather than from a laboratory.

Since the start of the Industrial Revolution the calcium carapace of minuscule animals, or foraminifera, in the Southern Ocean have lost one third of their weight, the study discovered.

The tiny organisms, about the size of a grain of sand, dwell in the surface layer of the world’s oceans.

They change CO2 into calciferous shells and after death the shells sink to the floor of the ocean thereby capturing CO2 infinitely.

They form a major element of the biological chain and are a defence against climate change.

The study, published in a science journal, contrasts the shells of forams, tiny marine creatures with shells, with comparable species found in pre-industrial era sediments.

The scientists learnt that a 30 to 35 per cent drop in shell weights had occurred.

The likely reasons for this include complex acidification, rising temperatures and nutrient wash from seashore farming.

This is the first time that acidification has been put down to carbon emissions, from burning oil, coal and gas.

Man-made carbon dioxide is the reason said William Howard of the Tasmanian Antarctic Climate and Ecosystems Cooperative Research Centre.

Howard said the passing of carbon from the sea surface ocean into the deeper water would be reduced if marine species were not making shells.

It may reduce the amount of carbon the oceans can absorb and we should be disturbed by that.

Dr Howard and his colleagues said sea acidification might have major implications for populations relying on coastal assets in the Indian Ocean, Australia, and Southern Pacific areas.

Greater amounts of acid could also affect krill, which for whales is the principal food source.

The publication of the study coincides with a scientific conference in Copenhagen, starting tomorrow which will brief leading politicians about the latest data on global warming.

Dr Howard and other top Australian scientists will attend.

The delegates will hear from Rajendra Pachauri, Chairman of the UN Intergovernmental Panel on Climate Change and from Lord Nicholas Stern, the author of the milestone study on the economic consequences of global warming.