Aug. 6 - Global shellfish populations are under increasing pressure brought about by ocean acidification. Scientists from the British Antarctic Survey say that oysters, mussels and crabs are finding it more difficult to develop their shells, making them vulnerable to predators and an overall decline that could impact other parts of the ecosystem. Jim Drury reports.
The world's shellfish are in trouble, according to findings by polar scientists. Oysters, mussels, lobsters and crabs are finding it harder than ever to develop their protective shells, making them vulnerable to predators. The British Antarctic Survey says ocean acidification caused by climate change is to blame for the thinning shells. Professor Lloyd Peck led the research conducted at 12 sites across the world. He says the calcium carbonate needed by the creatures to build their shells is increasingly difficult for them to extract. SOUNDBITE (English) PROFESSOR LLOYD PECK, BRITISH ANTARCTIC SURVEY, SAYING: "We've looked at these animals and their skeletons across temperature ranges because that's going to mimic what acidification is going to do in the sea. And what we've found is that where it gets colder and the calcium carbonate is harder to get out of the seawater the animals have thinner skeletons. So it looks very much as if pH changes in the future and acidified oceans will force animals to have smaller skeletons." The current threat is greatest in the polar regions, but will soon affect warmer climes. SOUNDBITE (English) PROFESSOR LLOYD PECK, BRITISH ANTARCTIC SURVEY, SAYING: "One of the critical times is when the calcium carbonate becomes under-saturated, so it becomes less than fully saturated in seawater. That's predicted to happen in Antarctica between 2040 and 2050, and in the tropical regions and in the temperate regions between 2050 and 2100, so we're looking at somewhere between the next 50 and 100 years for seeing those changes from saturated water to under-saturated water in many places around the world, but sooner than that in Antarctica." Human emissions of greenhouse gases include carbon dioxide from burning fossil fuels, some of it dissolving in the ocean to form acid. Seafood consumers will inevitably be affected, according to Peck, although he's more concerned with potential damage to the ecosystem. SOUNDBITE (English) PROFESSOR LLOYD PECK, BRITISH ANTARCTIC SURVEY, SAYING: "There are animals that we eat that are used for food consumption, like oysters and mussels and crabs and lobsters, they all make skeleton out of calcium carbonate and if it becomes very hard for them to make skeletons it means that it's likely to have a problem for their production for human consumption, but it also has problems on the ecological side because animals with hard skeletons are fundamental parts of the ecosystem." The survey's the latest in a series of warnings made by the scientific community about the harmful effects of global climate change. Jim Drury, Reuters