THE world’s coral reefs could disappear within a few decades along with hundreds of species of plankton and shellfish, according to new studies. Carbon dioxide, the gas already blamed for causing global warming, is also raising the acid levels in the sea. The shells of coral and other marine life dissolve in acid. The process is happening so fast that many such species, including coral, crabs, oysters and mussels, may become unable to build and repair their shells and will die out by 2050, say the researchers.
When CO2 produced by burning fossil fuels dissolves in the ocean, it forms carbonic acid. A little of this can benefit marine life by providing carbonate ions — a vital constituent in the biochemical process by which sea creatures such as corals and molluscs build their shells, which are made of calcium carbonate, the same substance as chalk, which is vulnerable to acidity. Even a slight increase in acidity would mean many creatures would dissolve. Others might be able to rebuild their shells but would be unable to reproduce.
Such a loss would have disastrous consequences for larger marine animals such as salmon, mackerel, herring, cod and baleen whales. These all feed on pteropods, or sea butterflies, one of the species most threatened by rising acidity.
These marine creatures do humanity a great service by absorbing half the carbon dioxide we create. If we wipe them out, that process will stop. We are altering the entire chemistry of the oceans without any idea of the consequences, say scientists.
