Save oceans from acidifying

Fish can do it by producing and excreting carbonates

THE marine carbon cycle is undergoing rapid changes. An excess of unregulated carbon will eventually acidify the oceans. A new study demonstrates that fish have the potential to save the marine carbon cycle.
Until now scientists believed that the calcium carbonate (CaCO3), which makes seawater alkaline, came from the external skeletons of microscopic marine plankton. But these carbonates are not water-soluble and sink to deeper depths forming sediments which stay intact for millions of years. This led researchers from the universities of Exeter, Miami, Ottawa, British Columbia and East Anglia to investigate what makes the sea alkaline at shallower depths (500-1,000 m). They found fish responsible for producing three to 15 per cent of marine calcium carbonate.
Fish drink calcium- and magnesium-rich seawater. To regulate the body