Studies show that as carbon dioxide levels have increased in the atmosphere over the past two centuries, seawater has become less saturated with aragonite and calcite. In the oceans, many sea creatures with calcium carbonate skeletons and shells also rely on those carbonate ions for aragonite and calcite to build their skeletons and shells. Carbonic acid dissociates into hydrogen ions (H +) and bicarbonate ions (HCO 3 -1), and the hydrogen ions bond with carbonate ions (CO 3 -2) in the water. As carbon dioxide (CO 2) dissolves in water (H 2O), it creates carbonic acid (H 2CO 3), which is a weak acid.

Ocean acidification itself is a fairly simple chemical process. She explains ocean acidification and its effects in more detail in the video above, and discusses how scientists use ancient shells from the sea floor to understand how ocean chemistry has changed over time and could change in the future in the second video, below. It is the other carbon dioxide problem. As we increase the acidity of sea water, it has an effect on organisms,” said Bärbel Hönisch, a biologist and oceanographer at Columbia University’s Lamont-Doherty Earth Observatory. “Ocean acidification has been called the evil twin of global warming. Without shells, the young oysters were vulnerable, and large numbers didn’t survive.īiologists traced the problem to changing chemistry in the ocean-the water was becoming more acidic and currents were bringing in water that contained less of a calcium carbonate mineral called aragonite that oysters need to build their shells.

Pacific Northwest are prized by restaurants around the country, but starting around 2007, the Pacific oyster population went into crisis. The oysters were hatching, but they weren’t secreting shells quickly enough to protect themselves. Oysters raised on the mud flats of the U.S. As excess carbon dioxide is absorbed into the oceans, it is starting to have profound effects on marine life, from oysters to tiny snails at the base of the food chain.