As the world continually emits carbon dioxide into the atmosphere, the oceans are taking a hit, absorbing some of it and growing more acidic. Among other effects, scientists have found that coral reefs and oyster hatcheries are deteriorating as a result.

However, scientists studying a type of sea snail report a bit of bright news in the ACS journal Environmental Science and Technology: The animal can adapt by rejiggering its shell-making process and other functions.

A lower pH in ocean waters means fewer carbonate ions are available to calcifying organisms, such as coral reefs and oysters, which need the ions to produce shells and skeletons.

While ocean acidification appears to cause damage to many calcifying organisms, recent studies have suggested that some of those organisms may be more resistant to acidification than previously thought. Sean D. Connell and colleagues wanted to find out how this might be possible.

The researchers exposed sea snails called periwinkles to the ocean conditions predicted for 2100, when some waters at a pH of 8.10 today are expected to reach a pH of 7.85. Although the animals' metabolism declined, they were able to speed up their shell-making by producing less-dense inner shells. In addition, they developed less-soluble shells, which are more resistant to future, harsher ocean conditions.

The researchers say these changes suggest that the periwinkle, and potentially other calcifying organisms, could have the ability to adapt to the acidifying oceans.

Research paper