Calcifiers Struggle in Changing Oceans

Calcifiers like mollusks, starfish and corals are struggling to survive in a changing ocean as a result of climate change, according to new research.

These organisms use calcium from their environment to create hard carbonate skeletons and shells that are necessary for stability and protection.

But as atmospheric carbon dioxide rises, the world's oceans are becoming warmer and more acidic. This impact of global climate change threatens the survival of calcifying species because of the reduced saturation of the carbonate minerals required for calcification.

Marine life first acquired the ability to calcify during the Cambrian era, when calcium levels in seawater increased. This characteristic promoted biodiversity, and led to the numerous calcifiers seen today.

"Today, modern calcifiers face a new and rapidly escalating crisis caused by warming and acidification of the oceans with a reduction in availability of carbonate minerals, a change driven by the increase in atmospheric carbon dioxide due to anthropogenic emissions and industrialization. The carbon dioxide itself can also directly cause metabolic stress," the authors said in a statement.

Contributors to the research have studied how ocean acidification thus far has negatively impacted bryozoans, a group of aquatic invertebrate filter-feeders, as well as sea urchins, oysters and mollusks.

In one study described by Nature World News, NOAA researchers discovered that increased ocean acidity is dissolving the shells of tiny marine snails off the West Coast.

Impacts on marine life is growing more apparent, it seems, because the ocean acidification rate is increasing 10 times faster than it did during a similar upheaval 56 million years ago - known as the Paleocene-Eocene Thermal Maximum (PETM).

"We are dumping carbon in the atmosphere and ocean at a much higher rate today - within centuries," study co-author Richard Zeebe, a paleoceanographer at the University of Hawaii, said in a news release. "If we continue on the emissions path we are on right now, acidification of the surface ocean will be way more dramatic than during the PETM."