A study by the University of California - Davis has found that marine animals are dissolving quickly due to warming waters and ocean acidification. These conditions are already occurring off the Northern California coast.

Researchers at the UC Davis Bodega Marine Laboratory published their study in the journal "Proceedings of the Royal Society B: Biological Sciences." They raised bryozoans, also known as "moss animals," in seawater tanks and exposed them to varying levels of water temperature, food and acidity.

They discovered that the creatures began to dissolve when they were grown in warmer waters and then exposed to acidity. Big portions of their skeletons disappeared in as little as two months.

In a post on UC Davis' official website, lead author Dan Swezey said that they expected some thinning or reduced mass. What they did not expect, though, was to witness whole features dissolve right before their eyes. He recently graduated with a PhD and works in professor Eric Sanford's lab at the UC Davis Bodega Marine Laboratory.

Bryozoans are described as colonial animals, similar but not related to corals. There are a lot of these creatures in California kelp forests. They are calcareous, using calcium carbonate to build their honeycomb-shaped skeletons.

The researchers found that bryozoans altered their chemical composition when raised under warming conditions. They build higher levels of magnesium into their skeletons, specifically if they were also eating less food. When bryozoans are exposed to acidic conditions, particularly those observed off coastal California, these changes predisposed them to dissolve.

It is unknown why bryozoans added more magnesium to their skeletons as temperatures become warmer. The researchers concluded that marine organisms with skeletons made of high-magnesium calcite may be vulnerable to ocean acidification since this type of calcium carbonate dissolves more easily than others.

The study highlights the increasing vulnerability of calcified animals to ocean acidification. This phenomenon occurs as the ocean absorbs more atmospheric carbon emitted through the burning of fossil fuels.