The acidity of continental shelf waters off the West Coast is dissolving the shells of marine snails.

These snails, called pteropods, are food for "pink salmon, mackerel and herring," a NOAA Headquarters news release reported.

Researchers believe the number pteropods in the area with dissolving shells have doubled since the pre-industrial era; the number could triple by the year 2050.

"Our findings are the first evidence that a large fraction of the West Coast pteropod population is being affected by ocean acidification," Nina Bednarsek, Ph.D., of NOAA's Pacific Marine Environmental Laboratory in Seattle, the lead author of the paper, said in the news release. "Dissolving coastal pteropod shells point to the need to study how acidification may be affecting the larger marine ecosystem. These nearshore waters provide essential habitat to a great diversity of marine species, including many economically important fish that support coastal economies and provide us with food.

"Ocean acidification" occurs when ocean water absorbs about a third of the carbon dioxide released into the atmosphere and becomes corrosive. This change is harmful to a variety of marine creatures, especially those with calcium carbonate shells or skeletons. This includes: "corals, oysters, mussels, and small creatures in the early stages of the food chain such as pteropods," the news release reported.

The team found the highest concentration of pteropods with dissolving shells off the coast of Washington to central California; 53 percent of these snails were found to have severely dissolved shells.

"We did not expect to see pteropods being affected to this extent in our coastal region for several decades," William Peterson, Ph.D., an oceanographer at NOAA's Northwest Fisheries Science Center and one of the paper's co-authors, said in the news release. "This study will help us as we compare these results with future observations to analyze how the chemical and physical processes of ocean acidification are affecting marine organisms."

Further research is needed to determine how these corrosive waters are affecting other species.

"Acidification of our oceans may impact marine ecosystems in a way that threatens the sustainability of the marine resources we depend on," Libby Jewett, Director of the NOAA Ocean Acidification Program said in the news release. "Research on the progression and impacts of ocean acidification is vital to understanding the consequences of our burning of fossil fuels."