California mussels (Mytilus californianus) live in beds along the western coast of the United States from Alaska to California with more than 300 other species sharing the beds or depending on the mussels in some way, researchers at the University of California, Davis, said.
Ocean acidification occurs when carbon dioxide, a greenhouse gas, is absorbed into the ocean, increasing its acidity.
That acidity is up by almost a third since the middle of the 18th century and the beginning of the Industrial Revolution, a UC Davis release said Thursday.
Increasing acidification has been shown to weaken the shells of mussels and diminish their body mass, researchers said.
"Because these mussels play such an ecologically critical role, a decline in their numbers could impact a wide range of other organisms," said Brian Gaylord, associate professor of evolution and ecology.
Although not an important fishery species, the California mussel is vital because so many other marine creatures depend on it for food and habitat, researchers said.