Shellfish

Pacific West Coast Acidification Rate Larger than Other Oceans

The ocean absorbs carbon dioxide from the atmosphere, which reduces pH levels and concentrations of calcium carbonate, a mineral used by shellfish to calcify their shells. As more carbon is released into the atmosphere, concentrations of calcium carbonate decrease and the shells of organisms like foraminifera get thinner, a trend Osborne saw clearly in the sediment cores she examined.

“The shell thickness record instantly showed a long-term declining trend,” she said. “It was really obvious across entire record.”

Alaska & Oyster Larvae in an Acidified Ocean

As the Pacific Ocean acidifies—a consequence of carbon emissions—oyster farms off California, Washington State, and British Columbia have struggled to get larvae to grow into seed, the stage when young oysters’ shells have formed. Though scientists are not quite sure why, the water off Southeast Alaska hasn’t seen the same deleterious effects. Now, entrepreneurs and investors are eyeing the state, looking to turn a profit off the short-lived gains of climate change.

Wild Blue Mussels Disappearing

The Gulf of Maine stretches from Cape Cod to Canada and is a key marine environment and important to commercial fishing. Blue mussels are used in seafood dishes and worth millions to the economy of some New England states, but are also important in moving bacteria and toxins out of the water.

Microplastic Impact on Oysters

The researchers then observed the oysters’ physiological responses to ingesting the microplastics. The most obvious effect was on reproduction. Oysters that were exposed to microplastics produced fewer and smaller egg cells and slower sperm. Exposed oysters also produced fewer larvae and their offspring tended to grow more slowly.