Fried, grilled, or raw on the half-shell, oyster lovers will eat them whenever they can get them. But oysters are more than a delicacy: they play a vital role in the health of ocean shorelines.
Now a new study finds that climate change could be behind an increasing threat to their health.
"We saw probably on the order of over 100,000 oysters that perished in northern San Francisco Bay [in 2011]," said Brian Cheng. He's a postdoctoral fellow at the Smithsonian Institution and lead author of the study just published in the Proceedings of the Royal Society.
The study looks at plumes of intense water vapor, known as atmospheric rivers, that travel long distances and deliver a lot of moisture. As climate change warms the atmosphere, it holds more water, making the phenomena more extreme. That all maters to oysters, said Cheng, because the increased rainfall flows into the Bay, giving the water a lower salinity and threatening the habitat for oysters. This led to a massive die-off of oysters in 2011, which the study focused on.
Cheng said there are three main reasons why oysters are so important to California's coast:
Building habitat. "You might be familiar with examples, such as coral reefs. They build structures for all the colorful fish to live in and around. Oysters are similar in that way – they build habitat for all these other animals and plants."
Preventing erosion and protecting the shoreline. "There's some evidence that they might actually reduce erosion and the effect of storm surge, and actually buffer the shoreline. So that's a good thing when we think of sea level rise and extreme storm events."
Culinary industry. "These oysters that we studied are wild oysters. They're the only native oyster on the West Coast. So understanding how these atmospheric rivers affect native oysters might also tell us how aquaculture might be affected."
View the study: Atmospheric rivers and the mass mortality of wild oysters: insight into an extreme future?