Increased carbon emissions are putting Puget Sound Dungeness crabs at risk, according to new research from the Northwest Fisheries Science Center in Seattle.
When fossil fuels burn, carbon dioxide is released into the atmosphere and much of it is eventually absorbed by the ocean.
Scientists say that process is changing the ocean’s chemistry by lowering pH levels, making the ocean more acidic. Ocean acidification is a well-known risk to oysters, which cannot develop strong enough shells in more acidic water.
New research suggests other marine animals, including Dungeness crabs, are at risk.
Jason Miller, the lead author of the research, said crab larvae in the study were three times more likely to die when exposed to pH levels that can already be found in Puget Sound. He reached that conclusion after researchers collected crab eggs in Puget Sound, putting them in tanks filled with seawater with different pH levels, and analyzed their survival rates.
"I have great faith in the resiliency of nature, but I am concerned," Miller said in a news release.
Paul McElhany, is a research scientist at the center, which is operated by the National Oceanic and Atmospheric Administration. a senior author on the paper. He said the acidification could threaten the development of future generations of Puget Sound crab.
Larvae in more acidified waters progressed more slowly than those in water with higher pH levels. Researchers suggested this would increase the window of time when crabs are vulnerable to predators and put them at a disadvantage when it comes to the timing of their development compared to that of their key food sources.
"Now the question is, how does that play out in terms of affecting their life cycle and populations overall?" McElhany said.
Dungeness crab is one of the Northwest’s most important fisheries. The 2014 harvest was worth more than $80 million dollars in Washington and nearly $50 million dollars in Oregon.
Hugh Link, executive director of the Oregon Dungeness Crab Commission, said the industry has been concerned about ocean acidifcation but was previously unsure of how it would affect Dungeness crab in particular.
"Any business that's got a vested interest in providing product from the Pacific Ocean needs to be concerned about this. It's a very large subject," Link said. "We've made a point of working with researchers any way we can. If there's a problem in the future, we want to be right on top of it with them, helping them any way we can to protect our interest."