A new study finds ocean acidification is already dissolving the shells and damaging the sensory organs of young Dungeness crab off the West Coast.
So far, it’s unclear what that means for Oregon’s most valuable fishery.
The ocean absorbs about a quarter of the carbon dioxide released by burning fossil fuels and that triggers a chemical process that makes ocean water more acidic.
Researchers with the National Oceanic and Atmospheric Administration were surprised to see acidic water having so much impact so soon.
“We found dissolution impacts to the crab larvae that were not expected to occur until much later in this century,” said Richard Feely, senior scientist with NOAA’s Pacific Marine Environmental Laboratory and one of the co-authors of the study.
The new findings came from studying crab collected from the ocean, but they build on previous lab research that reached similar conclusions. They sound alarm bells for scientists who had thought Dungeness crab weren't vulnerable to current levels of ocean acidification.
"This is the first study that demonstrates that larval crabs are already affected by ocean acidification in the natural environment," said Nina Bednarsek, senior scientist with the Southern California Coastal Water Research Project and lead author of the study. “If the crabs are affected already, we really need to make sure we start to pay much more attention to various components of the food chain before it is too late.”
Scientists say more research is needed to determine whether the damage to these baby crabs could one day impact the adult population of Dungeness crab that delivers about $170 million annually to the West Coast fishing fleet.
A 2017 study predicted crab populations will likely suffer as the ocean becomes more acidic because their food sources will decline.
Oregon's fishing industry isn't sounding alarm bells yet.
Tim Novatny with the Oregon Dungeness Crab Commission said so far the acidic water isn't affecting the fleet's ability to bring big, delicious, adult crab to market.
"You hate to see anything like this, of course, in your fishery," Novatny said. "But I think the thing to realize right now is that it doesn’t impact the crab people are seeing in the stores and on their menus."
Novatny said the industry does want to know more about what the new findings mean for future crab populations and what would prevent ocean acidification from becoming a bigger problem in the future.
"We highly encourage more research," he said. "This merits more study to find out why the crab have shown these effects and what we can do to slow these effects down."
The new study was the first to reveal a new impact of ocean acidification in discovering the damaged sensory receptors of the young crab. Hair-like receptors transmit important information, and scientists report the damage caused by acidic water could cause slower movement, impaired swimming and other problems.