Ocean changes pose new threat to Dungeness crab

Dungeness crabs will face a serious threat as oceans become more acidic, according to new research released this week.

The study, published in the scientific journal Global Change Biology, predicts that ocean acidification caused by increased carbon-dioxide levels will cause a decline in food sources for the Dungeness crab. The loss of food, it concludes, would lead to a significant decline in population within the next 50 years.

“More carbon-dioxide goes into the atmosphere, about 30% of that gets taken up by the ocean,” said Josh Lord with MBARI, “so when it goes into the ocean, a series of chemical reactions occur.”

And that series of chemical reactions leads to acidic ocean waters that will impact the ecosystem.

“Basically if you’re affecting one animal in the ecosystem, it can affect all the others just by changing food sources, changing predator prey interaction, changing competition between species,” said Lord.

The findings are not good news for the West Coast’s Dungeness crab fisheries, which are valued at about $220 million annually. However, some local fishermen around Moss Landing aren’t too worried as they’ve seen there fair share of ups and downs out on the water.

“I believe more in cycles. I think now it’s back to normal, but who knows what normal is?” said Tom Hart, who has been fishing for more than 50 years.

But down the line, there might not be much crab for fishermen to catch.