Increasingly acidic ocean conditions are threatening US shellfish populations, with the Pacific Northwest and Alaska expected to be affected first, and the Northeast likely to be hit the hardest, researchers said.

More acidic waters have already cost the oyster industry almost $US110 million ($141 million) in the Pacific Northwest, and conditions in the Northeast will cut into the $US300 million annual mollusk harvest in southern Massachusetts, according to an article published Monday in the journal Nature Climate Change.

Acidifying oceans are affecting the shellfish industry. Credit:Rick Stevens

The results are further examples that climate change is having a significant impact on both the planet and the global economy, and will continue to threaten the environment even if greenhouse-gas emissions are significantly curtailed.

"The mid-Atlantic and the Northeast make a ton of money off vulnerable species," said Lisa Suatoni, a senior scientist at the Natural Resources Defense Council and one of the paper's authors. "They have a lot to lose."