West Coast plankton being destroyed by ocean acidification ‘decades early’ say scientists

Posted on SeafoodNews.com: 30 Apr 2014

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 The problems of ocean acidity harming the marine food chain and ultimately upending West coast fishery produdtion could be coming much sooner than expected.  In a new paper published this week, NOAA scientists have found large scale evidence of severe dissolution of the shells of a major oceanic plankton, called a pteropod.

A NOAA-led research team has found the first evidence that acidity of continental shelf waters off the West Coast is dissolving the shells of tiny free-swimming marine snails, called pteropods, which provide food for pink salmon, mackerel and herring, according to a new paper published in Proceedings of the Royal Society B.
Researchers estimate that the percentage of pteropods in this region with dissolving shells due to ocean acidification has doubled in the nearshore habitat since the pre-industrial era and is on track to triple by 2050.
“Our findings are the first evidence that a large fraction of the West Coast pteropod population is being affected by ocean acidification,” said Nina Bednarsek, Ph.D., of NOAA’s Pacific Marine Environmental Laboratory in Seattle, the lead author of the paper.

The research team, which also included scientists from NOAA’s Northwest Fisheries Science Center and Oregon State University, found that the highest percentage of sampled pteropods with dissolving shells were from northern Washington to central California, where 53 percent of pteropods sampled had severely dissolved shells. The ocean’s absorption of carbon dioxide emissions is also increasing the level of corrosive waters near the ocean’s surface where pteropods live.

“We did not expect to see pteropods being affected to this extent in our coastal region for several decades,” said William Peterson, Ph.D., an oceanographer at NOAA’s Northwest Fisheries Science Center and one of the paper’s co-authors.
The research documents the movement of corrosive waters onto the continental shelf from April to September during the upwelling season, when winds bring water rich in carbon dioxide up from depths of about 400-600 feet to the surface and onto the continental shelf.
“Acidification of our oceans may impact marine ecosystems in a way that threatens the sustainability of the marine resources we depend on,” said Libby Jewett, Director of the NOAA Ocean Acidification Program. “Research on the progression and impacts of ocean acidification is vital to understanding the consequences of using fossil fuels.”