Rising acidity levels could trigger shellfish revenue declines, ...( Changes in ocean chemistry a conseq...)

Changes in ocean chemistry a consequence of increased carbon dioxide (CO₂) emissions from human industrial activity could cause U.S. shellfish revenues to drop significantly in the next 50 years, according to a new study by researchers at the Woods Hole Oceanographic Institution (WHOI).

Intensive burning of fossil fuels and deforestation over the last two centuries have increased CO₂ levels in the atmosphere by almost 40 percent. The oceans have absorbed about one-third of all human-generated carbon emissions, but the buildup of CO₂ in the ocean is pushing surface waters toward more acidic conditions.

This "ocean acidification" creates a corrosive environment for marine organisms such as corals, marine plankton, and shellfish that build carbonate shells or skeletons. Mollusks including mussels and oysters, which support valuable marine fisheries are particularly sensitive to these changes.

In a case study of U.S. commercial fishery revenues published in the June issue of Environmental Research Letters, WHOI scientists Sarah Cooley and Scott Doney calculated the possible economic effects of ocean acidification over the next 50 years using atmospheric CO₂ trajectories from the Intergovernmental Panel on Climate Change and laboratory studies of acidification's effects on shell-forming marine organisms, focusing especially on mollusks.

Mollusk sales by fishermen currently generate about $750 million per year nearly 20 percent of total U.S. fisheries revenue. The study assumed that mollusks harvests in the U.S. would drop 10 to 25 percent in 50 years' time as a result of increasing acidity levels, which would decrease these mollusk sales by $75 to $187 million dollars annually.

"Losses in primary revenue from commercial mollusk harvestsor the money that fisherman receive for their catchcould add up to as much as $1.4 billion by 2060," said Cooley.

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