Shellfish Threatened by Ocean Acidification

One effect of global warming that is not given enough reportage is ocean acidification. The effect of oceans absorbing more carbon dixoide is potentially more damaging than sea level rise because it impacts the bottom of the marine food chain. Acidification is responsible for mass die-offs of corals. Both corals and shellfish need carbonates in seawater to build their protective shells; higher acid levels dissolve carbonates. A recent study examined the effect on the long-term impact of acidification on the shellfish industry, a $1bn business in the United States. Shelled mollusks-oysters, clams and scallops--are extremely sensitive to changes in ocean pH.  Increased absorbtion of atmospheric CO₂ and waste dumping in the ocean that feeds algae blooms lower the ocean's acid-base balance measured by its pH level.

Mollusk harvests will decline in 15 of 23 coastal states studied. Massachusetts' Cape Cod region will be hit the hardest. Shellfishery there is a $300m a year business; in economically depressed New Bedford, 80% of its fishing revenue come from the harvest of sea scallop [photo]. The state allows 1,350 commercial fishing licenses annually. The states of Washington and Oregon only produce about $100m in direct sales of shellfish. State officials are aware of the economic ramafication of a decline in shellfish harvests, but little has been done to study the problem. Former Washington governor Christine Gregoire signed an executive order aimed at protecting the state's $270m industry. The recent study concludes that the economic impacts of acidification will be severe and broader than peviously thought.  Global warming: it's bad for business!