Thursday, June 18, 2009

Ocean Acidificaiton

Willapa Bay, one of the countries most productive oyster region has experienced its fourth consecutive spawning failure. Oysters whose larve are free floating prior to settling into a suitable location have been dying before successfully settling out. Increasingly scientists are coming to believe that the oysters are being impacted by changes in ocean chemistry known as ocean acidification. As the concenration of CO2 in the atmosphere rises, the ocean stores massive amounts of the carbon, chaning the pH of the ocean water from slightly alkaline to slightly acidic. The waters most affected are the deep, cold ocean water which upwells along our coast and has typically driven ocean productivity off our continental shelf. While the changes in ocean chemistry are subtle they may have profound impacts for ocean ecosystems where many animals form their exoskeletons with bicarbonate. From Coral Reefs to Zooplankton in the North Pacific the number of organisms directly effected is startling. Even more startling are the changes that could be wrought to marine ecosystems through alterations in their historic foodwebs. As atmospheric carbon concentrations rise, ocean acidification may have a more dramatic effect on marine ecosystems than the actual temperature changes associated with climate change. A fascinating article in the Seattle Times today covered the acidity problems in Willapa Bay.

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