Sea Life Suffocating
New MBARI report suggests rising CO2 levels are making it harder for marine animals to breathe.
Friday, April 17, 2009
Spiking carbon dioxide levels and expanding low-oxygen areas in the sea are making survival harder for marine animals, according to today's press release from the Monterey Bay Aquarium Research Institute.
The ocean absorbs about one-third of the CO2 released into the atmosphere by human fossil fuel burning. As greenhouse gas emissions rise, so does the amount of CO2 the ocean absorbs, causing a chemical reaction that makes the ocean more acidic. Scientists believe ocean acidification is linked to spreading low-oxygen "dead zones" that are suffocating marine life.
In an article published in today's issue of the journal Science, MBARI chemists Peter Brewer and Edward Peltzer suggest the combination of higher CO2 and lower oxygen levels are making it harder for marine animals to "breathe," or extract oxygen from seawater. That makes finding food, avoiding predators and reproducing harder, too.
Making matters worse, warming surface water means less oxygen is mixing into the deep sea, creating what the scientists call a "double whammy" of tough circumstances for marine life. Brewer and Pelzer are quantifying the impacts in a new "respiration index" that they hope will help scientists map and predict the ocean's dead zones.
"Previous studies have indicated that such oxygen minimum zones may expand over the next century," the press release state. "Brewer and Peltzer's research suggests that the effects of this expansion will be even more severe than previously forecast."