Rising ocean acidity means enforced weight loss plan for marine life
Two studies this week hammer home an increasing certainty that ocean acidification will spell disaster for marine ecosystems. Writing in Nature Geoscience, researchers provide the first evidence outside of the laboratory that rising acid levels in the Southern Ocean have already been thinning the shells of marine organisms.
The study finds that modern shell weights of microscopic shell-building creatures called forams are 30 to 35 percent lower than weights of pre-industrial forams preserved in sediments. If forams are any indication, other ocean life could be in similar trouble, which would cause major disruptions to the marine food chain.
But weight loss is only the beginning, according to a second study to be published online Friday in Geophysical Research Letters. A press release preview says that it will be the first paper to show that coral reefs will actually start dissolving almost everywhere if atmospheric carbon dioxide concentrations are allowed to double from current levels. Through data collection and a model of more than 9,000 reef locations, the study shows that such high CO2 levels would reduce coral growth rates to only 20 percent of their pre-industrial levels. In this scenario, coral weight gain wouldn’t keep pace with natural dissolution and destruction. The result: corals might just vanish.
Jessica Leber, Conservation Magazine, 12 March 2009. Article.
