Ocean acidification, caused by rising CO2 levels, is affecting not only coral reefs, but coastal ecosystems by changing everything from the ability of oysters to adhere to the riverbed to the extent of dead zones along the U.S. Pacific coast.
Ocean acidification is occurring because CO2 from the burning of fossil fuels is dissolving in the seas, creating a weak carbonic acid solution. Much of the attention on the problem so far has focussed on coral reefs, which are particularly vulnerable to changes in pH (see “Oceans of acid”).
Combination of impacts
But riverine and other coastal environments may also be unusually vulnerable because they face a range of additional threats from problems such as pollution and variable levels of acidity and organic matter flowing into them, said Richard Feely, an oceanographer at the National Oceanic and Atmospheric Administration’s Pacific Marine Environmental Laboratory in Seattle, USA.
“Each estuary is different [and]… in coastal ecosystems, we have to think about combined impacts,” he said at a scientific meeting of the Coastal and Estuary Research Foundation in Portland, Oregon earlier this month.
Another danger is that coastal systems are highly variable. Adding the problem of acidification on top of their natural variability might push them over tipping points from which they cannot recover, added Burke Hales, an oceanographer at Oregon State University in Corvallis.
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Holly Hight, COSMOS Magazine, 12 November 2009. Full article.
