So long, shellfish: Oysters falling victim to ocean acidification
Increasing ocean acidification has taken a big toll on Northwest oyster farms, and that could translate into a shellfish shortage.
Thu, Apr 29, 2010 at 09:57 PM
Could seafood fans be saying goodbye to shellfish sometime soon? Millions of oyster larvae have been dying in Northwest farms due to increasingly acidic ocean waters that robs them of their ability to grow shells, according to ABC News. The world’s oceans are absorbing more carbon dioxide than ever as greenhouse gas emissions increase on land.
"The chemistry is very simple. It is 101. Carbon dioxide makes the water more acidic, that is irrefutable," said Burke Hales, Oregon State University professor of oceanography.
Oyster farmers Mark Wiegardt and Sue Cudd of Whiskey Creek Shellfish Hatchery in Tilamook, Ore., called in Hales and his team when their larvae suddently started dying. The hatchery’s 8,000 gallon tanks were pumping in water from the Pacific Ocean, which turned out to be increasingly acidic.
But the oysters aren’t alone in this crisis. Clams, mussels, lobsters, shrimp and smaller-shelled sea creatures are forming weaker shells due to the increased ocean pH, which dissolves calcium carbonate, the material that allows shells to harden or calcify.
"At first, scientists thought, oh, isn't this great, the ocean's taking up carbon dioxide that's resulting in less greenhouse warming. And it's only later that scientists realize this carbon dioxide in the oceans forms carbonic acid, and that attacks the shells of marine organisms," explains Ken Caldeira, a climate scientist at the Carnegie Institute at Stanford University.
The United Nations Environment Program (UNEP) warns that if we allow ocean acidification to continue, we could lose shellfish for good – permanently altering ocean ecosystems and causing drastic changes to the food chain. The only way to prevent the ocean from becoming completely inhabitable for shellfish and other affected sea creatures is to drastically cut carbon emissions.
"Ocean acidification is irreversible on timescales of at least tens of thousands of years, and substantial damage to ocean ecosystems can only be avoided by urgent and rapid reductions in global emissions of CO2,” said Ahmed Djoghlaf of UNEP.