Wednesday, May 9, 2012

Will Coal Burning Power Plants Make Super Crabs?

The world’s oceans are changing, with waters today about 30 percent more acidic than they were two centuries ago, before the Industrial Revolution, according to the National Oceanic and Atmospheric Administration. Scientists say this is because the burning of coal, oil, and gas released a huge amount of carbon dioxide into the atmosphere that was absorbed by the water.
Of the CO2 added to the atmosphere by the burning of fossil fuels, about half appears to accumulate in the atmosphere, the other half being sequestered by either the ocean or terrestrial carbon sinks.  Scientists are still trying to quantify those fluxes, but yes, a lot of carbon is disappearing into the ocean. 
The chemical reaction between this pollutant -- C02 -- and water creates carbonic acid, according to Dr. Ries and other researchers.
Uh, that particular reaction has been known for a very long time.The only research needed is to read standard texts on water chemistry.
To discover how different forms of life will react to ocean acidification, Dr. Ries performed an experiment by growing 18 different species in laboratory tanks with varying levels of carbon dioxide. The result: the shells of crustaceans, including blue crabs, grew faster and larger in lab tanks with higher carbon dioxide levels.

Meanwhile, creatures that crabs eat—such as clams and oysters – suffered because of the pollution, with their shells becoming thinner and more fragile and growing more slowly.
More acidic water (by virtue of adsorbing CO2) has less of it's CO2, in the form of  carbonante ion (CO32-) and more as bicarbonate (HCO3-).  Carbonate is used by most shell forming organisms to form calcium carbonate (basically limestone), and decreased the carbonate decreases energetic ability to make the calcium carbonate.  It may or may not decrease actual calcification; it depends very much on the organism and the levels of carbonate (and hence pH).  And the paper tends to show that higher CO2 favors calcification by crabs, shrimp and lobsters, and decrease the calcification of bivalves.

So will this mean the crabs of the future will be super crabs, breaking everything in sight?  I doubt it.  The daily fluctuations of pH and carbonate ion in the Chesapeake Bay currently can be greater than his range of testing.

No comments:

Post a Comment