Scientists find higher concentrations of heavy metals in post-oil spill oysters from Gulf of Mexico
Color me stunned.
As the two-year anniversary of the Deepwater Horizon oil spill in the Gulf of Mexico approaches, a team of scientists led by Dr. Peter Roopnarine of the California Academy of Sciences has detected evidence that pollutants from the oil have entered the ecosystem's food chain. For the past two years, the team has been studying oysters (Crassostrea virginica) collected both before and after the Deepwater Horizon oil reached the coasts of Louisiana, Alabama, and Florida. These animals can incorporate heavy metals and other contaminants from crude oil into their shells and tissue, allowing Roopnarine and his colleagues to measure the impact of the spill on an important food source for both humans and a wide variety of marine predators. The team's preliminary results demonstrate that oysters collected post-spill contain higher concentrations of heavy metals in their shells, gills, and muscle tissue than those collected before the spill. In much the same way that mercury becomes concentrated in large, predatory fish, these harmful compounds may get passed on to the many organisms that feed on the Gulf's oysters.
"While there is still much to be done as we work to evaluate the impact of the Deepwater Horizon spill on the Gulf's marine food web, our preliminary results suggest that heavy metals from the spill have impacted one of the region's most iconic primary consumers and may affect the food chain as a whole," says Roopnarine, Curator of Geology at the California Academy of Sciences.
The research team collected oysters from the coasts of Louisiana, Alabama, and Florida on three separate occasions after the Deepwater Horizon oil had reached land: August 2010, December 2010, and May 2011. For controls, they also examined specimens collected from the same localities in May 2010, prior to the landfall of oil; historic specimens collected from the Gulf in 1947 and 1970; and a geographically distant specimen collected from North Carolina in August 2010.
Oysters continually build their shells, and if contaminants are present in their environment, they can incorporate those compounds into their shells. Roopnarine first discovered that he could study the growth rings in mollusk shells to evaluate the damage caused by oil spills and other pollutants five years ago, when he started surveying the shellfish of San Francisco Bay. His work in California revealed that mollusks from more polluted areas, like the waters around Candlestick Park, had incorporated several heavy metals that are common in crude oil into their shells.
More: http://www.eurekalert.org/pub_releases/2012-04/caos-sfh041812.php
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not only sells gulf shrimp but sells Chinese tilapia. 
