An analysis of Gulf of Mexico oysters shows an increase in the heavy metals vanadium, chromium, cobalt, and lead concentrations in oysters’ shells, gill, and muscle tissue since the 2010 Deepwater Horizon oil spill.
For the past two years, a team of scientists from the California Academy of Sciences has been studying oysters 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 scientists 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.
Oysters continually build their shells, and if contaminants are present in their environment, they can incorporate those compounds into their shells.
The team presented their data at a poster session at the American Geophysical Union meeting in December 2011, and is preparing their preliminary findings for publication.
Bottom line: A two-year analysis by a team of scientists from the California Academy of Sciences shows an increase in concentrations of the heavy metals vanadium, chromium, cobalt, and lead in the shells, gill, and muscle tissue of Gulf of Mexico oysters since the 2010 Deepwater Horizon oil spill.