Post-Spill Oyster Shell (IMAGE) California Academy of Sciences Caption Oyster shells like this one, collected from the Gulf of Mexico after the Deepwater Horizon oil spill, have been shown to contain higher concentrations of three heavy metals common in crude oil -- vanadium, cobalt, and chromium -- than specimens collected before the spill. Credit California Academy of Sciences Usage Restrictions With credit to the California Academy of Sciences License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.