Scientists from Alabama's Dauphin Island Sea Lab this month determined oil from the Gulf disaster worked its way up the food chain. In a report ("Oil carbon entered the coastal planktonic food web during the Deepwater Horizon oil spill") published in Environmental Research Letters, lead author Monty Graham shows that microscopic bacteria consumed oil, and an oil-specific carbon "signature" entered the plankton food web via bacteria-eating microorganisms. The findings occurred as late as August, after oil cleanup responders scaled back skimming operations.
The study and research program was funded by the National Science Foundation, the Marine Resources Division of the Alabama Department of Conservation and Natural Resources, and BP's Gulf of Mexico Research Initiative, which provided $500 million to research programs to determine the effects of the disaster. In a statement releasing the report, Graham said researchers never doubted oil would assimilate in the food web, but what they don't know are the effects.
"We showed with little doubt that oil consumed by marine bacteria did reach the larger zooplankton that form the base of the food chain," he said. "These zooplankton are an incredibly important food source for many species of fish, jellyfish and whales."
The researchers are using the results of the report to begin tracking how and at what speed the oil carbon moves from organism to organism. The National Oceanic and Atmospheric Administration (NOAA), the Food and Drug Administration and Department of Health and Hospitals are determining the toxicity of seafood in a separate investigation from the Alabama study.
Meanwhile, NOAA announced its 11th reopening of federal waters last week, adding an additional 8,403 miles of Gulf waters open to commercial and recreational fishing. — Alex Woodward