Summit County Citizens Voice

Oil entered foodweb from bottom up long after well was capped

By Summit Voice

SUMMIT COUNTY — Oil from BP’s failed Deepwater Horizon drilling contaminated the Gulf of Mexico‘s marine food chain from the bottom up, according to a new study showing that the oil was absorbed by tiny zooplankton.

Zooplankton are useful to track oil-derived pollution. They serve as food for baby fish and shrimp and act as conduits for the movement of oil contamination and pollutants into the food chain. The study confirms that, not only did oil affect the ecosystem in the Gulf during the blowout, but  was still entering the food web long after the well was capped.

“Our research helped to determine a ‘fingerprint’ of the Deepwater Horizon spill—something that other researchers interested the spill may be able to use,” said Dr. Siddhartha Mitra of Eastern Carolina University. “Furthermore, our work demonstrated that zooplankton in the Northern Gulf of Mexico accumulated toxic compounds derived from the Macondo well.” he said.

After the April 20, 2010 explosion on the drilling rig, crude oil gushed into the water at a rate of at least 53,000 barrels per day before the well was capped on July 15.

Oil  is a complex mixture of hydrocarbons and other chemicals. It contains polycyclic aromatic hydrocarbons (PAHs), which can be used to fingerprint oil and determine its origins. The researchers were able to identify the signature unique to the Deep Water Horizon well in the Gulf of Mexico.

The team’s research indicates that the fingerprint of the Deepwater Horizon oil spill could be found in some zooplankton in the Gulf of Mexico ecosystem at low levels as much as a month after the leaking wellhead was capped.

The extent of the contamination seemed to be patchy. Some zooplankton at certain locations far removed from the spill showed evidence of contamination, whereas zooplankton in other locations, sometimes near the spill, showed lower indications of exposure to the oil-derived pollutants.

“Traces of oil in the zooplankton prove that they had contact with the oil and the likelihood that oil compounds may be working their way up the food chain,” said Dr. Michael Roman of the University of Maryland Center for Environmental Science.

The study was led by East Carolina University with researchers from the University of Maryland Center for Environmental Science, Oregon State University, Georgia Institute of Technology, and U.S. Geological Survey. The paper, “Macondo-1 well oil-derived polycyclic aromatic hydrocarbons in mesozooplankton from the northern Gulf of Mexico,” was published in the February issue of Geographical Research Letters. It can be found here.

Filed under: BP Gulf oil spill, Environment, Marine biology, oil drilling, Summit County news Tagged: | Deepwater horizon oil spill, Environment, Gulf of Mexico, University of Maryland Center for Environmental Science, zooplankton