Exxon Valdez Lessons Applied in Gulf Coast Cleanup

Cleanup of the Gulf of Mexico coastal regions affected by the BP oil spill combines old fashioned 'cleaning' with scientific analysis.  Sand is washed and returned to the beaches as lessons learned by the Exxon Valdez spill in 1989 are applied here.

© 2010 National Geographic; partially funded by NSF; Field producing and videography by Fritz Faerber

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· Gulf Oil Spill News and Pictures

· Exxon Valdez Anniversary: 20 Years Later, Oil Remains

UNEDITED TRANSCRIPT:

MONTHS INTO THE GULF COAST BP OIL SPILL RECOVERY, IT APPEARS AS THOUGH MOST OF THE OIL HAS DISAPPEARED.

BUT THERE ARE STILL HEAVILY OILED AREAS.  SOME OF THE HARDEST HIT PLACES NOW SHOW ONLY SCATTERED TAR BALLS AND OTHER TRACES. BUT DIG A BIT, AND IT IS THERE.

VOX: OIL HIT GRAND ISLE, LOUISIANA EARLY AND OFTEN. TULANE UNIVERSITY RESEARCHER BRAD ROSENHEIM AND HIS STUDENTS VISITED SOON AFTER OIL WASHED ASHORE AND THEY’VE BEEN RETURNING FREQUENTLY TO STUDY THE CHANGES.

Brad Rosenheim, Isotope Geochemist, Tulane University
“We’re getting to a point now where when we dig these trenches the oil is hard to recognize by our naked eye. It blends in with other layers of organic carbon that one would expect in such a dynamic environment.”

THE TEAM IS STUDYING THE WEATHERING OF THE OIL IN DIFFERENT ENVIRONMENTS. AND AS VARIOUS PROCESSES BREAK DOWN THE OIL’S CHEMICALS, ROSENHEIM IS USING A DIFFERENT MEASURE TO IDENTIFY THE OIL – ISOTOPES.

Brad Rosenheim, Isotope Geochemist, Tulane University
“Hydrocarbons are made up of hydrogen and carbon chemically. But carbon is made up of different isotopes, meaning different numbers of neutrons in the carbon, as is hydrogen. So we can potentially have a carbon hydrogen bond that has several different isotopes attached to it.”

LOOKING FOR UNIQUE ISOTOPES MEANS SCIENTISTS CAN IDENTIFY THE OIL EVEN AFTER IT HAS BROKEN DOWN OVER TIME.

Brad Rosenheim, Isotope Geochemist, Tulane University
“What we’re looking at is to see what chemicals stick around the longest and also, probably more importantly, is to isotopically fingerprint some of the breakdown chemicals that would get incorporated into different parts of the ecosystem. Isotopically we may have a better chance at tracking the oil over the next several years than we would with just a chemical approach because of course it’s going to change chemically. “

VOX: AS ROSENHEIM STUDIES THE OIL, COLLEAGUE DEAN MOOSAVI AND HIS STUDENTS STUDY CHANGES TO THE ISLAND ITSELF. THEY’VE BEEN MEASURING EROSION AND BUILDUP OF THE BEACH FOR THREE YEARS. THEY REGULARLY VISIT THE SAME SPOTS AND MEASURE ELEVATION OF THE BEACH ALONG TRANSECTS OUT TO THE WATER. AND THE ISLAND MAY CHANGE AFTER THE SPILL AND CLEANUP ACTIVITY.

Dean Moosavi, Biogeochemist, University of Massachusetts-Dartmouth
“When the Exxon Valdez spill occurred in Alaska, there was tremendous concern for the wildlife, and Exxon and the companies they contracted went to great lengths to try to clean the rocky beaches and coves of Prince William  Sound. They used high pressure water washes, they used dispersants, they used various means to try and break up the oil and clean the oil off of the rocks. In many cases, they found that the efforts to clean the system actually were more harmful  than the oil itself had been because of the physical disturbance of the system. Here on Grand Isle, BP has learned lessons from that. You can see they are taking a much more cautious approach.”

“In terms of cleaning the sand, they have what looks like giant combines which come through, sift through the sand, capture materials that are sticking together, which are presumably contaminated with oil and haul those away to be steam cleaned, treated to remove the oil and then the sand is returned to the beach. Now that process is meant to be benign. And, for the most part it is. But you are still driving large vehicles back and forth over the beach. You are disrupting whatever stratigrophy is there. You are returning material that has been sterilized.”

IF MOOSAVI AND OTHER RESEARCHERS STUDYING THE GULF COAST’S TOPOGRAPHY FIND UNEXPECTED CHANGES THEY SUSPECT ARE LINKED TO THE OIL SPILL, THEY WILL NEED CONCRETE EVIDENCE TO DETERMINE WHETHER THE OIL OR CLEANUP PLAYED A ROLE. THAT’S WHERE MOOSAVI AND ROSENHEIM’S RESEARCH CAN BE VITAL.

Brad Rosenheim, Isotope Geochemist, Tulane University
“Now we’re going to see some changes in areas that did have oil wash up. And hopefully our work will help scientists determine if those changes, changes we would call geomorphological changes to the coastline can be assigned to any singular event of oil washed up or if it’s just business as usual on the Louisiana coastline.”

IT MAY TAKE YEARS TO KNOW THE SPILL’S TOTAL EFFECTS, BUT THE RESEARCH GATHERED AT GRAND ISLE BY BOTH RESEARCH TEAMS WILL GIVE SCIENTISTS IMPORTANT TOOLS TO MEASURE THE OIL’S IMPACT.