Dolphins living in one of the areas worst hit by the Gulf of Mexico oil spill were in bad shape a year later, with lung problems consistent with exposure to oil, according to a study assessing damage from the spill.
Government, academic and other researchers made comprehensive check-ups on 29 dolphins in Barataria Bay in August 2011 as part of the Natural Resource Damage Assessment—a federal process to determine both the extent of damage and how to repair it. Barataria Bay was one of the areas where pelicans struggled in heavy slicks and thick globs of oil washed onto marshy islands between April and July 2010.
Fourteen of the 29 dolphins examined in 2011 were in guarded, poor or grave condition. That compared to one out of 15 caught for comparison in Sarasota Bay, Florida, which was not involved in the spill, according to the study published Wednesday in the American Chemical Society journal Environmental Science & Technology.
National Oceanic and Atmospheric Administration scientist Lori Schwacke said she has made similar assessments in other groups of dolphins, sometimes in response to large numbers of deaths.
The study indicates a possible link to the oil spill but does not prove one, said Mobi Solangi, director of the Institute for Marine Mammal Studies in Gulfport, Mississippi.
"I think it's an important study. It's an important first step," said Solangi, who was not involved in the study.
He said shortcomings include lack of pre-spill data on dolphins in the bay, which has a history of pollution from industry, sewage and agricultural runoff carried by the Mississippi River. It also lacks comparison with the Florida dolphins, which probably spend more time in deep water than the pods found in Barataria Bay.
A statement from BP PLC said the company, "has been funding NOAA's work on this subject for over three years and requesting data throughout this period. The agency still has not provided BP with any data demonstrating that the alleged poor health of any dolphins was caused by oil exposure. Indeed, NOAA has not even provided BP an injury assessment on dolphins or any other species or habitat."
Schwacke said BP was given all of the data used in the paper. A BP representative was with the group that captured and released the dolphins, said Teri Rowles, coordinator of the NOAA Marine Mammal Health and Stranding Response Program and a co-author of the study.
The scientists said moderate to severe lung disease was five times more likely in the Louisiana dolphins than the Florida group.
NOAA said dolphins were checked again this year in Barataria and Sarasota bays, and in Mississippi and Alabama waters of the Mississippi Sound. Data from those four groups is still being analyzed.
Explore further: Fish detection system for toxins wins Chinese company invention award