These health problems are likely a result of the 2010 Deepwater Horizon oil spill. The study was conducted in 2011 as part of the Natural Resource Damage Assessment (NRDA) after the spill. Barataria Bay was “heavily oiled.” This study provides the first evidence that dolphins in these oiled areas have longer-lasting health effects, similar to those seen in laboratory studies of animals exposed to petroleum hydrocarbons.
The study concludes that the health problems seen in the Barataria Bay dolphins will lead to reduced survival and ability to reproduce.
Of the 32 dolphins sampled, 29 received comprehensive physical examinations. Researchers assigned 48% of the dolphins a “guarded or worse prognosis.” Of those, 17% were in “poor or grave condition” and were not expected to survive. Researchers also found that 25% of the dolphins were significantly underweight.
These results are especially striking when compared to dolphins sampled in Sarasota Bay, Florida, which was not oiled by the spill. Moderate to severe lung disease was five times more likely in Barataria Bay dolphins.
To rule out any other possible causes for the health problems, researchers tested samples of blubber for PCBs and commonly detected persistent pesticides, but they showed relatively low concentrations as compared to other coastal dolphin populations.
As part of the NRDA, researchers also performed additional health assessments in 2013 in Barataria Bay and Sarasota Bay, but the results are still pending.
Watch the following video to see the health assessment process:
To learn more:
- Read the full news release from NOAA: Scientists Report Some Gulf Dolphins Are Gravely Ill
- Check out this post from Oceana’s blog: Gulf Dolphins Are Still Sick After the Deepwater Horizon Oil Spill
- Read this Q&A with some of the researchers: Study Shows Gulf Dolphins in Poor Health following Deepwater Horizon Oil Spill
- Find the full study online here: Health of Common Bottlenose Dolphins (Tursiops truncatus) in Barataria Bay, Louisiana, Following the Deepwater Horizon Oil Spill
Copyright © 2013 by Marine Science Today, a publication of Marine Science Today LLC.