December 2013: In Louisiana’s Barataria Bay Bottlenose dolphins are five times more likely to suffer from lung damage and adrenal hormone abnormalities than any other dolphin populations as a result of the Deepwater Horizon spill, scientists have discovered.
Twenty-nine of the total 32 dolphins sampled in Barataria Bay received comprehensive physical examinations, including ultrasound examinations to assess lung condition and researchers assigned almost half (48 percent) of the dolphins a guarded or worse prognosis. In fact, they classified 17 percent as being in poor or grave condition, meaning the dolphins were not expected to survive.
The researchers also found that 25 percent of the Barataria Bay dolphins were significantly underweight and the population overall had very low levels of adrenal hormones, which are critical for responding to stress.
These findings are in contrast to dolphins sampled in Sarasota Bay, Florida, an area not oiled by the Deepwater Horizon spill. For Dr. Lori Schwacke, the study’s lead author and veteran of a number of similar dolphin health studies across the southeast, the findings are troubling: “I’ve never seen such a high prevalence of very sick animals — and with unusual conditions such as the adrenal hormone abnormalities.”
The study was conducted in August 2011 as part of the Natural Resource Damage Assessment (NRDA) by a team of government, academic and non-governmental researchers and results were published were published December 2013 in the journal Environmental Science & Technology.