Bottlenose dolphins in areas of the northern Gulf of Mexico that were heavily impacted by the Deepwater Horizon blowout disaster are showing signs of severe ill health, according to NOAA biologists.
Barataria Bay, Louisiana, located in the northern Gulf of Mexico, received heavy and prolonged exposure to oil during the Deepwater Horizon spill. Now, results of the comprehensive physicals of 32 live dolphins from the bay conducted in the summer of 2011 indicate that many of the dolphins studied are underweight, anemic, have low blood sugar and some symptoms of liver and lung disease.
Nearly half of the mammals studied also have abnormally low levels hormones responsible for stress response, metabolism and immune system function.
One of the individuals last observed in late 2011 has since died, and its body was discovered in late January.
Researchers, whose membership includes NOAA marine mammal biologists and their local, state, federal and other research partners, fear that other dolphins examined in the same study are in such poor health that they may not survive..
NOAA and its local, state and federal partners started the Barataria Bay dolphin study in 2011 as part of the Natural Resource Damage Assessment (NRDA), the process for studying the effects of the Deepwater Horizon oil spill. Preliminary results from the study are being released so that stranding responders and veterinarians can better care for live stranded dolphins and look for similar health conditions.
Gulf dolphins may have been exposed to oil through ingestion, inhalation or externally or could have routinely ingested oil from sediments or water while feeding or by eating whole fish. These are not likely routes of exposure for most people.
Seafood from the Gulf, undergoing an unprecedented level of testing since the oil spill, has been found to be perfectly safe and free of oil and residue of dispersant chemicals. Protocol for testing requires that testing begin only after visible oil is gone. The area in question in northern Barataria Bay remains closed to commercial fishing, due to visible oil along the shoreline.