Deepwater Horizon Spill Left Behind Sick Dolphins
March 28, 2012

Deepwater Horizon Spill Left Behind Sick Dolphins

NOAA marine mammal biologists are reporting signs of poor health in bottlenose dolphins in the Gulf Coast.

The dolphins, located in Barataria Bay, may be experiencing poor health due to exposure from the Deepwater Horizon oil spill of 2010.

NOAA biologists took comprehensive physicals of 32 live dolphins from Barataria Bay in the summer of 2011 and found many troubling health concerns, such as anemia, low blood sugar, and low weight. The biologists also found more than half of the sampled dolphins had abnormally low levels of stress and metabolism hormones.

The biologists fear these health issues will ultimately prove fatal for the bottlenose dolphins. In fact, one of the dolphins studied last summer was found dead this past January.

Working with local, state, and federal partners, NOAA began the Barataria Bay dolphin study in 2011 as part of the Natural Resource Damage Assessment (NRDA) to study the effects of the Deepwater Horizon Oil Spill.

By sharing the results of the study, NOAA hopes volunteers and veterinarians alike will be better suited to care for the dolphins and identify similar health concerns.

According to NOAA, more than 675 dolphins have been stranded in the northern Gulf of Mexico since February 2010. With a rate higher than 74 dolphins per year, NOAA has declared an Unusual Mortality Event (UME) and will begin to investigate the cause of death for as many dolphins as they can. Most of the dolphins stranded are found dead, however 33 dolphins have been found stranded and alive. These dolphins have been taken to rehabilitation centers to recover.

Another concern of biologists is the age of the dolphins begin found stranded. During the spring months, it isn´t uncommon to find fetal and stillborn dolphins stranded. However, since the UME in 2010 and 2011, there have been more of this age group of dolphin found stranded. NOAA is working with mammal health experts to discover the factors contributing to the high level of dolphin mortalities.

The Food and Drug Administration and NOAA, in association with the Gulf Coast states, have been using an agreed upon protocol to test the safety of Gulf Coast seafood and ensure that it is free of any residual oil or dispersant chemicals. When NOAA opened Gulf waters to fishing, they did so only after extensive testing. The Gulf States continue to test their seafood using the agreed upon protocol and routinely test the safety of their shellfish and other forms of seafood. Some wasters in the Barataria Bay region, however remain closed to commercial fishing as oil is still present and visible long the shoreline. These seafood tests can only begin once all visible oil has disappeared.

NOAA biologists are researching all the ways the bottlenose dolphins could have been exposed to the oil and dispersant chemicals. For example, the dolphins could have ingested or inhaled the dangerous chemicals, as well as eaten fish that were contaminated by the chemicals. While the dolphins may have been exposed to the chemicals in this type of manner, it is not likely that humans would be vulnerable to exposure in the same way.