Two years after the start of the BP oil spill, dolphins in the northern Gulf of Mexico are dying in unprecedented numbers. This month marks a record-shattering 26 consecutive months of above-average dolphin strandings. Only 5 percent of the stranded dolphins were recovered alive and their prognosis was usually poor.
The National Oceanic and Atmospheric Administration (NOAA) recently did an in-depth study of 32 dolphins in Barataria Bay, an area that was heavily oiled during the BP oil spill. The researchers found that many of the animals were underweight, anemic, had low hormone levels, low blood sugar, and some had signs of liver damage. These symptoms are consistent with those seen in other mammals exposed to oil. One of the dolphins in the study has since been found dead.
As a top-level predator, the poor health of dolphins in the most heavily oiled areas suggests possible ecosystem-wide effects of the oil. Dolphins can inhale oil vapors, ingest oil when feeding, absorb it through their skin or eat contaminated fish.
Scientists with NOAA are continuing to investigate the factors that may be contributing to the dolphin mortalities.