Scientists are overwhelmed with a sudden increase in the number of baby dolphin deaths along the Gulf Coast in the last few weeks.
The carcasses of 26 infant and stillborn dolphins have been discovered since January 20 along the shore of the Gulf Coast. The bodies have been found in marshes, on islands, and on beaches along 200 miles of coastline from Louisiana, across Mississippi to Gulf Shores, Alabama.
While the exact cause is still unknown, the unusually high number of dead young dolphins is being considered a result of the BP oil spill in April 2010.
The gestation period of dolphins is 11-12 months, meaning that calves born now would have been conceived at least two months before the oil spill began.
“It’s an anomaly,” said Moby Solangi, director of the Institute of Marine Mammal Studies in Gulfport.
According to Solangi, the number of dead dolphins is more than ten times the number normally found during this time of year, which is the calving season for 2,000 to 5,000 dolphins in the region.
“When the world sees something like baby dolphins washing up on shore, it pulls at the heartstrings, and we all want to know why,” said Blair Mase, marine mammal strandings coordinator for the Southeast region of National Oceanic and Atmospheric Administration.
Most of the carcasses, measuring just over three feet in length, were found during the past week in Mississippi and Alabama. BP cleanup crews found some of the carcasses. Others were discovered by park rangers, police and passersby.
“What makes this so odd is that the dolphins were spread out over such a large area,” Solangi said. Dolphins encountering oil on the surface of the water would face serious health consequences.
“We take short breaths. These animals take a huge breath at one time and hold it. And when they take it, the fumes stay in the lungs for a long period of time and they cause two types of damage, one of which is immediate to the tissue itself. Second, the hydrocarbons enter the bloodstream,” he said.
None of the carcasses bore any obvious outward signs of oil contamination. But Solangi said necropsies, the equivalent of human autopsies, were being performed and tissue samples taken to determine if toxic chemicals from the oil spill may have been a factor in the deaths.
Documented mortality in the adult dolphin population off the Gulf Coast roughly tripled from normal numbers last year, climbing from about 30 typically reported in a given year to 89 in 2010, Solangi said. The remains of ten adult dolphins have also been found so far this year.
Copyright © 2011 by Marine Science Today, a publication of OceanLines LLC.