Why are baby dolphins washing ashore in Gulf?
NEW ORLEANS - Scientists are trying to figure out what killed 53 bottlenose dolphins — many of them babies — so far this year in the Gulf of Mexico, as five more of their carcasses washed up Thursday in Louisiana, Mississippi and Alabama.
It's likely to be months before they get back laboratory work showing what caused the spontaneous abortions, premature births, deaths shortly after birth and adult deaths said Blair Mase, the National Oceanic and Atmospheric Administration's stranding coordinator for the Gulf Coast.
Calves and fetuses made up at least 85 percent of the deaths in Alabama, 60 percent or more of those in Mississippi and Florida, and 20 percent in Louisiana, according to NOAA figures.
The Mississippi and Alabama deaths are in areas where bottlenose dolphins go to calve, said Moby Solangi, director of the Institute for Marine Mammal Studies in Gulfport.
Solangi said he'd never seen anything like the calf deaths, or found word of anything like it in 30 years of records from his area - Alabama, Mississippi and east Louisiana.
However, Mase said 68 dolphins that washed up in east Texas in March 2007 also included an unusually large number of calves. The bodies were too decomposed to find the cause, she said.
Although scientists are investigating whether the deaths are related to last year's huge BP oil spill, Mase confirmed that toxins from oil or chemicals used to disperse it may be a less likely cause than cold or disease. That's because only one species of dolphin — and no other kind of animal — is dying, and because the calf deaths appear concentrated in Mississippi and Alabama rather than Gulf-wide.
The dolphins found Thursday include three off Louisiana and one each off Mississippi and Alabama, NOAA spokeswoman Kim Amendola said. The bodies had not been retrieved, so ages and sizes were not known, she said.
Dolphins usually calve in March and April.
Mase said dolphin stranding reports have been unusually high since January 2010. Last winter's deaths probably were caused by extreme cold, she said. "It was a very, very cold winter last year. We had a lot of turtle mortality, manatee mortality and dolphin mortality."
The Deepwater Horizon exploded into flames on April 20 and sank four days later. The spill response brought crews out to look for oiled wildlife and to clean the remote areas where most strandings occur, Mase said.
Because those areas are remote, there's no way to know the true numbers of dolphin strandings and deaths. "The number is not absolute — just a kind of barometer," Mase said.