More than 260 bottlenose dolphins have died in a series of strandings up and down the Gulf Coast from the Florida Panhandle to Louisiana since January, according to the National Oceanic and Atmospheric Administration.
The numbers are three times higher than normal, NOAA officials said, and they have now opened an investigation into what the agency calls an unusual mortality event.
“It is too early to determine any potential causes of the UME. Many of the dolphins recovered are very decomposed, limiting the ability to collect samples to determine cause of illness or death,” NOAA said on its website.
Also contributing to the problem of pinpointing a cause for the dolphins deaths is the fact that a number have stranded in remote locations, making it difficult to examine or recover the carcasses for testing.
Officials said some of the dolphins that have been recovered had visible skin lesions that are consistent with exposure to fresh water. Dolphins are usually found in water with high salinity or salt levels.
Investigators are looking into a range of potential reasons for the dolphin strandings, including too much freshwater spilling into the Gulf from a wet winter, problems with the animals’ food supply and even a lingering impact from the widespread 2010 Deepwater Horizon oil spill.
NOAA officials are asking people to report any sightings of stranded dolphins to authorities.