Federal scientists are trying to figure out why an extraordinary number of dolphins have died on the Gulf Coast.
Much of the 279 bottlenose dolphins stranded on the Gulf in Florida, Alabama, Mississippi, and Louisiana have died February 1, according to National Oceanic and Atmospheric Administration officials.
According to NOAA, the number of deaths is about three times higher than the normal rate of stranding for this period. About 78 percent of carcasses are too decomposed to be tested.
Previous suspects included the Deepwater Horizon oil spill in 201
] "[Dolphin] Reproduction in some of the most heavily oiled areas remains abnormal," she said.
At the same time, scientists studying dolphin cadavers have discovered "visible skin lesions consistent with exposure to freshwater," said Erin Fougères. Administrator for the marine mammal stranding program in the southeastern region of the NOAA fishery.
Nearly one in four stranded dolphins surveyed by scientists showed signs of freshwater exposure that may be related
NOAA scientists said Monday that 7,829 square miles of land and the Gulf Coast are expected to be part of an annual "dead." Zone "will be for wild animals, as seasonal river flows produce only small amounts of water – oxygen conditions under water.
The cause of what NOAA calls the "unusual death event" for dolphins continues to be the subject of scientific research, and officials said they are using an investigative team to investigate the deaths.  Scientists asked boaters and beach-goers who encounter stranded or dead dolphins on the Gulf Coast to stop themselves immediately and notify authorities such as the US Coast Guard.