(News-Press.com) - The two Atlantic spotted dolphins that died after beaching themselves off Fort Myers Beach on Thursday, normally are found up to 100 miles offshore.
"These are deep-diving animals," said Denise Boyd, a marine research biologist for the Florida Fish and Wildlife Conservation Commission. "Their lungs are made to expand."
The fact that the dolphins were so close to the beach indicates there was something bad going on, she said. "The fact that these are really far out of habitat is a significant concern. We really need to know why these animals are hitting the beach."
A state wildlife biologist said further beachings could be possible and urged anybody who comes across one to immediately call a law enforcement agency.
There are numerous reasons why the dolphins beached themselves, and a necropsy will be done to see if the cause can be found.
Marine mammal deaths are tracked by biologists and can be an indicator of overall ecological conditions. And unlike the death of a bottlenose, which lives along the coast and bays and rivers, Atlantic spotted dolphins rarely die in Lee County waters.
The biologist said there were too many possibilities to list for why the dolphins beached.
"There are so many reasons, we are really unclear," she said. She said that being so close to the surface for so long could injure the animal's internal organs.
"We will do a complete exam and sample to find out," she said, adding it could be weather, human activity, parasites, a virus, old age or that they were so closely linked that they simply followed each other in to the beach.
Boyd said that turbid water from Lake Okeechobee releases flowing into the Gulf here was not a concern for animals like these which live far out in the Gulf.
The two dolphins were pulled live on to the beach by two people walking by the pier at Times Square about 4 a.m.
One dolphin, a younger male, died quickly and the other, an adult female — both about the same size — was recovered by FWC officers and research staff and transported to Mote Marine Laboratory in Sarasota. It was unlikely the two were a mother-calf pair, the biologist said.
The female dolphin, which Boyd said showed signs of significant distress, later died en route to Mote.
Boyd added that area residents who find such animals should not try to push them back into the water but rather call authorities.
The cause of the stranding event and deaths are unknown. Barring blunt trauma or an obvious lesion or health issue, biologists are often unable to determine cause of death during these events until tissue samples are examined in a process that can take six months or more.
She said this particular species — Stenella frontalis — has never mass beached in this area before. Scientists consider a mass stranding two or more deaths of unrelated dolphins or whales, ie. not a mother and calf. This qualifies as the male is not the female's calf.