Possible sonar link in dolphin beaching probed
Submarine was conducting exercises a day before incident
The Associated Press
Updated: 8:46 p.m. ET March 5, 2005
MARATHON, Fla. – The Navy and marine wildlife experts are investigating whether the beaching of dozens of dolphins in the Florida Keys followed the use of sonar by a submarine on a training exercise off the coast.
More than 20 rough-toothed dolphins have died since Wednesday’s beaching by about 70 of the marine mammals, Florida Keys National Marine Sanctuary spokeswoman Cheva Heck said Saturday.
A day before the dolphins swam ashore, the USS Philadelphia had conducted exercises with Navy SEALs off Key West, about 45 miles from Marathon, where the dolphins became stranded.
Navy officials refused to say if the submarine, based at Groton, Conn., used its sonar during the exercise.
Sonar could pose danger
Some scientists surmise that loud bursts of sonar, which can be heard for miles in the water, may disorient or scare marine mammals, causing them to surface too quickly and suffer the equivalent of what divers know as the bends — when sudden decompression forms nitrogen bubbles in tissue.
“This is absolutely high priority,” said Lt. Cdr. Jensin Sommer, spokeswoman for Norfolk, Va.-based Naval Submarine Forces. “We are looking into this. We want to be good stewards of the environment, and any time there are strandings of marine mammals, we look into the operations and locations of any ships that might have been operating in that area.”
Experts are conducting necropsies on the dead dolphins, looking for signs of trauma that could have been inflicted by loud noises.
Several dolphins were euthanized after blood tests showed 13 of them were “not likely to recover at all and that they are suffering,” said Laura Engleby, a biologist with the National Marine Fisheries Service.
“Some were still not swimming on their own, and they couldn’t hold themselves up,” Denise Jackson of the Marine Mammal Rescue Team said.
More than 60 rough-tooth dolphins beached themselves Wednesday on flats and sandbars about a quarter mile off Marathon. Rescue teams moved the dolphins to a nearby canal where veterinarians have been conducting medical tests.
The remaining 31 live dolphins were being given Pedialyte — a drink normally given to dehydrated human babies — and fresh water, Jackson said.
Teams planned to move them by Saturday morning to rehabilitation facilities along the Keys or on the mainland, officials said.
Rough-tooth dolphins normally inhabit deep waters in the Gulf of Mexico and the Atlantic Ocean.
Marathon, in the middle of the Florida Keys, is about 46 miles east of Key West.
The Associated Press and Reuters contributed to this report