A dolphin washed up on a Sagaponack beach Thursday, one of two cetaceans to be discovered dead on South Fork beaches this week.
It was a white-sided dolphin, according to Robert DiGiovanni, the executive director and senior biologist of the , which responds when marine mammals are found distressed or deceased on New York beaches.
The dolphin is about 8-and-a-half feet long and weighs 407 pounds, DiGiovanni said. It was discovered just west of Gibson Lane by citizens who called the foundation’s hotline. He said local marine patrolmen helped foundation staffers load the dolphin onto a truck so it could be taken to Riverhead for a necropsy.
The dolphin had died within the past couple days, and the necropsy is being performed to try to determine what contributed to the dolphin’s death, DiGiovanni said. There was no obvious sign of trauma, he added.
A on a West Hampton Dunes beach late Wednesday was in an advanced stage of decomposition, dead for about a week, he said, adding that the only commonality between the two mammals is that they can both be found at the continental shelf break, though pygmy sperm whales are typically in water further south.
White-sided dolphins are usually seen far offshore and to the north of Long Island, DiGiovanni said. Historically, on average only one of this species of dolphin washes up in New York each year, he said, while common dolphins turn up year round, harbor porpoises are found in the winter months and warm-water species start turning up this time of year.
Because of the diversity of species, there is no slow season for the foundation, DiGiovanni said.
Performing necropsies on marine mammals, which are at the top of the ocean food chain, can tell biologists if there is something going on in the environment that needs to be addressed, he said.