Necropsy on dead humpback whale that washed ashore in Long Beach

A young male humpback whale with a misshapen dorsal fin underwent a necropsy where its body washed ashore in Long Beach, to determine what caused this member of a protected species to die, officials said Tuesday.

Though humpback whales usually are identified by the patterns of black-and-white spots on their flukes, this 27-foot-long juvenile stands out for another reason. "He has a very distinctive, disfigured dorsal fin," Jennifer Goebel, a spokeswoman for the National Oceanic and Atmospheric Administration, said by telephone. 

Rob DiGiovanni, chief scientist of the Hampton Bays-based Atlantic Marine Conservation Society, a nonprofit, said his team performed the necropsy, which was completed Tuesday afternoon.

"The animal had a full stomach" and lesions in the stomach and large intestines," a society spokeswoman said after the necropsy. Although no cause of death was determined, a pathologist will review samples with results expected in several months.

NOAA first declared an "unusual mortality event" for humpback whales in 2016. The term signifies "a stranding that is unexpected; involves a significant die-off of any marine mammal population; and demands immediate response," the agency said.

Scientists also are not certain why humpbacks and other whales are being spotted closer to the U.S. East Coast than in years past, though the waters are cleaner, and they could be following bait fish that are attracted to more plentiful seaweed. Swimming closer to shore also means the whales are spending more time in New York Harbor's shipping lanes.

"I think that there's so much about marine animals and just the ocean ecosystem we know nothing about, and I think all of our activities are impacting it one way or another," said Mendy Garron, a marine mammal response program coordinator with NOAA in Gloucester, Massachusetts. 

Seeing a humpback swimming "is kind of jaw-dropping," said Garron, recalling working as a naturalist on a whale-watching vessel. "It's just every day you look forward to going out and seeing these magnificent creatures."

The population of the humpbacks seen off the Atlantic coast — they breed in the Caribbean's West Indies — was estimated at 896 in 2015, NOAA's website says. A total of 103 humpbacks have stranded on the East Coast from 2016 to 2019, the agency says. New York led the list at 20, followed by Virginia at 19, Massachusetts at 18 and North Carolina at 14.

Necropsies — full or partial — were conducted on about half of the humpbacks; around half had been struck by vessels or trapped in fishing gear, NOAA said. 

Just a few weeks ago, a badly decomposed North Atlantic right whale was spotted floating about 5 miles south of Jones Beach, and with just 400 or so of these mammoth creatures still alive, scientists also brought it ashore to figure out why it died.

That whale was identified by the wounds left by fishing gear that in August was seen running through his mouth and possibly anchoring his tail to the sea bed in Canada's Gulf of St. Lawrence. High seas prevented rescuers from reaching him. 

An unusual mortality event for right whales was declared in 2017, one year after the finding for humpbacks.

Atlantic coast humpbacks were removed from the list of endangered species in 2016, the same year the unusual deaths began occurring. NOAA currently defines them as "not at risk." They remain safeguarded under the U.S. Marine Mammal Protection Act. 

NOAA says the world has 14 "Distinct Population Segments" of humpbacks. One is listed as threatened and four as endangered, which means there is a danger of extinction in much or all of its range. Nine did not need to be listed.

The necropsies are authorized by NOAA, which will analyze the samples and might not find a definitive cause of the whale's death, Goebel said.

The whale's carcass was first seen by the U.S. Coast Guard floating about 1 1/2 miles offshore near Jones Beach on Monday, the nonprofit said in a statement, warning mariners to steer clear.