SANDWICH, Mass. — When a group aboard a whale watch vessel spotted a dead humpback whale floating in the Stellwagon Bank National Marine Sanctuary off of Scituate, Mass. Saturday, May 4, whale experts around New England sprang into action.
They identified the whale as a female known as Vector, who was first seen and catalogued in 1984. They made plans to do a necropsy on the carcass, which made landfall Monday on a beach in the town of Sandwich.
The necropsy, performed Wednesday, did not produce clear evidence about the whale’s cause of death. But unlike the humpback named Spinnaker who washed up in Acadia National Park in 2015, experts said they saw no evidence that interaction with fishing gear had anything to do with the death.
Dan DenDanto, a senior scientist at Allied Whale, the marine mammal laboratory at College of the Atlantic, said he began seeing pictures on social media almost immediately after the whale was reported on Saturday.
“She was very fresh, that was obvious,” he said of the photos of the carcass that were circulating. “Her condition was being assessed by many people in real time through Facebook.”
The conditions were ideal, he said, for him and his colleagues to collect the skeleton of this whale, bring it back to Maine, and preserve and articulate it for an eventual museum exhibit.
Thanks to the extensive photo catalogs maintained by Allied Whale and the Center for Coastal Studies (CCS), the whale was quickly identified as Vector.
Researchers and whale watchers have been tracking her for 35 years. For the last 15 of those years, Vector has been seen every year, showing up in many parts of the Gulf of Maine, from Massachusetts to Nova Scotia. Her exact age was not known, but she had five confirmed calves.
It was Jooke Robbins, a senior scientist at CCS, who confirmed the identification, DenDanto said.
Most of the time when a whale dies, it sinks to the bottom and is never seen again. In this case, with the prevailing wind and tides, the experts could tell the carcass would soon wash up on a beach.
When that happens, it becomes the job of stranding response organizations, which work under agreements with the National Marine Fisheries Service under the authority of the Marine Mammal Protection Act.
Allied Whale is one of those stranding response groups. In Sandwich, Mass. where the whale made landfall Monday, the local stranding response organization is the International Fund for Animal Welfare (IFAW), which has an office in Yarmouth, Mass.
IFAW scientist Misty Niemeyer led the necropsy of the whale carcass. East Sandwich Beach was not a good location for the work, though, so they arranged for the whale to be towed to the nearby Sandy Neck Beach.
DenDanto asked Niemeyer if he could retrieve the skeleton for the Allied Whale collection.
IFAW “had plenty of talented people on the beach to do the job” of the necropsy, DenDanto said. But saving the skeleton makes the task more difficult and complicated, so he made the trip along with several Allied Whale staff and College of the Atlantic students to assist with the necropsy and to package the skeleton for transport back to Maine.
The whale was 47 feet, 7 inches long and about 40 tons. The necropsy team, led by IFAW, also included members from the New England Aquarium, CCS, Allied Whale, Boston University and NOAA. Local government agencies also assisted, and businesses provided a crane and other needed equipment. The remains were taken to a nearby landfill.
Cause of death undetermined
“The necropsy did not yield an obvious cause of death for Vector,” Niemeyer said in a statement. “Extensive samples were collected and are being sent for further testing, which may provide us with insights into what caused her death.”
Pathology results from those samples can take several months, she said.
“We will continue to gather data and contribute to the scientific community in order to further understand the causes behind the deaths of these whales.”
There’s a good chance Vector had had “fisheries interaction,” DenDanto said. “A high percentage of humpbacks do, and she’s an old lady.” But he said he saw “no reason to suspect fisheries interaction had anything to do with her death.”
Unusual Mortality Event
The stranding comes as an Unusual Mortality Event (UME) for humpbacks on the Atlantic coast enters its fourth year.
A UME is designated by a working group appointed by NOAA Fisheries when a “significant die-off” threatens the health of any marine mammal population. The working group designs plan to investigate the causes of the deaths, and to respond.
The current UME for humpback whales has been in effect since 2016. More than 25 humpback strandings occurred between Maine and Florida each year in between 2016 and 2018, compared with a previous annual average of closer to 10 per year.
Vector was the first humpback stranding in Massachusetts this year, Jennifer Goebel of NOAA Fisheries said, but the tenth humpback to strand in 2019. Those strandings were in Virginia, North Carolina and Georgia.
“To date, a portion of the whales have shown evidence of pre-mortem vessel strike; however, this finding is not consistent across all whales examined, and we are continuing to gather data,” Goebel said.
Vector’s bones will be buried in a compost pile at DenDanto’s home in Tremont. When they are dug up in about a year, they will have been thoroughly cleaned by bacteria and other organisms. Then he and his team will begin the work of reassembling them into the shape they were in when the whale was alive.
Before the stranding, DenDanto said, he had not been in any hurry to find another adult humpback skeleton to clean and articulate for an exhibit.
“I’ve done six,” he said, “and it’s not really on my bucket list.”
But Vector was different.
“She’s a powerful animal for me.” The fact that she had at least five healthy calves, he said, “speaks to humanity about the fact that she was a prolific breeder.”
And he’s been on the lookout for a mother humpback to combine with a humpback calf skeleton already in the Allied Whale collection.
That calf carcass washed ashore in the summer of 2012 on Little Cranberry Island. The calf was about six months old and 22-feet long. No cause of death was determined in that case either.
“Since that time I’ve been really interested in trying to find a mother” to display along with it, he said.
Some of his colleagues might be concerned about Vector’s skeleton being displayed with a calf that’s not her own, DenDanto said, but he thinks it could still be a powerful exhibit.
“There’s not a mother-calf pair displayed in the world, that I’m aware of.”