It’s no secret that a significant portion of Philadelphia goes to the Jersey Shore year after year. Turns out, humpback whales do too — sometimes staying for months at a time, according to a new study of the massive creatures.
Researchers spent seven years crisscrossing the ocean with powerful cameras, tracking the whales to learn how to protect them from harm.
Humpback whales are in the seventh year of an “unusual death” along the Atlantic coast, the US government says. In some cases they have died in a collision with a shipping vessel.
The busy waters of New Jersey and New York are a particularly problem area, said Rutgers University ecologist Danielle M. Brown, lead author of the new study.
“This is a risk area,” she says. “It’s important to know how long these whales stay here and whether they return to this busy area year after year as their exposure levels are increased.”
While the reasons for the increase in whale sightings aren’t entirely clear, one leading theory is the abundance of fish they like to eat, called menhaden, said Brown, a Rutgers PhD student who also works at a New York-based nonprofit called Gotham. whale .
Equipped with zooms aboard Gotham’s 29-passenger whale-watching boat, the American princess, she and her colleagues tracked humpback whales by looking for distinctive markings on their skin — mainly on the undersides of their tail fins, called flukes.
“It’s similar to a fingerprint in humans,” she said. “It’s unique to each humpback whale.”
The team surveyed the ocean during the spring to fall feeding seasons of 2012 to 2018, from Manasquan Inlet on the northern edge of Ocean County to New York’s Fire Island. They also welcomed photos from the public, provided they include a date and GPS location.
All told, the group identified 101 humpback whales in the study, 59 of which were seen multiple times. Most were juveniles 25 to 30 feet in length (adults can grow as tall as 60 feet).
The researchers then compared this “catalog” of whales with those of other whale-watching groups along the coast and found that dozens of the same humpback whales also fed there, including 15 in Cape May waters.
Matching the whales from photo to photo requires a keen eye, said study co-author Melissa Laurino, who helped identify Cape May’s 15 whales in her work as research director at Cape May Whale Watch & Research Center.
“It’s fun to watch whales and dolphins all season, but a lot of the research is behind a computer screen,” she says.
These West Atlantic humpback whales generally spend the winter breeding season in the Caribbean and then migrate north in the spring to feed on mackerel and herring – mainly in the Gulf of Maine and the waters of Eastern Canada and Greenland .
But judging by the increased number of sightings over the past decade, more humpback whales seem to be stopping in New Jersey and New York, where their main food source is menhaden. These fish, sometimes called bunker or pogy, are also sought after by the fishing industry, which sells them as bait and for use in fertilizers, pet foods and fish oil supplements.
For now, the ocean appears to have enough menhaden for both whales and humans, after regulators began imposing catch limits a decade ago (although some in the fishing industry argued the quotas were unnecessary).
But with the apparent increase in humpback whales off the coasts of New Jersey, New York and other Atlantic states, more whales are dying. In the past 6½ years, 161 humpback whales are stranded along the East Coast, including 57 in New Jersey, New York and Delaware, the National Oceanic and Atmospheric Administration says. The fate of the whales is not known in all cases, but most do not survive.
In New Jersey and New York, shipping ships pose one of the top risks to humpback whales, said Brown, the study’s author. Recreational craft can also pose a threat if they get too close and disrupt the mammals’ diets, she said. Boats should stay at least 100 feet (30 meters) away from humpback whales, further away if there are several boats in the area.
Determining a whale’s cause of death can be tricky, such as a humpback whale found at Wildwood Crest on July 10 trapped under a dock, said Bob Schoelkopf, director of the nonprofit Marine Mammal Stranding Center in Brigantine. It had been dead for several weeks and had deteriorated too much to tell how it had died.
Workers waited for high tide, then dragged the carcass to a remote part of the bay and tied it to some unused poles, said Schoelkopf, a co-author of Brown’s study.
“It stays there until it gets blunt,” he said.
Fishing vessels pose no major threat to humpback whales in this region, although close encounters can happen accidentally, Brown said. In June 2020, a humpback whale jumped out of the water at Seaside Park and slammed into a fishing boat with a loud thud. The two passengers were thrown into the water, but escaped unscathed.
In July 2021, a humpback whale got stuck in fishing gear in New York’s Ambrose Channel, but rescuers were able to break it apart.
With continued vigilance, Brown and her colleagues try to save the large mammals from harm. Since the end of the seven-year period covered by the study in the Journal of the Marine Biological Association of the United Kingdom, they have continued to take to the water with their zooms.
As of this summer, they’ve added 156 more to the area’s humpback catalog, for a total of 257.