Humpback whales are becoming a regular sight spotted along the Atlantic coast in New York and New Jersey.

The New York Bight, which stretches from Montauk on Long Island to Cape May in New Jersey, is a busy stretch of water. Aside from being the future home for offshore wind farms that could power about 2 million homes, nearly 7.5 million containers of goods already travel in and out of the New York-New Jersey Harbor every year.

This high-traffic waterway is now becoming increasingly popular with humpback whales, especially the younger ones, according to a new study from Rutgers University, the ecology nonprofit Gotham Whale and more than 20 other environmental organizations along the Atlantic Coast. Various theories could explain the whales' new attraction to the bight, ranging from cleaner waters created by environmental laws to climate change.

Whale sightings from 2011 to 2018 revealed that the New York-New Jersey Harbor isn’t just a pit stop during the course of their regular migration. These aquatic mammals stay in the bight area for nearly 40 days on average, and more than half of humpback whales spotted were seen multiple times within the same year or over several years. These visits, occurring mostly during the summer months, indicate that this industrial harbor is becoming a regular feeding ground for these mammoth long-distance swimmers.

“I've lived in New Jersey my entire life,” said Danielle Brown, the study’s lead author and a humpback researcher at Gotham Whale. “If you had told me when I was younger that we had whales this close to shore, I would've never believed you, so it was definitely surprising.”

The researchers’ data was based on humpback whale sightings collected from Gotham Whale boats and citizen scientists. Using the photos or descriptions that accompany sightings, researchers could create a catalog of individual whales, based mostly on the patterns on the underside of their tail flukes. It’s like a fingerprint, and no two are alike.

Propeller scars and boat impact injuries were also used as identity markers. On any given day, about 20 shipping freighters are docked in the harbor. Since 2016, more than 30% of the humpback whale fatalities on the U.S. East Coast, caused mostly by vessel traffic, occurred off the coast of New York and New Jersey. A dead humpback whale was discovered earlier this July under a dock in Middle Township.

This guest registry of New York City humpback whales was shared with researchers along the Atlantic Coast — at locations such as the Gulf of Maine, Montauk and Cape May — to confirm they had some of the same whales across their catalogs.

Not much is known about the bight’s humpback whale population because data sets only go back about 10 years, but the animals can grow to be more than 50 feet in length and weigh nearly 90,000 pounds. Humpback whales have made a comeback globally from being classified as vulnerable to extinction by the International Union for Conservation of Nature. Now, they are labeled “least concern” with a worldwide population of about 80,000, with 35,000 at home in North Atlantic waters. According to Brown, they have identified over 250 individual whales since 2011 that frequent the bight area.

A humpback whale was spotted spouting water and swimming through the Hudson River.

Researchers don’t have all the answers about why the whales are choosing to spend time in New York City waters despite the high risk from commercial and recreational vessel traffic. But the whales have been observed voraciously eating, specifically menhaden, a silvery 1-pound fish native to the Atlantic Coast from Nova Scotia to Florida. Menhaden populations have increased over the last decade, along those of with bottlenose dolphins and minke whales.

Meghan Rickard, a marine biologist for the New York State Department of Environmental Conservation (DEC), said that this data is important for plans and considerations being made for the management of humpback whales in the area.

Young and juvenile whales are feeding closer to shore, according to the study, while the older ones are seen further offshore. Brown said they are not fully sure of the reason, but it could be as simple as juveniles learning to feed and not fully understanding how to avoid the potential danger of ship strikes. Observed in other animals, the younger humpbacks are known to break away and travel further from the pack.

Brown credits this whale gathering to federal regulations from the early 1970s, such as the Marine Mammal Protection Act, Clean Water Act and the Endangered Species Act. The presence of menhaden is also an indication of cleaner water. These foot-long fish feast on phytoplankton — which depend on clean water. But Brown also points out that restrictions on the once heavy commercial fishing of menhaden has propelled the fish's abundance.

“Healthy fish stocks will bring in a healthy whale stock,” Rickard said. “Cleaning up the waterways and also just having a solid fisheries management plan for the menhaden also are factors in the healthy fish stocks.”

Another theory is that these colossal ocean creatures are swimming to the metropolitan area because they are being pushed out of their own natural habitats. A study found that the waters in the Gulf of Maine, where many of these whales also frequent, are warming faster than average. Brown thinks the warming of this major feeding ground may have driven humpback whales to migrate to new coasts.

For those potential reasons, the humpbacks may be braving New York Harbor, where their No. 1 risk is boat traffic. Brown said it is common to observe humpback whales with scars caused by swimming too close to a freight ship’s propeller or minor injuries from bumping into boats. During the summer months, it’s a feeding frenzy, and the cetaceans are distracted by eating as much as they can.

“Essentially they have a one-track mind, and are not necessarily looking out for vessels,” Brown said.

The DEC very frequently gets reports of run-ins with whales. Recreational boating season overlaps with humpback feeding season, but Rickard said there is room to share the waterways.

“Being more cognizant when folks are out enjoying the water and just paying attention to the whales will help support them being here safely,” Rickard said.

Researchers will continue observing the whales in the bight, and Brown hopes they will be able to fill in the blanks on their most basic biology, from diet to stress levels.

“Are they moving in and out of the New York Bight? That is a question we don't know the answer to,” Brown said.

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