Entangled North Atlantic right whale tracked for over 700 miles

By Doug Fraser 

Posted Nov 2, 2020 

PROVINCETOWN – Imagine you are swimming with a rope tied to your ankle and it’s connected to one of those heavy candles in a bucket. To stay afloat, you have to keep swimming, but your kicking motion causes the rope to cut deeper and deeper into your ankle. 

“It’s painful,” said Scott Landry, the director for the Center for Coastal Studies’ Marine Animal Entanglement Response team. He used the analogy to describe the grueling odyssey of pain for whales that have, in the course of travel or feeding, encountered vertical buoy lines marking lobster pots or other fishing gear, that lodge in their mouth, pectoral fins, or wrap around their tails. 

“It’s painful and difficult and you need constant momentum to keep the gear from skidding along the ocean floor because that is even more painful,” Landry said.

So it was a bit of a marvel that a tracking buoy attached to “Cottontail,” an entangled male right whale, revealed that he had traveled northeast from Nantucket over 700 miles in 10 days, until the tracking buoy broke free Oct. 30 off Yarmouth, Nova Scotia.

Cottontail was named for the distinctive pattern of white lice growing on a patch of hardened skin that resembles a fluffy bunny tail. But there was little that was soft and fuzzy when members of the Center for Coastal Studies’ encountered a very perturbed 11-year-old, 50-foot-long right whale two weeks ago, about 10 miles south of Nantucket.

Notified by an aerial survey team searching for a 4-year-old juvenile right whale that was also wrapped in fishing line, the rescue team sped south knowing they had little time to work before sunset and limited fuel.

Cottontail was burdened by hundreds of feet of heavy line. Rescuers thought it may also be dragging lobster pots or other fishing gear. The rope was wrapped around the whale’s narrow upper jaw with one end stretched out behind as it swam, while the other end dropped down, disappearing into the plankton-rich water below. 

Entanglement is one of the two leading causes of death for North Atlantic right whales, the most endangered of the great whales with around 356 individuals remaining. 

“Each whale is different, and every species is different, but right whales are generally more ornery,” said Landry. Adults of Cottontail’s size can weigh up to 70 tons, and those doing rescue work approach them carefully in small inflatable boats. Even if the whale seems docile enough, Landry said they treat each one as though it could kill the rescuers if it wanted to. 

The team was able to quickly cut away 100 feet of line on one side of its mouth using specially built grappling hooks with razor-sharp blades, but when the hook tethered to the satellite tag buoy caught onto the ropes, Cottontail spun around and started swimming towards them. 

“What we’re trying to do is help the animal, but he has no idea what we’re doing,” said Landry. “Most of the things we’re trying to do are very uncomfortable to the animal.”

“They will defend themselves,” he said.

The Center for Coastal Studies has been freeing whales from fishing gear and other lines since 1984 and pioneered disentangling free-swimming animals using special tools like a curved knife on a long pole, grappling hooks, and other instruments, many adapted from the whaling industry.

In the end, Cottontail did no harm to the rescue team. Short on fuel and daylight, they had to leave for the long trip back to Provincetown before they could try to cut the remaining line. Landry dismissed anecdotal tales of whales expressing gratitude for being released of the encumbering line and gear.

“I’ve been doing this for 20 years and I’ve never seen that,” he said. Even though the team may know the whale’s name and its history, the real motivating factor, especially with highly endangered right whales, is returning an animal to the population so that they can breed and rebuild the species. Female right whales that the team has freed have produced a dozen calves.

“Given the hard work, it is deeply gratifying to be successful, even to try,” Landry said.

Landry thinks Cottontail’s recently documented journey was likely a hunt for food. Unlike humpbacks, right whales are very particular, living mainly off a diet of oily copepods.

They feast until they deplete an area and then move across vast stretches of ocean without eating until they come to encounter another bloom of phytoplankton and copepods. 

Landry said Cottontail seemed able to feed, was thin but not emaciated. At one point the positions broadcast from the buoy to satellites and relayed to shore showed movements typical of a feeding whale. But soon after that, the buoy seemed adrift and a Canadian plane spotted it floating in the ocean on Oct. 30 with no right whales nearby. 

It’s possible, Cottontail will never be seen again. The ocean is vast and some whales are not seen for years then turn up alive. Others gradually starve as their food intake doesn’t match the energy needed to tow the gear, or they become further restricted in movement or feeding as the line continues to wrap around their tail or mouth. They succumb to infection, lose the blubber that both insulates them from the cold water and helps them float, and they sink when they die.

Landry thinks they may encounter Cottontail again, and the young whale may again be swimming free. By cutting the line from one side of his jaw, it is possible that the weight of the line and whatever he may be dragging below may pull the remaining line free. 

“I have a little bit of optimism that things may be going his way,” Landry said.