A difficult fishing gear entanglement on a humpback whale calf near Stellwagen Bank is prompting local experts to try a novel technique — sedating the calf.
The humpback is estimated to be seven or eight months old. It’s still nursing and has been seen with its mother, a whale called Lollipop.
Whale watch boats first reported the entanglement in late June. Since then, a joint team with the Center for Coastal Studies in Provincetown and the International Fund for Animal Welfare has tried ten different times to free the whale.
What makes the entanglement so difficult is that a strong fishing line called monofilament is wrapped around one of its flippers, cutting deeply into the whale’s flesh.
“There’s no trailing rope,” said Scott Landry, the head of the disentanglement team at the Center for Coastal Studies. “So, all the techniques that we would normally use to disentangle the whale are not going to be useful in this case.”
Not only is the line wrapped in an almost unreachable spot, it’s impossible to attach a beacon to the whale, he explained. That means each time they go out to free the whale, they first need to find it somewhere off the coast of Cape Cod using only visual cues.
With time running out, Landry’s team and a team led by veterinarian Dr. Sarah Sharp at the International Fund for Animal Welfare brainstormed how to get close enough to the whale to allow them to effectively cut the fishing line.
They decided to try sedating the calf, a technique that previously has only been used on adult North Atlantic right whales. It’s never been tried on a humpback whale, and never on a calf.
“There’s no strong reason to believe that a right whale will respond to a certain set of drugs in the same way that a humpback would,” Landry said.
Indeed, the group’s first two attempts to sedate the calf showed no changes to the calf’s behavior. But the team is taking it slow, he said.
“This is the necessary small step that we need to take to be as conservative as possible,” Landry told CAI.
The team will attempt the disentanglement every day that presents a clear enough weather window. Landry is calling for patience.
“I will be honest with the public that what we are facing to disentangle this calf is extremely difficult,” he said. “And we’ve disentangled hundreds of whales.”
