Humpback whale off Cape Cod freed from fishing gear entangling its tail

By Melissa M. Werthmann, Globe Correspondent

A young humpback whale is swimming with much less baggage today.

An underwater view of the entangled whale’s tail (Provincetown Center for Coastal Studies)

A fisherman called the whale rescue team at the Provincetown Center for Coastal Studies Tuesday after he saw the whale entangled in fishing gear just outside of Cape Cod Bay, said Scott Landry, director of the rescue team.

The team’s five members spotted the whale discovered that the whale was free-swimming, meaning it could still move around despite the thick rope tangled tightly around its body, he said.

“It was carrying fishing gear wrapped all around its tail,” Landry said. “It was likely entangled for many months and likely carrying the gear many, many miles. There’s often a big distance between where the whale actually gets entangled and where some random person spots it.”

The whale got wrapped up in the rope when it was younger and smaller, but as it grew, the ropes got tighter and caused deep lacerations, he said. The strong synthetic line wrapped around the whale’s body, preventing it from feeding or behaving normally, Landry said.

“The whale was so injured and unhealthy that it couldn’t raise its flukes,” he said.

To remove the line, Landry and his team first attached a control line and a buoy to make sure they could track the animal if he swam off or dove under the water. The team then attached more buoys until it became difficult for the whale to dive.

“We just want to keep it on the surface and as calm as possible,” he said. “The whale has no idea that we’re trying to help it out and it’s frightened.’’

Keeping their distance from the whale, rescuers used hook-shaped knives at the end of 30-foot poles to cut off the fishing gear. Three snips and the fishing gear dropped from the animal’s body.

The humpback, an endangered species, was free.

“Now everything is up to the whale,” Landry said.

“The whale was so injured and unhealthy that it couldn’t raise its flukes,” he said.

Landry’s team collected a biological sample and took photographs of the patterns on the underside of its flukes to see if they can match the animal to those in its database. Identifying the whale would prove useful if the same animal winds up in some trouble in the future, and provide information about humpbacks that may help the species survive.

“We gave it a much better chance of survival,” Landry said of the removal process.

This was the 11th successful whale rescue executed by the center this year. There have been 41 whales entangled this year, Landry said.

In the cases of the whales that were not rescued, the team either found the animal dead, were unable to successfully free the whale, or determined that the entanglement was not severe enough for intervention, he said.

Although more whales were entangled this year than last, Landry said his team has had one of the most successful years yet in terms of rescues. He noted that the fishing community is paying close attention to the issue of entangling animals in gear.

“The fishing community and the federal government are trying hard to prevent this kind of thing from happening, but we still don’t have great great answers for it,” Landry said.

Bay State fishermen now use rope that sinks to the sea floor instead of floating in the water, which can help prevent entanglements, he said.

Landry and his team this summer also rescued 15 entangled leatherback turtles, which are also an endangered species.