Crew members of a Coast Guard cutter conducted an unusual rescue operation near Cape Elizabeth on Sunday, freeing an endangered leatherback turtle that had become entangled in fishing gear.

The Coast Guard cutter Campbell, based in Portsmouth, New Hampshire, began looking for the entangled turtle after receiving a call from a good Samaritan. Upon locating the animal about 15 miles south of Cape Elizabeth, the Campbell dispatched a small boat to try to free the 6-foot-long turtle.

“The crew attempted to gain control of the leatherback, which proved to be no easy task as the frightened turtle frantically fought back, flipping through the water,” said Ensign Robert Chamberlain, one of the five members aboard the small boat.

The crew tied the boat to a fishing buoy and shut down the engine in order to avoid harming the turtle.

As another member carefully pulled the turtle alongside the boat, Ensign Jaime Chicoine cut the fishing line wrapped around the turtle’s large right flipper. Photos supplied by the Coast Guard show at least three crew members crowded at the bow of the boat, working to cut the line from the large flipper as a fishing buoy floats nearby.

The leatherback then swam away. The boat’s crew also salvaged the fishing gear, although it was unclear Monday the type of gear in which the turtle became entangled.

Measuring more than 6 feet in length and weighing up to 2,000 pounds, leatherbacks are the largest turtles in the world and one of the largest living reptiles, according to the National Oceanic and Atmospheric Administration. The turtle gets its “leatherback” name from the fact that, unlike other sea turtles, it does not have a hard, bony shell but instead has a leathery carapace of connective tissue.

They are listed as an endangered species throughout their range.

According to NOAA, Atlantic Canada has one of the largest seasonal populations of foraging leatherbacks. The agency says harvesting of the turtles – whether adults or their eggs from beaches – as well as incidental entanglement in fishing gear are the two primary threats to leatherbacks.

A Coast Guard spokesman, Petty Officer 3rd Class Ross Ruddell, said the Coast Guard works regularly with wildlife rescue organizations in New England and periodically responds to reports of entangled or distressed turtles. Last November, for instance, the Coast Guard transported 193 endangered Kemp’s Ridley sea turtles from the New England Aquarium’s rehabilitation center in Quincy, Massachusetts, to the warmer waters of Florida after the turtles became “cold-stunned” in the frigid waters off Cape Cod.