Animal's condition had deteriorated since it was first spotted July 4 in Canada.

PROVINCETOWN — Rescuers on Friday were able to cut fishing rope from an 18-year-old male North Atlantic right whale whose entanglement had impeded feeding and disabled one flipper, but the whale's prognosis is still guarded, according to the Center for Coastal Studies. Rescuers in Canada had tried throughout July to cut rope off the whale but had only partially succeeded.

“Many people have worked very hard on this case over the last few weeks,” Scott Landry, who directs the Center for Coastal Studies disentanglement team, said. “We have done all we can do for this whale. This case really highlights that preventing entanglements will be key to conserving this species.”

The physical condition of the whale had deteriorated significantly in the weeks since it was first seen July 4 in the Gulf of St. Lawrence. Rescuers off the Cape found the whale thin and covered with whale lice, with its mouth tied shut from the rope that was wrapped around its head. The rope had pinned the whale’s right flipper to its body and his baleen — basically a set of kerain plates the animals use to collect food such as zooplankton — was sticking out of his mouth.

During several hours of effort Friday, the rescuers pulled about 300 feet of heavy rope off the whale, but some remained wrapped around his head and through his mouth. As the whale begins to feed, rescuers said, the remaining rope may drop away.

North Atlantic right whales are considered at great risk since a population decline was discovered in 2010 after several decades of government regulations and scientific research to protect them. Officially, the population count was at 411 as of November, but since then seven known births occurred off Florida and Georgia and eight known deaths in June and July in the Gulf of St. Lawrence. Three entanglements, including the one addressed Friday off Cape Cod, were seen as well in Canadian waters.

Lobster and snow crab fishing rope entanglement and ship strikes are the two primary human factors that cause right whale deaths, according to researchers.

After the whale was first seen entangled, he was spotted again July 19 in Canadian waters by an aerial survey team. At that time, scientists went by boat to where the animal was and managed to attach a telemetry buoy so he could be tracked for a future attempt to cut the rope free.

Over the next two weeks, the whale swam east and out of the Gulf of St. Lawrence, then south past Newfoundland and Nova Scotia, during which time Canadian disentanglement teams were able to make some cuts to the rope. By Friday, after about 900 miles of travel, the whale was 60 miles east of Cape Cod. At that time, the center’s disentanglement team was launched in two boats, with help from the National Marine Fisheries Service in delivering telemetry data from the buoy and sending up an airplane survey team.

The rescuers added large floats and sea anchors to the entangling rope to slow the animal down and keep him at the surface. Despite his poor health, the whale was still very active and made many attempts to evade the rescuers’ approaches from the boats, at times being calm and at times thrashing and lashing out with his tail.

Adult right whales are generally between 45 and 55 feet in length and can weigh up to 70 tons.

Over several hours, while keeping a safe distance from the whale, the team used a specialized arrow fired from a crossbow to cut or at least fray the lines around the whale’s head. It also used hooked knives attached to poles to cut through several ropes. Eventually the whale submerged and within minutes the bindings slackened. Shortly thereafter the whale was seen a quarter-mile away.

The specific type of fishing associated with the rope that was on the whale has not yet been determined, a National Marine Fisheries Service spokeswoman said Tuesday.

Before Friday, the whale, whose movements and identifying marks are recorded in a right whale database maintained by the North Atlantic Right Whale Consortium, was last seen in Cape Cod Bay in March. The network of disentanglement teams along the East Coast will keep an eye out for the whale and monitor it for any signs of improvement or decline.

— Follow Mary Ann Bragg on Twitter: @maryannbraggCCT.

