Wildlife scientists made a dramatic rescue of an entangled humpback whale off Lana'i after tracking it for three days from the Big Island.

Sunday's rescue was the first disentanglement of the winter whale season, and the first time researchers here have deployed a radio tracking device to later locate the animal. The adult whale was dragging from its mouth loops of four different kinds of rope and three buoys, including two large orange floats called polyballs.

"The whole time we were tracking it, (the whale) never sounded. We believe it was exhausted. Dragging the gear was tiring it," said Edward Lyman, who worked with Dave Mattila to cut the animal free. Both are scientists with the Hawaiian Islands Humpback Whale National Marine Sanctuary.

When the whale was first spotted Thursday off the Big Island, teams from the Hawaiian Marine Mammal Consortium and the state Division of Aquatic Resources attached a VHF radio tracking device with a transmitter to the gear trailing from the whale. The animal initially moved from the Big Island into the 'Alenuihaha Channel, where the water was too rough to attempt a rescue.

On Sunday, the whale was spotted by a whale-watching vessel between Maui and Lana'i, and by the time a response team got to the area, it had moved to between Lana'i and Moloka'i.

Lyman said the team added floats to the entangling gear to slow the whale down, but ultimately opted not to add several more since the whale appeared to be acting in a predictable, calm manner and did not seem frightened by the presence of the rescue craft.

"This animal was being cooperative. It knew we were there. We decided we didn't need to slow it way down," Lyman said.

Lyman and Mattila were able to cut two lines from the left side of the whale's mouth, releasing all the trailing gear. A small amount of rope was left in the whale's mouth, both because it would be very difficult to remove and because in most similar cases, once the drag is released, whales quickly lose such remnants.

Once freed, the animal joined other humpbacks in the area.

An estimated 5,000 humpbacks migrate to warmer Hawaiian waters from their North Pacific feeding grounds to give birth, mate and socialize.

The rescue effort was overseen by the sanctuary's Maui-based staffers Lyman and Mattila, and Justin Viezbicke, its West Hawai'i coordinator. They worked with the Hawaiian Islands Whale Disentanglement Network, a consortium of federal, state and nonprofit agencies authorized to handle whales through NOAA's Marine Mammal Health and Stranding Response Program.

While this was the winter's first disentanglement, it was the third entangled whale spotted this season. One whale was deemed too lightly entangled to require assistance, and the other could not be found after the initial report of entanglement.

"Entanglement in fishing gear and marine debris poses a serious threat to many marine animals and is a major issue," said a statement from Naomi McIntosh, manager of the Hawaiian Islands Humpback Whale National Marine Sanctuary.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.