A tour vessel and a US Coast Guard aircraft initially spotted the whale. The animal had small-gauge line cutting into its tail. Observers found the whale in the waters of the Hawaiian Islands Humpback Whale National Marine Sanctuary, where humpbacks migrate each winter to mate, calve and nurse their young.
The rescuers worked from vessels to cut away 12m (40ft) of trailing line, but couldn't completely free the whale. However, they attached a satellite-tag buoy to the whale and relocated it later, when they were able to remove the rest of the tangle.
Altogether, rescuers removed more than 61m (200ft) of line and two buoys from around the whale! Neither of those two buoys identify where the gear came from, so the source won't ever be known.
Getting entangled in fishing gear can kill a whale by causing it to drown or starve, by getting caught in its mouth, by exhausting the animal as the creature drags gear behind it, or by causing injuries that lead to infection or blood loss.
So far, only three humpback whales have been found entangled this season around Hawaii, about a third of the typical number of reports by this stage. This effort was the first successful rescue of the season - well done to all those concerned!