Rescue teams were trying to untangle a blue whale after it became snared in crab nets off the coast of California on Monday.
The alarm was raised after the animal, about 80ft long (24m), was spotted about three miles off the coast of Orange county raising its head out of the water and not swimming normally.
It is rare for blue whales, the largest living animals on Earth, to become tangled in fishing nets and lines because they usually swim far from shore.
YouTube video showed the blue whale towing at least two marker buoys, attached by rescue teams to keep track of the animal.
Mike Milstein, a spokesman for the National Oceanic and Atmospheric Administration (NOAA), told KTLA News that the whale appeared to have a line or rope from a crab trap wrapped around its tail.
Chuck Gathers, who works for Captain Dave’s Dolphin & Whale Safari, which was helping authorities with the rescue, said the crab nets were pulling the whale’s tail down.
“Who knows how much weight it is? But to put a blue whale’s tail under water that far, it had to be quite a bit of weight,” he said.
A blue whale was entangled in fishing gear off the west coast of the US last year, the NOAA said.