Boats, planes, and helicopters have all been deployed in the search for a blue whale that has got tangled up in a rope off the southern Californian coast. The 25 meter (80 foot) cetacean was spotted dragging a 60 meter (200ft) line, and researchers have said that unless they remove it, the whale could die.

It was first spotted on Friday September 4, trailing the long line with what is thought to be a buoy from a crab pot attached to it, surfacing and occasionally diving. Rescuers were unable to get close enough to cut the line, and instead attached a second buoy to the line to make it easier to find the next day, but unfortunately, the whale disappeared overnight.

It’s thought that the animal probably went south, and while the whale appeared healthy, it won’t be able to drag the rope forever, and it is feared it will eventually get tired and die. While rescuers have previously managed to free smaller gray whales, such a rescue attempt has never been undertaken on a blue whale as this is the first time anyone in California has seen one entangled.

The Marine Animal Rescue group based in Los Angeles asks for anyone who sees the whale to report it to the authorities and under no circumstances try to free the whale themselves, as just a single flick of the animal's tail would be enough to flip a boat. 

Watch the video below to see rescuers free another whale, this time a humpback, which was also found entangled in a crab pot line last year near Monterey Bay, California: