The Vancouver Aquarium freed two sea lions trapped in marine debris on the west coast Of Vancouver Island last week, marking the first time sea lions have been disentangled in the Canadian wild.

Dramatic footage and photographs of the rescue were released today by the Marine Mammal Rescue Centre, which is based at the aquarium.

Veterinarian Martin Haulena, along with a team of colleagues from the MMRC, travelled by boat in search of animals ensnared in marine debris in the Barkley-Clayoquot Sound region. The group eventually came across two adult male California sea lions that appeared to be tangled in fish-packing strap.

After tranquilizing both sea lions, Haulena managed to cut one entirely free of the strapping, but was unable to remove all the debris from the second animal because its skin had already grown over the strapping.

Sea lions Vancouver Island rescue

Veterinarian Martin Haulena and a team from the Marine Mammal Rescue Centre attempt to cut a tranquilized adult male California sea lion from fish-packing straps. (Vancouver Aquarium )

Haulena says the intervention saved the sea lions “from a prolonged and very painful death.”

“We have been working with several people for many years to try to develop a safe and effective darting protocol for sea lions. This was the first time anyone has successfully darted and disentangled a sea lion in the wild in Canada, representing a great leap forward in our rescue program,” says Haulena.

The effort is a collaboration between the MMRC, DFO, Parks Canada and biologist Wendy Szaniszlo, and is intended to develop disentanglement techniques that currently do not exist.

The project started after a recent study found that during a six-year period, there was 408 reported incidents of sea lions becoming trapped in marine debris in Clayoquot and Barkley sounds.

It is not the first instance of the MMRC rescuing sea lions from certain death. In 2011, a California sea lion named Flash was nursed back to health after researchers found four feet of fishing line in his stomach and a hook lodged in his esophagus.