An orca calf found dead on a beach on the west coast of Vancouver Island has been identified through DNA as a member of the Gulf of Alaska's transient population.

The Vancouver Aquarium compared a tissue sample from the female with other samples from the Alaskan population to make the link.

Less is know about the Gulf of Alaska killer whales than the resident orcas that inhabit the waters off British Columbia, but the whales are known to spend time off the province's coast.

The transients are a small population, have a low reproductive rate and high levels of chemical contaminants and as a result are considered a species at risk.

Aquarium officials say the cause of the calf's death is unknown, but they point out that scientists believe survivorship for killer-whale calves in their first year is less than 50 per cent.

The endangered southern-resident killer whales that travel the waters off B.C. and Washington state are currently having a baby boom, with eight new calves being counted over the last year.