Marine conservation groups voice their strong concerns about orca health

LONDON: At least five white orcas have been spotted in the north-west Pacific – a sign that they may be becoming dangerously inbred, researchers say.

All-white orcas, which differ from the black and white ones, have been seen before, but they have been immature or adolescent. It’s thought they tend to die young, as the trait can be associated with health problems.

Researchers are concerned that at least one group of the predators, also known as killer whales, is starting to struggle, after between five and eight white orcas were off Russia’s Kuril Islands.

Although the sighting was made last year, researchers’ findings have only just been revealed in an academic paper published in the journal Aquatic Mammals.

Erich Hoyt, who works with the Far East Russia Orca Project, said white orcas were “quite rare”, and researchers in the Antarctic, where there were tens of thousands of killer whales, might not have seen one.

“To have up to eight in one area… is an indication that there may be inbreeding issues there,” said Hoyt, a member of a specialist cetacean group at the International Union for Conservation of Nature and a senior research fellow with the UK group, Whale and Dolphin Conservation.

“I think all large predators are in trouble on this planet because we are squeezing them from all angles. They aren’t treated as an endangered species… but that’s mostly because they haven’t been evaluated.”

Chemical pollutants, such as PCBs from widespread plastic rubbish in the oceans, are a particular problem.

Predators at the top of the food chain are the most severely affected.

“Killer whales are the most contaminated species on Earth,” Hoyt said.

One of the white whales, which researchers have named Iceberg, is believed to be at least 22 – he was mature when he was last spotted in 2010.

The conservation group Russian Orcas posted a photograph of Iceberg on their Facebook page, saying:“Russian waters appear to be the world’s number one area for white killer whales who may be leucistic (have patchy pigmentation) or true albinos.”

The reasons for Iceberg’s white colouring are unclear.

The colouring of a captive white orca called Chimo was the result of Chediak-Higashi syndrome, which caused medical problems. Chimo lived to 4, although females are able to live to 100. – The Independent

In San Diego on Thursday, activists from People for the Ethical Treatment of Animals, or PETA, painted themselves as killer whales to represent the number of orcas that have died prematurely at the Sea World theme park.