After cruising out of sight for several years, a male all-white orca known as "Iceberg" been spotted in the waters off the Russian coast. And he's not the only one.

White Orca1 2016 09 03
Image: Far East Russia Orca Project (FEROP)/Facebook
White Orca2 2016 09 03
Image: Far East Russia Orca Project (FEROP)/Facebook

Marine biologist Erich Hoyt, who works with the Far East Russia Orca Project (FEROP), actually spotted "Iceberg" back in August 2015 near the Kuril Islands, but the team delayed publicising the sighting until the release of a research paper on the region's white whales this week. 

"Five years on, Iceberg is still travelling with his family of fish-eating orcas, but he isn't the only all-white orca: we’ve now recorded at least five and maybe up to eight different white killer whales," says the group in a Facebook update.

Other pale whales spotted in the region include a female known as "Mama Tanya" and a juvenile named "Lemon". It's unclear whether these animals are true albinos or leucistic. Unlike albinism, which causes a complete lack of melanin throughout the body, leucism is a partial lack of pigment, and doesn't affect the eyes. Either way, it seems Russian waters are a hotspot for such sightings. 

"[Iceberg] is a breathtakingly beautiful animal," Hoyt says. "[But] it's a dubious honour. As reported in our paper, albinism probably indicates inbreeding of small populations."

Iceberg is believed to be 22 years old, which says something about the longevity of white whales. There's still a lot we don't know about how this mutation affects the animals in the wild. Healthy, adult orcas have virtually no natural predators, but their calves are vulnerable, and it's possible that white colouration makes them easier to spot. 

As members of such an exclusive club, Iceberg and his cohorts represent a very important research opportunity. Orcas in Russian waters are not well studied, and the FEROP team is working to find out more about their population structure and the threats to their habitat. The animals are not protected in this part of the world, and there are concerns about the capture of wild orcas for aquariums and theme parks. But despite some discussion on social media, researchers don't think such activity is to blame for the inbreeding problems. 

"As a large, highly mobile predator, killer whales are subject to all sorts of stresses and the fact that killer whales in many areas of the world live in small breeding units means that they may be susceptible to inbreeding."


Top header image: timnutt, Flickr