Scientists want to learn more about the first all-white, mature male orca ever seen.
- The whale was first spotted in the North Pacific.
- Scientists are trying to establish if the whale is an albino or not.
- Two other white orcas are known to live in the waters where "Iceberg" was spotted.
A team of Russian scientists say they will embark on a quest next week to observe the only all-white, adult killer whale ever spotted -- a majestic and elusive bull they have named Iceberg.
The researchers from the universities of Moscow and Saint Petersburg first spotted the orca's towering, two-metre (about six feet) dorsal fin break the surface near the Commander Islands in the North Pacific in August 2010.
Living in a pod with 12 other family members, Iceberg was deemed to be at least 16 years old, given the size of his dorsal fin, said Erich Hoyt, co-director of the Far East Russia Orca Project (FEROP).
"This is the first time we have ever seen an all-white, mature male orca," Hoyt told AFP. "It is a breathtakingly beautiful animal."
The scientists decided to hold back on releasing photographs of Iceberg until they were able to study him further, "but we have been looking for him ever since," said Hoyt.
Orcas can travel thousands of miles.
The scientists would like to establish whether Iceberg is albino -- a genetic condition that leaves animals unable to produce melanin, a dark pigment of skin, hair and the eye's retina and iris.
Many albino animals never grow into adulthood. Their visibility is a disadvantage in the hunt for food and protection against predators.
Two other white orcas are known to live in the waters where Iceberg was spotted, east of Kamtchatka peninsula in Russia's far-east, but they are juveniles.
In 1970, a two-year-old white orca, Chimo, was captured in Canada for a dolphinarium, and was diagnosed with a type of albinism after its death two years later.
"We want to find out a lot more about Iceberg," said Hoyt. "We would like to find out how he is able to survive as a white whale.
The FEROP team will set out for Bering Island next week as art of a project to study the social behaviour and communication of the Kamchatkan orca population, which they say is under threat from overfishing and plans to expand oil and gas exploration.