[Photo] Iceberg and his family group off the Commander Islands. CREDIT: © Far East Russia Orca Project http://www.russianorca.com/index.php?lang=en

A mature all-white male orca, the only one of its kind known, has been spotted in the North Pacific off the east coast of Russia, scientists announced Monday (April 23). After seeing its towering white dorsal fin breaking through the water's surface, the team named the distinctive beast "Iceberg."

Researchers first spotted the mature killer whale with his pod of 13 relatives in August 2010 in waters around the Commander Islands; he was seen twice that month, and photographed. When the researchers, part of the Far East Russia Orca Project, returned during the summer of 2011, they couldn't find him.

His pod is one of 61 identified social orca units, according to data collected by the Far East Russia Orca Project (FEROP) during their 12 years studying the killer whales.

"In many ways, Iceberg is a symbol of all that is pure, wild and extraordinarily exciting about what is out there in the ocean waiting to be discovered," said Erich Hoyt, FEROP co-director and research fellow from the Whale and Dolphin Conservation Society. "The challenge is to keep the ocean healthy so that such surprises are always possible."

In fact, the researchers suggest the area around the Commander Islands where Iceberg was first seen should form part of a network of reserves that would protect habitat for whale, dolphin and porpoise species off eastern Russia. Their call for such reserves, they say, is in response to overfishing and increased oil and gas exploration, which threatens marine mammals due to high noise levels, ship traffic and potential oil spills.

Iceberg appears very healthy at his ripe-old age of 16, an age determined by the size of his dorsal fin, which extends nearly 6.6 feet, or 2 meters, high, Hoyt said, adding that he seems to be doing OK socially as well.

But the team had wondered about Iceberg's health, particularly because of the only other record of a white orca. A 2-year-old female, all-white orca was captured at Sealand of the Pacific in Victoria, British Columbia, in 1970. Named Chimo, the whale died at age 4. Scientists discovered she had a rare genetic disorder called Chediak-Higashi Syndrome, which leads to partial albinism and a compromised immune system.

"But there is no evidence that Iceberg has anything like this," Hoyt told LiveScience. "We don't even know if he is a true albino."

From Iceberg's morphology, researchers think Iceberg is a fish-eater, unlike some groups of killer whales that primarily eat other marine mammals.

"His pod's sounds are different than most of the orcas around that area, so they could be from an area closer to the Arctic or in the Aleutians, we don't know," Hoyt said. In fact, one of the key elements of the orca project is to learn about the animals' unique dialects.

The team is leaving next month to begin their 13th year in the region studying orcas. "We are hoping to find his pod again," Hoyt said.