Scientia potentia est: mammals

Thursday, July 28, 2016

Mysterious New Whale Species Discovered in Alaska

Scientists say a dead whale on a desolate beach and a skeleton hanging in a high school gym are a new species. Yet experts have never seen one alive.Like many good mysteries, this one started with a corpse, but the body in question was 24 feet (7.3 meters) long.

Beaked whale

The remains floated ashore in June of 2014, in the Pribilof Islands community of St. George, a tiny oasis of rock and grass in the middle of Alaska's Bering Sea. A young biology teacher spotted the carcass half-buried in sand on a desolate windswept beach. He alerted a former fur seal researcher who presumed, at first, that she knew what they'd found: a Baird's beaked whale, a large, gray, deep-diving creature that occasionally washes in dead with the tide.

But a closer examination later showed that the flesh was too dark, the dorsal fin too big and floppy. The animal was too short to be an adult, but its teeth were worn and yellowed with age.

It's just so exciting to think that in 2016 we're still discovering things in our world—even mammals that are more than 20 feet long.

Phil Morin | NOAA's Southwest Fisheries Science Center

Beaked whale

It turns out, according to new research published Tuesday, that this was not a Baird's beaked whale at all, but an entirely new species—a smaller, odd-shaped black cetacean that Japanese fishermen have long called karasu, or raven.

"We don't know how many there are, where they're typically found, anything," says Phillip Morin, a molecular geneticist at the National Oceanic and Atmospheric Administration's Southwest Fisheries Science Center. "But we're going to start looking."

It’s rare to uncover a new species of whale. Advances in DNA research have helped scientists identify five new cetaceans in the past 15 years but two were dolphins and most were simple category splits between fairly similar species. This animal, in the genus Berardius, looks far different than its nearest relative and inhabits an area of the North Pacific where marine mammal research has been conducted for decades.

"It's a really big deal," says study co-author Paul Wade of NOAA's National Marine Mammal Laboratory. "If you think about it, on land, discovery of new species of large mammals is exceptionally rare. It just doesn't happen very often. It's quite remarkable."

Skeletons, Beaks, and Bone Powder
Morin and his team examined the St. George carcass, took bone powder from old museum specimens, and reviewed DNA tests of whales from the Sea of Okhotsk. They studied skulls and beaks and analyzed records from whaling fleets in Japan. They even tracked down a skeleton hanging from the ceiling in a high school gymnasium in the Aleutian Islands.

This skull of a newly discovered species of whale shows its blowhole vestibule and its nasal and frontal bones.

PHOTOGRAPH BY L. MICHELLE RIDGWAY

The scientists conclude in their study published in Marine Mammal Science that this type of whale, which has not yet been named, is nearly as far removed genetically from the Northern Hemisphere's Baird's beaked whales as it is from its closest known relative, Arnoux's beaked whales, which swim in the Antarctic Ocean. The differences, in fact, are so dramatic that the animal has to be something else, they say.

An Unrecognizable, Baffling Creature

Of the 88 recognized living cetacean species, including orcas and humpbacks, bottlenose dolphins and Dall's porpoises, 22 are beaked whales. The largest of those, Baird's beaked whales, also called giant bottlenose whales, can reach 35 to 40 feet (10.7 to 12 meters) and weigh more than 24,000 pounds (10,900 kilograms). They travel in large groups, may dive 3,000 feet (914 meters), and can be underwater for an hour. While beaked whales are still hunted in Japan, little about them is known. In part that’s because they spend so much time feeding and exploring vast, deep canyons far from shore.

When Christian Hagenlocher on St. George, a 35-square-mile (91-square-kilometer) island inhabited by 100 people, frequented by hundreds of thousands of seals, and visited by 2.5 million birds, pointed out the dead whale in Zapadni Bay to former seal researcher Karin Holser, she thought it was a Baird's beaked whale. But later, as tides and currents revealed more of the animal, Holser realized she didn't recognize it at all. She consulted a colleague's cetacean identification book and sent pictures to other experts in Alaska.

Baird's beaked whales range throughout the North Pacific from Russia and Japan to Mexico. Genetic variation among Baird’s beaked whales was tiny. But for the five new black specimens Morin tested, all initially from the Bering Sea or the Aleutians, the sequences differed from the Baird's beaked whales significantly.

"The genetic variation within the forms was little, while the divergence between them was much larger," Morin says. "That's our strongest argument."

The whale still needs to be formally described and named, and Morin's findings would have to be accepted by outside experts who track cetacean taxonomy. But Pitman and others say the case is strong that it’s a new species.

"We're doing increasing damage to our environment, and we can't even begin to conserve the biodiversity we know is out there," Morin says. "Yet there's so much more about our world we don't even understand."

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Source; nationalgeographic