Scientists Equip Narwhals as Arctic Oceanographers

April 23, 2007 — By Will Dunham, Reuters

WASHINGTON -- Scientists have enlisted some supremely qualified recruits to retrieve important data on one of the most remote and inhospitable places on Earth. And all these recruits want is a nice fish dinner.

That's because they are narwhals, a deep-diving arctic whale famous for the males' long, spiral tusk.

University of Washington marine biologist Kristin Laidre and colleague Mads Peter Heide-Jorgensen of the Greenland Institute of Natural Resources have equipped three narwhals with sophisticated satellite transmitters to send data on water temperatures in ice-clogged seas between Greenland and Canada.

"In a way, we've converted these animals into oceanographers," Laidre said this week. "We're not only learning about their ecology and biology, but we're collecting data that can be useful for bigger-picture climate change questions."

The whales are collecting data about Baffin Bay, their winter habitat between northeast Canada and Greenland. Baffin Bay joins with the Arctic Ocean to the north and west and the Atlantic Ocean to the south via Davis Strait.

Laidre said there had been essentially no such data on this region from wintertime, when it is covered in ice and impassable to ships. It is an important link in global ocean circulation and a good place to detect ocean changes in due to climate change.

But the whales thrive in these winter conditions. They dive to depths of 1.1 miles to feed on Greenland halibut, a deep-water flatfish living on bottom of Baffin Bay.

The devices placed on their backs record water temperatures at various depths and track narwhal movements and diving behavior, adding to the understanding of these elusive whales. The devices transmit 400 readings a day.

'FANTASTIC DATA'

"If you can attach an instrument to a whale that's going down to the bottom of Baffin Bay and coming back up again -- diving 1,800 meters over and over again -- you can collect some fantastic data that only very, very sophisticated oceanographic instruments can collect," Laidre said.

The U.S. National Oceanic and Atmospheric Administration and Greenland Institute of Natural Resources back the research.

The world narwhal population is close to 100,000, with about 50,000 to 70,000 in the Baffin Bay area, Heide-Jorgensen said. They grow to about 16 feet long, with the tusk adding up to 9 feet more. They weigh upward of 1.5 tons, with males bigger than females.

The aim is to equip eight to 10 whales with the devices. Doing so is easier said than done.

The scientists set nets to catch the whales, and monitor the nets 24 hours a day.

When a whale becomes ensnared, the scientists jump into two inflatable boats and rush to the scene, knowing they need to get the whale to the surface so it can breathe. The whales wildly try to escape, but calm down after being placed in a sort of sling between the boats, the scientists said.

The scientists then attach the devices with two plastic pins -- painlessly, they say -- to a ridge on the animal's back.

The three whales now sending data were trapped last summer. No whale has been harmed in the process, they said.

"Capturing a narwhal requires an extraordinary amount of patience and optimism," Laidre said.

Source: Reuters