Cutting-edge research used an ocean glider last summer to zigzag along the Arctic coast between Kotzebue and Wainwright and listen for marine mammals. Researchers found most of the protected animals favor offshore Bering Sea currents as opposed to near-shore Arctic Ocean currents. Walrus were most prevalent.
Mark Baumgartner, associate scientist with the Woods Hole Oceanographic Institution, a presenter at the Alaska Marine Science Symposium this week, spoke about using the Slocum Ocean Glider in Arctic waters. He said while it is known the Arctic is home to a diverse group of marine mammals, basic information about the ocean features and marine mammal distribution is "sorely lacking."
Baumgartner said the Arctic presents serious challenges for researchers because of difficult weather conditions and the cost of doing research from a vessel. The gliders, which look like torpedoes but are self-propelled using lithium batteries, may improve the capacity of scientists to get long-term data over a wide area at a reasonable cost.
The glider was launched "perilously close to the U.S.-Russian border" on July 12 and set on a zigzag course so it could intersect several different ocean currents in its path.
For the past two years, researchers had used an earlier model of the glider, but had deployed it for only a few days at a time while scientists focused their research from a vessel nearby. The 2015 study is a significant step forward, Baumgartner noted.
Over the course of the next two months, the glider wound its way up to Wainwright, where it was collected on Sept. 8.
"We put the glider in the water and just left it and hoped we could get it back two months later," he said, adding that doing so increased the duration and survey track by a factor of five.
The findings were in line with what other researchers at the three-day symposium found: Much of the food favored by whales in the Arctic is found in the Bering shelf waters. The glider picked up calls of fin, humpback and killer whales in the Bering shelf, while it heard only humpbacks and walrus nearer to shore in the Alaska coastal current area near Point Lay. Researchers were surprised not to see indications of more species, such as bearded seals and bowhead whales, but it is possible the timing of the glider's movement through the region was a factor.
In addition to the acoustic observations of marine life, researchers were able to record the current, temperature and salinity in the various areas the glider passed through. Numerous ship passages were also detected.
Baumgartner said the hope is researchers will be able to conduct a similar survey annually for the next five years so comparable data is established. The success of the glider in 2015 bodes well for gathering more data in the region in future years, he said.
"It is unprecedented for glider work in the Arctic," Baumgartner said.
This story first appeared in The Arctic Sounder and is republished here with permission.