‘Tis the (Field) Season

St. Paul Island

A three-month research stint on an isolated island in the Bering Sea might sound daunting to some. But not Chad Nordstrom, a Masters candidate with the UBC Marine Mammal Research Unit. The young researcher’s eyes illuminate when he describes the summer that lies before him—tagging female northern fur seals on St. Paul Island in the Pribilofs. He talks eagerly about the welcoming local Aleut community, the information his research team will glean from the telemetry tags, and above all, the time he will spend in The Box.

The box

To truly appreciate The Box, one must understand northern fur seal dynamics. In early summer, aggressive male seals rule the islands, controlling and guarding females within harems for mating. As the males do not take kindly to disruptions, researchers determined to tag females must move stealthily into the fray.

Enter The Box. Large enough to house three researchers, The Box is a veritable Trojan horse for fur seals. Every now and then, the researchers inside will lift it and scuttle a bit closer to the harems, until they are close enough to capture a seal, maneuvering her hind end into the box, equip her with a telemetry device, and send her back to the harem—curious about her new accessory, perhaps, but none the worse for wear.

Sleeping bag, check. Gas mask, check.
Nordstrom’s research is part of the larger Patch Dynamics Study, which is determining the effect of spatial variations in ocean biomass (i.e. prey) on predator-prey dynamics. This study is a component of the Bering Sea Integrated Research Program funded by the North Pacific Research Board. 

While the northern fur seal population on St. Paul Island has been decreasing by five percent each year for the past 15 years, the population on Bogoslof Island in the chain of the Aleutian Islands has been increasing exponentially since the 1980s. Researchers believe this difference may exist because seals on St. Paul have to work harder and swim farther to find food.

Nordstrom’s research counterpart, Dr. Brian Battaile, will perform an identical telemetry study on Bogoslof Island this summer, and the two will compare results. The cutting-edge Wildlife Computers telemetry tags they attach to the fur seals will record everything from how far the animals travel to forage, the depths and patterns of their dives, and qualities of the water where they find food. They will only tag females guaranteed to return with the data to nurse their pups on land.

With the help of two Australian fur seal researchers, Nordstrom will focus on the oceanographic aspects of the study. Battaile will specialize in foraging ecology, concentrating on how and where fur seals feed. His isolation will be far more intense than his colleagues, as Bogoslof is all of 0.7 square kilometers and completely uninhabited. To make for an even greater adventure, Bogoslof is the summit of an active submarine volcano; Battaile, his research assistant, and the four other scientists studying sea birds on the island will be equipped with gas masks and survival suits in the slim chance that something should go awry.

Understandably, Battaile regards the months with slightly more trepidation than his colleague.

Elsewhere on the coast…

Concurrent with the fur seal study, an ongoing Consortium study will return to the waters of southeast Alaska and the BC coast this summer to compare the prosperous Steller sea lion populations with those in the Gulf of Alaska and Aleutian Islands, where they are in decline. 

In collaboration with the Alaska Department of Fish and Game, Consortium researchers will be looking for branded sea lions that have been tracked for over 10 years (to determine movement patterns and birth and survival rates).  They will also be recording the presence of entangled sea lions, and collecting fecal samples to identify the prey species consumed. 

By determining where the sea lions go, what they eat, and whether they have established new rookeries, the researchers will be able to reconstruct the creatures’ life histories and find out exactly what makes them prosper—and fail.

And so, as the researchers test their gear and pack their bags (crossword puzzles, check. Emergency tsunami pager, check, etc. etc.), we wish them good luck and await an update on their adventures later this summer.

July 7, 2009