May 22, 2006 – Special Ops, Mission: To Track a Seal Options

[Patricia_Janes]

May 20, 2006 – Aboard the Healy
Longitude: 169 17.10 W, Latitude: 64 23.67 N

How do you sneak up on a seal to glue a tracking device on it? As we found out the hard way today, you do not use a bright orange boat with a loud motor and six people on board.

Gay Sheffield, a wildlife biologist with Alaska’s Department of Fish and Game, is onboard the Healy with one mission foremost in her mind: To gain a better understanding of the complex living habits of seals in the Bering Sea. Bearded seals, spotted seals, ringed seals, and ribbon seals all rely on sea ice for a resting place between dives to the seafloor as they forage for food such as clams, crabs, and other animals. They also use the ice as a clean place to give birth to pups. But other than knowing the basics, scientists understand very little about the seasonal movements and diving behavior of four species of seals that are associated with the ice in the Bering Sea.


In addition to studying seals, Gay Sheffield also studies whales.

In an effort to learn more about these marine mammals, Gay had an assignment: To catch a seal pup, glue a harmless tracking device onto the fur of the animal’s back, and then release the pup back into the Bering Sea. Once a day, this painless, noninvasive transmitter would send a signal containing information such as location and dive depth to a satellite. As a result, Gay would know the exact whereabouts of the seal and its diving habits for each day that the seal donned the device. In a few months, when the seal molts, or sheds its fur, the transmitter would fall off and Gay’s study of that particular seal would be complete.


This transmitter weighs just a few ounces, so it does not interfere with a seal’s everyday comings and goings.

The plan sounded straightforward enough. So Gay, Perry Pungowiyi—a native of St. Lawrence Island—and I climbed into a small boat, called a Rigid Hull Inflatable, along with three Coast Guard crewmembers. The boat was lowered off the side of the Healy and down several stories to the water’s surface. Then we sped off in the direction of the nearest ice.


Here I am with my dry suit on, just about to climb aboard the orange RHIB that’s hanging behind me.


Since seals are found near ice, we left the open waters surrounding the Healy to get to some pack ice.

We had a plan: All six of us were going to keep an eye out for seal pups. Then, the coast guard crewmembers would steer the boat to the pack ice and Gay and Perry would hop onto the ice. They would carefully grab the pup and dry off its fur with a rag. Next, they would spread a thin layer of glue on the seal’s back and put another layer onto the transmitter. After holding the transmitter for approximately five minutes until the glue dried, Gay would release the pup and we would start looking for the next seal.


Bill Conroy of the Coast Guard (left) and Perry keep an eye out for seal pups.

Despite our best efforts, we hit a snag. Our bright orange boat was a far cry from camouflaged. We stood out like a sore thumb amidst the Bering Sea’s blue-grey waters and white ice. To make matters worse, our loud engine cut through the sea’s silence like a knife. Anytime we got close to the seals, they gracefully slid off the ice and into the waters. With boat fuel at a minimum, it was time to call off the mission and head back to the Healy. Better luck next time.


This adult bearded seal was too big for us to catch. Even so, it wasn’t about to stick around. It quickly slid off the ice and into the water.