Project Methods and Field Activities June 2009
Two large support boats captained by Henry Goodwin and Virgil Naylor and two inflatable boats traveled daily to the pack ice near Kotzebue between June 19 and June 29, 2009. Approximately 40-50 % of the Sound was covered with sea ice when the project started with most ice clustered in an area running South to North between Goodhope Bay and Cape Krusenstern.
The seals were captured in large-mesh twisted-monofilament nets 180' x 26' with a 22” stretch mesh that were deployed from zodiacs in water channels within the pack ice near areas occupied by molting adults. The nets were visible to the seals which, apparently out of curiosity, approach them and accidentally became entangled. A sub adult weighing 406 pounds was captured on June 23. On June 25, an adult bearded seal weighing 558 pounds was captured and was the first adult bearded seal captured and fitted with satellite tracking tags in Alaska. The last seal captured was a sub adult weighing 434 pounds on June 26.
Captured seals were sedated, removed from the net, measured and weighed. Samples of their blood and skin were taken to assess their health and for DNA studies. Each seal was also instrumented with two SDRs: A SPOT tag, attached to the rear flipper, and a SPLASH tag, glued to the hair on the seals' head (picture 2). The head mounted tag provides more information than a back mounted tag as the head is out of the water more frequently and for longer periods than the back. The SPOT tag relays information on haul-out timing and seasonal movements, and will transmit for up to three years. The SPLASH tag, which will fall off when the seal molts the following spring, provides the same information as well as data on the timing and depth of the animals dives. The information collected with these two tags can be used to identify important habitats, describe foraging behavior and improve population estimates.
Soon after being released, all three bearded seals moved out of Kotzebue Sound and followed the Alaska coastline north (see maps). Further analyses will include investigations of the potential effects of bathymetry, ice concentration and ice extent on their movements and diving behavior. Owing to the success of this pilot program, the NMML plans to work with other communities to identify opportunities for working together to expand the study.