Gulf Apex Predator-prey
Project

 Fishery Industrial Technology Center
Kodiak, Alaska

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The harbor seal (Phoca vitulina) component of the GAP project was designed to assess the seasonal movements and health status of a local Kodiak population of seals in Chiniak Bay. For the Chiniak Bay population of seals we hypothesize:

  • This population of seals is relatively stationary, routinely occupying the same haulout and staying within Chiniak Bay.
  • This population of seals is in good health due to their increase in numbers since the early 1990's.

Evaluating the Movement Hypothesis

We utilize radio telemetry techiniques to evaluate the movements of the Chiniak Bay harbor seals. Radio telemetry is used in conjuction with time/depth recorders (TDRs - small data loggers measuring depth, temperature, saltwater resistance, light level, and time every 5 to 10 seconds!) to acquire a fine scale picture of what areas in Chiniak Bay the seals are occupying in a more 3-D perspective.


A habor seal displays its new headmountVHF tag which will be used to track the animal.


Graduate student Shawn Harper and Alaska Department of Fish and Game Biologist Vicki Vanek work on taking blood samples from a captured seal.

Evaluating the Health Hypothesis

To assess the general health status of the Chiniak Bay harbor seals we sample, analyze, and compare blood chemistry values and morphometric characterstics of the current population to assessments made during the early to mid 1990's in this area as well as other areas in Alaska, namely Prince William Sound were the seal population is still decreasing.

 

Capturing Harbor Seals and Retrieving Data

In order to meet the objectives of the GAP harbor seal project, seals were capture from their Middle Island haulout in Kalsin Bay in both October 2002 and March 2003. A "swimmer" and a skiff were used to set a beach seine around the haulout in order to net capture seals. Once a seal was captured, it was weighed and measured, outfitted with flipper tags, headmount VHF tag, and a combination VHF/TDR floatation tag. Small samples of hair, whiskers, skin, blubber, and blood were also collected from each seal for blood chemisty and genetic analysis.

Once the seals were released back into the wild the tracking process begins. The following radio telemetry tasks have been tested and performed to help address the movement hypothesis of seals in Chiniak Bay:

  • Receiver/Data Collection Computer Automated monitoring station operations
  • Flight tracking via plane and helicopter
  • Boat tracking using an Automatic Direction Finding system
  • Kayak, truck, and hiking tracking using handheld receiver and antenna

Additional data will be downloaded from the TDRs themselves once the seals molt them off and they are recovered. Once the TDRs are recovered there will be large amounts of data ready to be analyzed. For additional details on the harbor seal project, please contact Shawn Harper.

Two harbor seals are netted during a capture trip in March 2003.

Flipper tags are applied to both rear flippers once a harbor seal is captured.

Shawn Harper mounts a VHF tag to a captured harbor seal.

Note: Seal capture were made possible via cooperation with the Alaska Department of Fish and Game and the Alaska Sea Life Center under all appropriate federal permits.

               

Site created and maintained by GAP Personnel, Fishery Industrial Technology Center, University of Alaska Fairbanks.
Please contact foy@sfos.uaf.edu for site information.
Updated 14-Nov-2003