The core approach towards our goals and objectives is built around the deployment of electronic telemetry devices that we will deploy on sharks in Resurrection Bay and in Prince William Sound. With data received from these devices, combined with environmental / ambient data from open source repositories we will reconstruct likely movement paths for tagged sharks, and determine depths and water temperatures encountered by the tagged sharks. One challenged associated with tracking an animal like a sleeper shark that never reaches the surface, is that direct satellite tracking is not possible. Satellite transceivers or GPS devices need to be at the surface to link to or from a satellite – when they are submerged, the signal is too greatly attenuated by saltwater.
Such electronic tags serve as our ‘extended eyes’. However, this only works if we can gain access to the data recorded by the tag. Either we have to recover the tag and download the data, or we need to use a tag that can somehow transmit previously recorded data through a wireless system. Some of the tags you can learn about here through our shark tracking project use hybrid tags.
These tags record data in memory, and at a pre-programmed time detach themselves from their host shark, float to the surface of the ocean, and transmit the previously recorded data in a highly condensed form. Yet, does this kind of hybrid approach allow us to determine movement paths and space use? Maybe, as you can read in the next few sections.