Towed Hydrophone Arrays
One area of active technological development is the design and construction of towed hydrophone arrays. We have built several towed array systems for use in a variety of marine mammal survey projects from the arctic to the tropics. We are currently working on incorporating sensors (depth, tilt, magnetic bearing) into our arrays to provide more precise information on their locations. We are also experimenting with towing ‘dual’ arrays to allow locations of animals to be more accurately determined.

Sonobuoys
Sonobuoys are designed for the Navy to track submarines. However, they are also quite useful for monitoring and tracking marine mammal sounds. Sonobuoys usually are deployed from an airplane or boat and are monitored remotely using a radio receiver. This allows great operational flexibility because you do not have to remain in the immediate area to monitor the sounds. We use only passive (i.e. receiving only) sonobuoys so as to minimize any effects on the animals we are studying. Currently Bio-Waves is working with the The U.S. Coast Guard to help them monitor and mitigate potential impacts to marine mammals from their at-sea training. We are also experimenting with new GPS-enabled sonobuoys which will allow us to obtain better estimates of animal locations and movements.

Micro-electronic Tags
Another area where we are developing new technologies is in micro-electronic animal tags. Partnering with Desert Star Systems, we have developed a three-dimensional underwater tracking system that uses a small underwater acoustic micro-transponder to locate and relay information about the tagged animals. Tags are attached to the animal using harmless suction cups and upon detachment (usually after several hours to a day or more) data can be retrieved from the tag which also functions as a data-logger. This system was tested on blue and humpback whales in Monterey Bay and we are using the results to improve the system. We plan to use this system to tag and track humpback and minke whales in tropical waters.