Technology

At its heart, acoustic array technology is simple: permanently attach to an animal an acoustic tag that transmits information about that particular animal, and build a receiving system that captures and relays that information back to the researcher. A tag transmitting to a single receiver gives just presence or absence data. However, by building a tracking system composed of many receivers—especially seamless listening lines arranged in rows along migration corridors—far more powerful information can be obtained: the number of animals surviving to each line and the timing and direction of their movements.

The challenge is to make the system virtually perfect. The key sensor component of our arrays is the revolutionary acoustic technology developed by VEMCO and its parent company, Amirix Systems. Engineers at VEMCO pioneered the basics of the acoustic equipment in the late 1990s. Kintama built on their breakthrough technology, developing the methods and engineering standards necessary to deploy a reliable far-flung array of ocean sensors.

Acoustic technology is exciting for a number of reasons:

1. Acoustic tags are small enough to be implanted into animals about 10 cm long or greater;
2. The battery life of the tags can be up to 20 years;
3. Unlike radio telemetry or PIT tags, acoustic tags transmit over comparatively long distances in salt water, allowing the development of a single seamless tracking network for fresh and salt-water;
4. Temperature and depth data can be transmitted along with the identification code and new sensors are becoming available;
5. The technology behind the array is continually improving. Tags are growing smaller, with longer battery life, greater power, and the ability the transmit more information.