The next generation of multi-sensor acoustic tags: Sensors, applications, and attachments

Abstract

From Kooyman’s 1963 wind-up kitchen timer TDR, multi-sensor tags have evolved significantly over the last twenty years. These advancements, including high fidelity acoustics, have been driven by improved sensing and electronics technology, and resulted in highly integrated mechatronics systems for the study of free ranging animals. In the next decade, these tags will continue to improve, and promising work has begun in three key areas: (i) new sensors; (ii) expanding uses of existing sensors; and (iii) increasing attachment duration and reliability. The addition of rapid acquisition GPS and the inclusion of gyroscopes to separate the dynamic acceleration of the animal from gravitational acceleration, are underway but not widely available to the community. Existing sensors could be used for more and different applications, e.g., measuring ambient ocean noise. Tags attached to pinnipeds in the Southern Ocean, for example, could provide noise measurements from remote areas. Finally, attachment duration has been limiting for cetaceans because the suction cups typically used do not reliably stay attached for more than a day. We will present data on engineering efforts to improve attachments: (i) improved tag hydrodynamics; (ii) incorporating bio-compatible glues; and (iii) micro structuring tag components to utilize hydrostatic forces and enhance adhesion.