Comparing performance of bottom-moored and unmanned surface vehicle towed passive acoustic monitoring platforms for sperm whale detection

Abstract

Passive acoustic monitoring (PAM) is a more efficient method of monitoring the distribution and abundance of deep-diving cetaceans than conventional visual surveys. Many species produce identifiable acoustic signals during echolocation and communication which makes it possible to identify and classify based on their acoustical cues. Three different PAM platforms recorded data in overlapping time periods in the vicinity of the 2010 oil spill site: unmanned surface vehicle towed array, bottom-moored buoys, and Seaglider-mounted hydrophone. The detection rate of unmanned surface vehicle towed array and bottom-moored buoys were compared for their efficiency in detecting marine mammals. Detection events were obtained using independent detectors for each platform and then compared by feeding data through a common detector. The results of this study aid in the development of cost-efficient PAM methodology for mitigation and environmental impact assessment purposes. [This research was made possible by a grant from The Gulf of Mexico Research Initiative.]