Real-time passive acoustic monitoring of baleen whales from autonomous platforms

Abstract

An automated low-frequency detection and classification system (LFDCS) was developed for use with the digital acoustic monitoring (DMON) instrument to detect, classify, and report in near real time the calls of several baleen whale species, including fin, humpback, sei, bowhead, and North Atlantic right whales. The DMON/LFDCS has been integrated into the Slocum glider and APEX profiling float, and integration projects are currently underway for the Liquid Robotics wave glider and a moored buoy. In a recent evaluation study, two gliders reported over 25,000 acoustic detections attributed to fin, humpback, sei, and North Atlantic right whales over a 3-week period during late fall in the Gulf of Maine. The overall false detection rate for individual calls was 14%, and for right, humpback, and fin whales, false predictions of occurrence during 15-minute reporting periods were 5% or less. Agreement between acoustic detections and visual sightings from concurrent aerial and shipboard surveys was excellent (9 of 10 visual detections were accompanied by real-time acoustic detections of the same species by a nearby glider). We envision that this autonomous acoustic monitoring system will be a useful tool for both marine mammal research and mitigation applications.