Baleen whale sounds recorded in the Gulf of Mexico with a 192-element coherent hydrophone array

The Gulf of Mexico is a biodiverse ecosystem that is comprised of a variety of marine wildlife. The 192-element hydrophone array with a sampling rate up to 100 kHz, developed in-house at Northeastern University, underwent an experiment on the R/V Weatherbird II in April 2024. The array recorded acoustic data for roughly 48 h across 5 days, while deployed at an approximate depth of 80 m. Diel cycles were captured in numerous ecological hotspots including the West Florida continental shelf and slope, and the DeSoto Canyon. During the experiment, sounds from numerous marine species were detected, including potential sperm whales, bottlenose dolphins, pantropical dolphins, and baleen whales. The baleen whale calls, composed of low frequency pulses and tonal sounds, are believed to be produced by Rice’s whales, the only all year-round endemic baleen whale species. Each of these possible Rice’s whale sounds were automatically detected, then manually classified from spectrogram and time-series analysis based upon several features, such as minimum and maximum frequency values, bandwidth, time duration, and slope. These manually classified signals will then be used as templates to extract similar signals in the dataset, providing localization, source level estimation, and bearing time trajectories.