Shaping the acoustic field in the Gulf of Mexico: Marine mammals linked to topography and oceanographic features

Marine mammals shape underwater soundscapes through their vocalizations in ways influenced by their habitat use and behavior. Understanding the drivers of their movements and behaviors within the Gulf of Mexico (GoMex) can enhance our ability to predict local acoustic field variability in response to mesoscale oceanographic processes. To investigate these drivers, we derived daily species density estimates from an 18-station gulf-wide passive acoustic array from 2020–2023. We investigated the spatiotemporal distribution of sperm and beaked whales in relation to topography and oceanographic processes, including depth, slope, sea surface temperature, salinity, chlorophyll-a, upwelling, eddy dynamics (surface and depth), and Loop Current influence. We applied Boosted Regression Trees to learn and predict spatial distributions of these deep divers across the GoMex, finding that goose-beaked whales are associated with deep eddies near steep slopes, Gervais’ beaked whales follow surface and midwater eddies, and sperm whales frequent freshwater-influenced regions, avoiding Loop Current waters. These findings highlight how dynamic physical oceanographic conditions at the surface and depth interact with topography to drive cetacean occurrence. Mechanisms may include prey aggregation and compression. Marine mammals can provide indirect acoustic cues to help us understand deep processes tied to specific habitat features, and predict sound field variability.