The Marine Mammal Program at the NMFS Southeast Fisheries Science Center conducts long-term assessments of marine mammal populations throughout the Gulf of Mexico, southeastern US waters of the North Atlantic, and the Caribbean for conservation and mangement under the Marine Mammal Protection Act and Endangered Species Act. The SEFSC passive acoustics team collects vessel-based and long-term moored platform passive acoustic recordings to assess marine mammal distribution, density, and abundance trends, and to understand the role of natural and anthropogenic processes driving those trends. This research includes monitoring of man-made and natural sound to assess ocean noise impacts on marine mammals. We are additionally involved in restoration projects to mitigate the impacts of the Deepwater Horizon Oil spill on marine mammals in the Gulf of Mexico.  Research opportunities exist to 1) develop and implement advanced passive acoustic density estimation methodologies, including time-series trend analyses; 2) measure noise levels and characterize occurrence of anthropogenic noise sources and model impacts on marine mammals; 3) model the ecological features and processes driving marine mammal densities using moored passive acoustic data; and 4) conduct spatially-explicit risk assessments of noise sources (e.g. shipping, seismic surveys) using spatial data such as AIS data and marine mammal density models.