Decadal assessment of the sperm whale population trends in the northern Gulf of Mexico using acoustics

Passive acoustic monitoring data have been used to assess population trends of sperm whales in the northern Gulf of Mexico. In this paper, the variability of sperm whale abundance in the Mississippi Canyon area derived from acoustic data collected between 2001 and 2017 is discussed in relation to seasons, habitat type, ambient noise levels, and environmental disturbances. The results have shown that sperm whales were present in the region throughout the entire monitoring period with lower activity in winter months. A considerable habitat shift was observed after the 2010 oil spill with sperm whale activity higher at the sites further away from the spill site. The results clearly indicate the importance of long-term spatially distributed acoustic monitoring in characterizing changes in Gulf of Mexico marine mammal population and their habitat.