Prospects for short-term and long-term passive acoustic monitoring of environmental change impact on marine mammals

The Littoral Acoustic Demonstration Center, LADC, a consortium of scientists from four Gulf state universities and the U.S. Navy, was begun in 2001 to study underwater noise and acoustic propagation, and the impact of human activities in the ocean on marine mammals, with emphasis on the Gulf of Mexico (GoM) region. LADC has a library of broadband passive acoustic data, collected by autonomous bottom-moored buoys, which sampled the GOM region ambient noise state, seismic airgun array emissions, and/or marine mammal activities six times during the last decade. LADC acoustic data represent an opportunity to study the short- and long-term effects of environmental changes on the marine mammal population. Environmental factors include baseline anthropogenic noise levels, passages of tropical storms, seismic exploration surveys in the area, and the 2010 Deepwater Horizon oil spill accident. The talk summarizes recent findings on the relationship between regional population dynamics of sperm and beaked whales and abrupt environmental changes with emphasis on the recent GoM oil spill. Statistically significant results of the study suggest a need for establishing consistent acoustic monitoring protocols in the oceanic areas of current or potential industrial activities. [Past data acquisitions were supported by ONR, SPAWAR, JIP, NSF, and Greenpeace.]