Beaked whales, dolphins and endangered sperm whales make the Gulf of Mexico their home and are significant because of their sensitivity to environmental change; globally, marine mammals often serve as ‘ecosystem sentinels’ and this also stands true for the Gulf of Mexico.
Having conducted acoustic surveys in the Gulf of Mexico for over a decade, LADC is the only group that has baseline data indicating large numbers of deep-diving cetaceans were living near the Deepwater Horizon site. In 2007, LADC conducted a two-week survey in that area. In 2010, after the spill, LADC was funded by NSF, and given ship time by Greenpeace to conduct further surveys. So, now, 5 years later, LADC-GEMM is undertaking the next logical step in cetacean research near the spill site.
This study will provide relationships among short- and long-term marine mammal population variations with environmental factors such as natural and human-induced disasters, weather conditions, seasonal migration, industrial operational noise, and food supply. It pairs acoustical, oceanographic, and visual data collection with mathematical predictive modeling and integrated data analyses to understand patterns in species distribution, pollutants, and human activities. Monitoring marine mammal sounds is important because they do everything acoustically, using “clicks” to communicate with each other and explore their environment. Using integrated passive acoustic monitoring, the team will record the unique sounds that the whales and dolphins make…the collected acoustic data also will contain a wealth of information about the ocean environment the whales inhabit. Their computer programs will decode this information and pair changes in marine mammal populations with environmental factors.
During the acoustic surveys, about 200,000 readings per second will be collected. This enormous amount of data will be used to distinguish the identity and number of young adults, females and calves. From that, future population models will be developed to anticipate increases and decreases in the population that may help resource managers and responders to be better prepared for future environmental stressors and perhaps mitigate their effects. This has worldwide application for any country doing offshore oil drilling.
The GEMMproject is using some very interesting-some might say avant-garde- technology for collecting acoustic data, especially for marine mammal sounds. These include AUVs (Automatic Underwater Vehicles-gliders, ASVs (Automatic Surface Vehicle) and EARs (Environmental acoustic recording system) buoys.