Changes in marine mammal distribution and abundance, caused by environmental stresses or human activities, can have a major impact on the function of the entire deepwater ecosystem. This multidisciplinary consortium effort, which uses expertise from marine acoustics, biology, physics, engineering, mathematics, and computational predictive modeling, will equip scientists with an understanding of how the regional marine mammal population in the Northern Gulf of Mexico (GoM) has been affected by the 2010 Deepwater Horizon (DWH) oil spill. The research results will supply the first data sets for regional stock population health for several strategic species of marine mammals (endangered sperm whales, beaked whales, and dolphins) and will stipulate recommendations for needed mitigation efforts to improve various stock recoveries. The advancements in passive acoustic data collection and processing will provide relationships of regional abundance variations to long-term and short-term environmental factors, such as environmental disasters, weather conditions, natural seasonal migration, regional anthropogenic noise soundscapes due to industrial operations in an area, food supply, etc. The outcomes of the research, based on previously collected acoustic data from both before and immediately after the oil spill, plus new data collections, will not only provide an assessment of the long-term environmental impact of the recent spill event on deep-diving marine mammals, but will also aid in improving regulations, monitoring, and mitigation efforts for everyday industrial operations in the northern GoM. The new data processing and predictive modeling tools developed over the duration of this project will not only apply for forecasting regional population dynamics of marine mammals in the GoM but will also be applicable for studying the effects of environmental stresses on marine mammal populations in other parts of the world’s ocean.
The LADC-GEMM consortium scientists have been collaborating through the Littoral Acoustic Demonstration Center (LADC) since 2001. The team will bring to GoMRI the experience of 14 years of continuous acoustic research in the northern GoM. The LADC-GEMM consortium members include the University of Louisiana at Lafayette, the University of New Orleans, the University of Southern Mississippi, and Oregon State University. The consortium’s expertise and experimental capabilities are extended through collaboration with Proteus Technologies, LLC, R2Sonic, LLC, C&C Technologies, and Seiche Measurements Limited.
The LADC-GEMM consortium is in a unique position among those conducting passive acoustic studies in the GoM given its access to data unavailable elsewhere. Prior to the 2010 oil spill, LADC had conducted six broadband passive acoustic surveys in the GoM. In 2007, LADC conducted a two-week visual and acoustic survey of marine mammal activity just 9 miles and 23 miles from the DWH spill site, giving LADC a unique pre-spill baseline dataset of marine mammal activity and anthropogenic soundscapes near the oil spill site. Earlier surveys had also been conducted at sites 50 miles from the incident site. In September 2010, LADC returned to those same survey sites to repeat underwater acoustic recordings, gathering data to support the first and possibly only comparisons of pre- and post-spill estimates of the marine mammal populations in the vicinity of the event based on their acoustic activity.
The major LADC-GEMM consortium goals are to:
1. Establish a precedent of long-term consistent passive acoustic monitoring (PAM) of the marine mammal recovery after the oil spill, based on previously collected baseline data, continued data collection utilizing advanced PAM technology, and development of population dynamics prediction models;
2.Design and test a new cost-effective PAM approach for near real-time detection, characterization, and monitoring of the impact of environmental changes of different magnitude and duration on deep diving GoM marine mammals by utilizing the integrated experimental capabilities of the consortium, which will include bottom-moored listening buoys, deep-diving Seagliders, and autonomous surface vehicles;
3. Develop an integrated acoustic data processing technique, which will allow in-depth understanding of the relations between observed/predicted abundance variations and underlying reasons decipherable from collected acoustic data, such as anthropogenic noise soundscapes, food supply, stock composition (adults versus calves, females versus males, etc.), and seasonal migrations; and
4.Communicate the methods used and the results obtained to the public via presentations, teacher-training events about the technologies used, scientist-in-residence programs, web sites, videos, etc.