Goal: To help the U.S. Navy in the first systematic line-transect visual and acoustic survey of the waters around the Northern Mariana Islands and Guam, to determine population density estimates for marine mammals and sea turtles in the area.
Our Role:To conduct passive acoustic surveys using a towed hydrophone array
Time Period: Winter/Spring 2007
Prior to 2007, there were no systematic surveys of marine mammals conducted around the Northern Mariana Islands, a region with recent increased human activities, much of which is related to U.S. Navy activities. During the winter and spring of 2007, a large-scale marine mammal and sea turtle survey was conducted in pelagic waters around the Northern Mariana Islands, including Guam. The study area was over 500, 000 km2, an area larger than the state of California. Bio-Waves provided passive acoustic systems (towed hydrophone arrays and sonobuoys) and personnel to conduct passive acoustic surveys and monitoring during a three month vessel based line-transect survey. This survey resulted in new information and discoveries, including the re-discovery of a previous humpback whale breeding area, and acoustic data on sperm whales and a variety of dolphin species. In addition, Bio-Waves collected the first known recordings of sei whales (Balaenoptera borealis)in the western Pacific, and was able to gather data on the distribution and abundance of calling minke whales (Balaenoptera acutorostrata), which previously were undocumented in the area. The data collected in this study are being used to provide improved information for future environmental planning documents in the area. We are continuing to analyze this large acoustic dataset to better estimate the density and distribution of visually elusive species such as minke whales, sperm whales, and possibly beaked whales.
Partners: SRS-Parsons Joint Venture (now Mantech), Geo-Marine, Inc.
Sponsors: U.S. Navy (NavFac Pacific/PacFleet)