Technology for Acoustic Research in the Northeast

The Northeast’s Passive Acoustic Research Group uses a variety of technologies to conduct their research, including underwater vehicles, acoustic recordings, and ship-based surveys.

Studying Marine Mammals Using Autonomous Acoustic Technology

Our research has shown that underwater vehicles or “gliders” used for data collection work effectively as a tool for near real-time detection of baleen whales. Over the past five years we have collaborated with scientists from the Woods Hole Oceanographic Institution to develop autonomous gliders. They are equipped with a reliable acoustic detection algorithm to allow near real-time detection of North Atlantic right, fin, sei, and humpback whales. As part of this development we studied the distribution and habitat of Gulf of Maine marine mammals along predetermined transect lines using gliders equipped with instrumentation to:

• Record low and mid-frequency marine mammal vocalizations.
• Detect, classify, and remotely report vocalizations of interest.
• Measure high-frequency acoustic backscatter, chlorophyll fluorescence and oceanographic conditions.

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We are hoping to use and integrate this technology with conventional aerial- and vessel-based survey methods to monitor and assess marine mammal stocks. Although reliant on the animals calling, this approach is mobile and actively listens around the clock. It has a high likelihood of detecting species within its detection range. This should allow us to collect information on the presence and distribution of baleen whales in areas such as the Western Atlantic and in seasons such as winter, when conventional approaches are limited. This technology not only helps to address NOAA's monitoring and mitigation goals, but is also a valuable tool for addressing the data requirements of other federal agencies.

For More Information

• WHOI Autonomous Systems Lab    
• WHOI Mark Baumgartner’s real-time research
• WHOI Slocum Gliders

News Coverage

• National Geographic Daily News: "Sharp-eared Robots Find Whales-And Help Them Escape Danger."
• LiveScience: "Underwater robots pick up songs of 9 endangered whales."
• Associated Press: "Robots find rare whales in weather humans can't."

Partners: Woods Hole Oceanographic Institution    

Primary Funders: Office of Naval Research and the NOAA National Marine Fisheries Service Advanced Sampling Technologies Working Group, DOD ESTCP, U.S. Navy LMR, NOAA Office of Protected Resources 

Acoustic Data Archiving

Collecting long-term passive acoustic recordings can inform a wealth of different areas of a species ecology and help conservation and management goals. The process of collecting thousands of hours of data leaves us with petabytes (much bigger than a terabyte!) of data. These data need to be stored and archived so that they can be used for analyses now and in the future. As part of our effort to archive and store the data we have two endeavors underway: 

• Tethys, a temporal-spatial database built through the National Oceanographic Partnership Program. It is aimed at storing the metadata associated with both the data collection and analysis side of our work. 
• A pilot project with NOAA's National Centers for Environmental Information to work out needs and costs for long-term storage of passive acoustic recordings.

Partners: San Diego State University, Scripps, NOAA Fisheries Science Centers, NOAA National Centers for Environmental Information

Funders: NOAA Science & Technology, NOAA Office of Protected Resources

Integrating Passive Acoustics with Visual Data

In the Northeast we conduct:

• Ship-based visual survey: NOAA Ship Gordon Gunter
• Aircraft visual survey: NOAA Twin Otter 56
• Ship-board visual observations on NOAA Ship Henry Bigelow

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For a long time researchers have used visual surveys as the standard for collecting marine mammal data for understanding distribution, seasonal occurrence, and abundance. As passive acoustic technology and analytical approaches mature, they provide a unique long-term window into marine mammal occurrence and distribution. Acoustic recorders can listen for sounds 24/7 regardless of weather or darkness. 

Next we need to work out what the best approach is to merge these techniques. Attempts to estimate abundance from sounds are already underway. However, we can’t always accomplish this goal when some species change their calling rate depending on behavioral situation, age class, or social grouping. Species which produce more consistent calls are better candidates for estimating abundance.

In the Northeast we are taking two approaches to address these issues. 

1. Using our wealth of data to look at which density estimation from acoustic approaches may work, or even if we don't reach actual abundance, what can we gain from these approaches.
2. Looking at radically different approaches and exploring how we can use occupancy modeling to address how best to use two rich data sources: visual sightings and acoustic detections.

Acoustic Marine Mammal Towed Hydrophone Array Surveys

Another focus of passive acoustic research in the Northeast is to develop and test methods for monitoring spatial and temporal trends in relative cetacean abundance. See complete description of project on the Marine Mammal Acoustic Projects page.