We use acoustic technologies to study the sounds marine mammals make help us to understand their behaviors, locations, and population sizes.
The Northeast's Passive Acoustic Research Group uses sounds produced by marine mammals, other biological sounds, and human-made noise. The noises are a tool to understand the seasonal presence, distribution, behavior, and abundance of all cetacean species where possible.
Our use of acoustic technology focuses on:
We use long-term passive acoustic recordings collected throughout the Northwest Atlantic Ocean to investigate the seasonal and spatial distributions of baleen whale species with known call types. Our primary goal is to better understand the distribution and seasonal occurrence of marine mammals throughout the Northeast United States. By combining long-term recordings, we can examine shifts in distribution and occurrence. We can also monitor how species may alter their behavior as a result of climate changes and human activities.
In collaboration with colleagues throughout the Northwest Atlantic seaboard, we have created a comprehensive data set. Bringing available passive acoustic data together helps us to better understand the acoustic presence of the critically endangered North Atlantic right whale. We learn how their movements have changed, and where we should focus future research and management efforts.
Between 2004-2014 we collected and combined recordings from four different types of bottom-mounted recorders from 19 different organizations. Using a detector built by Mark Baumgartner we used verified North Atlantic Right whales upcalls to determine acoustic presence. We divided the data into regions based on geographical and biological relevance, and split into two time periods reflecting the witnessed their distribution shift in 2010. You may see the published results in Nature Scientific Reports.
Over time these data can provide novel insights into species movements in places that are otherwise hard to monitor visually. Previously a subset of these data was used to understand seasonal migrations of the North Atlantic minke whale. Results described temporal and spatial distributions, including how close to shore minke whales travel along the eastern seaboard. Our goal is to perform this same type of analysis for four other species of baleen whales: sei, fin, blue, and humpback. In addition to improving our baseline information on species distributions, we can also compare movements of species to see if they are shifting over time.
Collaborators:
An ongoing objective of passive acoustic research in the northeast is to increase our understanding of various marine mammal and fish species’ basic acoustic behavior. This will help us assess and improve the effectiveness of passive acoustic monitoring as a tool for long-term monitoring and management.
We use long-term acoustic recordings to investigate the seasonal and spatial distributions of species with known call types. Our primary goal is to contribute to the development of automated detectors to locate specific sounds within these recordings, allowing us to obtain useful information from large datasets.
We also combine visual and acoustic data collection methods to better understand the species-specific behavioral significance of known call types and to attribute unknown call types to species.
Arrays of simultaneously deployed recording units provide the means to identify call locations based on the time difference in their arrival on different receivers. Acoustic localization and tracking of marine mammals as they move through the array offer new insight on calling patterns and fine-scale movements. It also allows a more informed comparison of acoustic data with visual sighting information. Localization data also allow us to estimate source energy levels for different call types and species. These data can also improve our understanding of experienced sound levels and/or the behavioral reactions of groups of animals to passing vessels.
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. When used in conjunction with visual surveys, passive acoustic monitoring provides a way to detect marine mammals while submerged, during the night, and whenever weather conditions limit visibility. Acoustic monitoring also allows us to detect animals that may generally be difficult to see, such as harbor porpoises or beaked whales. We can then integrate these data with visual sightings to improve marine mammal abundance estimates.
During shipboard surveys we deploy a towed hydrophone array to detect and record cetacean vocalizations. In addition to helping inform visual survey data, these recordings provide baseline data on the vocalization characteristics of lesser known species. Strategically deployed sonobuoys also provide recordings of target species.
During acoustic surveys we continue to test newly developed passive acoustic monitoring software. This will improve our ability to detect, localize, and track cetacean groups as they pass the survey vessel. Increased automation will streamline data collection and processing and provide consistent results that can be compared across different regions and seasons.
Lastly, we are investigating the effects of active acoustic technologies (such as the ship’s echosounders) on detection capabilities as well as any behavioral response by marine mammals to the echosounders.
To further improve our data collection methods, NOAA Fisheries science centers convened a towed array workshop. Acousticians from six of the science centers developed and built towed arrays to standardize data collection across centers.
Our towed array research is one component of how we are working within the Atlantic Marine Assessment Program for Protected Species. This program focuses on using acoustics to estimate densities for sperm and beaked whales. We also focus on improving visual sighting data and species identification through improved integration and use of passive acoustic data.
Together with collaborators and colleagues, we have built the U.S. NorthEast Passive Acoustic sensing Network (NEPAN). NEPAN is a compilation of all current and near-term passive acoustic projects that will be taking part in the Northeast United States from 2014-2017.
NEPAN projects showcase a coming-of-age of passive acoustic technologies and their applications for conservation science and management. NOAA does not direct any core funding towards passive acoustic research. These projects can be seen as a whole but originate through separately-funded competitive research programs and involve many partners.
The following research projects currently make up NEPAN.
Region: The U.S. Northeast Gulf of Maine and the New York Bight
Aims: Collect near real time information on the acoustic presence of North Atlantic right whales, fin whales, sei whales, and humpback whales every 2 hours. This information is checked daily for accuracy and posted on Woods Hole Oceanographic's Robots 4 Whales site. We use real time moorings and electrical and wave gliders to demonstrate how each different platform operates and its role in collecting vital information on baleen whale presence and occurrence. We validate the acoustic recordings using a land-based platform, NOAA vessel surveys, and aerial surveys. Lastly, we use acoustic detections as a mechanism for decreasing the time spent searching for whales at sea using conventional vessel and aerial surveys.
Partners: Woods Hole Oceanographic Institution, Naval Facilities Engineering Command, New York State Department of Environmental Conservation
Funders: Department of Defense’s Environmental Security Technology Certification Program, U.S. Navy Living Marine Resources, NOAA Office of Protected Resources
Region: Nantucket Sound
Aims: To establish a real-time mooring to monitor the area in and around a U.S. Coast Guard gunnery range. We intend to use this information as a management tool so that the Coast Guard can view a website and decide whether to carry out an exercise depending on acoustic detection of North Atlantic right whales.
Partners: Woods Hole Oceanographic Institution, U.S. Coast Guard
Funders: U.S. Coast Guard
Region: Massachusetts Bay
Aims: Our passive acoustic work complements acoustic tagging work done by the Massachusetts Department of Marine Fisheries, who tag individual cod to send high-frequency acoustic pings. Bottom-mounted receivers record each time a tagged cod passes through the area. We use bottom-mounted passive acoustic recorders to listen for and to define the seasonal extent of the spawning season. In addition, electrical gliders follow line transects through the area listening both for the presence of cod spawning grunts and acoustic pings from tagged cod.
Partners: Massachusetts Department of Marine Fisheries, School for Marine Science and Technology at the University of Massachusetts Dartmouth, The Nature Conservancy, NOAA Stellwagen Bank National Marine Sanctuary, Woods Hole Oceanographic Institution
Funders: NOAA Fisheries Cooperative Research Grant, NOAA Saltonstall-Kennedy
Region: Georges Bank, Gulf of Maine, Mid Atlantic, Southeast U.S.
Aims: We focus on collecting long term seasonal occurrence data for baleen whales and toothed whales and dolphins throughout key areas on the shelf, as well as on the shelf break. A variety of bottom-mounted recorders are used depending on the objective (i.e., low- or high-frequency monitoring or both). On the shelf, we focus on baleen whale presence and their distance from shore while migrating. Off the shelf, we primarily focus on the occurrence of sperm and beaked whales.
Partners: Cornell University, Scripps Institution of Oceanography, JASCO Applied Sciences
Funders: Bureau of Ocean Energy Management, U.S. Navy N45
North Atlantic right whale Horton and newborn calf. Credit: Clearwater Marine Aquarium Research Institute, taken under NOAA permit #26919.
Spectators spot whales on a WhaleSENSE whale watching trip in Juneau, Alaska. Credit: NOAA Fisheries
An oceanic whitetip shark swims near the surface of the water. Photo courtesy of John Carlson.
