DMR is conducting archival passive acoustic monitoring (PAM) at 27 sites throughout Maine’s portion of Lobster Management Area 1 (LMA1) and parts of LMA3.
In addition to broadscale monitoring with PAM moorings, DMR has deployed a PAM mooring in the center of the Gulf of Maine Floating Offshore Wind Research. Data from this recorder will provide a better understanding of cetacean species’ presence in this area prior to the construction of the floating research array. We may potentially continue to monitor this area throughout the construction phase and some of the operational phase of this array.
These are in addition to eight PAM moorings deployed since 2020 in collaboration with Northeast Fisheries Science Center and the University of Maine.
Pictured is an archival PAM mooring. The 14” hard float provides buoyancy so that once the anchor is released the PAM mooring will float to the surface and DMR can retrieve it. The Apollo Mono beacon sends the latitude and longitude of the PAM mooring via satellite whenever it is at the surface. DMR will use these to track down any PAM moorings including those that may have been dislodged and come to the surface earlier than expected. The ST600 acoustic recorder is the instrument DMR uses to record ocean sounds at each PAM site. DMR reviews these recordings for North Atlantic right whale (NARW) vocalizations, which will indicate whale presence within, on average, a 10-kilometer radius of the PAM site. The VR2AR is an acoustic release and receiver that releases an anchor securing the PAM mooring to the ocean floor so that DMR can retrieve the PAM. The VR2AR release/receiver also detects acoustically tagged fish within a certain distance of the receiver.
In addition to broadscale monitoring with PAM moorings, DMR will investigate a passive acoustic tracking array. The tracking array will consist of five to seven PAM moorings that are centered around the Gulf of Maine Floating Offshore Wind Research Array. This higher density of PAM sites should allow for the location and tracking of vocalizing whales. Data from the tracking array could potentially lead to more detailed information, including estimated number of calling whales within the detection range of the acoustic recorder, vocalization rates, acoustic density estimates, and the depths at which whales vocalize. Four additional archival passive acoustic recorders will be placed in the corners of the grid cell to expand spatial coverage.
PAM moorings will be swapped out approximately every four months and the data downloaded, processed, and analyzed. Once the acoustic recordings have been analyzed and reviewed by DMR science staff, the NARW acoustic detection data will be uploaded to NOAA Fisheries Northeast Fisheries Science Center’s Passive Acoustic Cetacean Map, a publicly available portal for viewing PAM detections over different periods of time and areas.
Example of a spectrogram with North Atlantic Right Whale three upcalls in the Gulf of Maine with frequency on the Y-axis and time on the X-axis.
DMR asks that fisherman voluntarily avoid PAM mooring buffer zone areas to minimize potential gear conflict with PAM moorings to prevent significant data loss and minimize damage to fishing gear. These buffer zones are available for download in a variety of different file formats at the State of Maine's ArcGIS Hub website.
If a harvester accidentally entangles a PAM mooring, please contact jessie.mathews@maine.gov or nicole.velandia@maine.gov for instructions on returning it to DMR.