Observations of Baleen Whale Vocalizations in the New England Offshore Wind Lease Area from August 2023 to July 2024 Using Multiple High Resolution, Bottom-Mounted Hydrophone Arrays

Three high-resolution, 32-channel, linear hydrophone arrays coupled with real-time, autonomous baleen whale detector-classifiers were deployed on the ocean floor in the New England offshore wind lease area from August 2023 to March 2024. The purpose of the deployment was to monitor the construction area transit lanes for vocalizations from baleen whales, in particular North Atlantic right whales (NARW) and humpback whales. The hydrophone arrays were monitored in real time by human analysts with the assistance of an autonomous classifier, with real-time data transmitted to an on-shore command-and-control facility. During the deployment period, over 8,500 autonomous detection-classifications of NARW (n=2500) and humpback (n=6050) whales were recorded. The majority of detections occurred during the month of February, with about 2,000 NARW calls recorded in the first week of February alone. The NARW diel pattern shows that vocalizing whales are most active at dusk and near midnight, consistent with others historical measurements. Multiple periods of pile driving operations noise were also recorded and analyzed. Right and humpback whale detection ranges exceeding 15 nautical miles were confirmed via multi-system cross-fix localization when the same whale is detected on two or more arrays, including a few examples of multi-system localizations observed during pile driving in June 2024.