Beluga whale acoustic monitoring during pile driving at the Port of Alaska, 2021

Pile driving activities associated with the construction of the petroleum and cement terminal at the Port of Alaska (POA) in Anchorage, Alaska, occurred between April and November during the ice-free season of 2020 and 2021. The POA implemented a comprehensive marine mammal monitoring and mitigation program to reduce potential impacts of pile driving on marine mammals in Cook Inlet, as required by the Marine Mammal Protection Act and Endangered Species Act. During the 2021 open water season, the National Marine Fisheries Service (NMFS) funded a marine mammal passive acoustic monitoring (PAM) project concurrently with the POA monitoring and mitigation program; four moorings were deployed at two stations north and south of the port docks. The aim of the PAM project was to 1) determine if pile driving activities would deter belugas from crossing the port area, and 2) compare visual sightings and acoustic detections to determine the level of missed beluga presence by both monitoring methodologies.