Real-time Passive Acoustic Monitoring for Aggregations of Spawning Cod at South Fork Wind Farm
JASCO Applied Sciences
Developed by Ørsted and Eversource Energy, South Fork Wind (SFW) is a 12-turbine offshore wind energy project
located in federal waters off the Northeast coast. The 130 MW wind farm began construction in early 2022 and is
expected to be operational by the end of 2023. Upon completion, South Fork Wind (SFW) will produce enough clean
energy to power 70,000 homes.
The SFW project site is located near an area with complex
habitats, including a known spawning habitat for Atlantic cod.
Atlantic cod form spawning aggregations throughout their
geographic range, and male cod exhibit a complex set of spawning and courtship behaviors that includes vocalizations (low frequency grunts). These vocalizations can be detected using Passive Acoustic Monitoring to identify where and when spawning activity is occurring.
Due to the known presence of spawning cod near the wind farm area, the project’s approval included permit conditions to perform monitoring and adaptive management during the cod spawning season. In order to meet this requirement, Ørsted partnered with researchers at Rutgers University and JASCO Applied Sciences to develop a near real-time monitoring solution for Atlantic cod.
During the monitoring study, the objective was to determine the presence or absence of spawning cod within the windfarm lease area and to use the collected data to determine if an adaptive management strategy would need to be implemented during site preparation and construction.
A Slocum glider equipped with JASCO’s OceanObserver™ passive acoustic monitoring (PAM) system and oceanographic sensors was used to monitor for cod spawning activity within the project area. The glider can cover approx. 20km per day and was
programmed to perform alternating east-west and north-south transects of the wind farm area.
JASCO’s OceanObserver™ system onboard the glider processed the PAM data continuously using an automated grunt detector to quickly analyze the incoming data and assess whether any
candidate cod grunts were detected. The data was transmitted as frequency contour messages to the acoustic analysts ashore who then reviewed and verified them as cod grunts.
The glider team prepared daily summary reports for Ørsted, which included a map of the glider tracks from the previous day and the number and location of verified cod grunts that were detected. The glider monitored the South Fork Wind Farm area for 23 days, during that time it detected four confirmed cod vocalizations. The data collected will be critical to informing the responsible development of South Fork Wind, including construction schedule and micrositing
considerations, to minimize impact on Atlantic cod. To see the oceanographic data from this mission, visit our glider data website.