Ørsted and Eversource Energy partner with Rutgers Center for Ocean Observing Leadership and JASCO Applied Sciences to develop a near real-time monitoring solution for Atlantic cod, during the construction of the South Fork Wind Project.

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 offshore 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 (Gadus morhua).

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 Center for Ocean Observing Leadership 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 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 wind farm area. The glider can cover a distance of approximately 20km per day, and the glider was programmed to perform alternating east-west and north-south transects of the wind farm area.

JASCO’s OceanObserver processed the PAM data continuously using an automated grunt detector to quickly analyze incoming data and evaluate whether any candidate cod grunts were detected. The data was transmitted as frequency contour messages to the acoustic analysts ashore who 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.

Confirmed Cod Detection: -06:29 8 Mar 2023 UTC; Location: 41.108, -71.129

Confirmed Cod detection from 8 March 2023

Glider track for monitoring period 00:00:00 - 23:59:59 8 Mar 2023 (UTC)

Track map of the area covered by the Slocum Glider on 8 March 2023

The glider monitored the South Fork Wind area for 23 days, during which time it detected four 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.