Northeast
An autonomous undersea glider deployed in December 2019 is helping to map cod spawning habitat around offshore wind energy areas off southern New England. NMFS photo.

NE - NMFS cod study underway on New England offshore wind area

The study is underway at a critical time for the future of the fledging U.S. offshore wind energy. In August 2019 the federal Bureau of Ocean Energy Management was compelled to hold up its environmental impact statement for the Vineyard Wind project off Massachusetts, after NMFS insisted more information was needed about potential effects on the marine environment and fisheries.

A three-year study of cod and other commercial fish species is underway around New England offshore wind energy sites, part of a NMFS effort to better understand how proposed turbine arrays will affect the environment and fisheries.

With universities and other partners, the agency in December deployed a Slocum electric glider, a type of autonomous underwater vehicle that has proven highly successful in long-term oceanographic studies.

The glider’s instrument payload includes a hydrophone to detect the sounds of whales and of fish spawning, and an acoustic telemetry receiver to pick up signals from fish that have been captured and released with acoustic tags to track their movements.

Now surveying the area around Cox’s Ledge, the glider is covering an area that includes wind developer Ørsted’s planned South Fork wind energy area south of Rhode Island and east of Montauk, N.Y.

The survey is covering an area that includes the proposed South Fork Wind Farm south of Rhode Island. BOEM image.
The survey is covering an area that includes the proposed South Fork Wind Farm south of Rhode Island. BOEM image.

The survey is covering an area that includes the proposed South Fork Wind Farm south of Rhode Island. BOEM image.

Running on battery power, undersea gliders use a system of water ballast and pumps to slowly climb and dive in the water column, their wings generating lift and forward motion. With their long range and endurance, gliders can survey large areas for weeks at a time, occasionally surfacing to send collected data to vessels or shore by satellite uplink.

For this phase of the study, the acoustic data “will identify location and seasonal occurrence of hotspots for key commercial and federally listed fish species,” according to NOAA.

There is little specific information on Atlantic cod spawning in southern New England waters, according to project lead Sofie Van Parijs, who heads the Passive Acoustics Research Group at the Northeast Fisheries Science Center laboratory in Woods Hole, Mass.

Elsewhere, cod have been are known to form large, dense spawning aggregations in predictable locations relatively close to shore. That can make them vulnerable to disturbances that might affect spawning success, according to NMFS.

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