Floating wind farm proposal shows no long-term environmental effects on fish populations

A proposal to build a wind farm offshore of Grays Harbor shows no long-term environmental effects on fish populations are expected from construction or operation, according to an assessment.

The Environmental Effects Assessment for the project was published on Tethys, a repository for the Pacific Northwest National Laboratory.

According to the National renewable Energy Laboratory, America’s first offshore wind farm, located in Rhode Island, off the coast of Block Island, powered up in December 2016. The Energy Department’s Wind Vision Report shows that by 2050, offshore wind could be available in all coastal regions nationwide.

Proposed by Grays Harbor Wind LLC, the project would develop a floating wind farm offshore of Grays Harbor. 

Under the proposal, the project would entail “construction, installation and operation of a 1,000-megawatt (MW) offshore wind farm consisting of approximately 75 floating units, each containing a floating foundation and wind turbine generator”. 

The wind farm would be located approximately 16-24 miles west of Grays Harbor, at water depths of 360 to 700 feet, according to the assessment. 

The proposed coverage of the area would be approximately 102 square miles (65,000 acres) with a length of about 8.5 miles from north to south and a width of about 16 miles from east to west.

If constructed, the wind units would be floating and include export cables to shore and these actions could interact with marine wildlife, and the assessment addressed possible impacts to the surrounding area.

Looking at planning documents, the assessment found that;

  • No long-term environmental effects on fish populations are expected from construction or operation.
  • The greatest effects on fish are likely to occur within the wind farm at the offshore Project site once the wind farm has been constructed, resulting in increased numbers of fish within the wind farm and possibly increases in abundance outside the area.
  • Gray whales and humpback whales may migrate near the Project area. Whales can be affected by temporary construction noise. Such effects could be mitigated by carefully considering noise mitigation (including construction timing) when it is applied to marine species as a whole. During operation of the wind farm, cable interactions (either mooring lines or other cables that are draped in the water column) with marine life have a very low probability of occurrence but could result in injury to a sensitive species.
  • During construction of the electrical cable that connects the wind farm to the shore, there would be a temporary disturbance of benthic habitats, for example for shellfish. The habitat is expected to recover to natural conditions within months to a few years after cable installation.
  • Loss of benthic habitat during the operational lifetime of the wind farm is expected to be limited to small areas around the anchors. The anchors also provide new hard substrate habitat that can be used by benthic organisms. Groundfish populations are unlikely to shift their range in response to the new substrate.
  • The overall effects of climate change will increase pressure on marine wildlife in the Project area. Climate change will likely have an impact on marine wildlife in the Project area that is as large as, or greater than, that of an offshore wind development.

As noted in the assessment, construction would cause temporary increased noise in the area of work, although it was listed as unlikely to change salmon abundance or behavior. The introduction of electromagnetic fields was listed as possibly bringing changes in behavior, but migration pattern changes due to EMF were not anticipated.

Similar temporary, yet not permanent, changes to whales, Dungeness crab, and Pacific razor clam patterns were noted.

It was listed that potential environmental impacts to sea turtles could occur through collision or entanglement with floating cables. While the probability was low for encounters, the risk of injury was high.

At this time, the project is only conceptual, and the potential effects are based on current data and could change as plans develop.

During all Project phases (site assessment, construction, operation, and decommissioning) the environmental effects of offshore wind development need to be considered at three locations: the offshore wind farm area (offshore area), along the cable route, and within the Grays Harbor Estuary. 

Prior to any implementation the project would require further study.

“Evaluation of the full range of potential environmental effects would be conducted following an award of a lease from the Bureau of Ocean Energy Management (BOEM) as part of the leasing, National Environmental Policy Act (NEPA)/State Environmental Policy Act (SEPA) environmental review and permitting processes.” 


Off-shore Wind Farm Turbine
Phil Hollman from London, UK, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0>, via Wikimedia Commons