As the US begins to build offshore wind farms, scientists say many questions remain about impacts on the oceans and marine life

Published: November 15, 2023 8.22am EST

A row of monopiles that will be the base for offshore wind turbines, in the Atlantic Ocean off the coast of Martha’s Vineyard, Mass. David L Ryan/The Boston Globe via Getty Images

As renewable energy production expands across the U.S., the environmental impacts of these new sources are receiving increased attention. In a recent report, the National Academies of Sciences, Engineering, and Medicine examined whether and how constructing offshore wind farms in the Nantucket Shoals region, southeast of Massachusetts, could affect critically endangered North Atlantic right whales. The Conversation asked marine scientists Erin L. Meyer-Gutbrod, Douglas Nowacek, Eileen E. Hofmann and Josh Kohut, all of whom served on the study committee, to explain the report’s key findings.

Why did this study focus on such a specific site?

The Bureau of Ocean Energy Management, which is part of the U.S. Department of the Interior and regulates offshore energy production, asked the National Academies to conduct this study. Regulators wanted to better understand how installing and operating offshore, fixed-bottom wind turbine generators would affect physical oceanographic processes, such as tides, waves and currents, and in turn how those changes could affect the ecosystem.

For example, offshore wind turbines decrease wind speeds behind them, and the presence of their structures makes the water more turbulent. These changes could affect ocean currents, surface wind speeds and other factors that influence hydrodynamics – the structure and movement of the water around the turbines.

The Nantucket Shoals region is a large, shallow area in the Atlantic that extends south of Cape Cod. Our report focused on it because this is the first large-scale offshore wind farm area in the U.S., and the region has been included in several recent hydrodynamic modeling studies.

Map of the Nantucket Shoals region, showing current wind-power lease areas (colored zones) and water depth contours (red and white lines) in meters. NASEM 2023, CC BY-ND