Potential Hydrodynamic Impacts
of Offshore Wind Energy on
Nantucket Shoals Regional
Ecology

An Evaluation from Wind to Whales

_____

Committee on Evaluation of
Hydrodynamic Modeling and Implications
for Offshore Wind Development:
Nantucket Shoals

Ocean Studies Board

Division on Earth and Life Studies

Consensus Study Report

NATIONAL ACADEMIES PRESS 500 Fifth Street NW Washington, DC 20001

This activity was supported by Contract AWD-0001806 between the Bureau of Ocean Energy Management and National Academy of Sciences. Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of any organization or agency that provided support for the project. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the opinions or policies of the U.S. Government, nor does mention of trade names or commercial products constitute endorsement or recommendation for use.

International Standard Book Number-13: 978-0-309- 70668-1
International Standard Book Number-10: 0-309- 70668-8
Digital Object Identifier: https://doi.org/10.17226/27154

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Suggested citation: National Academies of Sciences, Engineering, and Medicine. 2024. Potential Hydrodynamic Impacts of Offshore Wind Energy on Nantucket Shoals Regional Ecology: An Evaluation from Wind to Whales. Washington, DC: The National Academies Press. https://doi.org/10.17226/27154.

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COMMITTEE ON EVALUATION OF HYDRODYNAMIC MODELING AND IMPLICATIONS FOR OFFSHORE WIND DEVELOPMENT: NANTUCKET SHOALS

EILEEN E. HOFMANN (Chair), Professor, Old Dominion University

JEFFREY CARPENTER, Research Scientist, Helmholtz-Zentrum Hereon

QIN JIM CHEN, Professor, Northeastern University

JOSH KOHUT, Professor, Rutgers University

RICHARD MERRICK, NOAA Fisheries (retired)

ERIN L. MEYER-GUTBROD, Assistant Professor, University of South Carolina

DOUGLAS P. NOWACEK, Professor, Duke University

KAUSTUBHA RAGHUKUMAR, Consultant, Integral Consulting Inc.

NICHOLAS RECORD, Senior Research Scientist, Bigelow Laboratory for Ocean Sciences

Study Staff

KELLY OSKVIG, Study Director

SAFAH WYNE, Senior Program Assistant

PAIGE NANKEY, Communications Associate

THANH NGUYEN, Financial Business Partner

OCEAN STUDIES BOARD

CLAUDIA BENITEZ-NELSON (Chair), University of South Carolina, Columbia

MARK R. ABBOTT, Woods Hole Oceanographic Institution

ROSANNA ‘ANOLANI ALEGADO, University of Hawai‘i, Manoa

CAROL ARNOSTI, University of North Carolina at Chapel Hill

AMY BOWER, Woods Hole Oceanographic Institution

LISA M. CAMPBELL, Duke University

THOMAS S. CHANCE, ASV Global, LLC (retired)

DANIEL COSTA, University of California, Santa Cruz

JOHN R. DELANEY, University of Washington (retired)

TIMOTHY GALLAUDET, Ocean STL Consulting, LLC

SCOTT GLENN, Rutgers University

MARCIA ISAKSON, The University of Texas at Austin

LEKELIA JENKINS, Arizona State University, Tempe

NANCY KNOWLTON (NAS), Smithsonian Institution (retired)

ANTHONY MACDONALD, Monmouth University

GALEN MCKINLEY, Columbia University

THOMAS J. MILLER, University of Maryland, Solomons

S. BRADLEY MORAN, University of Alaska, Fairbanks

RUTH PERRY, Shell Exploration & Production Company

DEAN ROEMMICH (NAE), Scripps Institute of Oceanography (retired)

JAMES SANCHIRICO, University of California, Davis

MARK J. SPALDING, The Ocean Foundation

PAUL WILLIAMS, Suquamish Tribe

Staff

SUSAN ROBERTS, Director

STACEE KARRAS, Senior Program Officer

KELLY OSKVIG, Senior Program Officer

CAROLINE BELL, Associate Program Officer

LEIGHANN MARTIN, Associate Program Officer

THANH NGUYEN, Financial Business Partner

DARRYL ACKER-CARTER, Research Associate

SAFAH WYNE, Senior Program Assistant

ERIK YANSIKO, Program Assistant

ZOE ALEXANDER, Program Assistant

Reviewers

This Consensus Study Report was reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the National Academies of Sciences, Engineering, and Medicine in making each published report as sound as possible and to ensure that it meets the institutional standards for quality, objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process.

We thank the following individuals for their review of this report:

Although the reviewers listed above provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations of this report, nor did they see the final draft before its release. The review of this report was overseen by RICHARD SEARS, Stanford University and KATHERINE FREEMAN, Penn State University. They were responsible for making certain that an independent examination of this report was carried out in accordance with the standards of the National Academies and that all review comments were carefully considered. Responsibility for the final content rests entirely with the authoring committee and the National Academies.

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Acknowledgments

The committee would like to thank the study sponsor, the Bureau of Ocean Energy Management (BOEM), staff who helped with the study, especially Mary Boatman, Desray Reeb, and Thomas J. Kilpatrick.

During the study process, several speakers joined the committee meetings to inform and enrich discussions. We thank the following individuals for their contributions during the study process: Cristina Archer (University of Delaware), Mary Boatman (BOEM), Yorick Broekema (Deltares), Göran Broström (University of Gothenburg), Changsheng Chen (University of Massachusetts Dartmouth), Ute Daewel (Helmholtz-Zentrum Hereon), Glen Gawarkiewicz (Woods Hole Oceanographic Institution), Sean Hayes (National Oceanic and Atmospheric Administration), Tom Johnson (Danish Hydraulic Institute), Seth Kaplan (Ocean Winds), Laura Morse (Invenergy), Ruth Perry (Shell Renewable and Energy Solutions), Andrew Pershing (Climate Central), Ole Petersen (Danish Hydraulic Institute), Jeffrey Runge (University of Maine), and Ariana Zampollo (University of Aberdeen).

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Contents

SUMMARY

A Dynamic and Evolving Oceanographic Regime

Understanding Hydrodynamic Effects

Potential Impacts to Right Whale Prey

1 INTRODUCTION

Origin and Purpose of the Study

Study Approach and Report Organization

2 OCEANOGRAPHY IN NANTUCKET SHOALS

General Description

Physical Oceanography

Biological Oceanography

3 HYDRODYNAMIC EFFECTS OF OFFSHORE WIND DEVELOPMENTS

State of Understanding

The Case of the North Sea: Hydrodynamics

Ability to Accurately and Precisely Estimate Perturbations Caused by Wind Turbine Generators

Applicability of Hydrodynamic Models to the Nantucket Shoals Region

Hydrodynamic Models for Shelf and Coastal Oceanography

Conclusions and Recommendations

4 POTENTIAL ECOLOGICAL IMPACTS OF OFFSHORE WIND TURBINES

State of Understanding

Effects of Hydrodynamic Perturbations on Ecosystem Dynamics in the Nantucket Shoals Region

Potential Impacts to the Prey Field of the North Atlantic Right Whale

Conclusions and Recommendations

REFERENCES

APPENDIXES

A Committee Biographies

B Public Meeting Agendas

C Commercially and Ecologically Important Fish and Invertebrates Found in the Nantucket Shoals Region

D Marine Mammals that May Occur within the Nantucket Shoals Region

E Marine Birds that May Occur within the Nantucket Shoals Region

Preface

The U.S. federal government has set a target of 80 percent renewable energy generation by 2030 and 100 percent carbon-free electricity by 2035. Realizing this goal will require a portfolio of renewable energy sources, one of which is development of a robust offshore wind energy industry in U.S. coastal waters to meet the U.S. target of 30 gigawatts of energy from offshore wind by 2030. Two offshore wind energy farms, with a total of seven wind turbine generators, now operate on the continental shelf of the U.S. East Coast. Plans are underway to expand the number of wind farms in this region by about a factor of 10 and the number of turbines by about two orders of magnitude. The scale of the anticipated expansion of the U.S. offshore wind energy industry has many implications for the coastal environment, one of which is impacts on the oceanography and ecology of the region within and surrounding the wind energy installations.

Beginning in 2009, the Bureau of Ocean Energy Management (BOEM) became responsible for offshore renewable energy (including wind) development in federal waters. The Department of the Interior announced at that time the final regulations for the Outer Continental Shelf Renewable Energy Program, as authorized by the Energy Policy Act of 2005. These regulations, in addition to the National Environmental Policy Act, provide the regulatory framework for the activities supporting the production and transmission of offshore renewable energy.

The Nantucket Shoals region of the U.S. East Coast continental shelf has been designated as a site for expansion of offshore wind energy capability. This region is characterized by complex hydrodynamics and ecology. The hydrodynamics of this region result from processes at spatial scales of variability that extend from oceanic (Gulf Stream warm core rings) to local (tidal mixing) and timescales of seasonal (stratification) to decadal. The ecology of the region is unique in that it supports aggregations of zooplankton that provide prey for the endangered North Atlantic right whales that migrate to the region to forage.

Modeling studies from the North Sea suggest that offshore wind farms can modify the local circulation and ecology with impacts that extend beyond the wind farm region. The extent to which wind energy farms may have similar effects on the hydrodynamics and ecology of the Nantucket Shoals region is of concern because of potential impacts on zooplankton–right whale interactions, a trophic connection not considered in current studies. As such, the charge to this committee was to assess the current state of understanding and the capability to detect impacts of offshore wind farms on the hydrodynamics and ecology of the Nantucket Shoals region.

Support for developing this report was provided by BOEM, and the committee gratefully acknowledges this support. The committee began its work by convening an open community webinar to introduce the committee and its tasks. This was followed by two public meetings to gather information about the current state of knowledge of environmental and ecological aspects of offshore wind energy development and the Nantucket Shoals region. Many individuals generously provided their expertise and time for the public meetings, which is much appreciated given the short notice provided for participating in the meetings. The committee extends its thanks to participants from the federal government, research institutions, private industry, and other stakeholder groups who participated in the public meetings, provided background information, and openly engaged in discussions.

The committee extends its wholehearted appreciation to the National Academies’ staff for providing the organization, support, and direction that made this report possible. The completion of this report in 4 months would not have been possible without the superb efforts of the study director Kelly Oskvig and program assistant Safah Wyne. Their gentle and ongoing guidance is much appreciated.

Offshore wind energy is integral to the future of renewable energy sources. Development of this capability must be such that it preserves the marine environment and its ecosystems and also recognizes changes and variability imposed by climate change. It is the committee’s hope that the recommendations in this report be used to stimulate future studies that can answer the questions important for responsible development of offshore wind in the Nantucket Shoals region and elsewhere.

Acronyms and Abbreviations

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