Offshore Wind Energy: Assessing Impacts to Marine Life

NOAA Fisheries’ ongoing work helps inform the Bureau of Ocean Energy Management’s analyses of proposed offshore wind activities’ potential impacts to marine species and habitats. 

Regulatory Requirements for Development

Several regulatory processes that help reduce offshore wind energy’s potential impacts to protected marine resources govern our work.

Conducting Consultations

Through the consultation process, we work with BOEM and other federal agencies to support the compliance of offshore wind activities with the Endangered Species Act, Magnuson-Stevens Act, and Fish and Wildlife Coordination Act. This process occurs before construction can begin and can be adapted as each project is developed. 

For example, after completing the Endangered Species Act formal consultation process with BOEM on an offshore wind project, we issue a Biological Opinion detailing how federal agencies’ actions may affect Endangered Species Act-listed species and critical habitat. We work with the action agency to propose measures to avoid and minimize harmful impacts and improve conservation. 

Assessing Impacts to Marine Mammals Under the Marine Mammal Protection Act

Under the Marine Mammal Protection Act, NOAA Fisheries can authorize the take of marine mammals incidental to otherwise lawful activities, including offshore wind activities. We are required to carefully review and use the best available scientific information in satisfying the requirements of the Act. We publicly announce each proposed incidental take authorization and seek input from the public during the comment period. 

We do not anticipate and have not authorized—or proposed to authorize—death or serious injury of whales for any wind-related action. The majority of take authorized for offshore wind activities has been by Level B harassment, which is a disruption of behavioral patterns or a temporary reduction in hearing sensitivity. These impacts are expected to be relatively short in duration. 

NOAA Fisheries must include mandatory mitigation measures that affect the least practicable adverse impact on affected marine mammals in all issued incidental take authorizations. Offshore wind developers undertake these measures to minimize impacts on marine mammals and their habitat. For example, mitigation measures may require: 

• Avoiding foundation installation during times when North Atlantic right whales are most likely to be using the area
• Using sound attenuation technology such as double bubble curtains to reduce noise levels from foundation installation
• Conducting sound field verification to understand noise levels produced during wind farm construction and operation
• Delaying or shutting down noise sources if marine mammals are within certain distances
• Implementing vessel speed and approach restrictions to decrease risk of marine mammal interactions with offshore wind vessels
• Requiring the use of protected species observers and acoustic monitoring during certain activities such as pile driving 

Incidental take authorizations also include mandatory monitoring and reporting measures. These measures support mitigation implementation and increase understanding of the impacts of offshore wind energy development on marine mammals and their habitat. We analyze data gathered during offshore wind project development to help agencies and developers identify and address gaps in our understanding of the impacts of offshore wind activities and ensure compliance with regulatory requirements. 

View a list of incidental harassment authorizations for offshore wind activities

Learn more about frequently asked questions about offshore wind and marine mammals

Working with BOEM on National Environmental Policy Act Requirements

We also coordinate with BOEM and other agencies to consider the environmental impacts of each proposed offshore wind project. The National Environmental Policy Act requires federal agencies to integrate environmental values into their decision-making processes by considering the environmental impacts of their major proposed actions. Under NEPA, we serve as a cooperating agency to:

• Evaluate the impacts of wind development activities on coastal and marine resources, including protected species and marine habitats
• Identify mitigation measures—such as noise reduction devices—and analyze how they would reduce the negative impacts of development
• Provide information and data about resources of concern that may be impacted by the projects

Learn more about each project’s review under NEPA

Advancing Marine Species Research and Monitoring Through Collaboration

With our partners, NOAA Fisheries conducts research to further our understanding of how offshore wind energy impacts marine species and their habitats. These research efforts can help inform offshore wind site selection, construction, and operations.

We work to understand how wind projects may affect endangered and threatened species that live in or migrate through offshore wind areas. We investigate how these species use habitats in proposed wind energy areas and how offshore wind development could impact their populations. We also maintain passive acoustic recording arrays—in collaboration with BOEM, states, regional coordinating bodies, and wind energy companies—to better understand offshore wind energy development’s impacts on marine mammals.

We worked with the Responsible Offshore Science Alliance, researchers, wind developers, and state and federal agencies to develop a framework and guidelines for offshore wind project monitoring. These can help offshore wind developers characterize, evaluate, and monitor the impacts of proposed projects on marine life and fishing operations. The guidelines will also help ensure that the data collected through project-specific monitoring efforts can be integrated into regional scientific surveys.

We are actively engaged in the Regional Wildlife Science Collaborative for Offshore Wind. This multi-sector group published a science plan to inform ongoing data collection and research in U.S. Atlantic waters. It focuses on developing regional research and monitoring priorities and data standards.

Learn more about the Regional Wildlife Science Collaborative for Offshore Wind technology workshop series

NOAA Fisheries and BOEM have developed a passive acoustic monitoring framework. It outlines minimum procedures, system requirements, and other components for effectively designing and implementing passive acoustic monitoring. This will help wind developers reduce the impact of offshore wind energy projects on marine species. The national framework covers offshore wind development before, during, and after project construction.

Learn more about the recommendations from NOAA and BOEM for the use of passive acoustic listening systems

Protecting North Atlantic Right Whales from Potential Impacts 

There are only approximately 380 North Atlantic right whales remaining, including about 70 reproductively active females. As this endangered species’ distribution overlaps with areas of offshore wind energy development, we worked with BOEM to establish a joint North Atlantic Right Whale and Offshore Wind Strategy. The strategy provides guidance for a coordinated effort across the federal government and with our partners to conserve and promote the recovery of this species while developing offshore wind energy.

Potential Ecological Impacts of Offshore Wind

As offshore wind develops, scientists will continue to learn about the ecological and other impacts of offshore wind energy. Site assessment, construction, operations, and decommissioning for offshore wind projects could interact with the marine environment and life on the seabed, in the water, and at the surface. For example, offshore wind energy projects may:

• Change the soundscape, which could adversely impact fish, marine mammals, and other species
• Introduce electromagnetic fields that could impact fish navigation, predator detection, communication, and the ability for marine life to find mates
• Alter local or regional hydrodynamics, which could change local and regional-scale ecosystems
• Create a “reef effect” where marine life cluster around the hard surfaces of wind turbines and associated structures
• Increase vessel traffic, which could lead to more vessel strikes
• Corrosion protection systems could release contaminants that could be consumed or absorbed by marine life

These impacts have the potential to affect organism life cycle stages—including larval dispersal and spawning—and species’ composition, abundance, distribution, behavior, and survival rates.