Overview

A consensus report of the National Academies of Sciences, Engineering, and Medicine titled Potential Hydrodynamic Impacts of Offshore Wind Energy on Nantucket Shoals Regional Ecology: An Evaluation from Wind to Whales (NASEM, 2024), examined the potential for offshore wind farms in the Nantucket Shoals region to affect oceanic physical processes and in turn impact ecosystem dynamics, including zooplankton productivity and aggregations relevant to right whale foraging and population health. Among other recommendations, the report outlined the need for observational and modeling efforts to fill knowledge gaps and inform decision-making regarding wind energy development and operations in the region. To delve further into specifically what observational and monitoring activities could best meet these needs, the National Academies hosted a follow-on workshop, entitled Field Monitoring Program to Evaluate Hydrodynamic Impacts of Offshore Wind Energy on Nantucket Shoals Regional Ecology: A Workshop, July 9–10, 2024 in Washington, DC. The workshop brought together participants from academia, government, and the offshore wind industry to explore examples of observational needs and discuss components of a field monitoring program that could help to advance models for elucidating the potential effects of wind energy development on Nantucket Shoals ecology.

Over the course of the workshop, participants engaged in a series of breakout sessions and full-group discussions to exchange information about current and planned research, monitoring, and modeling efforts; discuss key questions and potential priorities for research programs going forward; and examine challenges and opportunities involved in designing field monitoring programs to effectively and efficiently address these questions.

On the workshop’s first day, participants discussed the oceanographic and atmospheric parameters relevant to resolving key physical and ecological questions at two scales: individual turbine and wind energy area. On the second day, participants turned to the question of what components of a field monitoring program could be beneficial for providing the desired observations at appropriate resolution for both of these scales. Throughout the discussions, participants considered how existing instrumentation and data could be better leveraged to help fill knowledge

gaps; identified areas where new observations and research investments might be needed or be most impactful; and located areas where more tools or knowledge may be needed to guide monitoring approaches.

A key theme highlighted by many participants was the need to elucidate the connections between the ocean’s physical properties and biological processes. Such insights could be extremely valuable for predicting how zooplankton distribution and whale behavior might change in response to impacts from wind energy development, in particular as a result of the wind and water wakes caused by wind infrastructure. Several participants noted significant data gaps relevant to resolving the vertical structures of both physical and biological parameters and atmospheric and wave wakes, and they underscored the importance of conducting more research to determine how factors such as wakes, tidal mixing, and internal waves affect plankton aggregations, food webs, and whales’ foraging behaviors.

Multiple platforms, including fixed systems, buoys, gliders, moorings, aircraft, and satellites can be utilized to take measurements upstream, downstream, and across wind energy areas.. The impacts of wind farms may occur on different timescales, and different timescales are relevant when conducting research to understand these potential impacts. Many participants underscored the importance of both short- and long-term monitoring, including short-term monitoring for focused process studies along with long-term monitoring to assess change.

At the turbine scale, a key question is whether turbulence caused by a single turbine or combination of turbines could influence zooplankton patches or the nutrients and phytoplankton on which zooplankton depend. To answer this question, some participants highlighted the importance of studying atmospheric wakes with measurements at both the hub or turbine height and at the sea surface; to develop vertical profiles of atmospheric heat flux and stability; and to study how ocean wakes impact salinity, stratification, temperature, current velocity, current shear, surface waves, turbulence, nutrient supply, and zooplankton aggregations. Key parameters to measure include temperature, salinity, current, wind speed, wave fields, and zooplankton distribution at relevant scales. In addition, several participants noted the importance of stratification in hydrodynamics, highlighting the value of collecting measurements at multiple depths and studying processes such as salinity intrusions at the sea surface, mid-water column, and bottom boundary layers. Process studies conducted on short timescales can help to understand and represent ocean wakes; some participants suggested that these studies do not need to be conducted long term but can be repeated under different circumstances to observe how scour, stratification, corrosion, biofouling, benthic habitat, and other factors may affect turbulence and hydrodynamics.

Integrating multiple types of fixed and mobile observation platforms is important for understanding variability across time and space. Data collected at the turbine scale can become building blocks toward larger-scale models to isolate and assess wind energy area impacts. To characterize hydrodynamic impacts at the wind energy area scale, several participants also underscored the importance of monitoring water conditions before construction, during construction and operation, and after

decommissioning and of collecting upstream, downstream, and cross-shelf measurements. In particular, some participants discussed establishing temperature and salinity profiles at scales that span the baroclinic Rossby radius (2–10 kilometers); capturing stratification at a scale of 10 kilometers; and studying currents, surface wind, and the surface wave field. Measurements at the boundary layers—including surface, mid-water, and bottom—were also noted as important.

Throughout the workshop, participants pointed to ongoing and planned observations supported by a range of academic, nonprofit, government, and industry groups and considered how these and other programs could be leveraged, combined, and added to in order to generate additional insights and fill knowledge gaps. For example, some participants highlighted high-frequency radar, ocean glider surveys, and ship-based data collection efforts coordinated by the Northeastern Regional Association of Coastal Ocean Observing Systems; analyses of satellite, glider, and radar-based data being conducted as part of research projects; and the plethora of data that wind energy developers collect during their planning activities and permit applications, all of which might support ongoing monitoring during construction and operations. Participants also advocated for broader industry-sponsored studies such as Vineyard Wind’s Project Ocean W’aKEs.

Several participants also noted a variety of measurement techniques and research tools that could further enhance data collection, such as greater use of acoustic Doppler current profilers, drifters, foundation-mounted sensors, video plankton recorders, and other tools. Some participants noted that data collection efforts from studies that are focused on other topics, such as fisheries or climate, could potentially be leveraged to help characterize the potential impacts of wind energy development.

As planning and construction of wind energy projects in the Nantucket Shoals region continue to move forward, several participants emphasized that time is of the essence in answering questions about the potential impacts of these projects, making it critical to identify and align existing observational efforts and facilitate work to compare and contextualize the data. Measurements taken before construction or in places without wind energy infrastructure could potentially be useful to establish baselines or be used as controls; however, some participants underscored the challenges of establishing controls in ever-changing ocean systems that are simultaneously experiencing multiple pressures and shifts from both natural and anthropogenic sources. Many participants also emphasized the two-way relationship between models and observations; while a key goal of collecting data is to refine and improve models that can help identify mechanistic relationships and predict potential impacts, models can also be used to guide how and where measurements are taken so that they can be most useful.

Throughout the workshop, many participants stressed the importance of collaboration and open exchange of information. Given the complexity of deploying the diverse array of sensors and other data-gathering efforts, several participants noted that multi-institutional and multidisciplinary collaboration can be crucial to making the best use of research investments and sharing expertise and resources.

Related to this, some participants emphasized the importance of ensuring that adequate computational and staff resources are allocated to store, manage, and analyze data, especially for datasets that are large or collected continuously, and to follow best practices for data documentation and sharing in order to maximize the value and future utility of data collection efforts. To advance these efforts going forward, some participants underscored the importance of clear and frequent communication among researchers, developers, government agencies, and other stakeholders in designing and carrying out field monitoring programs.

Box 1 summarizes the components that participants highlighted throughout the workshop as being important for field monitoring programs, followed by the names of participants who raised the component for discussion.

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