Development of offshore wind as a source of renewable energy is a key part of the strategy to achieve necessary reductions in carbon emissions, mitigate climate change, and achieve state and national goals for renewable energy. The presence of offshore wind structures on the Outer Continental Shelf is likely to have some impact on the hydrodynamics of the surrounding ocean as water moves past these structures. The level of impact is highly dependent on both local oceanography and wind farm characteristics (e.g., turbine size and spacing). The spatial extent and magnitude of hydrodynamic effects and the nature of any associated ecological impacts are less certain but are likely to be up to an order of magnitude less than changes due to natural variability and climate change.
This white paper presents a comprehensive and objective summary of the current state of knowledge on the effects of offshore wind structures on ocean circulation and stratification and their relationship to the distribution and density of copepods and the suitability of foraging habitat for the critically endangered North Atlantic right whale (NARW). Key takeaways reflecting the state of our knowledge from a comprehensive literature review on this topic are summarized in the inset box below and discussed in detail in this white paper. Following the completion of the literature review, an Expert Workshop was held to further discuss the state of the knowledge, to identify some of the critical knowledge gaps, and to establish some priorities for future research that would address these gaps. Recommendations for future research were developed from the scientific literature, from reports developed by experts from state, regional, and national science organizations, and through conversations with scientists and regulators familiar with these topics during the Workshop.
The topic of offshore wind and its effects on hydrodynamics and ecosystems is one that has been widely researched, with a well-established body of peer-reviewed literature, and with many research activities currently underway and anticipated to continue into the future. The current state of knowledge on this topic is summarized here from the results of published research on the oceanographic conditions, copepod distribution, and NARW distribution and habitat use in the Western North Atlantic. The topic of climate change and natural sources of environmental variability in the Western North Atlantic is summarized to provide context for understanding the potential hydrodynamic effects of offshore wind turbines, which are caused primarily by the wind wake effect in the atmosphere and induced mixing in the ocean. Our current understanding of these effects based on observational and modeling studies are summarized. Potential ecosystem impacts of hydrodynamic changes on primary and secondary productivity as a result of offshore wind farms are discussed.