Abstract
This Birds and Bats Study (Study) used a variety of existing data to examine bird and bat use in the Area of Analysis (AoA), a 14,980-square-mile area of the ocean extending from 15 nautical miles from the coast of Long Island and New York City to the continental shelf break, slope, and into oceanic waters to an approximate maximum depth of 2,500 meters. Another principal objective of the Study was to determine the relative sensitivities of species and species groups to potential offshore wind farm-related impacts. Bird abundance and occurrence within the AoA were largely evaluated using six key sources: Menza et al. 2012, Balderama et al. 2015, Curtice et al. 2016, Kinlan et al. 2016, eBird 2017, and Normandeau 2017. Bird life histories and behavioral information relevant to offshore habitats were obtained from Birds of North America (Rodewald 2015), peer-reviewed journal articles, and other reputable sources, while impact sensitivities information primarily came from European research and Robinson Willmott et al. (2013). Data pertaining to use of offshore waters by bats are more limited, and this study primarily discusses information from two sources (Pelletier et al. 2013; Stantec 2016).
Abundance and occurrence data were used to develop a list of species most likely to be observed in the AoA annually (Table 1). Appendix A provides species-specific review of the 39 regularly documented species, including their spatial and temporal occurrence, behavior relative to use of the AoA, and potential impacts associated with offshore wind farms. Species-specific reviews are organized by species groups, which were determined by taxonomy, with one exception—“pelagic birds”, which comprise several disparate taxa that spend most of their lives in flight at sea. This study also addresses species groups (e.g., raptors and passerines) that may occur, but are not regularly documented in the AoA. Bats are discussed independently and collectively, given the limited information available.
While birds may occur anywhere in the AoA, data indicate that overall bird use is greatest in three core areas of the AoA: shallower waters along the northern and northwestern boundaries of the AoA, the Hudson Shelf Valley, and the continental shelf break (Figure 3). Regularly occurring species are generally concentrated in one or more of these core areas. For example, Surf Scoter (Melanitta perspicillata) (and waterfowl in general) use of the AoA is generally concentrated in shallow waters in the northern AoA and the shallower portions of the Hudson Shelf Valley. Conversely, Wilson’s Storm-Petrels (Oceanites oceanicus) (and pelagic birds in general) are most commonly observed near the continental shelf breaks. Available data suggest that bird species listed under the Endangered Species Act (ESA) have not been observed to regularly occur within the AoA. However, data show that one state-listed species, Common Terns (Sterna hirundo), regularly occurs within the AoA. Ongoing offshore studies of ESA-listed species, including rufa Red Knots (Calidris canutus rufa), Roseate Terns (Sterna dougallii), Piping Plovers (Charadrius melodus), and northern long-eared bats (Myotis septentrionalis), and state-listed Common Terns (BOEM 2017a), may provide insight on these species’ use of the AoA in the future. There are insufficient data to identify higher use areas for bats in the AoA; based on the data available (Stantec 2016), bat occurrence in offshore waters in general appears to be relatively low and concentrated during migratory periods.
Collisions and displacement are the two principal potential impacts on birds at offshore wind farms, especially during operations. Potential for collisions with turbines and associated structures is greater in areas of higher bird use, during periods of inclement weather or low light, and in species with flight behaviors that put them in rotor-swept areas. Species or individuals that avoid wind farms are less likely to collide with turbines, but may then be displaced from otherwise suitable habitats and exposed to barriers to movement. Section A.1, Table 1, and Table A.1 summarize the relative sensitivities of regularly occurring bird species to collision and displacement risks associated with offshore wind farms. The primary impacts of offshore wind farms on bats, if any, would likely be collision and, to a lesser extent, displacement during operations; however, very little is known about bat use of the AoA.
Guidelines have been developed for measures to avoid or minimize the potential impacts of offshore wind energy development on birds and bats. The recommended measures in these guidelines, which generally include regular consultation with the appropriate resource agencies, data collection, impact assessment, project siting that considers impacts on birds and bats, monitoring, and mitigation, are summarized in this Study. Guidelines evolve over time and new guidance or regulations may arise in the future. Developers should consult BOEM and other State and federal agencies for up-to-date recommendations or requirements.