The mid-Atlantic study area is a complex ecosystem with highly variable temporal and geographic patterns, and provides important habitat for a wide variety of marine wildlife over the course of the year. The study goal was to provide regulators, developers, and other stakeholders with comprehensive baseline ecological data and analyses that could help address environmental permitting requirements for current and future projects, and would serve as a starting point for more site-specific studies. In particular, we produced information that could be used to identify: 1) important wildlife areas, 2) data gaps, and 3) approaches for collecting and incorporating natural resource data into decision making.

Survey and Analysis Methods

Study methods and analytical approaches have substantial influences on resulting wildlife distribution and abundance data. Understanding the limitations of these methods is essential in order to interpret results. In this study, boat and high resolution digital video aerial survey methods each had particular strengths and weaknesses, though technological advances and the development of more sophisticated analytical approaches could help strengthen the digital aerial survey approach.

Geographic and Temporal Patterns

The mid-Atlantic region was important for wildlife year-round, including breeding and nonbreeding periods. This study also indicated the importance of offshore areas in migratory routes for many taxa, including rays, sea turtles, marine mammals, passerines, shorebirds, and seabirds. There were strong seasonal variations in community composition and wildlife distributions, largely driven by environmental variables such as weather, habitat characteristics, and prey distributions. Interannual variation was also substantial, and results presented in this report should be interpreted with caution when attempting to identify longer-term (e.g., interdecadal) patterns.

Areas offshore and south of the mouths of Delaware Bay and Chesapeake Bay were hotspots of relative abundance and species richness. These areas were likely attractive to many species due to gradients in salinity, water temperature, and primary productivity. Generally, we saw more individuals of many species in nearshore areas within 30-40 km of shore. Scoters were one driver of this pattern, as they were highly abundant, and large flocks occurred almost universally in nearshore areas. Red-throated Loons and Bottlenose Dolphins were also most consistently observed nearshore. Many species were more widely distributed across the study area, however, including Common Loons, Northern Gannets, and storm-petrels. Other species occurred primarily in offshore areas, including Common Dolphins, sea turtles, and alcids (including Atlantic Puffins, Dovekies, Razorbills, and murres).

Implications for Offshore Development

Risk to wildlife from offshore development can be thought of as a combination of exposure to construction and operation activities, hazards posed to individuals that are exposed, and the implications of individual-level effects for population vulnerability. Our baseline assessment focused on understanding potential exposure of wildlife to future offshore development. Future studies should focus on species most likely to be impacted due to their exposure, conservation status, or other factors.

This study is an important first step towards understanding the implications of offshore wind energy development for wildlife populations in the mid-Atlantic United States. Collectively, baseline data from this study and other studies along the eastern seaboard can be used to inform the responsible siting of future offshore wind energy projects, address environmental permitting requirements for current and future projects, and inform development of mitigation approaches aimed at minimizing potential effects.

References

  • Bailey H, Rice A (2015) Determining Offshore Use by Marine Mammals and Ambient Noise Levels Using Passive Acoustic Monitoring: Semi-Annual Progress Report. Sponsor Grant Number 14-14-1916 BOEM. 9 pp.
  • Crichton D (1999) The risk triangle. Natural Disaster Management 102–103
  • Fox AD, Desholm M, Kahlert J, Christensen TK, Krag Petersen I (2006) Information needs to support environmental impact assessment of the effects of European marine offshore wind farms on birds. Ibis (Lond 1859) 148:129–144. doi: 10.1111/j.1474-919X.2006.00510.x
  • Northeast Fisheries Science Center, Southeast Fisheries Science Center (2011) A Comprehensive Assessment of Marine Mammal, Marine Turtle, and Seabird Abundance and Spatial Distribution in US Waters of the western North Atlantic Ocean, 2011. Annual Report to the Inter-Agency Agreement M10PG00075/0001. 166 pp
  • O’Connell AF, Gardner B, Gilbert AT, Laurent K (2009) Compendium of Avian Occurrence Information for the Continental Shelf Waters along the Atlantic Coast of the United States, Final Report (Database Selection – Seabirds). Prepared by the USGS Patuxent Wildlife Research Center, Beltsville, MD

Photo Credits: Header photo © Kate Sutherland