Williams, K.A., I.J. Stenhouse, E.E. Connelly, and S.M. Johnson. 2015. Mid-Atlantic Wildlife Studies: Distribution and Abundance of Wildlife along the Eastern Seaboard 2012-2014. Biodiversity Research Institute. Portland, Maine. Science Communications Series BRI 2015-19. 32 pp.

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Executive Summary

The Mid-Atlantic Baseline Studies Project was funded by the Department of Energy’s (DOE) Wind and Water Power Technologies Office in 2011, with additional support from a wide range of partners. The study goal was to provide comprehensive baseline ecological data and associated predictive models and maps to regulators, developers, and other stakeholders for offshore wind energy. This knowledge will help inform the siting and permitting of offshore wind facilities on the mid-Atlantic Outer Continental Shelf.

Research collaborators studied wildlife distributions, abundance, and movements between 2012 and 2014. The specific study area was chosen because it is a likely location for future wind energy development offshore of Delaware, Maryland, and Virginia, including three federally designated Wind Energy Areas (WEAs). Project objectives were to:

  • Conduct standardized surveys to quantify wildlife abundance seasonally and annually throughout the study region, and identify important habitat use or aggregation areas. Boat-based surveys and high resolution digital video aerial surveys were conducted to reach this objective.
  • Develop statistical models to help understand the drivers of wildlife distribution patterns and to predict the environmental conditions likely to support large densities of wildlife.
  • Use individual tracking methods for several focal bird species to provide information on population connectivity, individual movements, and seasonal site fidelity that is complementary to survey data.
  • Identify species that are likely to be exposed to offshore wind energy development activities in the mid-Atlantic study area.
  • Explore technological advancements and assessment methods aimed at simplifying and minimizing the cost of environmental risk assessments.
  • Help meet regulatory data needs by contributing several years of data and analysis towards future Environmental Impact Statements.

This report is a synthesis of many aspects of the Mid-Atlantic Baseline Studies project. A more detailed examination may be found in the full project report (Williams et al. 2015) and related publications (e.g., Hatch et al. 2013 and others).

In this publication, we explore aspects of the mid-Atlantic ecosystem; describe our survey and analytical approaches; and present a range of results, featuring several case studies on specific species or phenomena. Each case study includes the integration of data from multiple study components, presenting a comprehensive view of wildlife distribution and movement patterns. Key findings include:

  • Boat-based and digital video aerial surveys each had specific advantages and disadvantages, but were largely complementary. Digital aerial surveys may be particularly useful for covering offshore areas at broad scales, where general distributions of taxonomic groups are a priority; boat surveys can provide more detailed data on species identities and behaviors, but are more limited in geographic scope due to their slower survey pace.
  • Habitat gradients in nearshore waters were important influences on productivity and patterns of species distributions and abundance. Areas offshore of the mouths of Chesapeake and Delaware Bays, as well as to the south of Delaware Bay along the coast, were consistent hotspots of abundance and species diversity, regardless of survey methodology or analytical approach.
  • The study area was important for wintering and breeding taxa, and its location also made it a key migratory corridor. There was considerable variation in species composition and spatial patterns by season, largely driven by dynamic environmental conditions.

The results of this study offer insight to help address environmental permitting requirements for current and future projects. These data serve as a starting point for more site-specific studies, risk analyses, and evaluation of potential measures to avoid and minimize risks to wildlife from human activity in the offshore environment.