The goal of this vulnerability assessment was to pilot the Refuge Vulnerability Assessment and Alternatives (RVAA) framework and examine potential effects of current and expected stressors on the stated objectives of the 2004 Comprehensive Conservation Plan for the Eastern Shore of Virginia and Fishermans Island National Wildlife Refuges. The primary purpose of the refuge complex is to support migratory bird species. Given the low elevation of the Refuge Complex and projected sea level rise in this area, the assessment particularly focused on the potential impacts of climate change on the sustainability of the refuge purpose. Projected sea level rise (SLR) was analyzed for impacts on all resources included in the assessment. The impacts of other relevant and readily mapped stressors, such as development, were also assessed for all resources.
NatureServe Vista was used to integrate spatial data and expert knowledge on many terrestrial and wetland resources (or "conservation elements") of the refuge complex; characterize scenarios; and spatially assess the cumulative impacts of resource management, development and other land uses, and rising sea level under climate change on refuge resources. Four scenarios — current baseline, and three future scenarios for the years 2025, 2050, and 2100 — were evaluated by intersecting priority resource distributions with each of the spatially defined scenarios to predict effects of stressors on resources. In addition to habitat- and species-based priority resources, the evaluation at each time step also assessed the potential impacts of sea-level rise on mission-critical infrastructure (transportation infrastructure, utilities, etc.).
Where Vista showed a priority resource overlapping with one or more stressors (e.g., development, sea-level rise) having negative effects on the resource in question, the stressor is expected to cause the loss or degradation of that resource in that area of overlap. The Vista results illustrated that even by 2025, sea-level rise is expected to cause the loss of substantial proportions of critical coastal habitats, including 80% of the beach habitat utilized by the northeastern beach tiger beetle, and 80-90% of coastal emergent marshes and wet grasslands. Proposed development would impact priority habitats in certain areas, such as along the corridor for the main north-south highway. Continued losses of coastal habitats are projected from sea-level rise in 2050 and 2100 as well.