A spatial conservation prioritization approach for protecting marine birds given proposed offshore wind energy development

• We developed spatial distribution models for several marine bird taxa in nearshore and offshore waters.
• We then prioritized areas for conservation using spatial prioritization software.
• Nearshore waters had the highest overall conservation priority ranking, although we also delineated key offshore areas.
• Hypothetical offshore wind developments in areas of high conservation priority appeared to reduce marine bird distributions.
• Current offshore wind farm development proposals are primarily in waters of low marine bird conservation priority.

There are currently no offshore wind energy developments (OWEDs) in North America, although numerous OWEDs have been proposed along the Atlantic Coast. Development pressure has been a catalyst for marine spatial planning (MSP) to identify suitable areas for OWED. However, integrating complex ecological information to guide OWED siting remains a substantial challenge. We developed spatial distribution models of marine birds from aerial surveys that we conducted from 2010 to 2012 throughout a 3800 km2 area off the coast of Rhode Island. For seven groups of marine birds, we constructed either a density surface model or a presence–absence model that incorporated relevant environmental covariates. We integrated our spatial models, along with uncertainty, using spatial conservation prioritization (SCP) software. This identified sites with high marine bird conservation priority that aided evaluation of proposed OWED sites. We found that shallow nearshore waters had the highest conservation priority overall, but we also detected key offshore areas of high priority. Hypothetical OWEDs placed in conservation priority areas significantly reduced the overall distribution of focal species. Currently proposed OWED sites are located in areas of relatively low conservation priority and so would not substantially reduce the overall distribution of marine birds. This SCP approach when combined with quantitative models of bird distribution given relevant environmental covariates provides a robust framework that satisfies the principles of ecosystem-based MSP. Thus, this combined SCP-distribution modeling framework should be extremely helpful to decision makers as they evaluate proposed siting locations of OWEDs in the context of a dynamic marine system.