In this project, “The Eelgrass Resource of Southern New England and New York: Science in Support of Management and Restoration Success,” we investigated genetic and other eelgrass (Zostera marina L.) information to advance both management and restoration science in southern New England and New York coastal waters. The project assessed the genetic diversity of eelgrass across the region and tested it against an experimental factorial design of stress parameters, to yield maps of eelgrass distribution and to discover eelgrass populations that are resilient to various stressors that occur regionally. We created a database of the multiple stressors of eelgrass and learned new information about scientific site selection for eelgrass restoration. Overall, we completed an evaluation of eelgrass genetic diversity and population differentiation across the region, detailed geographic studies of eelgrass genetic diversity and resilience, and conducted experimental testing of plant tolerance to multiple stressors in mesocosm experiments. The project contributes to regional eelgrass habitat sustainability through its insights into eelgrass ecology, genetics, and the conditions that affect eelgrass growth, while also yielding information for improved eelgrass restoration. The results of our study provide information on environmental parameters and stressors to eelgrass, information that both to improves site selection for restoration and identifies potentially resilient populations of eelgrass with adequate genetic diversity to be used as restoration donor sources.