Duck Harbor Beach is an area of relatively high wave energy in which one species, Zostera marina (eelgrass) has persisted. A wide tidal range exposes the shallow edge of the eelgrass bed at low tide. The permanently subtidal depths are characterized by linear, shore-parallel patches of eelgrass interspersed with sandbars, a pattern often found in high energy seagrass beds. Monitoring has occurred annually during peak summertime biomass since 2003. Monitoring results reveal both spatial and temporal heterogeneity in the eelgrass population in response to physical wave disturbance. The site has been rapidly losing eelgrass cover since 2006.