Restoring Eelgrass (Zostera marina) from Seed: A Comparison of Planting Methods for Large-Scale Projects

PROBLEM: Eelgrass (Zostera marina) seeds are being used in a variety of both small- and large-scale restoration activities and have been successfully used to initiate recovery of eelgrass in the Virginia seaside coastal lagoons, which lost eelgrass in the 1930s ‘wasting disease ’ pan-demic (Orth et al. 2006a). However, a major bottleneck with the use of seeds has been the rela-tively low rate of seedling establishment, generally 10 percent or less of seeds placed in the field (Orth et al. 2003). A recently developed underwater seed planter (Traber et al. 2003) represents an alternative method that could improve seedling success compared to techniques used in previ-ous Chesapeake Bay studies and elsewhere. PURPOSE: The objective of this study was to compare the effectiveness of different techniques of seeding for use in large-scale projects: injecting seeds into submerged sediments with a mechanical seed planter and hand-broadcasting seeds on the sediment surface using divers. BACKGROUND: Seagrass transplanting projects worldwide have traditionally relied on adult plants (Fonseca et al. 1998) using a variety of manual and mechanical techniques (Fonseca et al. 1998, Fishman et al. 2004, Treat and Lewis 2006). However, most techniques using adult plants are labor-intensive and time-consuming, requiring physical excavation of the donor material