We summarize eelgrass (Zostera marina L.) restoration and mitigation project results and recommendations of transplant practitioners in the Pacific Northwest since 1990. Our purpose is to provide current information for programs considering eelgrass restoration by providing a synthesis of what practitioners and researchers have learned through experimentation and monitoring of discrete projects throughout western Washington and British Columbia. Reports, papers, personal communications, and a workshop were used to gather data on these projects. Our general null hypothesis is that eelgrass can be restored to match natural eelgrass meadows in terms of structure and function. We conclude that, under favorable site conditions, and if the reason for the initial loss of eelgrass is understood and corrected, eelgrass can be restored. However, eelgrass restoration science is hampered by knowledge gaps, reducing restoration success. For example, mechanisms for recent eelgrass loss in the region are not obvious, which suggests that the scientific understanding of eelgrass biology and ecosystem conditions is inadequate to support environmental management actions in our region. To improve restoration project success in the Pacific Northwest requires further research into knowledge gaps, close evaluation of the performance of restoration projects, and dissemination of resulting information for use by future generations. Workshop participants identified an immediate need to construct a clearinghouse of eelgrass restoration and monitoring results that provides summaries and data from eelgrass enhancement efforts. Furthermore, we found that it was difficult to summarize the relative performance of the more than 30 projects reviewed because of variations in goals, project size, planting methods employed, performance criteria, duration of monitoring, intensity of monitoring, and data interpretation. Hence, we recommend that standard monitoring protocols be developed and results from these methods be reported through the clearinghouse and periodic meetings.
Pacific Northwest National Laboratory. Marine Sciences Laboratory ; Washington State Dept. of Natural Resources ; Grette and Associates, et al.
Plant activity, Restoration ecology, Marine biology, Plant growth, Ecosystems, Research projects, Case studies, Information dissemination, Environmental monitoring.