RESUMO
The restoration of eelgrass (Zostera marina L.) is a high priority in Puget Sound, Washington, United States. In 2011, the state set a restoration target to increase eelgrass area by 4,200 ha by 2020, a 20% increase over the 21,500 ha then present. In a region as large, dynamic and complex as Puget Sound, locating areas to restore eelgrass effectively and efficiently is challenging. To identify potential restoration sites we used simulation modeling, a geodatabase for spatial screening, and test planting. The simulation model of eelgrass biomass used time series of water properties (depth, temperature, and salinity) output from a regional hydrodynamic model and empirical water clarity data to indicate growth potential. The GIS-based analysis incorporated results from the simulation model, historical and current eelgrass area, substrate, stressors, and shoreline manager input into a geodatabase to screen sites for field reconnaissance. Finally, we planted eelgrass at test sites and monitored survival. We screened 2,630 sites and identified 6,292 ha of highly to very highly suitable conditions for eelgrass-ample area for meeting the 20% target. Test plantings indicated fine-scale data needs to improve predictive capability. We summarized the results of our analysis for the majority of the ~3,220 km of shoreline in Puget Sound on maps to support restoration site selection and planning. Our approach provides a process for identifying and testing potential restoration sites and highlights information needs and management actions to reduce stressors and increase eelgrass area to meet restoration objectives.
RESUMO
Planners are being called on to prioritize marine shorelines for conservation status and restoration action. This study documents an approach to determining the management strategy most likely to succeed based on current conditions at local and landscape scales. The conceptual framework based in restoration ecology pairs appropriate restoration strategies with sites based on the likelihood of producing long-term resilience given the condition of ecosystem structures and processes at three scales: the shorezone unit (site), the drift cell reach (nearshore marine landscape), and the watershed (terrestrial landscape). The analysis is structured by a conceptual ecosystem model that identifies anthropogenic impacts on targeted ecosystem functions. A scoring system, weighted by geomorphic class, is applied to available spatial data for indicators of stress and function using geographic information systems. This planning tool augments other approaches to prioritizing restoration, including historical conditions and change analysis and ecosystem valuation.