We will evaluate the ability to expand the current distribution of eelgrass in the lower Columbia River estuary for the purposes of enhancing feeding, refuge and rearing habitat for a number of fisheries species including juvenile Pacific salmon and Dungeness crab. We strongly suspect that limited eelgrass seed dispersal has resulted in the present distribution of eelgrass meadows, and that there are many suitable places for eelgrass to survive and form functional meadows. Our past success with eelgrass restoration in the northwest has largely been due to data developed on the factors controlling the growth of eelgrass in the region.  By assessing site conditions relative to growth requirements, we have been able to find suitable sites for eelgrass establishment.  Because of the river-driven dynamics, the lower Columbia estuary presents a challenge in this regard. Hence, we propose to use a unique, integrated approach to help locate and test the suitability of sites for eelgrass. We will modify a GIS-based model predicting site suitability based on site conditions and the present location of eelgrass in the system. To define conditions for eelgrass, we will utilize our experimental and field data gathered over the past 15+ years on light, temperature, salinity, substrata, current velocity, and nutrient levels. In collaboration with the Oregon Graduate Institute, we will use existing numerical models to produce maps of temperature, salinity and currents in the general outer estuary region (lower ~30KM).  Turbidity (from which light conditions will be calculated) will be assessed using an experimental turbidity product based on an algorithm of the diffuse attenuation coefficient of light, K(490), developed for the SeaWiFS satellite sensor, and modified for the Moderate-resolution Imaging Spectroradiometer (MODIS) instrument on board the Earth Observation System (EOS) spacecraft, Aqua. Based on these analyses, and utilizing the GIS-based model, we will identify potential sites for experimental planting of eelgrass.  Prior to final site selection we will examine the sites for any factors that may impact eelgrass through a unique geo-referenced video imagery data set collected of the entire estuary by the Lower Columbia River and Estuary Partnership. Finally, we will test a subset of these sites using experimental plantings of eelgrass in 100m2 plots. The initial efficacy of the plots to function as fishery habitat will be evaluate by sampling Dungeness crab presence in the plots. This integrated project should provide the first predictive maps of sites suitable for eelgrass and other submerged aquatic vegetation in the lower estuary.