The Contribution of Tidal Fluvial Habitats in the Columbia River Estuary to the Recovery of Diverse Salmon ESUs
NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION SEATTLE WA NORTHWEST FISHERIES SCIENCE CENTER
Pagination or Media Count:
The 2008 Biological Opinion on Operation of the Federal Columbia River Power System established estuary restoration goals for ten-year survival improvements of 9 for ocean-type and 6 for stream-type ESUs. To support these goals, a qualitative assessment process Columbia River Estuary Recovery Plan Module was devised to identify limiting factors and to prioritize estuary restoration actions based on their presumed survival benefits. The method ranks the potential benefits of various restoration projects based on published results and professional judgments about their relative effectiveness. Empirical estimates of survival benefits are unavailable, however, and the actual contributions of single or cumulative estuary actions to the survival goals in the Biological Opinion are unknown. Today scores of wetland restoration projects have been undertaken in the estuary as a method to recover at-risk salmon populations throughout the Columbia River basin, based in part on the latest information about the estuary s role as a productive nursery ground for juvenile salmon Bottom et al. 2005 2008 2011 Roegner et al. 2008 2010 2012 Johnson et al. 2011. Recent genetic data collected in the estuary have shown evidence of important stock-specific differences in estuarine habitat use Bottom et al. 2008 Teel et al. 2009 that have not been considered in the selection or design of restoration projects. Moreover, the population response to estuary restoration remains poorly understood because Research, Monitoring, and Evaluation RME programs have focused exclusively on the performance of estuarine-rearing juveniles rather than their ultimate contribution to adult returns.
- Hydrology, Limnology and Potamology