Pre and post-breach monitoring of the Qwuloolt Restoration project in the Snohomish River Estuary

In August 2015 the breaching and lowering of approximately 1500 meters of levee returned tidal inundation to the Qwuloolt Restoration Project a 150 hectare site in the lower Snohomish River estuary. Qwuloolt is one of several large restoration projects planned for the Snohomish estuary in the next decade for recovery of wild salmon and other biota. Together these projects could restore several thousand acres and constitute one of the most significant restoration efforts in Puget Sound. A comprehensive pre-breach monitoring effort for the Qwuloolt was conducted over the past six years to evaluate a broad suite of biotic and abiotic attributes (e.g., taxonomic composition of plant, invertebrate, fish, and bird assemblages; land forms, hydrology, and chemistry) attributes across project and reference sites. Results from the pre-breach monitoring provide an invaluable foundation for scientifically rigorous post-breach evaluation of project performance, and contribute to estuary-wide understanding of cumulative effects of restoration and basic estuarine ecology of Puget Sound. Preliminary post breach data over the first six months document rapid, dramatic change as tidal dynamics are reintroduced into a subsided, hydrologically isolated area, and the biota shift from relatively few species dominated by freshwater non-natives, to more native, estuarine species