Yaquina Tidal Wetland Restoration

This project restores a 55-acre tidal wetland site along the Yaquina River just upstream of the town of Toledo. The Yaquina estuary has lost about 70% of these vegetated tidal wetland habitats due to diking, ditching and tide-gating. This has reduced salmonid rearing habitat and other valuable ecosystem services. Restoration will increase tidal water inundation and connectivity to the marsh by removing about half of the remnant dike, filling drainage ditches, creating new tidal channels to increase rearing habitat for fish, placing sediment and large wood structures in strategic areas. Extensive seeding and planting of native forbs, shrubs and trees will also occur. These activities will also help to restore tidal flow, encourage the development of emergent wetland and transitional shrub and spruce swamp by fostering conditions that allow for the spread and establishment of high and low marsh vegetation and scrub-shrub and spruce swamps, to increase habitat diversity and complexity and provide traditional materials for native basketry and other uses. Additionally, restoring sediment and wood inputs and tidal flow will allow for the re- establishment of marsh vegetation whose growth and senescence is critical to building up the marsh plain which is highly subsided due to its long diking history, providing resiliency to sea level rise. Debris, including a remnant culvert, will be removed from the site. Conservation ownership in
perpetuity by The Wetlands Conservancy (TWC), will assure the restored ecosystem functions continue to sustain and support endangered coho salmon and other federally listed species (e.g. green sturgeon, eulachon). Other partners include: City of Toledo, Confederated Tribes of Siletz Indians, Oregon Central Coast Estuary Collaborative, Pacific Marine and Estuarine Fish Habitat Partnership, TWC, Pacific States Marine Fisheries Commission, Oregon Department of Fish and Wildlife and US Fish and Wildlife Service Partners for Fish and Wildlife.

Because the projects scheduled end date is after the PCSRF FFY 2019 award closes, no funds allocated for this project are reported as match to PCSRF funds.

The loss of historic vegetated tidal wetlands due to ditching, diking, and tide-gating activities has been recognized as a contributor to the decline of Oregon Coast Coho, which are federally listed as threatened, earning the Yaquina estuary designation as critical habitat, and estuary restoration as one of the necessary actions listed in NOAA’s 2016 Oregon Coast Coho Recovery Plan (Recovery Plan).

While the importance of estuarine habitats in the smolt stage of the coho salmon life cycle is well-documented, newer studies show that juvenile coho also use the deep and narrow channels of tidal marshes for foraging and growth. Juveniles were once thought “lost” to the population if they were washed out of their stream environment by high winter flows. However, chemical otolith analysis has led to the recognition that juveniles can reside for long periods of time in estuaries. The alternative life history pattern of these “nomads” is of benefit to the overall population of these endangered fish. Studies by NOAA and the Oregon Department of Fish and Wildlife (ODFW) in the Salmon River estuary 40 miles to the north of the Yaquina showed that after restoration, estuary-rearing coho contributed around 30% of the returning adults. Likely due to enhanced foraging and predator protection, many coho once thought lost from production are returning as adults (Jones et al. 2014). The more time these fish remain in estuaries as juveniles, the faster they grow, therefore, they have a higher chance of survival when they reach the ocean.

Similar to what has been seen in the Salmon River estuary, restoring natural hydrologic regimes in the Yaquina’s tidal wetlands will also help to increase coho survival and reproduction. This habitat restoration project will provide fish with full access to tidal channels, create new tidal channels, enhance habitat productivity, and increase areas for foraging, shelter, and winter refuge from high flows.