Estuaries occur where freshwater from streams and rivers mixes with salt water from the ocean. These unique, tidal environments are some of the most productive ecosystems on earth and provide important feeding and resting habitat for young salmon, migratory birds, and many other species. The Estuaries Vital Sign tells us about the extent of intact estuary habitat in Puget Sound.

Estuaries also have important commercial, recreational, and environmental value for people. Historically, these areas have been heavily developed for agricultural and industrial needs. Throughout Puget Sound, people are working to implement strategic restoration actions to restore the natural processes that create and maintain these valuable nearshore habitats.

Skokomish River Delta

Key Vital Sign Messages

  • There has been extensive historic loss of tidal wetland habitat in Puget Sound. While much of this loss has been in the large river deltas, smaller estuaries are also currently a fraction of their historic extent.
  • Estuarine habitat is shaped by the influences of tides, freshwater, sediment transport and sediment deposition. Restoration efforts that target these ecological processes maximize resilience and help to sustain continued ecosystem function in the face of change.
  • The estuaries of North Puget Sound (Nooksack, Samish, Skagit, Stillaguamish and Snohomish) historically made up over 80 percent of the tidal wetland habitat in Puget Sound. However, these large river deltas have experienced the greatest absolute loss of tidal wetlands and recovery at the Puget Sound scale is not possible without substantial restoration in this region. A number of watershed-based local teams, in collaboration with tribal and agency partners, are working to accelerate the pace of estuary restoration while maintaining landscape-scale benefits for agriculture, waterfowl and shellfish management, flood hazard reduction, and recreational use of these large deltas.
  • Since 2006, approximately 3,420 acres of estuarine wetland have been restored to tidal flooding in the 16 largest river deltas in Puget Sound. Large gains have been made in the Nisqually, Snohomish, Skagit and Skokomish deltas in this time period, with the Nisqually and Skokomish being notable because they represent large proportions of the historic tidal extent for these deltas. Early restoration progress often represents the least expensive and challenging projects in the region comparatively, with future actions increasing in cost and complexity.
  • The number of large-scale estuary restoration projects implemented depends on a successful combination of funding, available land, community support, knowledge, project development, and permitting.


Background Documents

Implementation Strategy

The Partnership and its affiliated network of researchers works with the three Strategic Initiative Lead Teams on Implementation Strategy development and operationalization. Please read more about these teams and our shared work at

Indicator Targets

Contributing Partners