A functioning, resilient Puget Sound ecosystem is defined to include tidally-influenced wetland habitats at the estuaries of Puget Sound’s major rivers that provide ecosystem functions, goods, and services. 75 percent of river delta tidal wetlands have been lost or degraded in Puget Sound. River delta estuaries, a unique environment where freshwater mixes with salt water and sediments collect, provide important feeding and resting habitat for young salmon, migratory birds, and many other species that cannot find these unique benefits in any other place in our landscape. These wetlands consist of several distinct habitat types ranging from tidal forests to unvegetated mudflats, all of which have a unique ecological role. Tidal wetland habitat also contributes to the Puget Sound ecosystem through the production of plant material, which fuels a rich food web as it decays. These areas are also highly valuable for people: they have been heavily developed and they provide some of the most fertile agricultural lands in the region. The Estuaries Vital Sign tracks indicators of restoration in the 16 largest river deltas in Puget Sound.