South Puget Sound Salmon Enhancement Group

Salmon and Estuaries

Salmonids use estuaries and nearshore areas for migration, juvenile rearing (smolt stage), refuge, and feeding. Salmon spend time in estuary areas to adjust from living in freshwater to living in saltwater through a process called smoltificaiton. Habitat for these young fish include, shallow tidal channels with eelgrass and fringing marsh areas that offer foraging opportunities and places to hide from predators. This stage of the salmon life cycle is marked by high growth rates. The bigger a smolt can get, the fewer the mouths that can swallow it whole. Although estuaries provide an abundance of food, salmonids are very selective about what they choose to eat. Food choices vary by the size and age of the salmon.

Hard Shoreline Armoring

Shorelines have suffered significant changes over the last 100yrs. Marsh, and wetland habitat bordering estuaries has receded considerably as urban areas have expanded. Bulkheads, seawalls and other hard shoreline armoring structures have disrupted shore drift. Shore drift being defined as the movement of material from eroding bluffs and streams, to shorelines. Wind and waves pick up these particles in one place and drop them off in another. This movement of sediment is responsible for maintaining the structure and habitat of Puget Sound beaches. The construction of hard shoreline armoring often involves the removal of shoreline vegetation, both for building ease and to increase viewing potential. The loss of vegetation means a reduction in shade, protective cover, organic inputs and food (insects) for smolts. Additionally, surf smelt, sand lance, and herring, that salmon feed upon; all spawn in the upper intertidal zone. Bulkheads degrade their spawning habitat.

Soft Shoreline Armoring: An Environmentally Friendly Alternative

A more natural alternative to hard shoreline armoring has been termed soft shoreline armoring. Soft shoreline armoring includes local materials such as gravel, sand, logs, and root masses to enhance the natural beach shape and processes. The process of replacing hard armoring with soft armoring restores degraded habitat and addresses long term erosion control. The increased shoreline complexity reestablishes the spawning habitat of forage fish. Stairs and beach access points can be designed to minimize shoreline intrusion. Also adding native vegetation helps improve site drainage and slope stabilization.

 SPSSEG Esturary Improvement Projects

• Allison Springs
• Frye Cove
• Case Inlet Bulkhead Removal
• Beachcrest
• Little Skookum Creek