Pacific salmon rely on nearshore waters and estuaries for survival during a part of their life cycle.     Salmon use estuaries and nearshore areas for migration, juvenile rearing, refuge, and feeding.

Pacific Salmon Species   chinook salmon chum salmon coho salmon pink salmon sockeye salmon cutthroat trout steelhead

a migratory path a place to adjust refuge from predators a rich food web

		A Migratory Path The nearshore region of Puget Sound includes shallow saltwater, nearby wetlands, estuaries, beaches, and bluffs. These areas are important zones for young salmon as they migrate from rivers to the sea. Salmon travel through estuaries twice; first as juveniles on their way to the sea, then as adults migrating back to spawn.
		A Place To Adjust Juvenile salmon move to estuaries for weeks or months as they grow and adapt to salt water before moving out to sea. Here is where salmon make a critical transformation from a freshwater to a saltwater fish, a process called smoltification. Changes in body chemistry, appearance, and behavior occur. When salmon return from sea as adults, they pause again in estuaries to adapt to freshwater, before heading upstream to spawn.
		Shelter In Shallows Because predators such as larger salmon and sculpins tend to avoid the turbid waters often found nearshore, these regions provide some protection for young salmon. Shallow tidal channels with eelgrass and fringing marsh plants offer places to forage and hide.
		A Rich Food Web Juvenile salmon experience the highest growth rates of their lives while in estuaries and nearshore waters. A complex detritus-based food web provides rich and abundant prey. Food production by marsh plants, seaweeds, eelgrass, epiphytes, and sediment microalgae surpasses food production in open waters. Despite the vast range of prey items to eat, juvenile salmon are very selective. The food chosen by young salmon varies with the size and age of the salmon.

Salmon & Shorelines: Habitat Loss

• Loss of Marshes
  When marshes are lost, young salmon lose food and shelter. Studies show a 73 percent decline in salt marsh habitats bordering Puget Sound. Nearly all salt marsh habitats within major urban areas along Puget Sound have been destroyed. The Puyallup River Delta, for example, lost 100 percent of its nearshore habitat.
 

• Pollutants
  Recent studies show that juvenile salmon may suffer adverse effects from passing through polluted estuaries and nearshore areas. Human-caused stresses (toxic chemicals, pathogens and parasites) can cause immune dysfunction, increased susceptibility to disease, and impaired growth.
 

• Bulkheads
  Bulkheads, seawalls, and other hard shoreline armoring structures can disrupt shore drift, starving beaches of sediments, and juvenile salmon of food and shelter. Bulkhead construction can also destroy shoreline vegetation, eliminating cover and food sources for young salmon.
 

• Loss of Shoreline Vegetation
  Loss of vegetation along the shore is of particular importance to juvenile salmon. Shoreline vegetation stabilizes the shoreline, provides shade, protective cover, organic input, and food (insects) to young salmon moving in close to shore.
 

• Docks & Piers
  Docks can block light to underwater habitats such as eelgrass meadows, a source of food and shelter for juvenile salmon and other marine life.
 

Related Topics

Related Links

Puget Sound Nearshore Environments: Salmon Use, Large River Mouth, King County Department of Natural Resources. A color illustration showing zones used by juvenile salmon.

Wild Salmon: Our Precious Natural Resource, Washington State Department of Fish & Wildlife. Salmon/Steelhead species information.

WildWatchcams: Salmon, Washington State Department of Fish & Wildlife. Salmoncam.

Salmon Friendly Seattle, City of Seattle, Washington. Seattle efforts to save salmon, salmon-friendly practices, and much more.

Contaminant Exposure in Juvenile Salmon, NMFS Publications. Puget Sound estuaries, pollution, and juvenile salmon health.