Spawning Chinook Photo: © IDFG 2004

Salmon and Wetlands

Riverine wetlands benefit young salmon directly, by providing them with shelter during the start of their lives. Riparian areas, or areas along streams or rivers, continue to benefit salmon indirectly throughout their lives, by helping to keep streams and rivers cool and free of sediment. The wetland vegetation shades the pools along the bank, and it also traps sediments during floods and binds the banks to prevent erosion. Sediment-free water is essential to salmon. For example, salmon eggs and alevin (hatchlings) depend on ample flows of clean water through gravel to bring them air and food. Sediment can smother the eggs and young salmon, and rob them of food. Sediment can also trap young salmon upstream and prevent their migration to the ocean. Likewise, sediment can block adult salmon downstream and prevent their return to spawning sites.

The wetlands of estuaries, such as at the mouth of the Columbia River, also provide essential resting and feeding places for salmon. Young salmon spend at least a short time in these quiet waters before moving into the ocean; fall Chinook salmon spend months there before beginning their adult journeys. Returning salmon also may rest briefly in the nutrient-rich waters of the estuaries, consuming one last massive meal before they journey to their spawning grounds.

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