Temporary Residence by Juvenile Salmon in a Restored Estuarine Wetland

Juvenile Pacific salmon utilizing the recently restored Lincoln Avenue wetland system in the Puyallup River estuary, Tacoma, Washington, were studied during their spring seaward migration in 1987 and 1988. Mark/recapture experiments indicated that 0.06% of the outmigrating juvenile chum salmon (Oncorhynchus keta) and 0.59% of the outmigrating juvenile chinook salmon (O. tshawytscha) entered the wetland. Estimated residence times of individual juvenile chum salmon averaged approximately 2 d (range 1–9 d) and juvenile chinook salmon approximately 5 d (volitional) and 38 d (spray-marked) (total range 1–43 d). The restored wetland system currently provides habitat for the temporary residence of migrating juvenile chum and fall chinook salmon, but rigorous evaluation of the benefit of residency is constrained by the lack of data from comparable natural wetlands.