title: Rearing in natural and recovering tidal wetlands enhances growth and life-history diversity of Columbia Estuary tributary coho salmon Oncorhynchus kisutch population.
abstract: This study provides evidence of the importance of tributary tidal wetlands to local coho salmon Oncorhynchus kisutch populations and life-history diversity. Subyearling and, to a lesser extent, yearling O. kisutch life histories utilized various estuary habitats within the Grays River, a tidal freshwater tributary of the Columbia River estuary, including restoring emergent wetlands and natural forested wetlands. Migration timing data, size distributions, estuary residence and scale patterns suggest a predominance of subyearling migrant life histories, including several that involve extended periods of estuary rearing. Estuarine-rearing subyearling O. kisutch exhibited the greatest overall growth rates; the highest growth rates were seen in fish that utilized restoring emergent wetlands. These results contrast with studies conducted in the main-stem Columbia River estuary, which captured few O. kisutch, of which nearly all were hatchery-origin yearling smolts. Restoration and preservation of peripheral and tributary wetland habitats, such as those in the Grays River, could play an important role in the recovery of natural O. kisutch populations in the Columbia River and elsewhere.
authors.affiliation: University of Washington, School of Aquatic and Fishery Sciences, 1122 N.E. Boat Street, Box 355020, Seattle, WA 98195-5020, U.S.A.
authors.forename: B E
authors.initials: BE
authors.lastname: Craig
authors.forename: C A
authors.initials: CA
authors.lastname: Simenstad
authors.forename: D L
authors.initials: DL
authors.lastname: Bottom
mesh_terms: D025041:Animal Migration; D000818:Animals; D063366:Estuaries; D017684:Oncorhynchus kisutch / Q000254:growth & development*; D045483:Rivers; D014861:Washington; D053833:Wetlands
keywords: Pacific salmon; habitat restoration; migration; nomad; resilience; scale pattern analysis