Record Details
Seasonal and interannual variation in juvenile salmonids and associated fish assemblage in open waters of the lower Columbia River estuary
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Seasonal and interannual variation in juvenile salmonids and associated fish assemblage in open waters of the lower Columbia River estuary |
| Names |
Weitkamp, Laurie A.
(creator) Bentley, Paul J. (creator) Litz, Marisa N. C. (creator) |
| Date Issued | 2012-10 (iso8601) |
| Note | This is the publisher’s final pdf. The published article is copyrighted by National Marine Fisheries Service, NOAA, Scientific Publications Office and can be found at: http://fishbull.noaa.gov/. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. |
| Abstract | The transition between freshwater and marine environments is associated with high mortality for juvenile anadromous salmonids, yet little is known about this critical period in many large rivers. To address this deficiency, we investigated the estuarine ecology of juvenile salmonids and their associated fish assemblage in open-water habitats of the lower Columbia River estuary during spring of 2007–10. For coho (Oncorhynchus kisutch), sockeye (O. nerka), chum (O. keta), and yearling (age 1.0) Chinook (O. tshawytscha) salmon, and steelhead (O. mykiss), we observed a consistent seasonal pattern characterized by extremely low abundances in mid-April, maximum abundances in May, and near absence by late June. Subyearling (age 0.0) Chinook salmon were most abundant in late June. Although we observed interannual variation in the presence, abundance, and size of juvenile salmonids, no single year was exceptional across all species-and-age classes. We estimated that >90% of juvenile Chinook and coho salmon and steelhead were of hatchery origin, a rate higher than previously reported. In contrast to juvenile salmonids, the abundance and composition of the greater estuarine fish assemblage, of which juvenile salmon were minor members, were extremely variable and likely responding to dynamic physical conditions in the estuary. Comparisons with studies conducted 3 decades earlier suggest striking changes in the estuarine fish assemblage—changes that have unknown but potentially important consequences for juvenile salmon in the Columbia River estuary. |
| Genre | Article |
| Identifier | Weitkamp, L., Bentley, P., & Litz, M. (2012). Seasonal and interannual variation in juvenile salmonids and associated fish assemblage in open waters of the lower columbia river estuary. FISHERY BULLETIN, 110(4), 426-450. |
