Diet of juvenile and adult American Shad in the Columbia River

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Abstract

The diet of juvenile and adult American shad Alosa sapidissima captured from various locations in the Columbia River was investigated during 2007 and 2008. Collection efforts in 2007 were restricted to fish collected from existing adult and juvenile fish collection facilities located at Bonneville Dam and to adult shad captured by angling downstream from Bonneville Dam. In 2008, we used gillnets, electrofishing, beach seining, or cast nets to collect juvenile and adult shad from the saline estuary near Astoria (approximately river km 24) to just upstream from McNary Dam (approximately river km 472). We examined the stomach contents of 436 American shad captured in 2007 and 1,272 captured in 2008. Fish caught within the river were much more likely to contain food items than fish removed from fish collection facilities. The diet of age-0 American shad varied spatially and temporally, but was comprised primarily of crustaceans and insects. Prey diversity of age-0 American shad, as assessed by the Shannon Diversity Index, increased with decreasing distance to the estuary. Pre- and partial-spawn adult American shad primarily consumed Corophium spp. throughout the Columbia River; however, post-spawn adults primarily consumed gastropods upstream of McNary Dam.

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Publication type Report
Publication Subtype USGS Unnumbered Series
Title Diet of juvenile and adult American Shad in the Columbia River
DOI 10.3133/70043647
Year Published 2011
Language English
Publisher U.S. Geological Survey
Publisher location Portland, OR
Contributing office(s) Western Fisheries Research Center
Description 30 p.
Larger Work Type Report
Larger Work Title Impact of American shad in the Columbia River. Final Report Performance Period: May 1, 2007 – January 15, 2011.
First page 9
Last page 38
Country United States
State Oregon, Washington
Other Geospatial Bonneville dam
Google Analytic Metrics Metrics page
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