Multi-Scale Action Effectiveness Research in the Lower Columbia River and Estuary, 2011 - FINAL ANNUAL REPORT

Multi-Scale Action Effectiveness Research in the Lower Columbia River and Estuary (Final Annual Report, 2012)

“…Despite the confounding factors limiting our ability to discern geographic origins of some fish in our samples, the genetic stock compositions presented in this report are similar to results obtained earlier (Sather et al , 2012. The percentage of Upper Columbia River Summer/Fall juveniles in our unmarked SRD samples collected in 2012 (33%) is consistent with previous years' results (33%-35%).…”

“…The five stock groups contributing minor percentages to the 2012 samples (1%-8%) were also the same in the two previous periods, as were the three stock groups estimated to be absent or nearly absent. In addition, the seasonal shifts in SRD habitat use reported by Sather et al ( , 2012 was also apparent in our current results with Spring Creek Group Tule Fall run fish most abundant from February to April and Upper Columbia River Summer/Fall stock group in April to July. While very few Chinook salmon juveniles were analyzed from November and December sampling (n = 16), these included spring run juveniles from the Willamette River stock group which were also identified in previous years' fall collections.…”

“…The trends in fish community composition noted at the SRD are similar to those observed during previous years of sampling (Sather et al , 2012. During the 2012 sampling effort, beach seine catches were dominated by native taxa, but non-native species composed 15 of the 27 species captured.…”

“…The highest densities of native taxa (excluding salmon) occurred during fall. Threespine stickleback accounted for 90% of the total catch during the sampling period, which accounts for a higher proportion noted during previous years of sampling (Sather et al 2012).…”

“…Three species of salmon, unmarked and marked, were captured at the SRD sites during the October 2011-December 2012 time period. Juvenile steelhead, while rare in beach seine catches at the SRD (Sather et al 2012, were not captured via beach seine during 2012. However, these species were captured via boat electrofishing during May and June.…”