Authors: Gina M Benigno Ted R Sommer
Publish Date: 2007/11/28
Volume: 600, Issue: 1, Pages: 297-305
Abstract
Although seasonal floodplains represent one of the most dynamic and productive of aquatic ecosystems the sources of this productivity are poorly understood We examined composition and sources of chironomid drift in the Yolo Bypass the primary floodplain of the Sacramento River We found that invertebrate drift during winter floodplain inundation is dominated by a single species the newly identified chironomid Hydrobaenus saetheri Diptera Chironomidae In order to determine sources of chironomids in the Yolo Bypass invertebrates were sampled from several potential sources prior to and during initial floodplain inundation Rehydration of dried floodplain sediments from several locations showed that H saetheri dominated insect emergence from this colonization pathway By contrast H saetheri was not a substantial component of inundated floodplain ponds or of tributary inputs to the floodplain We conclude that the initial pulse of invertebrate abundance in Yolo Bypass floodwaters is dominated by chironomid emergence from sediments in multiple regions of the floodplainWe owe special thanks to Chris Hogle and Laura Bermudez for assistance with field sampling and to Peter Cranston at UC Davis for assistance with chironomid identification and specifically for his efforts to identify H saetheri Ted Grosholz provided valuable input to the study design and Paul Lutes and Peter Moyle provided access to laboratory facilities at the UC Davis Center for Aquatic Biology and Aquaculture Dave Feliz California Department of Fish and Game graciously provided access to the Yolo Bypass Wildlife Area sampling sites Initial sorting of invertebrates to family was done by Wayne Fields Tag Engstrom and Colleen Hatfield CSU Chico provided comments and advice that greatly improved the clarity of the manuscript Funding was provided by the CALFED Ecosystem Restoration Program
Keywords: