Unscreened water-diversion pipes pose an entrainment risk to the threatened green sturgeon, Acipenser medirostris.

Autor: Mussen TD; Wildlife, Fish, and Conservation Biology Department, University of California Davis, Davis, California, United States of America., Cocherell D; Wildlife, Fish, and Conservation Biology Department, University of California Davis, Davis, California, United States of America., Poletto JB; Wildlife, Fish, and Conservation Biology Department, University of California Davis, Davis, California, United States of America., Reardon JS; Wildlife, Fish, and Conservation Biology Department, University of California Davis, Davis, California, United States of America., Hockett Z; Department of Civil and Environmental Engineering, University of California Davis, Davis, California, United States of America., Ercan A; Department of Civil and Environmental Engineering, University of California Davis, Davis, California, United States of America., Bandeh H; Department of Civil and Environmental Engineering, University of California Davis, Davis, California, United States of America., Kavvas ML; Department of Civil and Environmental Engineering, University of California Davis, Davis, California, United States of America., Cech JJ Jr; Wildlife, Fish, and Conservation Biology Department, University of California Davis, Davis, California, United States of America., Fangue NA; Wildlife, Fish, and Conservation Biology Department, University of California Davis, Davis, California, United States of America.
Jazyk: angličtina
Zdroj: PloS one [PLoS One] 2014 Jan 15; Vol. 9 (1), pp. e86321. Date of Electronic Publication: 2014 Jan 15 (Print Publication: 2014).
DOI: 10.1371/journal.pone.0086321
Abstrakt: Over 3,300 unscreened agricultural water diversion pipes line the levees and riverbanks of the Sacramento River (California) watershed, where the threatened Southern Distinct Population Segment of green sturgeon, Acipenser medirostris, spawn. The number of sturgeon drawn into (entrained) and killed by these pipes is greatly unknown. We examined avoidance behaviors and entrainment susceptibility of juvenile green sturgeon (35±0.6 cm mean fork length) to entrainment in a large (>500-kl) outdoor flume with a 0.46-m-diameter water-diversion pipe. Fish entrainment was generally high (range: 26-61%), likely due to a lack of avoidance behavior prior to entering inescapable inflow conditions. We estimated that up to 52% of green sturgeon could be entrained after passing within 1.5 m of an active water-diversion pipe three times. These data suggest that green sturgeon are vulnerable to unscreened water-diversion pipes, and that additional research is needed to determine the potential impacts of entrainment mortality on declining sturgeon populations. Data under various hydraulic conditions also suggest that entrainment-related mortality could be decreased by extracting water at lower diversion rates over longer periods of time, balancing agricultural needs with green sturgeon conservation.
Databáze: MEDLINE
Externí odkaz: