Unscreened water-diversion pipes pose an entrainment risk to the threatened green sturgeon, Acipenser medirostris
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...
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Published in | PloS one Vol. 9; no. 1; p. e86321 |
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Main Authors | , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
Public Library of Science
15.01.2014
Public Library of Science (PLoS) |
Subjects | |
Online Access | Get full text |
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Summary: | 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. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Competing Interests: The authors have declared that no competing interests exist. Current address: Sacramento Regional County Sanitation District, Sacramento, California, United States of America Conceived and designed the experiments: DC NAF JJC. Performed the experiments: TDM DC JBP JSR ZH AE HB. Analyzed the data: TDM NAF JJC. Contributed reagents/materials/analysis tools: NAF MLK. Wrote the paper: TDM NAF JJC. |
ISSN: | 1932-6203 1932-6203 |
DOI: | 10.1371/journal.pone.0086321 |