Efficacy of a sensory deterrent and pipe modifications in decreasing entrainment of juvenile green sturgeon (Acipenser medirostris) at unscreened water diversions

Abstract

Water diversions pose a risk to passing fishes. We evaluated the effectiveness of several methods for preventing green sturgeon from being pulled into a simulated water diversion. We made recommendations for future management practices from the data that include considerations of fish sensory ecology as well as feasibility of implementation.

Hydraulics Near Unscreened Diversion Pipes in Open Channels: Large Flume Experiments

“…We investigated the relationship between the hydraulic fields surrounding an unscreened diversion pipe and fish swimming behavior under relevant diversion and channel flow characteristics, using a large flume at the J. Amorocho Hydraulics Laboratory (JAHL) of University of California, Davis. Results of the fish behavior and entrainment risks near unscreened water diversions with and without various fish protection devices were reported recently by Mussen et al (2013Mussen et al ( , 2014aMussen et al ( , b, 2015 and Poletto et al (2014Poletto et al ( , 2015. Mussen et al (2013) evaluated juvenile Chinook salmon (mean fork lengths between 12.5 and 13.3 cm) entrainment risk and their behavioral responses to an unscreened diversion pipe under various channel flow and diversion rate conditions during day, night, and in turbid water conditions.…”

“…Most of the smaller sized irrigation pipes used in these waterways are currently unscreened (CalFish, ). These unscreened water‐diversion pipes are potentially harmful to migrating and resident fishes, including several threatened or endangered species (Turnpenny et al ., ; Nobriga et al ., ; King and O'Connor, ; Gale et al ., ; Kimmerer, ; Grimaldo et al ., ; Mussen et al ., ; and Poletto et al ., , ). Fish entrained into these diversions (drawn in with water inflow) are either killed directly by physical damage from the pumps, or indirectly through stranding in the seasonally irrigated canals, ditches, and fields supplied by the water diversions (Mussen et al ., ).…”

Experimental evaluation of the effect of a light-emitting diode device on Chinook salmon smolt entrainment in a simulated river

“…A 0.15-m/s sweeping velocity was generated to simulate a river current, and a water withdrawal rate through the pipe of 0.57 m 3 /s. This set-up simulated ecologically and hydraulically relevant conditions common to the Sacramento river and near-identical set-ups have been utilized in several experiments investigating Chinook salmon smolt and green sturgeon Acipenser medirostris (Ayres, 1854) behavior and entrainment (Mussen et al, 2013(Mussen et al, , 2014a(Mussen et al, , b, 2015Poletto et al, 2014Poletto et al, , 2015Ercan et al, 2017). A detailed description of the flume and its operational methods can be found in Mussen et al (2013).…”

Sturgeon in the Sacramento–San Joaquin Watershed: New Insights to Support Conservation and Management

“…To potentially improve mitigation strategies at unscreened water diversions, the efficacy of several methods to reduce green sturgeon entrainment was tested at unscreened water diversions: a strobe light sensory deterrent and two structural pipe modifications, which included a terminal pipe plate and upturned pipe configuration (Poletto et al 2014b an average of 44.0% of fish were entrained through the diversion pipe. Though the presence of the strobe light did not significantly affect fish entrainment rates, the terminal pipe plate and upturned pipe modifications significantly decreased the percentage of fish entrained relative to control conditions.…”