Bringing the Missouri River into the Laboratory

By Columbia Environmental Research Center

By Aaron DeLonay, Kimberly Chojnacki, Maura Roberts, Susannah Erwin

February 10, 2020

A conceptual rendering of the Ecoflume to be constructed at the U.S. Geological Survey, Columbia Environmental Research Center drawn to approximate scale (A, sideview; B, overhead view). The flume is a continuous-loop, racetrack flume 1.5 meters wide and 1.0 meters deep with transparent walls in the straight sections to observe sturgeon. (Rendering courtesy of Erik Steen, St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN).

The Comprehensive Sturgeon Research Project (CSRP) scientists from the U.S. Geological Survey, in collaboration with scientists at Saint Anthony Falls Laboratory (SAFL) at the University of Minnesota, are working to complete the design of a large, indoor Ecoflume to study the early life-stages of pallid sturgeon from egg deposition through the first year of life. The design of the flume is guided by results of successful preliminary studies conducted at SAFL in 2018 (see previous blog post, Going with the flow) with free-embryo pallid sturgeon and by computational fluid dynamics modeling. The proposed Ecoflume designed for CERC will be an oval, continuous-loop, racetrack flume with an overall length of approximately 11.5 meters and volume of nearly 9,500 gallons. Water will continuously recirculate through the 1.5-meter wide by 1-meter deep channel of the Ecoflume at velocities up to 1 meter per second. A novel, removable paddlewheel system shown to be safe for sturgeon embryos and free embryos will be used to move the water (0–0.5 meters per second) in the Ecoflume for studies with the earliest life stages. A pump system with diffuse jets will be used to move water (0–1.0 meters per second) for studies with larvae and juveniles with greater swimming capacity. The Ecoflume will be temperature controlled and scientists will have the ability to modify substrate and bedforms to simulate conditions like that experienced by young sturgeon in the Missouri River. The Ecoflume will be instrumented with digital imaging systems and acoustic Doppler velocimeters to study pallid sturgeon behavior, micro-habitat selection, energetics, growth, survival, and comparative responses of shovelnose sturgeon and other native species under controlled fluvial conditions. Studies will provide insight into monitoring activities and management actions at a scale that is not -possible in the large, turbid, Missouri River. The Ecoflume is anticipated to be completed in spring of 2021.

Pallid sturgeon free embryos (11 days post-hatch) during preliminary design studies in the EcoFlume at Saint Anthony Falls Laboratory, University of Minnesota. A novel paddlewheel system moved water through the continuous-loop flume at 0.1 to 0.25 meters second without harming pallid sturgeon early life stages.