Going with the flow
June 27, 2018
Laboratory studies of the Comprehensive Sturgeon Research Project (CSRP) are designed to examine environmental conditions that control development, behavior, and survival of pallid sturgeon. To date, laboratory experiments have been conducted in facilities capable of simulating a limited range of physical conditions. To bridge the gap between laboratory environments and actual river conditions more effectively, the next generation of experimental work requires facilities that better approximate the real river.
In mid-June 2018, CSRP researchers began a series of trials with recently hatched pallid sturgeon in a flume located at the University of Minnesota, Saint Anthony Falls Laboratory (SAFL) in Minneapolis, Minnesota. Each trial has a different stage of development from newly hatched, drifting free embryos to larvae at the onset of active feeding (What is a free embryo? See previous blog entry “A Change is Gonna Come”). In contrast to the challenges of working in a deep, muddy, and unpredictable river, the flume provides an experimental channel where scientists can control and manipulate conditions like water velocity, water quality, sediment transport, and substrate. The SAFL flume is a continuously flowing oval; 7.5 meters in length and 1.8 meters wide. The flume uses a motor-driven paddlewheel for moving water and is capable of maintaining hydraulic conditions that are appropriately scaled for young sturgeon and other river fishes. The flume is also equipped with an acoustic Doppler velocimeter (ADV) that is moved through the flume on a computer-driven carriage to map velocity and other hydraulic metrics with high-resolution.
In the experimental trials at SAFL, researchers are evaluating movement, behavior, and survival of the free embryos or early larvae as velocities range from 10 to 25 centimeters per second. The performance of each life stage will be analyzed in relation to flume configuration and velocity fields. This collaboration between USGS and SAFL scientists and engineers will produce data to improve understanding of drift rates of larval pallid sturgeon and to design a new flume to be built at the USGS – Columbia Environmental Research Center.
