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Missouri River Dye Trace Experiment at Searcy’s Bend, Missouri

By Brandon Sansom, PhD and Robert Jacobson, PhD

May 6, 2021


Aerial imagery showing the study extent of the dye trace experiment
Aerial imagery showing the study extent of the dye trace experiment in the Missouri River near Huntsdale, Missouri on May 5, 2021. Several fluorometers were deployed throughout the reach to monitor the concentration of dye. Additional videos and photographs were captured using unmanned aerial systems (UAS’s) at a select site near the middle of the study reach and images of the entire reach were captured from a fixed-wing aircraft.

CERC scientists conducted a dye-trace experiment on the Missouri River near Hunstdale, MO on May 5, 2021 in cooperation with scientists from the USGS Geomorphology and Sediment Transport Laboratory – Integrated Modeling and Prediction Division in Golden, CO, the USGS Geosciences and Environmental Change Science Center – National Unmanned Aircraft Systems Project Office in Denver, CO, Missouri University of Science and Technology, the U.S. Army Corps of Engineers, and Surdex Corporation St. Louis, MO. The scope and scale of the experiment was unprecedented on the Missouri River.

The study involved releasing approximately 23 gallons of Rhodamine-WT into the river about two miles downstream of the Interstate-70 bridge in Boone County, MO. Rhomamine-WT is a non-toxic but very visible dye that is frequently used to study time of travel in river systems. Scientists monitored the dispersal of dye downstream for five miles using a series of in-situ fluorometers installed throughout the river. In addition, a series of videos and photographs were captured using multiple aircraft.

The results of the dye experiment will help scientists better understand how age-0 pallid sturgeon disperse downstream and how they are able to find suitable habitat in the complex flow of the Missouri River. In particular, the data will be compared to computer simulations to evaluate how well the computer models predict transport of larvae into restoration projects — called interception-rearing complexes, or IRCs — designed to increase growth and survival of pallid sturgeon. The results will also be useful for predicting transport and fate of contaminants, for example after an oil spill. Moreover, comparing the results from in-situ sensor and remote sensing images may improve the ability to monitor dye dispersal using remote sensing technology in future dye-release experiments.

Aerial imagery collected from the fixed wing aircraft on passes 1 (left) and 2 (right) after the dye release
Aerial imagery collected from the fixed-wing aircraft on passes 1 (left) and 2 (right) after the dye release. Approximately 20 minutes elapsed between the acquisition of these images.