Working in the pouring rain, biologists with the Nebraska Game and Parks Commission release a 3 kilogram non-reproductive male pallid sturgeon into the Missouri River.
Severe weather rocked the United States the last two weeks creating tornadoes in the Southeast, thunderstorms in the Midwest, and snow in Nebraska. This didn’t stop the field work. In fact, the fishing seemed to improve as severe weather moved into the Missouri River Basin and scientists braved the elements to locate fish.
Telemetry tracking of migrating reproductive pallid sturgeon has shown various behaviors during spring weather events. When water temperatures dropped in the Upper Study Section in 2007 and 2010, fish were observed to stop swimming upstream, swim back DOWNstream, or just hold where they were. When storms caused the Lower Missouri River levels to rise and water temperatures to drop in 2010, telemetry data showed a fish pause her upstream migration and tuck-in close to the bank, presumably for protection from the fast water and flood debris. When the flooding calmed down, she continued her upstream migration and successfully spawned.
It is very difficult to discern what exact environmental cues are triggering pallid sturgeon behavior and spawning success. But by correlating movement and behavior with environmental and physical conditions repeatedly over time, scientists are gathering evidence and developing theories to explain these mysteries.
