By Kimberly Chojnacki and Aaron DeLonay
In mid-June, 4 USGS research crews from the Lower Missouri River packed up their equipment and headed north to the Upper Missouri and Yellowstone Rivers in Montana (figure 1). Two boats and crews were deployed to help track the migration behavior of large, fast moving, adult pallid sturgeon up the Yellowstone River, and to determine when and where they are spawning (figure 2). Another boat and crew carried advanced sonar equipment to observe and record spawning behavior. And a hydrology research crew was deployed to characterize habitat at spawning sites. The crews drove two days from Columbia, Missouri to Sidney, Montana where they joined biologists from Montana Fish, Wildlife and Parks (MFWP) and researcher, Pat Braaten, from the USGS Project Office in Fort Peck, Montana. Pat and his colleagues from MFWP have been tracking adult pallid sturgeon on the upper Missouri River from Lake Sakakawea upstream to Fort Peck Dam, and up the Yellowstone River to Intake Dam (figure 1).
The large rivers used by pallid sturgeon have been modified and altered to meet human needs, including flood control, irrigation, navigation, hydropower, and recreation. The Upper Missouri and Yellowstone rivers are unique within the range of the pallid sturgeon in that the morphology of their channels has not been significantly altered and the Yellowstone still retains a natural hydrograph and temperature regime unaltered by large dams. Scientists hope that by observing and comparing the behavior of pallid sturgeon in different parts of its range, they can gain insight into how sturgeon migration, spawning, and recruitment may be altered in response to different threats.