USGS scientists have been working this summer and fall with the U.S. Fish and Wildlife Service’s Columbia Fisheries Resource Office to map river habitat at sites where they are sampling for young sturgeon. The crew is targeting age-0 sturgeon. These include fish that hatched this year and generally range in size from 10-110 millimeters, or fish that are a little less than half an inch long to about 4.5 inches long. One of these river habitat sites is just upstream from Hartsburg, Missouri near river mile 161 on the right descending bank. At this site, a wing dike has been removed and there is large sandbar. The USFWS has trawled 500-meter-long transects at this site for multiple years. Several times this summer and early fall our habitat crew has coordinated to map depth, velocity, and substrate in conjunction with those sampling efforts.
We have mapped the site about once a month since June. Our maps at the USGS gage upstream at Boonville, Missouri range in discharge from 131,000 to 246,000 cubic feet per second. We mapped the entire bend in August using our multibeam echosounder to get an idea of how the bar fit into the larger hydraulic context of the bend in Missouri River.
Our detailed maps focus on the region where the USFWS crews sample for young sturgeon. We mapped the trawl locations in detail using GPS for navigation and positioning, a single-beam echosounder to measure depth and an acoustic Doppler current profiler (ADCP) to measure velocity on transects with 5-meter spacing. We will combine this high-resolution depth and velocity data with the locations where young sturgeon were sampled in trawls. This will help us learn more about the places in the river where young sturgeon are found and how these habitats change with changes in discharge.
By Carrie Ellliott