Research and Monitoring
The video above describes a seining effort to count young Colorado pikeminnow. The video voice-over is Tom Chart, former Program Director for the Upper Colorado River Endangered Fish Recovery Program.
Research and monitoring produce information to evaluate progress to recovery and guide management efforts. Program partners provide the science to support decision making regarding recovery actions, to see what is working and what isn’t, and make adaptive improvements.



Releases from Flaming Gorge Dam provide flows that benefit larval razorback sucker in the Green River.
This razorback sucker was captured on the San Juan River. It was tagged, weighed and measured, then released back into the wild.
Netting for invasive northern pike happens in the early spring prior to spawning. By removing these fish before they spawn, it reduces the populations in the river.


Biologists capture native and nonnative fish in the eddy below the Piute Farms Waterfall. The waterfall is located below Mexican Hat, Utah.
U.S. Fish and Wildlife Service biologists, weigh, measure and scan for a passive integrated transponder (PIT) tag, on a treatened humpback chub.
A fish biologist releases an endangered Colorado pikeminnow back into the Colorado River after monitoring it’s weight, length and PIT tag.
PIT Tag antennas in the Upper Colorado and San Juan Basins
The recovery programs began installing permanent interrogation arrays within the basin in 2008. These are relatively large systems. Antennas are composed of one or more linked 15’ panels which are anchored to the substrate. These installations are strategically located, frequently on tributary rivers, near their confluence with the mainstem or are integrated into various infrastructure on the mainstem rivers (diversion dams, fish passages). When a fish swims near an antenna panel, the array logs an encounter. Encounters are sent to a server by an automated process.
Video above is of a permanent antenna on the White River. You can see the structure because of low water. Fish cross the antenna and PIT tag data is recorded.
Video shows placement of a portable submersible antenna in the Colorado River.
