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.

Aerial view of Flaming Gorge Dam and Reservoir
A USFWS biologist displaying an endangered razorback sucker captured on the San Juan River while conducting native fish surveys
Biologists remove entangled fish from a trammel net while performing native fish surveys

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.

A photo of the Piute Farms Waterfall which flows into Lake Powell. A raft sits just downriver of the waterfall electroshocking for fish
USFWS biologists scanning a humpback chub for a PIT tag captured on the Colorado River at Black Rocks while conducting native fish surveys

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.

A bar graph illustrating the total number of fish encounters by type since 1979. bonytail were detected most frequently by permanent antennas
Researchers began deploying PIT tag antennas just 15 years ago, the amount of data they have collected is incredible. Today, these units collect over 90% of our annual encounter records for Colorado pikeminnow, razorback sucker and bonytail. Due to the remote habitats selected by humpback chub and their affinity for staying put, PIT tag antennas have not recorded many encounters for this species.

Permanent Interrogation Array Antennas