Earth Notes: Endangered Razorback Suckers

Mar 15, 2017

With humped back and small eyes, the razorback sucker is an odd-looking fish. Native to the Colorado River basin but now endangered, it’s been found recently in an unexpected place, the large artificial reservoir of Lake Powell.  

Razorback researchers on Lake Powell
Credit Travis Francis

In 2011 and 2012, researchers with the U.S. Fish and Wildlife Service and Utah Division of Wildlife Resources surveyed the San Juan arm of the lake and found hundreds of razorback suckers. Even better, many of them were untagged, indicating they might be wild and breeding naturally, rather than reintroduced.   

Using tracking devices, biologists observed some of the fish traveling great distances between Lake Powell and tributaries. Other razorbacks spent their entire lives in the lake. That prompted a similar study in the Colorado River arm of the lake—and they found razorback suckers are breeding there too, perhaps as many as 3,000 of them.

Fish and Wildlife Service biologist Travis Francis suspects that razorbacks are breeding in these locations because conditions resemble the environment in which they evolved three to five million years ago, when lava dams on the Colorado created natural reservoirs similar to Lake Powell.  

Biologists and resource managers are keen to learn more about how razorbacks in the lake are interacting with those in the rivers, because genetic diversity is important to survival of the species.