Catfish Wranglin’ on the San Juan River

by Karen Burke, Native Aquatics Technician

It was a clear, cool day in the Southern Utah desert as we rolled through the dust and dirt to the put-in near the town of Montezuma Creek, Utah. We were to spend four days on the San Juan River electrofishing primarily in search of non-native channel catfish and the native, endangered razorback sucker and Colorado pikeminnow. I was excited and nervous for my first work trip that would also be my first multi-day river trip.

Colorado pikeminnow
Photo:  John Caldwell UDWR

razorback sucker
Photo: John Caldwell UDWR

The project we would be working on is in conjunction with the San Juan River Basin Recovery Implementation Program. This program aims to protect and recover populations of the native Colorado pikeminnow and razorback sucker in the San Juan River while continuing to develop water resources. The Colorado pikeminnow is a large, carnivorous fish and a top predator of the Colorado River system. They can grow up to 6 feet long and sport a smooth, slender body, a large mouth, and pharyngeal teeth (teeth located on the gills in the back of their throat). The razorback sucker is one of a few native sucker fish that is recognized by its obvious and unique sharp hump or keel behind its head (hence the name razorback). They have fleshy lips on the underside of their head, can grow up to about 3 feet long, and feed on plankton as well as various bottom-dwelling organisms and material.

One challenge to the survival of these native endangered fish species has been habitat alteration and fragmentation in the river system. This has occurred largely due to human influence and infrastructure. For example, dams and diversions trap sediment and nutrients while altering historic flow rates. Channelization along with introduced and now invasive plant species (such as tamarisk and russian olive) alter stream morphology by stabilizing banks and preventing the river from taking its historical, meandering course. This historical stream morphology provided habitat for these fish in backwaters and throughout a large floodplain. Another major cause of native species decline is competition and predation by non-native species, like the channel catfish. Reducing the numbers of non-native fish can be a key step in restoring native fish populations. It is obvious that restoring the native fish populations in the San Juan River will take lots of effort and perhaps some major changes. For now, our crew would be doing our part by catching the wretched channel catfish so that we could estimate their populations and remove them - all in a valiant effort to help our spectacular native fish thrive.

Raft e-fishing on the San Juan
Photo:  Karen Burke UDWR

I got thrown right into learning the ways of electrofishing from our rafts. I soon realized that one minute the water will be calm and undisturbed, and then suddenly you are bombarded with numerous fish surfacing all at once. As the fish appeared I did my best to scoop them up into the net. I was even working up a sweat at times. The different fish species would tend to each respond in a unique way to the shock. The flannel-mouth suckers (another native fish, but not endangered) would spastically thrash, the razorback suckers would dart along the surface of the water, the catfish would float along totally stunned, and the elusive Colorado pikeminnow would surface for just a moment and propel themselves quickly away.

Karen with channel catfish
Photo:  Chelsea Gibson UDWR

The most chaotic moment of electrofishing occurred when Brian and I ventured down a precarious side channel. We became completely surrounded by catfish, many more than I could possibly net. I did my best as Brian attempted to spin the boat in every direction to catch as many as possible. In that moment, it became apparent to me how crucial catfish eradication efforts are in this river system. The numbers of these non-natives in the San Juan River are impressive. With the many that we are able to catch on these trips, there is hope that native fish species will be able to better compete for habitat and avoid predation.

Karen on the "sticks"
Photo:  Chelsea Gibson UDWR

The second morning we awoke to a river that took on a reddish-brown complexion. There would be more electrofishing in these muddy waters and my first chance to row the boats. I quickly came to love the feeling of navigating the waters and the excitement of avoiding obstacles. The remaining days on the beautiful San Juan River to the take out at Mexican Hat, Utah quickly floated by as the geology became more fascinating and beautiful and I began to learn the nature of whitewater.

The trip was filled with cute young catfish, heinously disgusting old catfish, and even some of the lovely native fish species. The most memorable catfish of the trip appeared not to have any eyes and had a large bloody lesion on its side. I was a bit horrified. The trip left me dreaming of being surrounded by fewer ugly channel catfish and more native sucker fish and Colorado pikeminnow. These dreams would soon come true on the Green River.