I recently volunteered, through Trout Unlimited, to help with some research being done by a CSU Masters Student and funded by Colorado Parks and Wildlife. The task was to electrofish for brook trout in two streams close to the cabin--Sheep Creek and George Creek, collect data on their size, and then take a small clipping from a fin to use for genetic analysis. There were four of us on this expedition including Dr. Kurt Fausch a retired professor at CSU from whom I learned a lot about fishes, fisheries, native versus non-native species, reclamation, and more. He is the author of a book For the Love of Rivers, which you can learn more about at the website: fortheloveofrivers.com. He is passionate about what streams and rivers bring to the human experience beyond the obvious--water. The others were masters student, Audrey as well as an undergraduate, Matt.

Brook trout are not native to Colorado, yet they are the most populous species in our streams. They were likely imported from the east in the late 19th century. Because of their spawning cycle (fall, not spring) and aggressive feeding, they have replaced native species such as a variety of cutthroat trout in most Colorado waters. There are a variety of research and reclamation projects going on to bring the cutthroat back. Around here, the native species is the greenback cutthroat.

I can't say I fully understand Audrey's research. But, I know she is heavily involved in a project to reintroduce native cutthroat trout into some headwaters in the Long Draw area. In order to understand how the introduced trout will move throughout the area, breed and migrate, she is doing genetic diversity studies on the existing brook trout. To have something to compare with, she needs genetic information from brook trout in other areas and George Creek and Sheep Creek were two of the chosen sites.

We drove into George Creek by taking S County Road 169 where after a few miles, we took a 4WD road to ACME Creek road. It was a pretty rough road and I was proud of our Ford Expedition's performance in 4WD over the rocks and washout. We even drove through the burned out area from a wildfire a few weeks ago. We did not take the obvious ACME Creek Road because of a need to do a river crossing at Sheep Creek which has a lot of water right now. We eventually arrived at George Creek and prepared for the electrofishing.

The sign here is an old sign from a previous attempt to introduce greenback cutthroat. The road continues on to Cornelius Creek.

Over the past several years, brook trout have been removed from George Creek in preparation for stocking with the native and threatened greenback cutthroat. This attempt has been unsuccessful based on our electrofishing experience. We managed to catch well over 100 brook trout along a few hundred meter span of the river. Don't get too excited if you are a fisherperson. None of them were "keepers". In fact, the majority were less than a year old (about 50 mm in lengh), the rest were one year old and perhaps a few that were 2 years old or older. The fish hatch in spring and then grow in the summer, and they will grow at a roughly uniform rate. As a cold-blooded animal, they halt growth in the winter. So, we could tell age from the length of the fish. The biggest one was perhaps 6" long, probably 3 years old. In fact, I learned that there are bones in a fish that get a new layer each day, so sectioning those bones and counting the "rings" can tell the age in days! We did not do that. Instead, Matt carefully measured the length of each fish while I recorded the length on paper. He also took a genetic sample from any fish one year old or older and Audrey carefully collected and tagged each sample in a separate envelope.

Matt and Audrey processing the fish we caught.

One of the bigger trout from George Creek.

Electrofishing sounds a bit scary. (And, it was when there was some lightning later in the day.) But, it is largely harmless to the fish. You wear a backpack that has a battery in it along with controls to set up the electic shock parameters (wave shape, frequency and voltage). There is an anode probe and a cathode "tail" that come from the backpack. You walk along the stream with the tail dragging in the water, and press a trigger on the anode probe to create an electrical path through the water. This shocks any nearby fish for a few seconds. The goal is to catch the stunned fish in a net and move it to a bucket of water quickly. The fish recover within a few seconds. After catching a bucket of fish, we'd stop for a while to process them.

George Creek is quite small so it was mostly a 2-person project with someone to carry the bucket (me).

We wore waders, which insulated us from the shock. But, I'm told it can be quite an experience to accidently touch or fall into the water while using the electrofishing machine. So, we had a protocol to yell out "OFF" if I fell while trailing behind with the bucket. 

I had a net too. And, I snagged a few of the fish. But, the more experienced people did the bulk of the "catching" work.

After we were done at George Creek we had lunch and then moved on to Sheep Creek. And, we decided to take the ACME Creek road back to County Road 80C and brave the water crossing. The road was actually in pretty good shape since they likely graded it and cut trees on the way to help with gaining access during the fire. The water in Sheep Creek was pretty fast and pretty deep since they are letting a lot of water out of Eaton Reservoir (for the city of Greeley). But, the Expedition plowed right through without any problems. 

At Sheep Creek, we used two electrofishing machines, Kurt took one and Matt the other. They each had nets and Audrey was netting also. I, again, was the bucket boy. I did not want to wade in the fast water and risk dumping the bucket of caught fish. That would not have been good at all. So, I walked along the bank. When they'd net a fish they would hand the net to me and I'd hand them an empty net. I'd then carefully dump the fish into my bucket and we'd move on. It was hard work, at least for those in the water. It rained some, along with lightning. Not a good idea to be standing in water electrofishing with lightning around, so we'd take advantage of those times to process the fish we'd caught so far.

Kurt, Matt and Audrey working a nice deep hole.

Kurt and Audrey in some fast water.

Matt was quite persistent in making sure we got every fish, even if it meant getting into a tangle of downed trees.

Audrey's goal was 40 brook trout from Sheep Creek. We got 41, along with a couple of nice brown trout (8" long or so), a sucker of some kind, and a fourth species that I don't recall. There is a lot of fish diversity in Sheep Creek. I've even caught a rainbow trout a few times.

In all, a long and tiring day, but very interesting and rewarding. I'm glad to say that as far as I know, we only lost one fish out of the roughly 200 caught. And, the results of the survey and genetic testing will help in the eventual restoration of native species to Colorado waters.

One final note. We observed COVID-19 safety protocols throughout the day by wearing masks. Yes, we were outdoors, but also in close proximity to each other. So, my only regret of the day is that I don't really know what any of those folks look like!