Clear Creek Macroinvertebrate Sampling

Samples taken annually in Sept. No samples taken in 2013 - high water.

Samples not taken above Gravel pit in 2017 or at the Gravel Pit in 2021.

No Samples 2020 - COVID. Slices represent % of total of sample Species under 10% not indicated in key

The chart to the left is a summary of the data collected from 2010 to 2021. The macroinvertebrates population in Clear Creek is diverse with all four of the major orders that are important to fly fishers represented: Ephemeroptera (Mayfly), Plecoptera (Stonefly), Tricoptera (Caddis fly), and Diptera (Midge).

A couple of interesting observations on the data.

Since 2010 the distribution of the macro invertibrates has shifted from predominately Midges to Mayflys, primarily Baetis. In 2021 we saw another significant shift at both sites that were tested

Super Family Description

(Mayhem Gulch and above the Gravel Pit) where the porportion of Mayflies dropped and Caddis flies increased. This change is unexplained and may just be sampling variation.

Common Name %

(Mayfly)

PLECOPTERA (Stonefly)

TRICHOPTERA (Caddisfly)

The table to the left shows the % breakdown within each family of the genera. This data is from all three Clear Creek sites since our sampling started in 2010. There are a few other orders represented in the sampling, i.e. aquatic worms, beetles and mites.

DIPTERA (Midge)

This gives a general idea as to the specific type of insect you might try using when fishing Clear Creek canyon.

CPW fish survey data suggests that the brown trout population is stable with approximately 2400 fish per mile at a test site approximately one mile below the Highway 119 junction.. Although they are small, 7 to 12 in on average, they are naturally reporoducing and anecdotally have good weight to length ratios.

CPW has been trying to establish a Whirling Disease resistent strain of naturally reproducing rainbow trout for quite a few years by annually stocking Rainbow Trout fingerlings. There is some evidence of the Rainbows reproducing, but currently the population density is not sufficient to curtail stocking efforts.

This is the link to the CPW fishing summary for Clear Creek.

https://cpw.state.co.us/thingstodo/Fishery%20Survey%20Summaries/ClearCreek.pdf