The Roaring Fork Conservancy is studying the effects of drought on invertebrate populations #COdrought

Macro Invertebrates via Little Pend Oreille Wildlife Refuge Water Quality Research
Macro Invertebrates via Little Pend Oreille Wildlife Refuge Water Quality Research

From Aspen Public Radio (Marci Krivonen):

“We just started hearing a lot about it from local fishing guides that they just weren’t seeing the hatches on the river, from local anglers, and even from residents on the Fryingpan,” he says. The problem was the bugs weren’t hatching. The hatches are key to good fishing because the bugs are dinner for trout.

A winter-time phenomenon called anchor ice could be to blame. It’s ice that builds up on the riverbed instead of on the river’s surface and it happens in cold temperatures and shallow waters.

“The river ran at 39 cubic feet per second for almost four months last winter and you probably remember we had a pretty cold winter as well, so there was a lot of concern,” Lofaro says.

The Roaring Fork Conservancy is so concerned it decided to replicate a study done following the 2002 drought. This multi-year analysis will examine bugs in the river, take water temperatures throughout the winter and look at the economic impact of a slower fishing season.

Today a team is collecting bug samples from the Fryingpan River as part of the study. Bill Miller is a biologist from Fort Collins. He is carefully moving bugs and mud into a small container. The contents will be taken to a lab and examined under a microscope.

“In a sample like this, there’ll be hundreds of bugs, so we can’t really tell what the diversity is until we get it into the lab and then go through and sort the sample, and get all the identifications and put them in their classifications,” he says.

The more diversity and the higher amount of bugs mean the stream is healthy. The team is taking samples from three sites along the river and will compare the findings to previous years.

A few miles downriver, a separate team is decked in waders and spread across the width of the river. They’re slowly trudging upstream and catching fish in nets.

This is called “fish shocking” but the team isn’t really shocking the fish. They’re dipping long, metal poles into the river that send out an electrical current. The current attracts fish. For the team of ten, it’s hard work.

More Roaring Fork River Watershed coverage here and here.

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