Concerns about the health of the Fryingpan River have spurred a Basalt-based conservation group to raise funds to study populations of insects and other critical indicators.

Anglers, environmentalists and residents of the Fryingpan River Valley believe they have detected a drop in the number of insect hatches along the famed trout-fishing stream this year. Now scientists will be employed to test the theory.

Roaring Fork Conservancy has raised $35,000 to conduct studies into the Fryingpan River’s health. The conservancy is a nonprofit organization focused on water quality and quantity issues in the Roaring Fork watershed.

A consulting firm with expertise in river issues will count the number of macroinvertebrates this fall and next spring on the Fryingpan. The same firm conducted a count about a decade ago to create a baseline.

“The bugs don’t seem to be there the way they have been,” said Rick Lofaro, executive director of the conservancy. Numerous observers have noticed insect hatches only in isolated pockets, he said. There seem to be fewer areas of hatches and less density in the hatches that exist, he added.

The consultant — Miller Ecological Consultants — will also study the extent of Didymosphenia geminata, an invasive algae also known as rock snot. The presence of the American dipper bird population will be studied because it is regarded as an indicator of a healthy ecosystem. The water flows and temperatures will also be assessed.

The studies are collectively being called the Comprehensive Lower Fryingpan River Assessment. The town of Basalt has pledged $5,000 for the bug study and $10,000 for the economic study, Lofaro said. Other funds came from private sources.

Lofaro said the observers are concerned that the decrease in bugs could potentially affect fish populations. The 13 miles of the Fryingpan River below Ruedi Reservoir is designated a “gold medal fishery” because of the size and density of trout. The Roaring Fork River below the confluence is also gold-medal water.

The Fryingpan River is one of the most popular fly-fishing spots in the world and pumps millions of dollars annually into the economy. The conservancy is updating a study it authorized in 2002 to estimate the economic impact.

Lofaro said there have been low flows on the river, which could be affecting its health. “Two years of drought, it’s a concern,” he said.

Studies have indicated that minimum winter flows of between 70 and 80 cubic feet per second are best for the health of the stream, Lofaro said. Last winter, the U.S. Bureau of Reclamation, which manages the Ruedi water, reduced flows to the minimum of 39 cfs for an extended time because operators feared the snowmelt wouldn’t be enough to fill the reservoir.

Records show the flows on the lower Fryingpan River ranged between 38 and 40 cfs from Nov. 7 through March 18 for a total of 132 days, and they hovered between 41 and 46 cfs from March 19 to April 29, another 42-day stretch.

A river with lower flows and slow-moving water faces a greater risk of anchor ice. Super cold temperatures can cause ice to form on the river bottom as well as along banks and in slow-moving areas. That ice can affect the habitats where insect larvae live, Lofaro said. When ice dams break, they can scour the river bottom the same as running a bulldozer over it, he said. That is also detrimental to insect larvae.

An objective of the river assessment is to determine solutions for managing water releases from Ruedi Reservoir in a way that will prevent negative environmental and economic impacts, according to an outline of the project supplied by the conservancy.

Lofaro said officials with the Bureau of Reclamation were made aware of the concerns at an annual meeting on Ruedi Reservoir management in July. Reclamation bureau spokeswoman Kara Lamb said the agency recently performed an Environmental Assessment as part of contracting available water from Ruedi Reservoir. Modeling done as part of that study didn’t anticipate new effects on the lower Fryingpan River, she said. Therefore, the bureau doesn’t agree that additional studies are necessary.

Lamb also noted that the water releases from Ruedi Reservoir dam are dictated by the project’s rules and regulations as approved by Congress. Altering those rules requires Congressional approval.

scondon@aspentimes.com