Invasive Species in Colorado Trout Streams

How Can Colorado Fly Fisherman Prevent the Spread of Aquatic Hitchhikers?

In recent years, there has been a noteworthy concern about the health of our trout streams and the impact due to harmful effects non-native invasive species can have on a river. First of all, aquatic Hitchhikers as described by the Aquatic Nuisance Species (ANS) Task Force are “aquatic and terrestrial organisms, introduced into new habitats throughout the United States, therefore producing harmful impacts on aquatic natural resources in these ecosystems and on the human use of these resources.”

Fly Fishermen who spend any amount of time fishing their favorite water would be exceptionally disappointed to find out the fish jumping on the local trout stream were Asian Carp not his beloved rainbow and brown trout.  It is devastating to find that a microorganism is growing in the head waters of his beloved high country watershed causing the water to be depleted of life sustaining oxygen.  But these are modern possibilities. Already, carp, New Zealand Mud Snails, Northern Pike and even smallmouth bass have impacted popular trout streams in Colorado.

Why Is This Concerning?

It is a definite concern that other invaders may someday threaten our aquatic resources located here in the Colorado River Drainage. Protecting our aquatic resources is important for all users but fly fisherman have the opportunity to take the lead in the fight against aquatic hitchhikers.  The spreading of harmful plants, animals, fish and other organisms threatens Colorado’s water habitats. Further examples include mussels, rusty crayfish, Didymo or “Rock Snot” and many others.

There are even trout streams throughout the country where non-native rainbow and brown trout have been removed to protect native populations of cutthroat or brook trout.

How Are They Getting Here?

Aquatic Nuisance Species hitch rides on clothing, boats in addition to any item used in the water.  Consequently, this means your waders and wading boots too.  The non-native aquatic hitchhikers are readily transported to other waters via many popular recreational activities. When brought to another lake or river, the nuisance species may spread.  If the habitat is compatible, these species become established as a result and cause drastic changes to our aquatic resources.

Stopping aquatic hitchhikers requires only a few simple preventative procedures.

How to avoid the spread of aquatic hitchhikers:

·        Remove any visible mud
·        Eliminate water from equipment before transporting
·        Wash clean and dry anything that contacted water including boats, trailers, equipment, clothing, dogs, waders and wading boots.
·        Never release plants, fish or animals into a body of water unless they came out of that body of water

How to clean your fly fishing gear free of Aquatic Hitchhikers

·        Use hot water (140 degrees F) or salt water to clean your gear
·        Wash your dog (as close to gear as some can get) with as warm a water as possible and brush its coat
·        Spray the boat, trailer, rods, reels, nets waders and wading boots.  If hot water is not available use a high pressure spray.
·        Dipping equipment into a 100% vinegar solution for 20 minutes will kill all your hard to get aquatic hitchhiker species
·        Use a one percent salt solution for 24 hours to replace the vinegar dip (2/3 of a cup salt per 5 gallons water)
·        Dry Equipment, if possible. Hence, fisherman should allow for five days drying time before entering new waters.
·        Finally, make a switch to a rubber souled wading shoe like the Simms Guide Wading Boot.  Kudos to Simms who only manufactures and markets rubber bottomed wading boots

Why should we fear Aquatic Hitchhikers in Colorado

·        Reduce game fish populations
·        Ruin boat engines
·        Render lakes/rivers useless for fishing, boating and swimming
·        Dramatically increase the operating costs of industrial processes like dam maintenance, water plant operation and power plant operation.
·        Reduction of native species
·        Directly affect human health
·        Reduce real estate and tax values
·        Adversely effect economies due to water dependent communities

Final Thoughts:

Especially relevant is the cost of invasive species in the United States exceeds one billion dollars per year. Therefore, fly fisherman should come together and stop the spread of invasive species. You may find more information on the subject you may visit The Stop Aquatic Hitchhiker web site at .  The web site belongs to ANS Task Force public awareness campaign. US Fish and Wildlife Service and US Coast Guard sponsors the site.

The Aquatic Nuisance Species (ANS) Task Force is an intergovernmental organization that is dedicated to preventing and controlling aquatic nuisance species. In addition to implementing the Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990.  Visit the web site; for a worldwide prospective on invasive aquatic species.

Brody Henderson, Senior Guide and Web Content Writer