What Are Invasive Species?
Invasive species are plants, animals, insects or diseases that are not native to Colorado and have harmful negative effects on the economy and environment. They are introduced accidentally or intentionally outside of their native range. Because they are not native, they have no natural competitors or predators. Without these checks and balances, the invaders are able to reproduce rapidly and out-compete native species. Invasives have harmful effects on natural resources and disrupt our use of land and water in Colorado.
Aquatic Nuisance Species (ANS)
Aquatic Nuisance Species (ANS) are aquatic plants and animals that invade lakes, reservoirs, rivers and streams. Examples of ANS are the zebra mussel, quagga mussel, New Zealand mudsnail, Asian carp or Eurasian watermilfoil. ANS can also include fish pathogens and diseases, such as viral hemorrhagic septicemia (VHS) or whirling disease.
Invasive Species are Everyone’s Problem!
Invasive species damage Colorado’s lands and waters, hurt the economy, ruin recreational opportunities, result in a loss of property values and threaten public health. They consume enormous amounts of water reducing the supply for livestock, wildlife and humans. They impede water distribution systems for municipal, industrial and agricultural supplies. They can damage boats, gear and fishing equipment, and impair all forms of water based recreation. They displace wildlife habitat and reduce forage, shelter and range for big game and other native species.
Invasive species are the second greatest threat to biodiversity after habitat loss. These species completely alter the food web and destroy habitat that native wildlife need to survive. Invasive species compete with native organisms for limited resources, alter habitats, reduce biodiversity and are capable of causing extinctions of native plants and animals. This can result in huge economic impacts and fundamental disruptions of Colorado’s ecosystems.
Overall, economic costs associated with the management of invasive species in the United States are estimated to exceed $120 billion per year (Pimetal, 2005). In many cases, once an invasive species has established a population, eradication is nearly impossible. Prevention through education and personal action is the best method to prevent the spread of these harmful invaders.
Anglers, You Can Make A Difference!

Keep your angling gear free of mud, plants and organic debris between each and every use. Unknowingly moving a species from one body of water to another, even within different stretches of the same river, can start a domino effect of invasion causing irreversible ecological damage.
Clean, Drain and Dry
Inspect
Examine all equipment including waders, footwear, ropes, anchors, bait traps, dip nets, downrigger cables, fishing lines, and field gear before leaving the water body.
Clean
Thoroughly remove any visible material, including plants, animals and mud on footwear and gear with a stiff brush and then disinfect using one of the following four methods:
- Submerge in a quaternary ammonia-based cleaner
(6 oz per gallon of water) for 20 minutes - Soak in 140°F water for 10 minutes
- Freeze overnight
- Dry for at least 10 days
Drain
Completely drain water from boat, motor, bilge, bladders, wells and
bait containers away from the ramp.
Dry
Allow everything to dry completely between each use. Most ANS,
such as New Zealand mudsnails, can survive several days out of water
and can be transported on footwear or gear
More Ways to Help…
- Join the Colorado Parks and Wildlife Aquatics Nuisance Team
- Be a responsible pet owner. For more information, please visit Don’t Let it Loose.
Video by Jessie Ermark. Jessie is an educator with Colorado Parks and Wildlife.