Invasive species are insects, animals, plants, or diseases that are introduced to an area outside of their native range and that cause distinct harm to the native species and people that live there. Invasive species are so damaging because, entering into a new ecosystem, they are without natural competitors and predators, and are thus able to rapidly spread, displacing native species. Invasive species can be harmful not only to native species, but also to existing infrastructure and ultimately, the economy. According to Colorado Parks and Wildlife, the United States spends upwards of $200 billion a year trying to reduce the spread of invasive species. Below are some of the most damaging invasive species in Colorado, and what you can do to help slow their spread.

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1. Freshwater Mussels

Quagga Mussels - US Department of Agriculture - Flickr - OutThere Colorado
The Quagga mussel is an aquatic invasive species. These mussels attach to hard surfaces such as pipes, screens, rock, logs, boats, and ropes. Photo Credit: USDA, photo by Bob Nichols (Flickr).

Invasive Quagga Mussels, as well as European Zebra Mussels, have both made their way into the waterways and lakes of Colorado, posing significant harm to Colorado’s ecology and infrastructure. Unintentionally brought to the United States on trans-oceanic ships, these mussels have traveled across the United States on the bottom of recreational boats and are rapidly spreading. Due to their rapid proliferation and dense colonies, these species have been known to displace native aquatic species, as well as clog up water infrastructure, such as pipes and dams.

Zebra mussel cluster - D. Jude - NOAA Great Lakes Environmental Research Laboratory - Flickr - OutThere Colorado
Zebra mussel cluster. Photo Credit: D. Jude, Univ. of Michigan, NOAA Great Lakes Environmental Research Laboratory (Flickr).

To slow the spread of these mussels, first learn to identify them by their ability to stick to hard surfaces, something no native mussels can do. Second, make sure you always clean any equipment that has been submerged in water before moving from one body of water to another. Finally, report to Colorado Parks and Wildlife any time you think you may have found either of these two species.

2. Yellow Toadflax

Yellow Toadflax - Peter O'Connor - Flickr - OutThere Colorado
Yellow Toadflax. Photo Credit: Peter O’Connor (Flickr).

Don’t let the beauty of this yellow flower trick you: its aggressive reproduction and ability to spread rapidly has caused this Mediterranean native to force out native grasses across the Centennial State. Identified by its conspicuous yellow and cream-colored snapdragon-like flower, Yellow Toadflax should always be removed when found anywhere in Colorado. To exterminate the flower, Colorado authorities recommend a combination of mowing, hand removal, and herbicides.

3. Emerald Ash Borer

Emerald Ash Borer - US Department of Agriculture - Flickr - OutThere Colorado
Emerald Ash Borer beetle. Photo Credit: US Department of Agriculture (Flickr).

The Emerald Ash Borer is a half-inch long, Asian beetle that has decimated Ash trees across the United States since its introduction in 2002. While the beetle is sometimes mistaken for a variety of native beetles, it can be identified by its elongate, narrow body, and its vivid, emerald green sheen. As far as removing this invasive species from Colorado goes, the most impactful action you can take is helping to slow its spread by never transporting firewood from one location to another destination, as the beetle might be transported with it.

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4. Northern Pike

Northern Pike - Mike Nielsen - Flickr - OutThere Colorado
Northern Pike. Photo Credit: Mike Nielsen (Flickr).

First introduced to Colorado in 1950, then again in 1970, the Northern Pike is a voracious predator that has drastically reduced native fish populations in some rivers. Growing as large as thirty pounds and three feet long, the Northern Pike has come to be a revered trophy for Colorado fisherman and is known for its tendency to destroy fishing gear due to their sharp teeth and violent fight. To reduce their numbers, fisherman should never release any Pike they catch.

Refer to Colorado Parks and Wildlife for more information on these and other invasive species, and always remember to report invasive species to your local wildlife officials.

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