Dave Britton, U.S. Fish and Wildlife Service The Difference Between "Native" and "Invasive"Native species are organisms that have resided in an environment for a very long time — long enough that they've actually co-evolved with all the other organisms in that environment. When an ecosystem is comprised of native species, the natural habits and life cycles of all organisms work together to support their shared ecosystem. In short, native species all benefit from one anothers' presence. Conversely, invasive species are organisms that aren't native to their present environment. They were native to someplace else, but now that they've been moved, all the other plants and animals from their ancestral home aren't around to keep them in check. This arrangement usually presents huge problems for native species. With no one to check their activities and population, invasive species can proliferate wildly and overrun the ecosystem, throwing it out of balance.
NPS / Jake Frank How Aquatic Invasive Species SpreadAquatic invasive species (AIS) are non-native organisms that live in watery habitats, like ponds, lakes, rivers, streams, and oceans. Sometimes, they're called aquatic nuisance species (ANS), but both terms can be used interchangeably. Both aquatic plants and animals can be invasive. In order to travel, aquatic plants typically require damp or wet conditions to stay alive. If a boat isn't properly drained and dried, water can pool in nooks or creases, giving invasive plants a lifeline until the boat is used again. Aquatic animals, meanwhile, don't always need partial or total submersion to survive. Crayfish can crawl from land to a nearby body of water all on their own. Critters like mussels can cling to an object when it's wet and just hang there. Adults can survive dry conditions for days or months, biding their time until whatever they've stuck to is submerged again. Their larval offspring (called "veligers") can survive in small amounts of standing water for several days. Aquatic plants and animals are usually small enough to escape human notice, and their offspring may be too small for human eyes to see. Their small size and ability to survive dry spells is a huge part of what makes AIS so easy to accidentally transport from one body of water to another.In 2007, invasive quagga mussels were found in Lake Mead National Recreation Area. Shortly after that, more were found in the Colorado River Basin and associated waters. All of these detections were hundreds of miles away from the nearest known quagga mussel infestations at the time, proving that recreational watercraft can (and does) transport invasive species over great distances across land. Commercial rafting companies that operate at Dinosaur National Monument also operate on or adjacent to river systems with known quagga and zebra mussel infestations. This includes the waters of the Colorado River around Lake Mead and Glen Canyon National Recreation Area. Anyone using water recreation equipment has a critical role to play in protecting Western waterways from the spread of aquatic invasive species. A Natural and Economic DisasterAquatic invasive and nuisance species are usually introduced to new areas unintentionally. However, back in the 1800s and 1900s, the purposeful introduction of aquatic nonnative species was common. Sometimes, it was done in a misguided attempt to manage native species whose populations exploded after humans had eradicated or displaced their native predators. Sometimes, they were introduced to enhance recreational fishing opportunities in an effort to drive tourism. Unfortunately, the introduction of nonnative species almost always has terrible consequences, not just environmentally but economically and recreationally as well. One study by Crystal-Ornelas et al. found that invasive species cost the United States around $1.21 trillion dollars between 1960 and 2017. That figure includes both management costs as well damages caused by invasive species. Although nonnative species affect a variety of economic sectors, the agricultural industry is the most impacted. The USDA reports that invasive species have cost an average of about $26 billion per year since 2010. Invasive mussels are some of the most expensive and challenging threats to economic, environmental, and recreational resources.
Sam Stukel, USFWS Pacific Region The Threats of Invasive MusselsAs far as aquatic invasives go, zebra and quagga mussels (abbreviated together as "ZQM") are expensive to manage, but make no mistake — stopping their spread is vital to the continued environmental, recreational, and economic wellbeing of Western states. Their long legacy in the East gives us a good idea of what a future with ZQM could look like here in the West if these mussels aren't appropriately managed. As larvae, ZQM are impossible to see. They drift in freshwater river currents or float in the water column, and can survive in small amounts of water for many days. As adults, ZQM adhere to underwater objects with root-like "byssal threads" that are difficult to dislodge. Once stablished, they can clog water pipes, hampering local water supply and distribution efforts. They also infest hydropower infrastructure by blocking intakes and mesh screens. This has terrible consequences for communities, industries, fisheries, and agricultural areas that rely on clean freshwater and hydropower.
Mara Koening, USFWS Environmental and Recreational CostsEnvironmentally, ZQM are in constant competition with native mussel species for food and space. In the eastern United States, they've been known to disrupt food webs, as well as gather and store toxins in their bodies through a process called "bioaccumulation." These toxins can be passed on to native predators if the mussels are ingested. When those predators get eaten themselves, the toxins may become even more concentrated as they make their way up the food chain (a process called "biomagnification"). In the world of water recreation, ZQM infestations of boats, docks, pilings, and equipment means significant property damage. When the mussels die, their decay can be quite stinky. Their sharp shells often collect on beaches or boat ramps where they can cut into the feet of shoeless visitors and their pets. Fortunately, the implementation of science-based monitoring, inspection, and decontamination strategies has proven to stop the rapid spread of invasive mussel species.Aquatic Invasive Species of Concern at DinosaurYou can track the current status of aquatic invasive species in the West by visiting the USGS Nonindigenous Aquatic Species Information Resource. The following species are either already present in the rivers and streams of Dinosaur National Monument, or they have been found in waterbodies nearby. For the ones that are already here, our goal is to keep them from spreading beyond Dinosaur to other rivers in the Upper Colorado River Basin. For the ones that aren't here yet but have been found nearby, we want to keep them from being introduced here at Dinosaur. You can read more about each species and how they typically spread below. Viewing more pictures in the AIS photo album can help you learn to recognize them.
Robyn Draheim, Center for Lakes and Reservoirs (Flickr), CC BY-NC 2.0, cropped Already at Dinosaur As their name implies, New Zealand mudsnails are native to the freshwaters of New Zealand. They're very tiny, only about 4-6 mm long as adults. Almost all New Zealand mudsnails are females that reproduce asexually (this means that the baby snails are genetic clones of their mothers). Rather than laying eggs like other snail species, New Zealand mudsnails give live birth. Once born, the baby snails already contain developing embryos inside them. Upon reaching maturity at 3 mm long, the young snails can produce around 230 new females each year, which also grow and start multiplying in their turn. Some estimates indicate that a single snail and its offspring can produce about 2.7 billion snails in just 4 years. New Zealand mudsnails have been known to consume up to half of the food resources available in streams. They're also linked to declines in aquatic insect populations, which are an important food source for native fish. Animals that turn to eating the snails don't seem to fair well either. A 2008 study on the Green River showed that trout who had eaten New Zealand mudsnails were in much poorer shape compared to those without the snails in their system. In feeding trials where trout were only fed New Zealand mudsnails, 54% of the snails survived being eaten and passed by the fish! The trout, meanwhile, experienced deteriorating body conditions similar to starvation. Although New Zealand mudsnails are already present at Dinosaur National Monument, we want to keep them from spreading to nearby waters. Due to their small size, New Zealand mudsnails often go unnoticed on shoelaces, boots, waders, and boating equipment. They can also survive on wet surfaces and in small amounts of standing water for up to 50 days. 
Alan Schmierer (Flickr), Public Domain Already at Dinosaur Virile crayfish are native to many North American rivers and streams east of the Continental Divide, but they're invasive here in the West. Sometimes called "northern crayfish," these small crustaceans are usually reddish-brown or greenish with orange-tipped claws. As adults, the claws are often studded with white or yellowish knobs called "tubercles." Like other crayfish species, virile crayfish are omnivorous. They're just as happy to scavenge detritus on the river bottom as they are to eat plants and live prey. Thanks to their large size, virile crayfish are also able to bully young native fish out of prime hiding spots, which makes them easier for predators to find. In addition to competing with native fish for food and cover from predators, virile crayfish are also known to eat native species, such as juvenile reptiles, amphibians, and fish eggs. There are no native crayfish species in the Upper Colorado River System or the state of Colorado west of the Continental Divide, but virile crayfish have already been found here at Dinosaur. Regardless of how they were introduced, our goal is to keep them from spreading out of Dinosaur to nearby waters. 
Ryan Hodnett, Wikimedia Commons Present in Nearby Waters Quagga mussels are native to eastern Europe. Their shells can vary widely in color, usually ranging from brown to black to cream, with dark bands. Baby mussels (called "veligers") are microscopic. They float around in the water column for several weeks before settling onto a solid surface to mature. Adult quagga mussels have been known to make their homes on the shells of native clams, as well as on docks and boating equipment, and can survive out of water for 3-5 days. Quaggas can clog water intakes, disrupting hydropower and water distribution systems, which greatly increases maintenance costs. In nature, they outcompete native mussels and other filter-feeding invertebrates by removing nutrients from the water column. Quagga mussels are also capable of accumulating pollutants in their tissues. In the Great Lakes region, they've been linked to outbreaks of avian botulism, an illness that has caused the deaths of tens of thousands of birds. Our goal is to keep quagga mussels from being introduced to the rivers and streams of Dinosaur. 
Debra Kornblut, USFWS Pacific Region Present in Nearby Waters Zebra mussels originally come from southeastern Europe. They're named for the pattern of white and brown stripes on their shells. Baby mussels (called "veligers") start their lives as microscopic larvae, invisible to the human eye. In nature, the larvae float in the water column for 4 to 8 weeks before settling onto a solid surface to mature, but they can survive in small amounts of standing water for many days. As adults, zebra mussels can cling to almost anything. They may latch onto rocks, the shells of native clams, boating equipment, or even grains of sand. Adults stay in one place, filtering nutrients from the water column, which robs native species of this important food source. They often form dense clusters, with newer generations piling on top of older ones, smothering them. Zebra mussels usually live about 4-5 years, with females typically producing between 100,000 and 500,000 eggs per year. While they're currently present in the Lower Colorado River System, they haven't made it to Dinosaur and the Upper Colorado River System yet. Our goal is to keep them at bay. 
Missouri Department of Conservation Present in Nearby Waters Rusty Crayfish are named for the reddish-brown blotches that adorn the sides of their carapace (the middle part of their body, just above the tail). These freshwater crustaceans are native to the Ohio River Basin of the United States, but are invasive here in the West. In fact, there are no native crayfish in the Colorado River Basin, or in Colorado west of the continental divide. They could have been introduced by anglers as bait for fish, or they may have been illegally stocked by fisheries as a food source. Like most crayfish, rusties are opportunistic feeders. They prey upon a variety of aquatic plants, deep-water invertebrates, and detritus, as well as small fish and fish eggs. They compete directly with native species for food, resources, and cover from predators. This pushes young native fish out in the open where they become easy prey. Here in the West, their voracious appetites and devil-may-care diets have led them to damage underwater habitats that are important for native fish species. Our goal is to keep them from being introduced here at Dinosaur. Love the Rivers? Help Us Protect ThemDinosaur National Monument contains world-class whitewater boating and fishing opportunities. Public pressure to experience the Green and Yampa rivers increases each year, but the National Park Service also has an obligation to protect the river corridors from overuse and the threat of aquatic invasive species (AIS). As a result, Dinosaur's rafting permits are one of the hardest to get in the country. In 2024, we recieved 18,446 permit applications for only 436 available daily and multiday boat launches. Those applications came from all 50 states, the District of Columbia, and 16 foreign countries. Successful permit holders came from 26 different states and Poland, many of which have confirmed quagga and/or zebra mussel infestations. Motorized watercraft aren't allowed to be used recreationally in Dinosaur National Monument, but non-motorized watercraft can transport AIS too. Keeping water recreation equipment clean and dry between uses is the best way to protect Western waterbodies from aquatic invasive species.
NPS / Glacier National Park What We're DoingBoat Cleaning StationsThe Western Regional Panel on Aquatic Nuisance Species (WRP) was first formed in 1997. Their mission is to help limit the impacts, introduction, and spread of AIS to the western regions of North America. Today, the panel includes 19 Western U.S. states and 4 Canadian provinces, all working together to stop the spread of aquatic invasive species. They have proven that conducting regular boat inspections, cleaning, and decontamination are some of the most effective ways to stop the spread of invasive mussels and other AIS. Here at Dinosaur, we're adding new boat cleaning stations at boat ramps across the park to educate visitors and give them the tools they need to clean their gear after every use. Species Monitoring Using eDNA Species monitoring is a critical element of invasive species management. In the past, direct observation was required in order to conduct population and biodiversity surveys. Park staff needed to spend lots of time in the field in hopes of finding the species they were looking for. They also needed some level of expertise in species identification. Now, in addition to observational surveys, the National Park Service is using a new technology called "environmental DNA (eDNA)" or "eDNA." Living organisms are constantly shedding DNA into the world around them in the form of saliva, skin cells, hair, scales, or even poop. In terrestrial habitats, that DNA usually ends up in the soil. In aquatic ecosystems, it settles into the sediment at the bottom of a waterbody or may even be present in the water itself. By taking samples of the sediments, water, or soil and analyzing the DNA contained in those samples, we can get a much better idea of what species are present in a given environment. Here at Dinosaur, we're using eDNA to search for invasive aquatic species, like mussel veligers. Knowing the status of each species helps us determine the most appropriate management techniques, work with our partners to monitor the spread of AIS, and keep the public informed about what's happening on their public lands. What You Can DoThe simple act of cleaning your watercraft and gear is the best way to prevent the spread of AIS. Anything that spends time in or on the water needs to be scrubbed, drained, and dried after every single use. This process helps to dislodge invasive species and their veligers (tiny offspring that humans can't see) and prevents them from colonizing new waters. When watercrafts and equipment are properly cleaned, drained, and dried between uses in different waterbodies, the risk of transporting AIS is eliminated. To protect the rivers, you must clean, drain, and dry your gear after every use!How to "Clean, Drain, Dry!"CleanWhen you're done using your equipment, remove it from the water for cleaning. If you're at a water access that has a boat cleaning station, take advantage of the specialized tools available there to clean your equipment. To keep invasive species from spreading, stay away from storm drains and other bodies of water while you do the following:
Drain
Dry
Video TutorialsColorado Parks and Wildlife has produced several video tutorials on how to clean different kinds of watercrafts. Select from the links below to view the different tutorials.
Environmental Factors
Dinosaur National Monument is shaped by numerous environmental factors, such as invasive species, wildland fire, and climate change. 
Nature
While Dinosaur is known for prehistoric life, today, the monument provides habitat for more than 1,000 native species of plants and animals. 
Boating in the Monument
Boating and rafting are some of the best ways to experience the remoteness of Dinosaur. |
Last updated: April 22, 2025