An upstream battle for the Razorback sucker
The Razorback is one of four endangered fish living in the Colorado River. Recently, it has been the poster fish for the success of the Fish and Wildlife Service’s efforts to protect endangered species. This fish might actually make a full comeback in the Colorado River, after many years of near extinction. In order for the comeback to occur, however, efforts might need to focus on making the river more habitable for the Razorback sucker and other sensitive riparian species.
The Razorback has a life cycle closely tied to the unique ebb and flow of the Colorado River. This fish begins its life as an egg on the cobble bars in the river. Once hatched, it continues its life as a larva in search of a protected area to grow without the threat of being eaten by a bass or pike. For the Razorback, this means a slow-moving floodplain on the edge of the river. Predators are not able to survive in the shallow, slow floodplains. As the river level drops and the larva grows, the now late-teenage Razorback sucker can move back to the main river to live out his adult life.
Habitat is everything for the Razorback sucker. A healthy riparian habitat allows for floodplains along the river. Tamarisk and Russian Olive with their thick roots and dense growth are not native to the area. These plants were introduced because they were thought to be drought resistant and decorative. However, they suck up water and create dense river banks. Their wall of roots and vegetation encroach into the river channel, impeding natural river system processes, which includes light flooding in the spring, along the Colorado.
Tom Chart, director of the Upper Colorado River Endangered Fish Recovery Program, explains, “In a perfect system, when you had the natural flow of the river and you had willows, the river was able to create a greater complexity of habitats. The tamarisk takes that away. Tamarisk locks the channel and cuts down on the river’s ability to do its work.”
Chart says that in order for the floodplain habitat to work, the river must mimic its natural flow. There are many dams along the Colorado River, and the dams create a fairly consistent flow of water throughout the year, regardless of heavy rains, dry summers or large snowfall. Water is also withdrawn throughout the system and consumed for municipal, industrial and agricultural purposes, decreasing the amount of water historically flowing in the river.
In a natural flowing river, the flow will be very high in the spring; high enough to create overflow on the banks and marshy floodplains. The flow will then recede throughout the summer and be much lower in the fall.
Agencies and landowners in charge of the dams along the Colorado have been conscious about the flow management along the river, understanding that species depend on this fluctuation to survive. The coordination of agencies has been successful, and flow management has largely been a success. The Razorback sucker larva, however, are still not surviving. This leaves one more way to help the Razorback survive along our section of the Colorado River: We must decrease tamarisk and restore the habitat.
“The floodplain habitats that we are talking about really are crucial for that animal to complete its life phase and life cycle. … We have critical habitat that goes all the way up to Rifle,” Chart explained. He continued to tell the story that many of the original brood stock for the Razorback sucker hatchery came from an area just outside of Rifle, on private property.
The Razorback suckers are still making it up the river as far as Rifle, but we as stakeholders of this watershed need to do what we can to help maintain proper habitat for the fish so the offspring can survive. Many organizations are focusing on tamarisk removal and habitat restoration. These projects will be essential to helping the Razorback sucker, and many other riparian species that we love in Colorado, survive and thrive.
Annie Whetzel is with the Middle Colorado Watershed Council.
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