The Razorback Sucker is endemic to the Colorado River basin and protected under the Endangered Species Act. Once found throughout the warm water reaches of the basin, the Razorback Sucker’s basinwide decline is believed to be a result of myriad anthropogenic habitat alterations and negative interactions with introduced fishes. Razorback Sucker spawning occurs as spring runoff increases river discharge. Upon hatching from eggs deposited in river substrate, larvae drift with river current into flooded off-channel nursery habitats. Despite ongoing stocking of Razorback Sucker into the Colorado River, studies show that natural recruitment necessary for self-sustaining wild populations is lacking, and populations in the upper Colorado River continue to require maintenance via stocking of adult fish.
A stretch of 64 miles of the Colorado River between Moab and the confluence with the Green River has been identified as a priority reach for recovery of Razorback Sucker. The Matheson Preserve is the only site within this reach capable of providing suitable nursery habitat as identified in recovery goals. However, the Matheson Preserves’ current value to razorback recovery limited by an abundance of non-native fishes and reduced frequency and duration of flood events.
Competition and predation by non-native fishes are linked to reduced survival and growth rates of stocked Razorback Sucker larvae in wetlands, potentially resulting in total mortality. However, experimental survival rates of Razorback Sucker larvae in ‘reset’ floodplains (i.e. those free of non-native fishes at entrainment) are thought adequate to sustain populations and age-zero Razorback Sucker in floodplain environments outgrow predation risk from non-native fish spawned in the same year. Thus, a combination of ‘reset’ conditions and exclusion of all but larval non-native fishes during inundation should contribute to optimal Razorback Sucker survival.
In recent years, overbank flows of the Matheson Preserve occur infrequently; approximately once each decade. Discrete portions such as the Central Pond, however, achieve connection through gated canals at lower flows. In light of the recently documented presence of wild Razorback Sucker larvae at the mouth of the Central Pond inlet, the Central Pond was modified to achieve inundation in three of every five years and to drain completely (i.e. achieve ‘reset’ conditions) and concurrently integrate a redundant fish exclusion apparatus and improved head gate for water level management. Additional water sources to maintain adequate levels in the entrainment area are diverted to entrainment area from naturally occurring springs located on the north-west end of the preserve. We believe that management of the Central Pond with this suite of features can contribute significantly to the recovery of Razorback Sucker.
This project provides a functional, floodplain wetland that offers Razorback Sucker, as well as other native fish including Bluehead Sucker, Flannelmouth Sucker, Roundtail Chub, and Bonytail Chub, suitable nursery habitat during spring flooding, as well as offering other ecological benefits to the Matheson Preserve. Floodplain connectivity has been restored in a variety of flow scenarios, entrainment of wild Razorback Suckers into the Central Pond has been documented, large bodied non-native fish are excluded, water quality and quantity is maintained for sufficient amounts of time post-entrainment to ensure survivability and growth of larval Razorback Sucker, and juveniles were successfully released back into the Colorado River.
Human Interest/Community Benefit:
The Scott and Norma Matheson Wetlands Preserve in Moab, Utah, is an oasis in the desert—a stark contrast to the surrounding redrock cliffs and arid desert. This lush oasis attracts more than 200 species of birds, amphibians—including the northern leopard frog—and aquatic mammals such as the beaver, muskrat and elusive river otter. The Matheson Wetlands – a refuge for both nature and people—is the result of a community effort. In 1990, the land was at risk of being developed, but The Nature Conservancy (TNC) and the Utah Division of Wildlife Resources were able to step in. The Preserve’s 900 acres makes it the largest wetland complex on the Colorado River in Utah. TNC and the Utah Division of Wildlife Resources jointly own and manage it. The rarity of the wetland ecosystem in an arid environment, coupled with the area’s diversity that attracts a wide variety of wildlife species and the utilization of the wetlands by migratory birds, were the main reasons The Nature Conservancy became involved with the Moab Sloughs. Though many people visit the preserve to bird watch, others come to enjoy the sounds and sights of nature. School groups also visit the preserve to study wetlands and the creatures that inhabit these wetlands. The Utah Division of Wildlife Resources has conducted a mist-netting program to analyze bird usage in the preserve. Other studies have looked at population trends of northern leopard frogs, waterfowl and breeding birds.
The Matheson Wetland Preserve is also considered an outdoor classroom.
Located near Moab, Utah, several teachers bring their students to the Matheson Preserve, particularly fourth-grade students who visit the preserve during August or September to do hands-on science activities that align with Utah’s core science curriculum. This curriculum includes the study of wetlands. The Matheson is also used as an outdoor classroom for local groups such as the Girl Scouts of the USA. In May, for International Migratory Bird Day, there is a public event held on the preserve where local fisheries experts for the DWR discuss the endangered species of the Colorado River and the ongoing project.
Project Timeline:
The feasibility study of this project was completed in 2017. In 2019, the Central Pond water control structure and backwater channel were installed. Diversions structures and pipes were installed from the Watercress Spring (2020) and Mill Creek (2021-2022) to provide backup water sources to maintain water levels for native fish larvae during crucial summer months. The Central Pond was expanded in 2020-2021 by dredging out a deeper portion that will provide adequate water for fish until October for optimal survival.
In the spring of 2019, larval Razorback Sucker were spotted in the Colorado River adjacent to the wetlands and were successfully entrained into the Matheson Preserve via the partially completed backwater channel. In the fall of 2021, the first juvenile Razorback Suckers that reared in the Matheson Preserve were successfully released back into the Colorado River
Partners:
This project was funded or supported by the Desert Fish Habitat Partnership, The Nature Conservancy, Utah Division of Wildlife Resources, Utah Department of Transportation, Utah Endangered Species Mitigation Fund, Utah’s Watershed Restoration Initiative, Utah Division of Forestry, Fire and State Lands, the Colorado River Recovery Program, an Enterprise Grant, Utah Division of Water Rights, USFWS Partners for Fish and Wildlife, Natural Recourse Conservation Service, Moab Area Watershed Partnership, Utah Division of Water Quality, Bureau of Reclamation, Jones and Demille Engineering, and Bliesner Keller Engineering.
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