Harsh living conditions exist for the Virgin River’s native fish species, but the Utah Division of Wildlife Resources’ biologists say they are doing okay.
This river is home to six fish species found nowhere else:
— Desert suckers are colorful fish. The males develop orange and black stripes during the spawning season. They can grow up to 33 cm and are endangered.
— Speckled daces are one of the river’s healthiest native fish species. They are 2-3 inches long and can have olive or yellow sides and backs.
— Flannelmouth suckers are the largest native fish in the river. They can grow to be up to 2 feet long and 6 pounds. Its population is declining and biologists are working to restore its habitat.
— Virgin spinedaces are medium-sized silvery fish with scattered black blotches. Their declining population is a top priority.
— Virgin River chubs can grow to be 18 inches long. They have a sloped forehead, humped back and thin tail. They are a rare and endangered minnow only found in southwestern Utah, southern Nevada and northern Arizona.
— Woundfins are silvery fish with large fins and scaleless bodies. They are an endangered species found only in a small section of the Virgin River.
The river faces pressure. Many depend on the river, and it is tapped in southwest Utah to meet the needs of a growing population. Non-native species, low flows and high water temperatures threaten these native fish. This is why groups have created projects to help conserve the native species and protect the environment home to an array of plant and animal species.
In their most recent project focused on the chub, the biologists gathered data from six locations around Southern Utah. Division staff set traps at these locations, each net about 500 meters long. The traps can catch both native and non-native fish, which tells the biologists the condition of the fish population.
The nets are placed overnight, allowing fish to swim into the open end and trap themselves inside. In the morning, staff arrive to measure the fish. Measuring gives the biologists a sense of their size and age. They also look for parasites or any other health indicators.
Generally, the team captures more adults than young fish. This year, they captured a nearly even split with 674 adults and 671 juveniles. The number of fish of different ages can give insight into whether the population is expanding or declining. The chub had a big reproduction year because of good snowpack and spring runoff. The team will need to compare these numbers to previous years to better understand the chub’s population trends.
The river’s unique ecosystem runs through an arid landscape. It can have extremely high flows, or years where it dries up in midsummer. When it rages, it can cut new banks and wipe out trees and other vegetation. This creates a harsh living environment for the fish, but the ecosystem depends on the natural cycles of the river.
“Everything from plants to mammals in the desert need a healthy desert river to survive,” said Southern Utah University biology professor Dillon Monroe. “Monitoring populations of the Virgin River chub tells us how responsibly we are using this limited resource so that the rest of the environment can still use it too.”
Nature preserves around the river have been created. They protect the habitat so the native fish and migratory birds can survive. Without these preserves, many of these species would go extinct, causing issues for the wildlife. Learning about how changes to the river affect this habitat is important to all. This river’s ecosystem is vital to humans and many of these rare species. The Virgin River plays a role in tourism, recreation, agriculture and local economies.
Check out The Nature Conservancy to learn more about conservation efforts and preserves being created.
Author: Maddi Munro
Photographer: Gannon Lovisa
Editor: Chevy Blackburn
Copy Editor: Kayd Johanson
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