TUCSON, Ariz.— The Center for Biological Diversity filed a lawsuit today against the U.S. Fish and Wildlife Service to force it to decide whether to protect Utah’s least chub and Nevada’s Fish Lake Valley tui chub under the Endangered Species Act.

Today’s lawsuit, filed in federal court in Tucson, says the Service is violating the Act by delaying action on the imperiled fishes, which are threatened by groundwater pumping in a region experiencing catastrophic drought. The lawsuit also seeks decisions relating to the protection of 10 other plants and animals.

“These small fishes are an incredibly important part of the Great Basin’s natural heritage, and they’re teetering on the brink of extinction,” said Krista Kemppinen, Ph.D., a senior scientist at the Center. “The longer the Service waits to protect these fishes the greater the chance that they’ll disappear forever. We’re in the midst of an extinction crisis and these little minnows are running out of time.”

The Center sought Endangered Species Act protections for the least chub and the Fish Lake Valley tui chub in 2021. However, the Service has yet to make a final determination on whether these two fishes should be protected under the Act, leading to today’s litigation.

Species background

Least chub is a gold-colored minnow, typically less than 2.5 inches long, endemic to Utah’s Bonneville Basin. It’s the only species in its genus, Iotichthys. The main threat to the least chub is proposed groundwater pumping to support human population growth in Cedar City, Utah. The proposed Pine Valley Water Supply Project would pump billions of gallons of groundwater from Utah’s West Desert, threatening springs the chubs depend on.

Fish Lake Valley tui chub is an olive-colored minnow, less than 5 inches long, found in just one spring system in Nevada’s Fish Lake Valley, in Esmeralda County. The springs that the fish relies on are threatened by groundwater over-pumping. Most of the groundwater pumped in Fish Lake Valley is used in the production of alfalfa. Other threats include lithium and geothermal energy development.