News and Activities

Muddy River, Nevada, Fish Study Underway

Date Posted: March 12, 2004

Southern Nevada Field Office (SNFO) contaminant staff completed the second field season of a two-year study on contaminant uptake in Muddy River fishes. The Service partnered with U.S. Geological Survey (USGS) and Nevada Department of Wildlife staff to capture 11 species of fish (a total of over 1800 individuals), of which only the Virgin River chub (Gila seminuda) and Moapa speckled dace (Rhinichthys osculus moapae) were native. The Muddy River, located approximately 50 miles northeast of the city of Las Vegas in Moapa Valley, flows south from numerous natural springs at its headwaters, to the Overton Arm of Boulder Basin on Lake Mead (a distance of 26 miles). The Muddy River has been adversely impacted by habitat modification, introduction of non-natives, and degraded water quality. The Muddy River is currently listed on the 303(d) list of impaired waters under the Clean Water Act due to elevated levels of total phosphorus, arsenic, boron, and iron. Once completed, the study will determine if adjacent land uses in this watershed are posing a risk to the Virgin River chub, a species of concern in the Muddy River and federally listed as endangered in the Virgin River. The results of the study (available in late 2004) will ensure that environmental contaminants do not hinder ongoing recovery and restoration efforts for the Muddy River ecosystem.

Erik L. Orsak 702-515-5230


Last updated: June 12, 2015