Colorado Pikeminnow Population Trends in the Colorado River

Authors: Darek Elverud

Year: 2024

Abstract

Multiple pass population estimates of Colorado Pikeminnow (Ptychocheilus lucius) in the Colorado River began in 1992. The current sampling rotation includes three consecutive years of sampling followed by three years when sampling does not occur. The study area begins at Government Highline Dam near Cameo, Colorado and continues downstream to the confluence of the Colorado and Green rivers. Approximately 180 miles of river are sampled per pass with four or five passes being completed each year when flows are sufficient. Boat mounted electrofishing units are the primary gear utilized to capture Colorado Pikeminnow. Trammel nets are also utilized in flooded backwater habitats during periods of elevated river flows. The Colorado Pikeminnow population in the Colorado River peaked in 2005 and subsequently began to decline for the next decade. The most recent estimates of adult Colorado Pikeminnow abundance in the Colorado River indicate an increasing trend and significantly higher abundance of adult Colorado Pikeminnow.