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Rearing Pond Water Quality's Effects on Endangered Razorback Suckers
Date Posted: December 10, 2005The Service's Grand Junction Office conducted field work associated with the Refuge investigation entitled "Water Quality Assessment of Grow-out Ponds Used for Colorado River Endangered Fish Propagation." Grow-out ponds are ponds used to grow fish to an appropriate size for releasing. The purpose of this study is to assess water quality conditions and fish food supplies in 16 grow-out ponds which are currently being used by the Colorado River Recovery Program to propagate juvenile endangered razorback suckers, and to better define factors associated with these water quality conditions which may limit growth, condition, and survival of razorback suckers in both grow-out ponds and after stocking in the Colorado and Gunnison rivers. Of particular concern are high selenium concentrations found in water, sediment, and food items in some of these grow-out ponds. Selenium concentration from razorback suckers held in the hatchery, as a basis for comparison for those kept in grow-out ponds for six months, and those stocked in the Colorado and Gunnison rivers for at least six months to help assess risk from selenium exposure in grow-out ponds. This project involves about 68 acres of ponds and wetlands, and about 21,000 razorback suckers produced by USFWS hatchery personnel. Project partners include; the Colorado River Fisheries Project, U.S. Geological Survey Western Slope Sub-district office, and the U.S. Geological Biological Resources Division (MURR) at Columbia Missouri.
Last updated: June 12, 2015