Determination of selenium in fish from designated critical habitat of the Gunnison River, Colorado, summer 2011

This report presents results for the summer 2011 sampling of muscle plugs from common carps (Cyprinus Linnaeus), roundtail chub (Gila robusta), and bonytail chub (Gila elegans) inhabiting critical habitat in the Gunnison River in Western Colorado. Total selenium in fish muscle plugs was determined by instrumental neutron activation analysis. Total selenium concentrations (range and mean ± standard deviation) in micrograms per gram dry weight for each species were as follows: common carp: 8.5 to 35, 13 ± 7.8; roundtail chub: 5.5 to 11.2, 7.3 ± 1.6; bonytail chub: 0.8 to 8.6, 3.9 ± 4.2. Selenium concentrations in muscle plugs from 4 out of 15 roundtail chub, all 15 common carp, and 2 out of 5 bonytail chub exceeded the 8 micrograms per gram dry weight toxicity guideline for selenium in fish muscle tissue.