CONTAMINANTS EVALUATION OF MARAIS-DES-CYGNES-NATIONAL-WILDLIFE-REFUGEIN KANSAS AND MISSOURI, USA

At the new Marais des Cygnes National Wildlife Refuge in Linn County, Kansas, and Bates County, Missouri, USA, we evaluated long-lived conta minants before acquisition of the land for the refuge. We sampled sedi ments at 16 locations and fish at seven locations. The samples were an alyzed for metals and for chlorinated hydrocarbon compounds. Selected sediment samples also were analyzed for aliphatic hydrocarbons. Arseni c concentrations in sediment samples from six locations were elevated compared to US norms, but arsenic was not detected in any fish composi te. Mercury concentrations in largemouth bass from two locations were comparable to the 85th percentile concentrations in nationwide fish co llections. Most sediment concentrations of other metals were unlikely to have detrimental effects on biota. No chlorinated hydrocarbons were detected in any sediment sample. Chlordane compound concentrations in fish composites from two sites at the eastern end of the sampling are a were 0.127 and 0.228 mu g/g wet weight, respectively, which are high enough to cause concern. Most aliphatic hydrocarbons detected were fo und at low concentrations and probably were natural in origin. We conc luded that there are no serious contaminants concerns within the proje ct area, but past use of arsenical pesticides may mean a legacy of ele vated soil arsenic levels in parts of the area and some use of banned pesticides such as chlordane and DDT likely is still occurring near th e refuge.