Metals, boron, and selenium in Neosho madtom habitats in the Neosho River in Kansas, USA

In 1991 and 1992 we determined the levels of metals, arsenic, boron, and se lenium in the Neosho River drainage in southeastern Kansas, the primary hab itat for the threatened Neosho madtom (Noturus placidus). We evaluated conc entrations in sediments, mussels (Quadrula pustulosa and Q. metanevra), and fish (Percina phoxocephala, Cyprinus carpio, and Ictiobus bubalus) from th ree sites on the Neosho River and one site on the Cottonwood River. We also evaluated contaminant concentrations in C. carpio composite samples collec ted by the Kansas Department of Health and Environment (KDHE) at two additi onal locations on the Neosho River in 1990-92. Sediments were contaminated by lead. Concentrations of selenium, boron, and most metals in mussels were low to normal for biota. Arsenic levels in mussels and fish suggest low-le vel contamination of biota. Aluminum, barium, manganese and strontium conce ntrations were much higher in mussels than in fish. Five fish composite sam ples had cadmium concentrations that indicate chronic deleterious effects o n biota. Lead concentrations in six fish samples were elevated. Mercury con centrations in most large fish composites exceeded concentration for protec tion of animals that might consume them. We believe that reductions in cadm ium, lead, and mercury contamination, in particular, would benefit aquatic life in the river.