U.S. Fish and Wildlife Service

This opportunistic investigation explored levels and potential effects of organochlorine pesticides and heavy metals as factors limiting Sonoran mud turtles (Kinosternon sonoriense) at Quitobaquito Springs. Turtles found dead between 1989 and 1993 and pond sediments from Quitobaquito Springs were analyzed for pesticides and metals. Current levels of organochlorines are low and do not pose a threat to turtle survival and reproduction. Fat reserves in Sonoran mud turtles appeared relatively low suggesting an inadequate diet and possible dietary stress. Mean concentrations of boron, chromium, selenium, strontium, and zinc were significantly higher in turtles from Quitobaquito Springs than in softshell turtles from the highly contaminated Gila River. High concentrations of several elements in combination with a protein restricted diet may be a factor limiting turtle survival. Present address: U.S. Fish and Wildlife Service, 1500 N. Decatur # 1, Las Vegas, NV 89108 Present address: Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721 __________________________________________________________________