HR: 1330h
AN: H13A-10    [Abstracts]
TI: Toxicity and Geochemistry of Missouri Cave Stream Sediments
AU: * Lawler, C A
EM: calwvf@mizzou.edu
AF: University of Missouri Columbia, Department of Geological Sciences 101 Geological Sciences Building, Columbia, MO 65211 United States
AU: Besser, J
EM: jbesser@usgs.gov
AF: U.S. Geological Survey Columbia Environmental Research Center, 4200 New Haven Rd., Columbia, MO 65201 United States
AU: Wicks, C M
EM: wicksc@missouri.edu
AF: University of Missouri Columbia, Department of Geological Sciences 101 Geological Sciences Building, Columbia, MO 65211 United States
AB: Water and sediment quality are among the most important variables affecting the survival of stygobites. In Tumbling Creek Cave, Taney County Missouri the population of the endangered cave snail, Antrobia culveri, has declined significantly over the past decade. The cause of the population decline is unknown but could be related to the quality of streambed sediment in which the cave snail lives. The objective of this study was to determine the toxicity and concentrations of heavy metals in the sediment of Tumbling Creek Cave and five other caves in Missouri. These sediments were analyzed to assess possible point sources from within the recharge areas of the caves and to provide baseline geochemical data to which Tumbling Creek Cave sediments could be compared. Standard sediment toxicity tests and ICP-MS analysis for heavy metals were conducted. Survival and reproduction of the amphipod, Hyalella azteca, did not differ significantly between cave sediments and a control sediment. However the growth of amphipods differed significantly among sites and was significantly reduced in sediments from Tumbling Creek Cave relative to controls. Concentrations of several metals in sediments differed substantially among locations, with elevated levels of zinc and copper occurring in Tumbling Creek Cave. However, none of the measured metal concentrations exceeded sediment quality guidelines derived to predict probable effects on benthic organisms and correlations between sediment metal concentrations and toxicity endpoints were generally weak. While elevated metal levels may play a part in the cave snail's decline, other factors may be of equal or greater importance. Ongoing analyses of persistent organic contaminants and total organic carbon in cave sediments, along with continued water quality monitoring, may provide data that will allow us to better understand this complicated problem.
DE: 1045 Low-temperature geochemistry
DE: 1099 General or miscellaneous
DE: 1831 Groundwater quality
DE: 1899 General or miscellaneous
SC: Hydrology [H]
MN: 2005 Joint Assembly