HR: 14:15h
AN: B13A-04    [Abstracts]
TI: Bioturbation and Bioaccumulation: Defining Access and Availability at the Sediment-water Interface
AU: * Reible, D
EM: reible@mail.utexas.edu
AF: University of Texas, EWRE C1786, Austin, TX 78712 United States
AU: Lu, X
EM: lux@mail.utexas.edu
AF: University of Texas, EWRE C1786, Austin, TX 78712 United States
AU: Chai, Y
EM: ychai@mail.utexas.edu
AF: University of Texas, EWRE C1786, Austin, TX 78712 United States
AB: Traditionally, the transport and fate of hydrophobic contaminants at the sediment-water interface has largely been assumed to be controlled by sediment erosion and resuspension processes. Many sediment contaminants, however, lie in stable depositional environments where exposure and risk is defined by bioturbation, the mixing activities of benthic organisms, and bioaccumulation, the uptake of contaminants by these organisms, causing both direct toxic effects and indirect effects through the food chain. The observational field evidence indicating the importance of these processes has recently been reported by Thibodeaux (2005). This presentation will focus on efforts to understand and quantify these processes through experiments and modeling. Estimation of the depth and intensity of organism mixing processes and the relationship of desorption phenomena to accumulation in these organisms will be discussed. The coupling of physicochemical and biological processes will be emphasized. Pore water concentrations will be identified as a key indicator of exposure and risk. Deterministic models showing promise at predicting the dynamics of pore water concentrations and stochastic models reproducing some key characteristics of benthic community behavior will be developed.
DE: 1869 Stochastic processes
DE: 1871 Surface water quality
SC: Biogeosciences [B]
MN: 2005 Joint Assembly