Invited presentation to be given by Louis Thibodeaux at the Workshop on the Benthic Boundary Layer, Max Planck Institute, Germany, June 1996. Completion of two experiments with tubificid worms in field-contaminated Rouge River, Michigan sediments. Completion of an experiment examining the influence of bioturbation on contaminant migration through a thin layer sediment cap. Completion of an experiment with amphipods in inoculated sediments. Exploration of a lumped parameter mixed cell model, a distributed parameter diffusion and bioturbation mass transfer model, and a statistical model of mass transfer by bioturbation.
Paper detailing influence of amphipods and thin layer cap phenomena is under preparation.
Development of analytical techniques allowing evaluation of selenium speciation in a cooperating study of bioturbation and elemental dynamics at the University of Sydney. The original proposal indicated that the primary focus of the first year of activity would be to conduct experiments with organisms that displayed different functional interactions with sediment and to examine the behavior of benthic organisms in aged field-contaminated sediment. These tasks were addressed by the completion of experiments employing Rouge River sediments and by the use of both the Limnodrilus and the amphipod, H. azteca . The fluxes normalized by sediment loading, or the effective bioturbation mass transfer coefficient, was essentially identical to that measured previously in laboratory inoculated sediments 2 . The observed bioturbation fluxes, however, are still significantly higher than that observed in the control cells.