The effect of TBT on the structure of a marine sediment community - a boxcosm study

The effect of tri-n-butyl tin (TBT) on an intact marine sediment community after five months exposure was investigated. Changes in the structure of ma cro- and meiofauna communities were determined, as well as the functional d iversity of the microbial community using BIOLOG microplates for Gram negat ive bacteria. Development of tolerance in the microbial community was inves tigated using Pollution Induced Community Tolerance (PICT) experiments with fluxes of nutrients as effect indicators. TBT affected the structure and r ecruitment of the macro- and meiofauna at nominal additions of 30-137 pmol TBT/m(2) sediment. Number of species, diversity, biomass and community simi larity was reduced at these concentrations compared to control. Species tha t molt seemed to be the most tolerant since they were predominant in boxes that had received the highest TBT addition and echinoderms were the most se nsitive species. Renewed addition of TBT in PICT experiments with sediment from each boxcosm showed that TBT had an effect con individual nutrient flu xes from all sediments. Analyses of the flux patterns revealed a memory of previous TBT exposure, either due to induced tolerance or other community c onditioning. (C) 2001 Elsevier Science Ltd. All rights reserved.