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.