Toxic effects of tri-butyl-tin (TBT) on autotrophic pico-, nano-, and microplankton assessed by a size fractionated pollution-induced community tolerance (SF-PICT) concept

The effects of tri-bulyl-tin (TBT) on autotrophic pico-, nano and microplankton were assessed by a marine enclosure experiment. In accordance with the pollution-induced community tolerance (PICT) concept, an increased tolerance was found for microplankton in enclosures amended with 0.01, 0.6 and 10 nM TBT. In contrast, nanoplankton showed increased tolerance only in an enclosure amended with 10 nM TBT. Neither the entire phytoplankton community nor picoplankton showed increased tolerance. These observations are discussed in terms of the ecology of pico-, nano-and microplankton. In all enclosures amended with TBT, primary production by nanoplankton declined, and primary production by picoplankton increased: changes that are interpreted as indirect effects of TBT. A comparison of TBT levels found in polluted coastal areas and in off-shore areas indicates that phytoplankton communities might be affected by TBT. Size fractionated measurements of TBT tolerance in phytoplankton communities were proven to increase the sensitivity of the PICT concept. (C) 1998 Elsevier Science B.V.