Background In the present study, we report the analytical results of pp2DDT, pp2DDE and pp2DDD determination in lake water, plankton and zooplanktivorous fish of Lake Maggiore (Northern Italy), rather recently polluted by DDT of industrial origin, in order to understand the bottom-up pollution transfer among the abiotic and biotic components of the lake ecosystem. Materials and methods: Fourteen water sampling campaigns were carried out from March 2003 to January 2009 in the water column of the deepest point (Ghiffa) of Lake Maggiore. Suspended and dissolved pollutants were determined separately. Three sampling campaigns were carried out from July 2008 to January 2009 for zooplankton and pelagic fish, and DDT residues were analysed by HRGC coupled with ECD and MS. Moreover, food items were detected in fish stomachs. Results and discussion: Starting from 2007, the DDT contamination along the water column became rather homogeneous, probably because no flooding or other relevant hydrological events occurred; although steadystate condition should be expected, lipid normalised concentrations of pp2DDE and pp2DDD in zooplankton exceeded the levels of the same compounds in zooplanktivorous fishes. Conclusion: As this finding represents a thermodynamic paradox since bioaccumulative pollutant concentrations are expected to increase along the trophic chain, it was supposed that the abiotic and biotic lake components were not in a steady-state condition in Lake Maggiore.
The role of zooplankton in DDT biomagnification in a pelagic food web of Lake Maggiore (Northern Italy)
Guzzella L;P Volta
2010
Abstract
Background In the present study, we report the analytical results of pp2DDT, pp2DDE and pp2DDD determination in lake water, plankton and zooplanktivorous fish of Lake Maggiore (Northern Italy), rather recently polluted by DDT of industrial origin, in order to understand the bottom-up pollution transfer among the abiotic and biotic components of the lake ecosystem. Materials and methods: Fourteen water sampling campaigns were carried out from March 2003 to January 2009 in the water column of the deepest point (Ghiffa) of Lake Maggiore. Suspended and dissolved pollutants were determined separately. Three sampling campaigns were carried out from July 2008 to January 2009 for zooplankton and pelagic fish, and DDT residues were analysed by HRGC coupled with ECD and MS. Moreover, food items were detected in fish stomachs. Results and discussion: Starting from 2007, the DDT contamination along the water column became rather homogeneous, probably because no flooding or other relevant hydrological events occurred; although steadystate condition should be expected, lipid normalised concentrations of pp2DDE and pp2DDD in zooplankton exceeded the levels of the same compounds in zooplanktivorous fishes. Conclusion: As this finding represents a thermodynamic paradox since bioaccumulative pollutant concentrations are expected to increase along the trophic chain, it was supposed that the abiotic and biotic lake components were not in a steady-state condition in Lake Maggiore.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
