Aim of the present study project was to verify in situ, in a complex transition environment as it is the Venice Lagoon, the transfer of pollutants (heavy metals) from sediment to animals (Mytilus galloprovincialis) living in the water column, seeking, at the same time, to display the relationships between biotic and abiotic compartment that could help the understanding of the phenomena involved in this process. Firstly, an in vitro experimentation has been developed, allowing to study the processes in controlled conditions. A special instrumentation, able to reproduce the pollutant’s passage (Cadmium) from sediment to mussels, has been developed. The research in laboratory has been divided in two main parts: the tests conducted in static condition tests and the ones in dynamic conditions. The scope was to know thoroughly the role of sediment perturbation on pollutant release and its consequent organism bioavailability. Both cadmium sediment content and oxygen water column concentration have been used at different concentration values. Cadmium bioaccumulation and metallothionein (MT) content in mussels were quantified too. MTs are in fact known to be subjected to genetic induction and are used as metal exposure biomarker. Furthermore, cadmium chemical partition in sediment and tissue compartmentalization have been evaluated. In this phase of the research it was necessary to define methodological protocols concerning sediment diagenesis and spiking, mussel feeding and harvesting, test enclosure parameters variability and more suitable sediment/mussel/biomarker analysis. Moreover a simple, cheap and handy device has been created to test the reached Cd chemical partition steady state in spiked sediment, without mixing it. This device has been named PWS (Pore Water Sampler). Afterwards, the research has been conducted directly in the environment. Three seasonal campaigns have been carried out (Autumn 2001, Spring and Autumn 2002). Six sites in the central part of the Venice Lagoon have been chosen along a supposed pollution path from high contaminated area of the industrial zone of Porto Marghera to an area closer to the Venice Lido and subject to a major water exchange with sea. In every site Cd and Zn bioaccumulation and metallothionein content in local M. galloprovincialis specimens (passive biomonitoring) collected during the three campaigns have been quantified. Limitedly to the last two campaigns passive biomonitoring has been placed side by side of the transplantation of M. galloprovincialis specimens (active biomonitoring) coming from a mussel farm located in a clean area of the Venice Lagoon. The data obtained have been correlated with cadmium content in bottom sediment and in sediment/suspended particulate sampled with special cages at the same depth of local and transplanted mussels. Also for in situ samples the metal’s partition has been considered decisive, so it has been evaluated both in abiotic matrix (geospeciation) and in the biotic one (compartmentalization in the organism).

Trasferimento di inquinanti tossici da sedimenti a molluschi in ambiente di transizione.

MANENTE, Sabrina
2004-01-01

Abstract

Aim of the present study project was to verify in situ, in a complex transition environment as it is the Venice Lagoon, the transfer of pollutants (heavy metals) from sediment to animals (Mytilus galloprovincialis) living in the water column, seeking, at the same time, to display the relationships between biotic and abiotic compartment that could help the understanding of the phenomena involved in this process. Firstly, an in vitro experimentation has been developed, allowing to study the processes in controlled conditions. A special instrumentation, able to reproduce the pollutant’s passage (Cadmium) from sediment to mussels, has been developed. The research in laboratory has been divided in two main parts: the tests conducted in static condition tests and the ones in dynamic conditions. The scope was to know thoroughly the role of sediment perturbation on pollutant release and its consequent organism bioavailability. Both cadmium sediment content and oxygen water column concentration have been used at different concentration values. Cadmium bioaccumulation and metallothionein (MT) content in mussels were quantified too. MTs are in fact known to be subjected to genetic induction and are used as metal exposure biomarker. Furthermore, cadmium chemical partition in sediment and tissue compartmentalization have been evaluated. In this phase of the research it was necessary to define methodological protocols concerning sediment diagenesis and spiking, mussel feeding and harvesting, test enclosure parameters variability and more suitable sediment/mussel/biomarker analysis. Moreover a simple, cheap and handy device has been created to test the reached Cd chemical partition steady state in spiked sediment, without mixing it. This device has been named PWS (Pore Water Sampler). Afterwards, the research has been conducted directly in the environment. Three seasonal campaigns have been carried out (Autumn 2001, Spring and Autumn 2002). Six sites in the central part of the Venice Lagoon have been chosen along a supposed pollution path from high contaminated area of the industrial zone of Porto Marghera to an area closer to the Venice Lido and subject to a major water exchange with sea. In every site Cd and Zn bioaccumulation and metallothionein content in local M. galloprovincialis specimens (passive biomonitoring) collected during the three campaigns have been quantified. Limitedly to the last two campaigns passive biomonitoring has been placed side by side of the transplantation of M. galloprovincialis specimens (active biomonitoring) coming from a mussel farm located in a clean area of the Venice Lagoon. The data obtained have been correlated with cadmium content in bottom sediment and in sediment/suspended particulate sampled with special cages at the same depth of local and transplanted mussels. Also for in situ samples the metal’s partition has been considered decisive, so it has been evaluated both in abiotic matrix (geospeciation) and in the biotic one (compartmentalization in the organism).
2004
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10278/27424
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