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(09-01) Bioavailability of trace metals in suspended particulate matter to mussels. Qadah, Diab*,1, Mubiana, Valentine1, Blust, Ronny1, 1 Department of Biology, Antwerp, Belgium, Belgium ABSTRACT- Worldwide mussels are used as sentinels of environmental pollution in biological monitoring programs. To correctly interpret the results of these programs it is essential to understand the way in which these organisms are exposed to the pollutant present in the environment. This study aims to determine to what extent metals associated to particulate matter contribute to metal availability and accumulation by bivalves. Bivalves are selective filter feeders that continuously extract particles from the external environment. Since suspended matter is often enriched with metals they are a potential source of metals to bivalves. The loading of suspended matter with metals depends on the size and binding characteristics of the particles. The size selective clearance of particles from the external environment by the filter feeders was studied by following the changes in the concentration and size distribution of the particles present in the exposure solution as function of time. The particle size-dependent distribution of metals in the suspended matter was determined by collecting suspended matter on membrane filters of different pore sizes and subsequent digestion and metal analysis of the filters. The assimilation efficiency of the metals was determined by comparing the concentrations of the metals and corresponding radiotracers in the ingested suspended matter, the soft tissues and collected faecal material. Metals concentrations in the different matrices were determined by ICP-MS. The results show that metals associated to particulate matter are available for uptake but that the assimilation efficiency is variable. Depending on the specific conditions metals associated to particles may be a more or less important source than metals in solution. Based upon these results a model has been constructed that can be used to estimate the importance of the different sources for metal uptake in mussels. Key words: metals, suspended matter, bioavailability, mussels |
