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(10-06) Trophic transfer models: can they predict ecological effects? Boxall, AListair*,1, Baird, Donald2, 1 Cranfield Centre for EcoChemistry, Derby, Derbyshire, England2 Institute of Aquaculture, Stirling, Scotland ABSTRACT- A range of trophic-transfer models is available to predict the movement of toxic substances through food chains. These models differ in complexity, in the nature and extent of assumptions made of the system and chemical properties, and in their predictive capacity. Here, we confront these models with data sets from a range of ecosystem level studies published in the recent literature. These studies cover contrasting aquatic ecosystem types, including both marine and freshwater habitats from both tropical and temperate regions. Substances studied span a range of persistent, bioaccumulative substances with varying chemical properties, and toxic modes of action. While existing models aim to provide information on the accumulation of toxic substances within biota, they do not ultimately aim to predict effects. Indeed, as we shall argue, there is increasing evidence that uptake of substances and ecologically important effects may not always be directly related, particularly concerning substances which impair feeding behaviour and hence energy flow within ecosystems. Indeed, we believe it may be time to consider replacing the simplistic body-burden / toxic threshold concept with a more sophisticated, yet also more ecologically realistic model which partitions the body burden into effects compartments. Key words: trophic transfer, food chain, body burden |
