TA4 Integrating Sublethal Responses and Ecologically Relevant Endpoints
204 Oregon Ballroom
8:00 AM - 12:00 PM, Tuesday
() Food availability and quality as an important ecological factor to explain differences in the ecotoxicological effect of chemicals.
Smolders, Roel1, Baillieul, Marc1, De Coen, Wim1, Blust, Ronny1, 1 University of Antwerp, Antwerp, Belgium
ABSTRACT- In order to increase the ecological relevance of toxicity testing, field experiments using indigenous or transplanted organisms can provide valuable information to unravel the ecological and toxicological effects of pollutants on organisms, communities and ecosystems. However, since toxicants may have an impact on virtually all levels of structural and functional integrity of aquatic ecosystems, it is very difficult to differentiate among the impact of direct, toxicant-related, and indirect effects (e.g. through effects on trophic cascades or food availability). It has previously been shown that there can be important differences in the response of organisms to toxicants with changes in food quality or quantity. We present the results of a number of field and laboratory studies using fish and daphnids that were aimed at unraveling the impact of differences in food availability on ecologically relevant endpoints like growth, condition and reproduction of fish and invertebrates. The main question that will be addressed is whether increases in food quality and/or quantity have a significant impact on the general well-being of aquatic organisms. Furthermore, we tried to evaluate whether well-fed organisms are more resistant towards toxicant stress than starved organisms. From the results, it was concluded that factors describing the structural and functional properties of aquatic ecosystem, like food availability and quality, are essential to fully appreciate the effects of toxicants during field exposure.
Key words: Field exposure, Food availability, Ecological relevance