Anthropogenic Stressor and Parasite Interactions in Aquatic Environments

Abstract: Aquatic environments are under increasing stress due to human activities. Most of the research in aquatic ecotoxicology has focused on chemical pollutions. The way to evaluate how likely it is that an ecosystem may be impacted by the exposure to chemical stressors involves two complementary approaches, the monitoring of the physicochemical status of the ecosystems and the assessment of disturbances on biological compartments. The latter can be performed through the study of community structures or the use of. Significant efforts of research have been dedicated to the development of biomarkers. In 1994, Depledge defined a “biomarker” as a biochemical, cellular, physiological or behavioral variation that can be measured in tissue or body fluid samples at the level of the whole organism that provides evidence of exposure to one or more chemical pollutants. However, the contribution of biomarkers to ecological risk assessment is questioned due to the lack of knowledge of dose–response relationships, their ability to describe, explain and even predict potential effects at higher levels of biological organization (i.e. population and community) and their natural variability. Another issue about biomarkers is that a number of internal and external factors, other than the water chemistry, influence the uptake, retention and bioaccumulation of contaminants and in fine biomarker responses.