ABSTRACT
It could be argued that the most crucial task for ecotoxicologists is to ensure that the structure and the function of ecosystems are preserved. It is also the most difficult. The linkages between biochemical, physiological, individual, population and community responses to pollutants are shown diagrammatically in the Introduction. The dilemma is that as the importance of a change increases so does the difficulty of measuring it and relating it to a specific cause. In this chapter, a number of specific examples will be considered to illustrate the approaches that have been used to tackle this important problem of ecotoxicology, involving the use of biomarkers. These examples are as follows:
1. DDE-induced eggshell thinning in raptorial and fish-eating birds;
2. reproductive failure of fish-eating birds on the Great Lakes of North America;
3. reproductive failure of molluscs caused by tributyl tin;
4. the forest spray programmes of eastern Canada.
