ABSTRACT

In the first place, a pollutant interacts with an individual organism. If the concentration of the pollutant is high enough, it will have a harmful effect upon that individual. A critical question in ecotoxicology is whether harm to the individual leads to an effect at the population level. Figure 4.1 illustrates the sequential linkage between harmful effects at the individual level and consequent changes at higher levels of biological organization, that is, at the levels of population, community, and ecosystem, respectively (see Ramade 1992).