Host-parasite interactions in polluted environments

In: Journal of Fish Biology, Jg. 73 (2008), S. 2133-2142
Zeitschriftenaufsatz / Fach: Biologie
In recent years, there has been an increasing number of papers showing how parasitism and
pollution can interact with each other in aquatic organisms. In addition to synergistic negative
effects of both stressors, there are also indications of antagonistic interactions. The latter are
related to the reduction of pollutant levels in infected hosts compared with uninfected
conspecifics. As reduced pollutant concentrations are usually correlated with less adverse
effects, it might be advantageous to be infected if hosts are confronted with environmental
pollution. On the other hand, possible pathological effects might reduce a potentially beneficial
effect of parasites. There are also examples, however, which show that parasites may enhance
toxic effects of pollutants by interfering with host-protection mechanisms. In these cases,
a parasitosis would have exclusively negative effects on the physiological homeostasis of their
hosts. This presentation summarizes the current knowledge on interactions between parasites
and pollutants with respect to their effects on the host’s health.