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RESEARCH PRODUCT

Parasites as Indicators of Water Quality and the Potential Use of Helminth Transmission in Marine Pollution Studies

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Publisher Summary This chapter focuses on parasites as indicators of water quality and the potential use of helminth transmission in marine pollution studies. There are good reasons for focusing on parasitic organisms in general and helminth parasites in particular, in the search for highly sensitive indicators. First, there are more parasitic than free-living species. Second, helminth parasites have complex life cycles and the different developmental stages have widely differing requirements, therefore, each stage must be assessed separately for sensitivity to environmental change, thereby widening the choice of potential indicators. Many biotic and abiotic factors affect the numbers and distribution of marine. With regard to numbers, there is much information on prevalence, intensity, mean intensity, relative density or abundance, and diversity. In some instances, a parasite may be directly susceptible to the toxic effects of pollutants, in which case pollution may reduce infection prevalence and intensity. If the host is more susceptible than the parasite to the pollutant, its resistance to infection may be lowered, leading to higher prevalence and intensity.