Water quality monitoring and aquatic organisms: the importance of species identification.

Abstract

Several methods have been used to ana yze the effects of human activities on aquatic environments. They include the use of selected chemical and physical parameters, as well as a variety of biologi cal measurements that range from bacterio logical analyses to bioassay studies of fish and other aquatic organisms. Although macroinvertebrates are rarely used in bio assay studies,1 they have proven to be ex tremely useful in water quality monitoring in two different methods of investigation: studies of community diversity and use as indicator organisms. The first approach to water quality anal ysis with macroinvertebrates involves de termining the degree of organization that is present in the structure and composition of the component species of the benthic community. These mathematical expres sions, termed diversity indexes, are widely used and of great potential value.2-4 There are, however, many problems inherent both in the choice of an index5 and in the in