Research Product

This material has been prepared to enable the investigator to select bioassay organisms which will be most useful for the detection and evaluation of pollution. Ideally, the selected species or community of different species would reflect not only the presence or absence of specific pollutants but also relative pollution levels and their periodic fluctuations, and perhaps identify factors other than chemical that contribute to environmental degradation. The species selected should be of value in circumscribed geographic locations as well as in larger water areas. Such an ideal type does not exist, of course, and bioassay organisms may be grouped functionally into two general categories as either monitoring or indicator types. The demarcation between these two is not always sharp and there are numerous exceptions to the following generalized definitions.