Research Product

Until fairly recently, water quality bioassay techniques have been limited to observations of the lethal concentrations of a pollutant. Such measures as LD50 , TLm50, and LC50 were, and still are, commonly used to assess the acute effect of a pollutant, usually based on the mortality of adult organisms. While this approach was probably inevitable as a step in the evolution of both the philosophy and techniques of bioassaying, it has become abundantly clear that this concept has serious limitations as a measure of the effects of a pollutant on the environment. The need for additional, more comprehensive measures of organismic response to contaminants has stimulated the search for new testing techniques in a variety of disciplines, including behavior. The most important advantage to using behavior as a tool to measure stress is that the results of behavioral tests often lend themselves to a direct interpretation regarding environmental quality as related to possible consequences at the population and ecosystem levels. Also complex biochemical and physiological responses of an organism may be reflected in rather easily observable acts. Although behavioral measures may suffer in regard to quantification because of the high degree of inherent variation, they are highly sensitive to stress. The general aim of the workshop was to explore various aspects of applying behavioral measures to bioassay. Although in a few instances the use of behavioral bioassays has reached the standard test stage, the state of the art is still very young. Consequently, the scope of the discussion was intended as a beginning toward integrating a variety of basic research techniques into logical steps towards developing standard tests.