Status and use of biological indicators for evaluating the effects of stress on fish

Abstract

Laboratory bioassays and other conventional methods of assessing stress on aquatic organisms generally lack ecological realism because of the many environmental factors that can influence stress responses at all levels of biological organization. The biological indicator approach involves measurement of a suite of selected stress responses at several levels of biological organization to assess sublethal stress effects on fish, to give early warning of stress, and to obtain insights into causal relationships between stressors and effects manifested at higher levels of biological organization. The types of stress responses measured range from those at the subcellular and biochemical levels to those at the ecosystem level; the responses segregate along gradients of toxicological and ecological relevance and of response time.