BEHAVIORAL-RESPONSES AS INDICATORS OF ENVIRONMENTAL ALTERATIONS - APPROACHES, RESULTS, DEVELOPMENTS

Over the past 15 to 20 years, growing awareness of anthropogenic alterations of aquatic environments has led to a search for sensitive and ecologically relevant effect indicators and meaningful early-warning signals at various levels of biological integration from subcellular biophysics and biochemistry to ecosystem function. Besides playing its role in basic ecology, the integrative whole-organism behavioural response has long been used in mammalian toxicology and pharmacology. For its use in assessing effects of physical and chemical changes of the environment on fish, however, broader ecology-oriented concepts and new quantitative methods were needed, and are now being developed. Published data are relatively numerous in the areas of unconditioned preference-avoidance responses (relating to habitat selection and maintenance), and changes of locomotor activity. More complex effects on intra- and interspecific interactons have recently attracted increased attention. Recent technical and methodological advances include instantaneous response digitization and computerized video image analysis. Apparent strengths and weaknesses of present behavioural testing are presented, and some research needs and current developments are pointed out.