Methods of biodiagnostics in aquatic ecotoxicology

Introduction. Modern ecotoxicology for the detection, quantitative and qualitative assessment of the content of toxicants in the environment and living organisms uses the entire spectrum of chemical-analytical methods. However, methods of biodiagnostics are specific to this science. Materials and methods. The paper summarizes information on the use of modern methods of biodiagnostics in aquatic ecotoxicology: biomarking, biotesting and bioindication. Results. The main advantage of biodiagnostics over physicochemical methods of analysis is the ability to identify the biological consequences of the action of a single stress factor or their combination. At the same time, biodiagnostic methods allow fixing the additivity, antagonism and synergy of their joint action. Biomarking differs from other biodiagnostic methods in response time from several minutes to several days, high sensitivity and sufficient specificity, since it gives the ability to register the changes occurring in the biological system at the early stages of the action of factors at their low intensity and at the same time identify the nature of the stress factor. Biotesting has a slower response time than biomarking (from several hours to several weeks), but the ecological significance at the level of an individual is more obvious: the death of an organism, a decrease in reproductive ability up to the cessation of reproduction, disruption of growth, development, various types of behavior, etc. Bioindication is characterized by a sufficiently long-time delay of responses of supraorganismal biosystems to the action of a stress factor from several weeks to several years. At the same time, it makes possible assess more adequately and reliably the changes that have occurred over a long period of timeof stress factor action in order to predict options for the further development of ecosystems. Limitations. Methods of biodiagnostics in aquatic ecotoxicology have no restrictions on their use. However, unlike the methods of physicochemical analysis, they do not allow a quantitative, and sometimes a qualitative assessment of the stress factor. Therefore, they should be used in conjunction with the methods of qualitative and quantitative physicochemical analysis. Conclusion. Thus, the biodiagnostic approach, including biomarking, biotesting, and bioindication, together with physics and chemicals analysis plays an important role in the modern integrated system for assessing the ecological state of water bodies and anthropogenic impact on them.