The book "Methods of biological analysis of fresh water", created by the team of authors, provides a unique and comprehensive guide for specialists, scientists and students engaged in the study and monitoring of aquatic ecosystems. This book is a real storehouse of knowledge, revealing to the reader modern methods and approaches to the study of freshwater resources, their quality status and biological diversity. It contains the most relevant and time-tested techniques that allow to conduct in-depth analysis of water bodies, identify environmental violations and develop measures to eliminate them. The main idea of the book is to show how with the help of biological methods it is possible to obtain the most accurate and comprehensive picture of the state of fresh water. The author's team, which unites experts in the field of hydrobiology, environmental diagnostics and water resources, shares its practical knowledge and experience, supporting them with modern scientific research. As a result, we get not just a collection of techniques , and full leadership, which will help to understand the intricacies of biological analysis , learn to interpret the results correctly and apply them in real-world settings whether it’s scientific research State monitoring or environmental impact assessment . The book "Methods of biological analysis of fresh water" is suitable for a wide range of readers. It will be of interest to students of environmental and biological faculties, graduate students, researchers, specialists in environmental services and water management, as well as everyone involved in environmental protection and monitoring of water bodies. For those who are just beginning their journey in the field of hydrobiology or environmental analysis, the book will be an excellent tutorial, and experienced professionals - a valuable source of new ideas and approaches. The book pays special attention to the definition of biological indicators, methods for assessing water quality by the state of aquatic organisms, as well as modern technologies for collecting and analyzing biological samples. It details topics such as biodiagnostics of contaminants, the use of microscopy and molecular techniques to identify species, and the integration of biological data with chemical and physical indicators of water. Such an integrated approach makes the book particularly valuable for those who seek accuracy and completeness in assessing the ecological state of freshwater. The style of presentation of the authors is clear and practical, which makes it easy to absorb complex technical details even for beginners. At the same time, the book contains many examples from real practice, which makes it not only a theoretical manual, but also a practical guide. This publication is the result of many years of research and field work, so it is filled with live cases and recommendations based on real situations. If we talk about the place of the book in the literature on environmental topics, then “Methods of biological analysis of fresh water” can be compared with classical works on hydrobiology and environmental monitoring, but at the same time it has its unique relevance and practical value. It combines scientific rigor and accessibility, which makes it an indispensable assistant in work and study. This publication is an excellent choice for those who want not only to understand the basics of biological methods of analysis, but also to learn how to apply them to solve modern environmental problems. In general, the book “Methods of biological analysis of fresh water” is not just a collection of techniques, but a real guide in the world of hydrobiological research. It will help to uncover the secrets of aquatic ecosystems, understand their complex relationships and learn how to protect them from negative impacts. For everyone who values environmental science and strives to preserve the purity and biodiversity of freshwater, this publication will be an indispensable assistant and source of inspiration.