The book "Training and field practice on the course "Ecology" (water ecosystems)" by the authors of Seven B. P. and Zubishina A. A. is a unique textbook that will become an indispensable assistant for students studying ecology and related disciplines . This edition, published by Yaroslavl State University, immerses the reader in the world of aquatic ecosystems, revealing their complex relationships and importance for the biosphere. From the first pages of the book, the authors offer readers not only theoretical knowledge, but also practical skills that will help in further professional development. This manual is ideal for undergraduates, graduate students, and anyone interested in ecology, biology, and conservation. If you study aquatic ecosystems, then this book will become your reliable companion in study and scientific research. The book covers a wide range of topics related to aquatic ecosystems, from their structure and functions to research and conservation methods. The authors describe in detail the different types of bodies of water, their flora and fauna, as well as the impact of human activity on these ecosystems. Readers will be able to learn about modern methods of assessing the state of water resources, as well as how to conduct field research, which makes this manual especially valuable for future ecologists and biologists. The topics raised in the book are more relevant than ever. In the face of global climate change and constant pressure on natural resources, understanding of aquatic ecosystems is becoming critical. The authors emphasize the need to protect and restore water bodies, which makes the book not only a textbook, but also a call to action for all who are not indifferent to the fate of our planet. The style of the authors is characterized by accessibility and clarity of presentation. They use many examples and illustrations, which makes the material easy to perceive. The 7th . P. and Zubishin A. A. have extensive experience in the field of ecology and environmental protection, which gives their work additional value. Their previous publications are also devoted to environmental issues and environmental protection, which confirms their expertise in this area. The book will be of interest not only to students, but also to teachers, researchers, as well as anyone interested in environmental issues. It can become the basis for coursework and thesis, as well as a useful resource for research. Readers interested in the topics of ecology, sustainable development and environmental protection will find in this manual a lot of useful information and inspiration for their projects. If you are looking for a high-quality and informative guide to ecology, especially in the context of aquatic ecosystems, then “Training and field practice on the course “Ecology” (aquatic ecosystems) will be an excellent choice. This book will not only expand your knowledge, but also help you become a more conscious and active participant in nature conservation. Do not miss the opportunity to immerse yourself in the fascinating world of ecology and learn more about how we can save our water resources for future generations.