Lake and river lessons: a free resource and tribute to limnologist Bob Wetzel
9 October, 2026
We are thrilled to have the opportunity to share an update from members of the International Society of Limnology (SIL), introducing an up-to-date textbook on lake and river ecosystems, and a series of accompanying free tutorials.
Founded in 1922, SIL is the oldest and only international society entirely devoted to inland waters. Their mission is ‘promoting excellence in studying and managing inland waters and addressing global issues through the fostering of interdisciplinary approaches and the transfer of knowledge’.
This impressive and extensive free online resource from SIL is a tribute to limnologist Bob Wetzel, providing a collection of video tutorials that support the latest edition of ‘Wetzel's Limnology: Lake and River Ecosystems’ introducing the key concepts in each chapter.
Keen to take a deeper dive into lake and river ecology?
For many, over decades, the go-to reference textbook to learn more about inland water ecosystems was “Limnology” by Robert ‘Bob’ G. Wetzel. This was first published in 1975, and then updated by Professor Wetzel in 1983 and 2001.
Bob Wetzel passed away in 2005, but interest in his landmark textbook continued to grow, leading the publishers to commission a fully updated, multi-author edition.
With cooperation from the Wetzel family, Ian Jones at the University of Stirling (UK) and John Smol at Queen’s University (Canada) coordinated the editing of a completely new edition. Recruiting more than 50 authors globally, each chapter in this latest 4th edition, published in 2023, has been extensively revised and brought up to date by specialists in each topic.
Blelham Tarn in the Lake District, Cumbria, UK (left). Screen capture from ‘Zooplankton’ in the ‘Wetzel’s Limnology SIL Videos’ series. Photo credit: Stephen Maberly, UK Centre for Ecology & Hydrology. Esthwaite Water in the Lake District, Cumbria, UK (right). Screen capture from ‘Zooplankton’ in the ‘Wetzel’s Limnology SIL Videos’ series. Photo credit: Ian Winfield.
“For the 4th edition of ‘Wetzel’s Limnology’, the editors brought together contributions from over 50 expert limnologists, with illustrative examples from all parts of the world. For our SIL video series, our aim was to build on that same diversity of expertise, voices and examples, to showcase limnological research in action, and to convey the incredible biological richness and importance of lake and river ecosystems. ”
Wetzel's Limnology: Lake and River Ecosystems, 2023, Academic Press
Edited by Ian D. Jones and John P. Smol, this 4th Edition presents a fully updated revision of Wetzel’s classic “Limnology” textbook - last published in 2001.
Paperback & eBook available here
Wetzel's Limnology: Lake and River Ecosystems is an essential textbook for undergraduate and graduate students in limnology, and also a standard reference book for seasoned limnologists and other scientists.
Wetzel’s Limnology: SIL’s free video series
To support knowledge exchange and understanding of lake and river ecology, SIL members felt that an open-access educational video series based on individual chapters in the book would be an ideal way to introduce, explain and promote limnology. The videos would also be a fitting tribute to Bob Wetzel, who played a major role in SIL as General Secretary and Treasurer for 37 years, and who was a guiding force in limnological research and education.
These ideas were enthusiastically received by the editors, authors and the publisher, and the first videos were launched around the time of publication of the updated edition of ‘Wetzel’s Limnology’. A total of 23 of these short videos, each 10 to 15 minutes long, are now freely available, online with more in progress. They cover a broad range of topics in physical, chemical, biological and applied limnology, with captions in English, French, Spanish, and other languages.
You can view the collection of Wetzel videos on the SIL website.
An online resource celebrating the world’s rich diversity of lake and river ecosystems
Of special interest to freshwater ecology enthusiasts will be many of the videos containing original clips and photos illustrating aquatic animals, plants and microscopic life, including viruses, bacteria, phytoplankton, bottom-dwelling algae and zooplankton.
For example, the ‘Benthic animals’ video has remarkable clips by Hungarian ecologists of predatory benthic invertebrates, and in the ‘Algae & Cyanobacteria’ video, renowned phycologist John Wehr presents all the major groups found in freshwaters.
Colourful dragonflies. Screen capture from ‘Benthic animals’ in the ‘Wetzel’s Limnology SIL Videos’ series. Photo credits: Michael T. Bogan (University of Arizona, USA) and Barbara Barta (Centre for Ecological Research, Hungary).
“I think the videos are really professionally done, and I ask my limnology students to watch them before my lectures, as they add context to lectures and students can hear directly from the authors (experts) and watch limnologists in action. Many limnologists have contributed ideas, images, narratives and amazing video clips to this series.”
Highlighting critical challenges facing freshwaters
Wetzel’s Limnology SIL Videos cover a number of key issues for freshwater ecosystems. Addressing important questions, such as, why can the water quality of lakes and reservoirs deteriorate so rapidly, with the sudden appearance of toxic algal blooms?
Several chapters in ‘Wetzel’s Limnology’ consider this crucial topic, which is addressed in the Wetzel’s Videos on harmful blooms, shallow lakes, and a pair of videos on nitrogen and phosphorus in lakes and rivers.
This SIL video on phosphorus features limnological research in the Experimental Lakes Area, Canada, the classic Mortimer experiment at lake Windermere, in England, and the work by the UK Centre for Ecology & Hydrology on phosphorus management for water quality of lakes in the United Kingdom and abroad.
“We are very pleased the SIL videos are capturing the imagination of so many students and members of the public about lake and river ecosystems, and about the value and importance of limnology.”
“The videos have collectively received more that 20,000 views to date, and we expect this interest to grow as more videos become available.”
Interested in discovering more?
Visit the International Society of Limnology (SIL) website.
View the full YouTube Playlist of Wetzel's Limnology SIL videos.
The collection of Wetzel Videos – on the SIL website.
