There’s a Fungus Among Us… Even in Freshwater

Freshwater Fungi

Celebrated annually on February 2nd, World Wetlands Day aims to raise global awareness about the importance of healthy freshwater systems for people and our planet. This year, the theme for World Wetlands Day is “Wetlands and Human Wellbeing” to highlight how all aspects of human wellbeing –physical, mental, and environmental – are tied to the health of the world’s wetlands. 

Freshwater life – that’s fish and birds and salamanders, right? Crayfish, mayflies, mussels? A water lily floating on top? Freshwater life is all this, and so much more – and it includes fungi! 

If you are surprised to hear there are fungi that live in freshwater, then you are not alone. These fungi really are out of sight, out of mind, and not just because they live in freshwater; they are also microscopic in size. But they are real powerhouses when it comes to ecological function. Just like their terrestrial counterparts, aquatic fungi provide the ecological basis for other organisms to thrive. They break down complex plant material into more digestible components that can then be used by other aquatic critters as a food source. In short, freshwater fungi support aquatic food webs, since predators, such as amphibians and fish, in turn eat the aquatic critters that benefit from the fungi’s work. Like other microorganisms, the makeup of freshwater fungi in our waterways is likely to influence the well-being of many species, including threatened species and conservation priorities, think freshwater mussels or hellbenders! And ultimately, they contribute to human well-being – after all, healthy freshwater means healthy humans! 

Here at the Global Center for Species Survival, we first started making a splash about freshwater fungi with the publication of our Fantastic Freshwater report, in collaboration with Shoal, the IUCN Species Survival Commission’s (SSC) Freshwater Conservation Committee, and several International Union for Conservation of Nature (IUCN) Species Survival Commission (SSC) Specialist Groups that focus on conserving freshwater life. What we realized at the time is that a really important Specialist Group was still missing from the IUCN SSC’s portfolio of groups: one dedicated to the conservation of aquatic fungi.  

This gap has now been filled. Working in collaboration with a recently-established research consortium on aquatic fungi in Europe (check out project FUNACTION, funded through Biodiversa+, which aims to develop knowledge and strategies to inform conservation priorities and measures for aquatic fungi in Europe) and reaching out to other researchers working in aquatic fungi conservation around the world, the IUCN SSC recently welcomed the IUCN SSC Aquatic Fungi Specialist Group (AFSG) into their fold. This is a unique group amongst IUCN SSC Specialist Groups, as it sits under the umbrella of three of the IUCN SSC’s conservation committees: the Fungal Conservation CommitteeFreshwater Conservation Committee and Marine Conservation Committee. 

The AFSG will focus on creating the infrastructure necessary for conservation assessment and planning, by creating a database or inventory of aquatic fungi. After all, aquatic fungi are not any particular taxonomic species group of fungi; they are simply those fungi that rely on aquatic habitats for the whole or part of their life cycle. The AFSG wants to develop the scientific and coordination basis for the first conservation assessment as well as planning and action efforts for aquatic fungi. Through linkages with projects that are already underway, such as FUNACTION, the AFSG will help to improve the monitoring of these important organisms and likely also be at the forefront of new species discovery! 

As part of the increased conservation focus on aquatic fungi, the Indianapolis Zoo is funding an exciting project of aquatic fungi discovery, right here on our doorstep. Led by AFSG member Huzefa Raja from the University of North Carolina Greensboro, we will start a freshwater fungi safari, right here in our White River in Indianapolis. What’s a freshwater fungi safari, we hear you ask?  

Since freshwater fungi are minute, microscopic organisms, a freshwater fungi safari is nothing like looking for the Big Five in Africa. Collection and identification of aquatic fungi species requires special techniques. Freshwater fungi researchers collect woody or herbaceous debris that has been submerged in a river, lake, or wetland for a significant length of time. Any collected debris is then taken to the lab where they are incubated to promote reproduction. Identification of the species then occurs under the microscope. 

Huzefa plans on collecting White River fungi over the course of 2024 and identifying and cataloging the species he finds – it is highly likely that he will discover new species not previously recorded. We will also use the project to get as many people as possible informed if not enthused about freshwater fungi. The project starts this year, with the goal of collecting in multiple freshwater habitats in Indiana, so keep an eye out for more news about our freshwater fungi safari coming to a river near you! Let’s go on a Freshwater Fungi Safari! 

This blog was a collaboration between experts at the Global Center for Species Survival, including Freshwater Conservation Coordinator Monni Böhm and Plants & Fungi Conservation Coordinator Cátia Canteiro, as well as Huzefa Raja and Isabel Fernandes from the IUCN SSC Aquatic Fungi Specialist Group, and Ian Harrison and Topiltzin Contreras from the IUCN SSC Freshwater Conservation Committee. 

Published February 2, 2024

Monika Böhm, Ph.D.

Dr. Monika Böhm is the Freshwater Conservation Coordinator for the Global Center for Species Survival.

Learn more about freshwater conservation and Monni.

Cátia Canteiro

Cátia Canteiro is the Plants & Fungi Conservation Coordinator for the Global Center for Species Survival.

Learn more about fungal conservation and Cátia.