At first glance, mystery snails may seem harmless. These large freshwater snails, commonly found in lakes, ponds, and slow-moving rivers, spend much of their lives grazing along muddy bottoms. But behind their unassuming appearance lies a complex story that continues to challenge scientists and natural resource managers.
Mystery snails are native to Asia but have been established in North America for more than a century. First sold in food markets and later spread through waterways and human activities, they are now found in many lakes and rivers in Minnesota.
Research has shown that high densities of mystery snails can alter the feeding behavior of native snails and reduce populations of some native species. Their large populations can also produce substantial shell accumulations when die-offs occur, creating a build up of shell deposits on shorelines and affecting recreation.
The presence of mystery snails in a lake also raises questions about parasites and human health. They can host a variety of parasites, including one called cercariae that could pass on to humans as swimmer’s itch. They are also known hosts of the native parasite Aspidogaster conchicola, which can spread to native freshwater mussels. While the presence of these parasites does not necessarily mean disease outbreaks will occur, it highlights the importance of understanding how introduced species interact with native ecosystems.
MAISRC researchers are tackling the complex life of the mystery snail with four distinct research projects, working together to build a comprehensive understanding of how these invasive snails affect Minnesota lakes and how they can be managed.
One project examines where mystery snails occur, their habitat preferences, and whether they threaten culturally and ecologically important wild rice beds, while also evaluating hand-removal efforts as a management tool. A second project investigates the role mystery snails may play in the transmission of swimmer's itch parasites, helping researchers understand potential connections between aquatic invasive species and human health. A third project focuses on broader ecosystem impacts, studying how mystery snails alter food webs, compete with native species, and influence nutrient cycling and water quality in invaded lakes.
Finally, a technology-focused project is developing new tools that combine robotics, image analysis, and predictive modeling to improve detection and monitoring of mystery snail populations. Together, these projects span the full spectrum of mystery snail research. MAISRC research is looking at early detection and population monitoring, ecological impacts, public health concerns, habitat protection, and management strategies. The knowledge from these projects will provide the science needed to guide future decision-making in Minnesota waters.
The story of mystery snails reminds us that solutions to aquatic invasive species are rarely simple. Understanding their biology, ecology, and impacts is essential for making informed decisions about managing our lakes and protecting native aquatic ecosystems. Visit the project links to the right to learn more.
This text from MAISRC's June 2026 newsletter.