Chinese Mystery Snails (Cipangopaludina chinensis)
The Chinese mystery snail is a large, freshwater snail native to East Asia. It was introduced to North America in the late 19th century through the aquarium trade and as a food item. Since then, it has established populations in many lakes and slow-moving rivers across the Northeast and Midwest.
Chinese mystery snails reproduce quickly and can reach high densities on lake bottoms, where they compete with native snails and benthic organisms for food and space. They may alter nutrient cycling and contribute to algal blooms by releasing phosphorus into the water. Large die-offs are common and can result in thousands of empty shells washing ashore, creating unpleasant odors and conditions for lake users. Although they do not harm humans directly, they can serve as hosts for parasites that may affect fish or other wildlife.
In Chazy Lake, Chinese mystery snails have been detected during aquatic plant and invertebrate surveys. While their full impact on the lake’s ecosystem is still being studied, their presence is concerning, especially given their potential to displace native snails and alter food webs. CLWI encourages lake users to thoroughly clean, drain, and dry boats, gear, and bait buckets to reduce the risk of spreading this and other aquatic invasive species. Continued monitoring and public education remain central to controlling the snail’s spread.
Chinese mystery snails reproduce quickly and can reach high densities on lake bottoms, where they compete with native snails and benthic organisms for food and space. They may alter nutrient cycling and contribute to algal blooms by releasing phosphorus into the water. Large die-offs are common and can result in thousands of empty shells washing ashore, creating unpleasant odors and conditions for lake users. Although they do not harm humans directly, they can serve as hosts for parasites that may affect fish or other wildlife.
In Chazy Lake, Chinese mystery snails have been detected during aquatic plant and invertebrate surveys. While their full impact on the lake’s ecosystem is still being studied, their presence is concerning, especially given their potential to displace native snails and alter food webs. CLWI encourages lake users to thoroughly clean, drain, and dry boats, gear, and bait buckets to reduce the risk of spreading this and other aquatic invasive species. Continued monitoring and public education remain central to controlling the snail’s spread.