The Bureau for Risk Assessment & Research (BuRO) has issued advice regarding the risks of three types of freshwater snails to the Director of Nature at the Ministry of Agriculture, Fisheries, Food Security and Nature (LVVN). The advice is to alert sellers of aquarium plants to hitchhiking freshwater snails and to encourage them to take measures to prevent the hitchhiking of freshwater snails. Additionally, it is advised to inform aquarium owners about the existing ban on releasing animals.
Introduction in the Netherlands
The three types of freshwater snails hitchhike with the import of aquarium plants. Chinese pond snails and Florida pond snails are also sold in Europe as aquarium pets. American pond snails are already present in the Netherlands, and Chinese pond snails can establish themselves in the Netherlands. Florida pond snails require a warmer climate. The freshwater snails can end up in surface waters due to intentional or unintentional release by aquarium owners.
Effects of American pond snails, Chinese pond snails, and Florida pond snails
No scientific studies have been found that demonstrate that the three assessed freshwater snails have effects on biodiversity and ecosystems. However, it is known that freshwater snails are an (intermediate) host for various parasites, including flatworms. The consequences of these parasites vary greatly depending on the parasite and the animal species. For example, a pond in Germany has seen a significant decline in small pond salamanders likely caused by the presence of American pond snails, which enabled the life cycle of the parasite Parastrigea robusta.
Control
Completely eliminating freshwater snails in surface waters is not feasible, possibly with the exception of a surface water that is not connected to other surface waters at an early stage of invasion.
Preventing further introduction into nature
The further introduction of freshwater snails into nature can be prevented by countering the hitchhiking of these animals with aquarium plants and not emptying the contents of aquariums into surface waters. There is already a ban on releasing animals into surface waters.
Documents
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Advice from BuRO on the risk assessments of three types of non-native freshwater snails in the Netherlands
Alert sellers of aquarium plants to hitchhiking freshwater snails and encourage them to take measures to prevent it ...
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Risk assessment of the American pond snail
This report is an assessment of the ecological risk posed by the freshwater snail American pond snail (Gyraulus parvus) ...
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Risk assessment of the Chinese pond snail
This report is an assessment of the ecological risk posed by the freshwater snail Chinese pond snail (Gyraulus chinensis) ...
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Risk assessment of the Florida pond snail
This report is an assessment of the ecological risk posed by the freshwater snail Florida pond snail (Planorbella duryi) ...