Beware of the New Zealand Mud Snails
New Zealand Mud Snails are an invasive species of snails originating from fresh water lakes in New Zealand and have made their way to U.S. freshwater streams and lakes. Although these invasive snails have yet to invade Manitowish Waters, they have made a successful living nearby in the Great Lakes. The best mitigation of an invasive species is to understand what it is, be aware of its location, and most importantly, prevent its spread to new locations. Why should you be aware of New Zealand Mud Snails and reduce their spread? New Zealand Mud Snails are extremely successful invasive species as they have a high tolerance to many different water qualities (salinity, turbidity, temperature, productivity, etc.), reproduce at a high rate (20-120 embryos per brood), have an ability to reproduce asexually, and have no known predators. The significance of asexual reproduction is that no males are needed for fertilization and new clones (offspring) can be reproduced by the female’s terms. All of these qualities make New Zealand Mud Snails a great candidate to colonize and persist in our lakes (probably most lakes), because they can tolerate most conditions and produce many offspring who will also tolerate most conditions. In addition to their successfulness as an invasive species, they also compete with native aquatic species by taking up space and consuming the same food source. Their ability to reproduce at such an extraordinary rate may lead to the displacement of other native species by occupying the same habitats and overwhelming the food supply for other primary consumers, and thus affecting higher trophic levels. The presence of New Zealand Mud Snails in our lakes could greatly reduce native aquatic herbivores and therefore reduce the food supply for many fish species. In layman’s terms, New Zealand Mud Snails have the capability to collapse our lake ecosystems, which have cascading effects on water quality and the public’s ability to enjoy recreational activities on the lakes.
How can you identify a New Zealand Mud Snail? To accurately identify a Mud Snail, look for tiny snails ranging from 2-6 mm with light brown or dark brown spiraling shells. Due to their small size and ability to blend in with darker materials, New Zealand Mud Snails can be easily overlooked and most often unnoticed. It is imperative that you inspect and clean your boats, gear, clothing, and any other equipment that was used in the water thoroughly before leaving. Not only will these measures prevent the spread of New Zealand Mud Snails, it will mitigate other threatening invasive species, protect our native species and ecosystems, and save our communities up to billions of dollars.
This is one of three articles written by Abby Good. Abby is a rising senior at the University of Iowa, majoring in Environmental Science with a focus in bioscience and minoring in biology. Her career interests are in conservation and air quality.
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“New Zealand Mud Snail.” New Zealand Mud Snail | National Invasive Species Information Center | USDA