The Invasive New Zealand Mudsnail Found at New Location

The invasive New Zealand mudsnail (NZM) was identified in the Musconetcong River in 2018, and marked the beginning of the MWA’s quest to track its distribution throughout the stream. The NZM poses a threat to river ecosystems due to its rapid asexual reproduction. Over the course of 3 years, one female snail has the potential to produce 40 million offspring. Without any natural predators keeping populations down, NZMs have the potential to rob native macroinvertebrates of habitat and resources. If the presence of NZMs results in decreased macroinvertebrates, then a decrease in fish is soon to follow.

It was known that the NZM only existed downstream of Bloomsbury, up until recently. As part of the new National Fish and Wildlife Foundation (NFWF) grant to track the NZM’s distribution, the MWA Water Quality Team has sampled six new locations along the river – one of which being a fishing access point on New Hampton Road. Upon first arrival to the site this spring, NZMs were found. Snails were mostly situated on woody debris and leaf packs near the river bank. The discovery of NZMs upstream of Bloomsbury is surprising since the snails have not yet been found at any other upstream sites. However, this confirms the fact that the snails do not generally migrate long distances upstream on their own, but are transported by people.

Those who fish on the Musconetcong River use gear like waders and nets where the small NZM can attach and almost go unnoticed before being moved to another site. To solve this issue and prevent further spread of the snail, the MWA will be installing up to 30 decontamination stations at popular fishing locations along the river. Anglers traveling from site to site will now be able to clean the NZM from their gear before it hitches a ride to a new section of the river. Until then, anyone using the river should proceed with caution and partake in their own decontamination routine. Cleaning gear with a scrub brush and/or 409 spray is effective against the snail, as well as freezing gear for 24 hours.

Until the NZM’s limiting factor is discovered and a natural remedy can stop their spread, it is the user’s responsibility to ensure that the spread of the snail is slowed. This way, the health of the Musconetcong River can be maintained for its own benefit, as well as for the benefit of those who recreate and appreciate the river.

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