Daniel Kelly | Fondriest Environmental
Introduced to the Great Lakes in the 1870s, the faucet snail is native to Europe and is distributed in parts of Scandinavia and Greece. The snail likely made its way to North America on timber transport ships. Another possibility is that the snails were transported in vegetation that had been used as packing material for shipping.
Each faucet snail is about 12 to 15 millimeters in height at full size, and has a color that ranges from brown to black with a circle pattern going around its shell that some say resembles tree rings. When pointed upward, the shell opening for faucet snails is on the right and may be difficult to locate because it has a small cover.
Though it appears to not be much of a threat because of its small size, the faucet snail can be quite detrimental to organisms that prey on it because it is a carrier of three major parasitic types of flatworm. When eaten by waterfowl, these flatworms have been found to injure or kill. In addition, birds affected by the parasites have been seen flying and diving erratically following infection.
Faucet snails are commonly found on rocky shorelines, the bottoms of lakes and rivers, docks and most all other objects that can be placed in water. In the United States, they have expanded rapidly to all of the Great Lakes, as well as many of their tributaries. Several water bodies in the Pacific Northwest also deal with the invasive species.
In these regions, the snails function as scrapers and water filterers, as they feed on algae in substrate and use their gills to clean suspended algae in the water column. This occurs as faucet snails suck algae in, condense it and then siphon it out into pellet-like packages that are eaten by larger animals up the food chain.
Prevent Its Spread
Unfortunately there are no known biological or chemical control methods that can be used to mitigate the spread of faucet snails. Scientists did attempt to cover colonies of faucet snails with sand in a 2007 study on the Mississippi River, but the success of that physical method was not documented.
Some ways to help prevent the spread of this invasive species is to inspect boats and other equipment for aquatic animals, plants and mud before using them in new waterways. If any faucet snails are found, report the sighting to the appropriate department of natural resources.