Aquatic Invasive Species

Aquatic invasive species (AIS) records are assigned statuses of "verified", "observed", or "no longer observed" based on AIS Status Guidance. In general, "verified" populations are established and have been verified by a taxonomic expert. Populations with the "observed" status have not been verified by a taxonomic expert or do not have established populations. Populations with the "no longer observed" status include populations where a reproducing population did not establish. Our inventories are not necessarily exhaustive so it is important to report occurrences. To report new discoveries visit: https://dnr.wisconsin.gov/topic/Invasives/report.html. See the Aquatic Invasive Species Guidance for information on how statuses are assigned. Personally identifiable information on data collection forms may be provided to requesters to the extent required by Wisconsin's Open Records Law [ss. 19.31-19.39, Wis. Stats.].

Species currently tracked on these lists are: Asiatic Clam (Corbicula), Banded Mystery Snail, Bloody Shrimp, Bohemian knotweed (Polygonum bohemicum), Brazilian Waterweed, Brittle Waternymph, Butterfly dock, Chinese Mystery Snail, Curly-Leaf Pondweed, Daphnia lumholtzii , Eurasian Water-Milfoil, European Frogbit, Faucet Snail, Fishhook Waterflea, Flowering Rush, Giant hogweed (Heracleum mantegazzianum), Giant knotweed (Polygonum sachalinense), Golden Creeper, Graceful Cattail, Hairy Willow Herb, Hybrid Eurasian / Northern Water-Milfoil, Hydrilla, Japanese Hops, Japanese Mystery Snail, Japanese knotweed (Fallopia japonica), Japanese stiltgrass (Microstegium vimineum), Java Waterdrop / Vietnamese Water Celery, Lesser celandine (Ranunculus ficaria), New Zealand Mudsnail, Ornamental water lilies (non-native Nymphaea sp.), Parrot Feather, Pennywort, Phragmites (non-native), Poison Hemlock, Policeman’s helmet (Impatiens glandulifera), Purple Loosestrife, Quagga Mussel, Queen of the meadow (Filipendula ulmaria), Rainbow Smelt, Red Swamp Crayfish, Reed Manna Grass, Round Goby, Rusty Crayfish, Sacred Lotus, Seaside Goldenrod, Southern Cattail, Spiny Naiad, Spiny Waterflea, Starry Stonewort, Water Hyacinth, Water Lettuce, Western Mosquitofish, Yellow Floating Heart, Yellow Iris, and Zebra Mussel.

* Observed – This is a record that has been observed in the field, but a specimen has not been verified by a taxonomic expert or an established population has not been found within the waterbody. Only dead AIS or few individuals of one age class have been observed, not an established breeding population. This will include dead individuals observed outside their growing season that will need to be revisited during target times to verify. This also includes historic monitoring data that has not been verified by a taxonomic expert.

** Purple Loosestrife - DNR has only a partial list of locations. For more extensive data, visit the Great Lakes Indian Fish and Wildlife Commission (GLIFWC) website [exit DNR].

** Fish species - This web page only has a partial list of locations. For more extensive data, visit the Wisconsin Department of Natural Resources Map of Distribution of WI Fish Species [exit DNR].