Bayfield County AIS Project

10/10/2026

10/08/2026

Despite being desirable backyard pond plants, water lettuce (Pistia stratiotes) and water hyacinth (Eichhornia crassipes) are regulated as prohibited invasive species in Wisconsin, making them illegal to own or sell.

When introduced into natural habitats, these species can cause serious harm – their aggressive growth often results in dense mats that can impact native species, water quality and recreation. Water lettuce has recently been discovered on a lake (pictured) where it may have been dumped by someone cleaning out their pond for the winter.

Never dump your pond plants, regulated or not. Instead, safely dispose of invasive plants in the trash by placing them in clear bags and labeling them with “Invasive plants- approved by DNR for landfilling”.

Think you found an invasive species on a waterbody? Report findings to your Regional DNR AIS Biologist: apps.dnr.wi.gov/lakes/invasives/Contacts.aspx?role=AIS_POC

07/16/2026

Our next AIS of the week is the purple loosestrife (Lythrum salicaria)!

This AIS can grow between 3-7ft tall and prefers moist soils and shallow water. Early detections is important as, like many AIS, purple loosestrife can outcompete native species.

Sign-up for Snapshot Day 2026 to search for purple loosestrife near you!
https://wav.extension.wisc.edu/events/aquatic-invasive-species-snapshot-day-2026/



----
Source: https://dnr.wisconsin.gov/topic/Invasives/fact/PurpleLoosestrife
Photo: Paul Skawinski

07/10/2026

How many larvae of Galerucella calmariensis beetles can you see on these purple loosestrife leaves? Look close! We are raising these larvae as a biocontrol project in a mass rearing tent. We will release the 1,000s of beetles that will hatch into purple loosestrife infestations within our region to help manage the purple loosestrife.

06/25/2026

Lettuce tell you about this AIS!

Pistia stratiotes, also know as water lettuce or tropical duckweed, is a floating perennial that looks like, you guessed it, a head of lettuce. It has been documented in the US as far back as 1765 by William Bartram, an American naturalist and explorer.

While it is uncertain what the native range is for water lettuce, it is classified as a "prohibited" in WI, or a plant not currently found in Wisconsin, with the exception of small pioneer group "that are isolated to a specific watershed, but which, if introduced into the state, are likely to survive and spread, potentially causing significant environmental [impact]".

It can form dense mats on the surface of water, degrading "water quality by blocking the air-water interface and significantly reducing oxygen levels in the water, impacting underwater animals such as fish."

Help us search for this AIS during Snapshot Day 2026! https://wav.extension.wisc.edu/events/aquatic-invasive-species-snapshot-day-2026/

_____

Photo by Paul Skawinski. Source:https://dnr.wisconsin.gov/topic/Invasives/fact/WaterLettuce

05/21/2026

Registration is now open for our next webinar taking place on Wednesday, July 8, 2026 at 01:00 PM Central Time.

"Genomic surveillance of zebra mussel populations using genotyping by sequencing" featuring Daryl Gohl discusses zebra mussel expansion in the United States, the cost of prevention and mitigation of zebra mussel infestations, and how Gohl's team is making recent research information accessible through an online web app to help inform AIS management strategies.

Register today! https://umn.zoom.us/webinar/register/WN_yWU5nMdUQl-3tArpJKRT4g #/registration

05/21/2026

05/20/2026

Crews in the Town of Eagle are restoring a spring-fed stream system and removing decades-old man-made ponds. FULL STORY⬇️

05/06/2026

04/22/2026