2022 - 2024 Invasive Species Report released by Department of Natural Resources

Recently the Department of Natural Resources (DNR) released the 2022-24 Invasive Species Report highlighting the work that has been done on both aquatic and terrestrial invasive species in the state, including efforts to stop organisms in trade.

Between DNR staff, citizens and partners, over 1,000 locations throughout the state are monitored for aquatic invasive species (AIS) every year. According to the report, these monitoring efforts have pinpointed approximately 150 different new populations of common AIS such as mystery snails and purple loosestrife. 

The focus on AIS has looked at various pathways by which invasive species can come into the state. These pathways toward which efforts were directed include recreational activities and service providers, non-recreational fishing and aquaculture, organisms in trade, transportation and utility corridors, state and federal agencies, maritime commerce, canals, dams and diversions. All of these pathways are described in detail in the states AIS Management Plan.

The 25-page report highlighted some top level accomplishments in invasive species as well as information on individual species with which the department had dealt in the three year time period covered by the report. Under the heading of aquatic surveying and monitoring activities, the department has maintained a public resource page, the Aquatic and Wetland Invasive Species Monitoring webpage, which has a variety of resources for citizens. Here interested individuals can learn more about identification of invasive species, see known locations of various AIS and also review protocols for citizens as well as department staff. Resources were also provided to staff by invasive species personnel regarding proper decontamination and disinfection of equipment and gear, both aquatic and terrestrial-based.

A good deal of work was also done with Organisms in Trade (OIT). This has been a new focus for the department, with several recent presentations at various venues talking about how the state is combatting AIS through this pathway. Protocol has been designed to help staff and partners to conduct education and outreach around OIT. Protocol to monitor OIT at pet stores and fresh food stores has also been developed in the last few years. Partners were also trained on this protocol and the recording and tracking of findings. Pet stores were provided with invasive species information, outreach was done to teachers and teacher organizations and the department continued to work with the Division of Public Safety and Resource Protection to provide assistance with species identification.

Dock service providers and recreational activity providers were also included in AIS outreach and education efforts. The department developed a database of dock service providers and also created mailing templates explaining the issues with AIS in the state and produced decontamination kits to be handed out to those entities. 

The report stated that every county except Burnett County have had a confirmed finding of emerald ash borer (EAB). New detections were made in Polk, Rusk, Washburn and Taylor counties in 2022-23. This did not bring about any regulatory changes, however, as EAB was federally deregulated in January of 2021 and the state of Wisconsin rescinded its statewide quarantine in July 1, 2023. 

Under the heading of response efforts, the plan details responses to several invasive species in the state. One of those is red swamp crayfish. The species is classified as prohibited, which means it cannot be transported, possessed or transferred in any way without a permit. Permits are not given for recreational activities such as crayfish boils, but the department does issue permits for research and educational purposes. Department staff has responded to only two red swamp crayfish reports, which were reports of single crayfish. The areas around those two reports will continue to be monitored.

European frogbit

European frogbit, a prohibited invasive species in Wisconsin, was found for the first time in the state in 2021. The goal with European frogbit has shifted from eradication to more containment and control efforts. Because this invasive species is found mostly on the shores of Lake Michigan in different areas, partnerships have been set up with the various counties as well as the state of Michigan to assist in this fight.

Spongy moth

The report also mentioned spongy moth impacts and response. Spongy moth, formerly known as Gypsy moth, is a terrestrial invasive that is responsible for hundreds of thousands of acres of defoliation in Wisconsin’s forests. Bayfield and Marinette counties have been the hardest hit, with 145,000 acres and 95,000 acres defoliated, respectively. Six areas in the state were selected to be included in the 2024 Spongy Moth Suppression Program because those sites contain high-value trees in state parks or forests. This aerial spraying program compliments the Wisconsin Department of Agriculture, Trade and Consumer Protection’s (DATCP’s)  program, which includes aerial spraying in nine western counties.

Bearskin Trail work

The wild parsnip control program on the Bear Skin Trail was also highlighted. In the last four years, the work under this program has been seen to significantly reduce that invasive species. This year, signage was made available to state and county forests as well, to educate the public about coming into contact with wild parsnip.

Other aerial attacks

Both invasive cattail and phragmites in several wildlife areas and state natural areas has taken place in 2022 and 2023, according to the report. This work has been done using helicopters and drones in order to get to the hard-to-reach places where these invasive species have been found. In these areas, application of herbicides would not be feasible using traditional methods. Approximately 750 acres have been treated this way in those two years, opening up channels for recreational watercraft users and improving habitat conditions for wildlife.

Enforcement

The report also spoke a great deal about enforcement and OIT. While law enforcement has been working under federal grants to do much of the enforcement work where invasive species are concerned, there is a great deal more work to do than the man hours funded under those grants.

A small working group of DNR conservation wardens dedicate part of their time to aquatic species in trade industries. From 2019 to early 2024, wardens have found more than 35,000 individual specimens in their work. Best estimates stated that the number of specimens transported into the state in that time frame is likely more than 10 times that amount.

Wardens have worked with the Department of Justice to prosecute several suppliers of crayfish, with the biggest issue being red swamp crayfish. Self-cloning marble crayfish have also been known to be shipped into Wisconsin, the report said, in numerous shipments. 

Pet stores

In 2023, DNR law enforcement visited 22 pet stores. Three violations were recorded due to Malaysian trumpet snails. These invasive species are often hitchhikers on aquarium plants. They are considered pests, even by pet stores, and the goal is not to sell these snails. However, they do need to be destroyed so they do not make their way into the local ecosystems.

DATCP was also busy monitoring organisms in trade. They recorded 38 invasive species violations in 2023. Twenty-two of those were regulated species. They included Bishop’s goutweed, chocolate vine, autumn olive, burning bush, woodland forget-me-not and Japanese wisteria. 

Partnerships making a difference

The report also detailed several partnerships between the DNR and other entities in the state, The Lake Monitoring and Protection Network (LMPN) was one of those partnerships. Many lake-lovers in the Northwoods are quite familiar with LMPN and are active monitoring lakes for aquatic invasive species. This program now provides non-competitive funding annually to perform core network activities, where the program historically has used a competitive process to divide approximately $1 million among the state’s 72 counties. 

Another partnership included in the report was that of the partnerships with the Cooperative Weed Management Areas (CISMAs). The CISMA here in the Northwoods is the Wisconsin Headwaters Invasives Partnership (WHIP). These entities, of which there are 14 in Wisconsin, help private land owners to control invasive species on their lands.

Looking toward the future

The report also details future needs for those fighting invasive species in Wisconsin. One area the report explored was that of biocontrol. The purple loosestrife biocontrol program is used here in both Oneida and Vilas counties. A specific species of beetles have been released onto that particular invasive species. These beetles eat purple loosestrife plants throughout their life cycle, stressing the plants and knocking back populations. 

The report stated that other species, too, could benefit from biocontrol programs. Species such as spotted knapweed, leafy spurge and black swallow wort would all benefit from this type of management.

Another area of concern for the future is the need of continued funding where terrestrial invasive species are concerned. Currently, the report said, funding for efforts involving terrestrial invasive species is not stable, nor sufficient to always take the quick action needed to fight these invasive species, or to continue that fight for several subsequent years, which is needed in most cases.

Funding is needed, too, to expand the messaging surrounding slowing the spread of invasive species. Signage, interpretive kiosks and boot brushes at parks, natural areas, wildlife areas and other places helps to reinforce those messages. The hope, given continued funding, would be to help change social norms and practices for those not only recreating, but also working, in the state’s natural places.

To read the entire 2022-24 Invasive Species Report, head to the DNR website dnr.wi.gov and enter “2022-24 Invasive Species Report” into the search box.

Beckie Gaskill may be reached via email at [email protected].