Are We Slowing the Spread of Aquatic Invasive Species in Wisconsin?

You may have seen aquatic biologists in wetsuits swimming around a boat landing the past two summers. The biologists, including DNR staff, County, University and Tribal partners, have increased efforts to search for aquatic invasive species (AIS) in lakes with public boat landings. Federal funding from the Great Lakes Restoration Initiative (GLRI) has allowed biologists to begin collecting baseline data on the statewide distribution of AIS, including mussels, snails, plankton, aquatic and wetland plants. Partners in the project will search approximately 200 randomly selected lakes a year from 2011 through 2015. The data collected will help to determine if our AIS outreach, education and regulations have been enough to slow the spread.

DNR Statewide Baseline AIS Monitoring
Yellow squares are lakes monitored in 2011 and red circles are those to be monitored in 2012.

In 2011 monitoring teams searched 186 lakes and a similar number have been visited this past summer although the data is still rolling in. The results from 2011 show that 77 percent of the lakes surveyed had at least one invasive species observed. These results need to be taken in context as 52% of the lakes contained only one or two species of invaders, and no single invasive species was found in more than 45% of lakes. Some of the most troublesome invasive species such as Eurasian water-milfoil and zebra mussels were found much less frequently; at 33% and 16% of suitable lakes respectively. There is definitely a regional bias as most invasives, with the exception of Chinese mystery snails, appeared in a much higher proportion of lakes in the southern half of the state than they did in the north.

 In addition to collecting data on the distribution and rate of spread of AIS in the state, the surveys also serve as surveillance for new populations of invasives. A handful of new aquatic plant and animal populations have been found by the project teams each year and control and containment planning was initiated by the regional DNR AIS coordinator. For example Eurasian water-milfoil (EWM) plants were discovered in Anvil Lake in Vilas County by a GLIFWC monitoring team this summer. The discovery led to a more thorough survey to map the extent of the population and a substantial coordinated effort by the Anvil Lake Association, GLIFWC, Onterra (a lake management consultant) and DNR to handpull over 60 EWM plants. The lake will be revisited in upcoming years to determine if the rapid response action was successful.

 An added bonus to the project is that we’re building a group of skilled naturalists by placing new staff and citizens with experienced biologists. With 15,000 lakes in the state, DNR wouldn’t be able to find and control aquatic invasive species without help from our partners and citizen volunteers. We hope to include more citizens and lake organizations in this monitoring effort in the future as they are the eyes on the water that will most likely notice new invasives as they arrive.

To find maps and information about the distribution of aquatic invasive species in Wisconsin, visit:

Entry written by Scott Van Egeren
This entry was posted in Contain and Control Invasive Species, Invasive Species, Monitoring and tagged , , , . Bookmark the permalink.

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