In recent years, three invasive species of aquatic plants have been found in Pool 5 of
the Mississippi River near Buffalo City, WI. These three species – water hyacinth (Eichhornia crassipes), water lettuce (Pistia stratiotes), and parrot feather (Myriophyllum aquaticum) – are plants often found in the water garden and aquaculture
trade. They can be very invasive when introduced into natural waterbodies. Water hyacinth and water lettuce were first found in 2011 in Pool 5; in 2012 parrot feather was found in an isolated bay of Pool 5. Nearly one thousand water lettuce and water hyacinth plants were found in Pool 5 in 2011 and by 2012 the populations exploded into the tens of thousands. These species had not been found to this extent in Wisconsin before so immediate action was taken to prevent the spread of these invasive species to other areas of the Mississippi River and possibly to inland lakes. Multi-agency rapid response control efforts included a team of experts from the Wisconsin DNR, Minnesota DNR, U.S. Fish and Wildlife Service, U.S. Army Corps of Engineers and county aquatic invasive species (AIS) coordinators as well as interested citizens and university scientists.
Parrot feather is currently a prohibited invasive species in Wisconsin regulated by Chapter NR 40 of the Wisconsin Administrative Code (commonly known as NR 40 or the invasive species rule). Water hyacinth and water lettuce are not yet included on the state’s regulated list, but have been proposed for inclusion as prohibited invasive species. It is illegal to possess, transport, transfer or introduce a prohibited species, with certain exceptions. On Oct. 28, 2013 DNR released proposed revisions to NR 40, along with the draft economic impact analysis documents. The current proposal calls for adding 51 new species for listing as prohibited including the plants water lettuce and water hyacinth. DNR is accepting public comments on the economic impacts of the proposed revisions through Dec. 31, 2013. Read the full press release to learn more.
In September 2013, staff from Wisconsin DNR as well as other government agencies and non- profit groups concluded that the intensive efforts of the multi-agency rapid response team were successful in controlling the invasive water hyacinth, water lettuce and parrot feather from areas mapped with original infestations. Learn more about the discovery of these Pool 5 invaders and the multi- agency team’s efforts in containing these species in DNR 2013 Water Success Stories.
In addition to sharing your opinion on NR 40 revisions, there are ways you can help prevent the spread of plants commonly used in aquaculture:
- Build your aquascapes away from natural waterways and flood zones.
- Learn to recognize invasive species.
- Purchase and plant non-invasive and native plants.
- Check plant orders for unwanted invasive hitchhikers.
- Do not use invasive plants, fish, crayfish or snails in your garden.
- Do not release any plants, fish or invertebrates into natural waters.
- Learn more on how you can “Protect Your Water Garden” at http://dnr.wi.gov/topic/invasives/documents/ss1115PondsBro.pdf.
Entry written by Heather Smith, DNR Water Management Specialist