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Aquatic Invasive Species


Launching and retrieving boats and personal watercraft is the main way invasive species are transmitted into lakes.

Invasive Species - How Invasive Plant Species Can Destroy Wall Lake

What is an invasive species?

  • Invasive species are non-native species that have the potential to become established and spread widely and cause ecological or economic harm or pose a risk to human health.

Why should we be concerned about invasive species?

  • Invasive species threaten biodiversity because they compete with native species for food and habitat.  Invasive species can also kill or displace native species, destroy habitat, and alter food sources.  In addition, they have adverse economic effects on property values.  Invasive species can also be a health risk to humans by introducing disease and toxins.

How bad is the invasive species problem?

  • It is very bad across the country, in Michigan, in Barry County, and in many nearby Hope Township lakes.  Fortunately Wall Lake, because of limited non-resident boat trailer traffic, has had relatively few problems with invasive species – thus far.

How do invasive species get in Wall Lake?

  • By launching and retrieving infected boats and personal watercraft.

  • Note:  2019 - New Boating and Fishing Laws to Prevent the Introduction and Spread of Invasive Species.  Click here to learn more.

What invasive species do we have in Wall Lake?

  • Currently we have two, and at times three, invasive aquatic plant species in Wall Lake - Eurasian Milfoil, Cabomba, and Purple Loosestrife.

    • Eurasian Milfoil is currently present in small amounts in Wall Lake.  It grows below the water surface.  A couple decades ago it was widespread and a terrible problem in Wall Lake.  It is now well controlled through professional aquatic invasive species management.

    • Cabomba was discovered by our professional lake management company in one location in Wall Lake in the summer of 2019.  This is very concerning as Cabomba is notoriously aggressive and difficult to treat.  Nevertheless, a herbicide was promptly applied, and Wall Lake will be regularly monitored for regrowth.  Cabomba is a submersed, sometimes floating, but often rooted, freshwater perennial plant.  Cabomba is extremely competitive, persistent, and resistant to most herbicides.  It grows into thick mats that crowd out native plants.  It is very difficult to treat.

    • Purple Loosestrife has been observed in some years in small amounts in our wetlands and along the shores of a few homeowners.  The problem with this plant is that it can take over the wetlands and prevent them from functioning normally and filtering sediment and acidity from our incoming water.   It can grow from 2-7 feet tall.

What invasive species exist in nearby lakes?

  • Many nearby lakes have aquatic invasive plants, and some have Zebra Mussels.

  • Starry Stonewort has appeared recently in Hope Township lakes.  Starry Stonewort is a grass-like algae that rapidly grows in long strands up to seven feet long.  It grows underwater and forms a dense mat over the entire bottom of a lake.  This mat prevents fish from bedding and has devastated the fish populations of many lakes.

  • Cabomba, also knows as Fanwort, is a submersed, sometimes floating, but often rooted, freshwater perennial plant.  Cabomba is present in many Hope Township lakes.  Cabomba is extremely competitive, persistent, and resistant to most herbicides.  It grows into thick mats that crowd out native plants.  It is very difficult to treat.

  • Phragmites is a perennial wetland plant that quickly spreads through marshes and wetland areas, robbing the fish, plants and wildlife of nutrients and space; blocking access to the water; spoiling shoreline views; and posing a fire hazard.  It can grow to be over 15 feet tall and crowds out other plants.

  • Gull Lake is an example of of an area lake that has problems with Zebra Mussels.  These mussels multiply in astounding numbers.  One female zebra mussel can produce up to 500,000 eggs per year.   All takes is for one mussel to get into a river or lake and then they multiply very rapidly.  Zebra mussels cling to everything in the water.  Their shells are very sharp and are the cause of many injuries.  Walking on the shore, swimming, climbing dock ladders, playing on rafts - all of these activities become very dangerous due to the presence of zebra mussels.  Also, they adversely affect the insect balance in the lakes and rivers they infect, and therefore harm fish populations.  In addition, they cause aquatic plant life to overgrow.

  • Another potentially devastating invasive plant species is Hydrilla.  Hydrilla is being transported north towards Michigan from southern states.  This plant is highly resistant to herbicides, grows 6 inches per day, and in just a couple seasons can completely cover the top of a lake in a mat several feet thick that will kill all plant and animal life in a lake.  Hydrilla has been detected in lakes near the southern border of Michigan.

What can be done about invasive aquatic species in Wall Lake?

  • Prevention.

    • Protect and preserve our existing wetland native plant community.

    • Minimize launching and retrieving of non-resident boats and jet-ski’s.

    • Wash boats, watercraft, and trailers prior to entering Wall Lake.  A new State of Michigan law is in effect as of 3-21-19 that makes it a crime to transport aquatic organisms, including plants, into a waterbody on a boat, watercraft, or trailer.

In addition, for many years the Greater Wall Lake Association has contracted with Professional Lake Management (PLM) for aquatic invasive species management in Wall Lake.  PLM's services include:

  • Monitoring.

    • Plants in Wall Lake are surveyed by members of The Greater Wall Lake Association and a professional lake management weed control company.

  • Early Detection.

    • This allows for a rapid response to treat a small area before it can spread.

  • Rapid Response.

    • Treating small areas is less expensive and more effective.

  • Maintenance Control.

    • Frequent monitoring and treating invasive species is time consuming and requires persistence and dedication.  But it pays off by keeping invasive species at a minimum.


Michigan DNR/DEQ video about boat washing:  Stop Aquatic Hitchhikers.

Michigan EGLE video about boat washing:  Cleaning Boats and Equipment.

Michigan Boater's Guide To Selective Aquatic Invasive Plants

Michigan State University Extension Field Guide to Invasive Aquatic Plants

What can you do to help?

  • Support efforts to minimize launching and retrieving of non-resident boats and personal watercraft in and out of Wall Lake.  The GWLA is actively working on this.

  • When you do launch and retrieve your boats and personal watercraft on Wall Lake, please don’t transport aquatic plants or zebra muscles into Wall Lake.  This can be prevented by cleaning your boats and trailers before and after launch, including disinfecting and draining water from bilges and livewells.  Also, it is a good idea to dispose of unused bait in the trash rather than dumping it in the lake.  In addition, do not transport fish to waterbodies other than where they were originally caught.  Lastly, it is possible to disinfect livewells and bilges with a mixture of 5 gallons of water and ½ cup of bleach.

  • Feel free to contact anyone on the GWLA Board with questions.


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