Yellow Iris can be controlled by glyphosate-based herbicides. Plants growing near standing water should be treated with an herbicide approved for aquatic use to minimize harm to amphibians.  No effective biological control agent is known at this time. 

In 2017 the SCLA AIS & Water Quality Committee began YFI mitigation using mechanical removal.  Since 2023 the committee has coordinated an herbicide treatment program with a licensed, WDNR approved contractor.

If you find Yellow Flag Iris, and the plant is accessible, take extreme care by removing the plant:

• Wear gloves; skin irritation can occur with contact with plant roots.
• Clip flower heads and pull or dig out plants and roots.
• Place all plant material in garbage bags and take to Town of Spider Lake Solid Waste, at no charge.
• If you cannot access the roots of the plant, remove the flowers and seed pods (wearing gloves), bag the material, and take it to Town Hall Solid Waste, at no charge.
  

If you are unable to check your property or need help to remove Yellow Flag Iris, let us know by contacting: Spiderchainoflakes@gmail.com. 

Tell us your property location, and site of Yellow Flag Iris on your property. We will ask volunteers to check your property and remove plants from your shoreline.

CURLY-LEAF PONDWEED - present

Curly-Leaf Pondweed has been identified in many areas of Big Spider Lake. It also is transmitted by boats and trailers that drag weeds from an infected lake. This species forms dense mats that can prevent boating, swimming, and fishing and displaces native plants needed for the food chain on our lake. In July, the plants die back and pile on the shoreline causing an increase in phosphorus and undesirable algal blooms.

BANDED MYSTERY SNAILS - present

Banded Mystery Snails are present in the Spider Chain of Lakes. At the present time there are no treatment options for this invasive.  The negative effects are that a large scale die-off can create a foul odor.  The sharpness of the shells on your shoreline can be a problem for bare feet.  They become a nuisance attaching to docks, lifts and boats. 

Photo of Banded Mystery Snails: 

Banded Mystery Snails are  1-1.5 inches tall with horizontal brown bands on shell.   
The invasive "Chinese Mystery Snail" shown right has NOT been detected in Spider Chain of Lakes.

BLUE-GREEN ALGAE -  SEASONALLY PRESENT
(Information provided by Gina LaLiberte, Water Resources Management Specialist, WI DNR)

Blue-green algae grow in every lake in Wisconsin. Clumps of blue-green algae that normally grow on the lake bottom have been floating to the surface of lakes in the Spider Chain. The good thing about these clumps is that they are easily noticed and therefore can be avoided, unlike other blue-green algae that grow as microscopic particles dispersed throughout lake water. These latter kinds of blue-green algae, which grow to nuisance levels known as blooms that discolor water and form floating scums, are not what are growing in the Spider Chain. However, the same precautions that keep people safe from blue-green algae blooms would also apply to these clumps of blue-green algae.

Some blue-green algae can potentially make toxins that can make people and animals sick if they swallow lake water containing blue-green algae or if they inhale blue-green algae in water droplets, as might happen if they water ski through a heavy accumulation of blue-green algae. Some people may be susceptible to rashes and other irritation from skin contact with blue-green algae, such as if it is rubbed against the skin under clothing.
The floating clumps of blue-green algae in the Spider Chain are easily seen because of the bright blue-green color, and thus it's easy for people to avoid swimming in areas with high densities of the clumps and avoid accidentally swallowing them. Dogs won't necessarily avoid the clumps of blue-green algae, so it is important for pet owners to prevent their dogs from ingesting the clumps via drinking the lake water, eating any material that may be washed up on shore, or licking it from their fur after swimming.

         

You cannot tell if accumulations blue-green algae are producing toxins just by looking at them, so be wary of any high concentration of blue-green algae in water, whether it is dense accumulations of microscopic particles that discolor the water or areas with high concentrations of floating clumps of blue-green algae.

Even if water is clear, it’s always a good idea to avoid swallowing any untreated surface water because it can contain blue-green algae, bacteria, viruses, or parasites that can make people and animals sick.

Blue-green algae are easily moved around by wind and currents. The location and density of these blue-green algae clumps in the Spider Chain will likely change daily until they eventually dissipate, so it is important for you to assess conditions for yourself before swimming or participating in other water recreation.

If you use common-sense precautions, you can safely enjoy recreation on Wisconsin’s lakes and rivers:

• Choose locations without noticeably green water for swimming, because wind can concentrate blue-green algal blooms into near-shore areas. Do not swim in water that looks like "pea soup", green or blue paint, or that has a scum layer or puffy blobs floating on the surface.

• Do not boat, water ski, etc. over water that looks like "pea soup", green or blue paint, or that has a scum layer or puffy blobs floating on the surface (people can be exposed through inhalation).

• Do not let children play with scum layers, even from shore.

• Always take a shower after coming into contact with any surface water (whether or not a blue-green algae bloom appears to be present; surface waters may contain other species of potentially harmful bacteria and viruses).

• Always avoid swallowing untreated surface water – it may contain pathogens other than blue-green algae which could make you ill.

It's important to choose the clearest water possible for dogs to swim in, and to keep dogs out of areas with algae accumulations or dense particulate matter that might be blue-green algae.

There is additional information about blue-green algae at the DNR’s website and at the Wisconsin Department of Health Services website:

https://www.dhs.wisconsin.gov/water/bg-algae/index.htm

PURPLE  LOOSESTRIFE - PRESENT

Numerous strands of this very harmful aquatic plant exist on the shoreline of Clear Lake and Big Spider Lake. When purple loosestrife invades, it impacts the lake by forming thick stands that prevent recreation, displacing fish from the shelter where they reproduce and rear their young, and crowd out native aquatic plants and insects which upsets the entire ecosystem.

SCLA is working to control Purple Loosestrife infestation. In early spring, the plants are dug up by volunteers who remove plants from the lake and also create small nurseries for the Gallerucella beetle. SCLA volunteers raise over 40,000 beetles that are then transferred to the stands on Clear Lake. The Gallerucella beetle is a native predator of the loosestrife plants and eats the new seedlings before they can take root for a new growing season. After eight seasons of release a reduction in the size of the stands was observed.  

NORTHERN PIKE - PRESENT  

Northern Pike are invasive to the Spider Chain of Lakes.  In an effort to remove them, the WDNR increased the daily harvest limit in 2024. Check the WDNR website for current fishing regulations and daily limits. Please join us in removing these invasive fish who harm other species in the lake. 

The Spider Lake Musky & Pike Research project funded by the WDNR and private citizens launched in 2024.  It will help identify the impact of Northern Pike on Muskies and other native fish and ultimately inform practices that could reduce Northern Pike in the chain of lakes.  LEARN MORE: go to NEWS page of the SCLA website.

SPIDER LAKE PIKE PROJECT 

Mission: Our aim is to eradicate Northern Pike from the Spider Chain of Lakes.  We encourage anglers to catch and keep or donate Northern Pike:

1. Harvesting Northern Pike will reduce the pike population and help improve musky, walleye and other native fish habitat.
2. All pike must be legally caught.  Pike must be removed from the lake and transported home or donated.

In 2024 anglers removed over 1,300 Northern Pike from the Spider Chain!

To record your catch go to Spider Lake Pike Project at:  https://spiderlakepikeproject.com/home.php.