Invasive Species

Here's how you can help

COLA is actively recruiting shoreline monitors for invasive aquatic plants. If we can get enough people involved, we may be able to control invasives by hand-pulling. Please let us know if you are interested in helping out.

If you spot curly leaf pondweed or Eurasion watermilfoil in the lake, you can let COLA know through this "Lake Observation" form. It's one more way we can all keep our lake in great shape.

There are currently two invasive aquatic plant species found in LCO, curly leaf pondweed (Potamogeton crispus L.) and Eurasian watermilfoil (Myriophyllum spicatum L.). Both grow very rapidly in water with high nutrient concentrations.

 

Curly Leaf Pondweed

Curly leaf pondweed

Curly leaf pondweed

A small curly leaf pondweed (CLP) infestation was first discovered in LCO in July 2006. The infestation was located near the entrance of Musky Bay and encompassed a dense patch that was approximately 0.20 acre.

After 2006, CLP spread throughout LCO. The annual midsummer die‐off of curly leaf pondweed (CLP) releases nutrients back into the water column, which trigger algal blooms and create turbid water conditions. In recent years CLP infestation has been brought under moderate control using both herbicides and hand-pulling (more).

Curly leaf pondweed identification

 

Eurasian Watermilfoil

A small patch of Eurasian watermilfoil (Myriophyllum spicatum L.) was discovered in little LCO in 2015. Eurasian watermilfoil spreads very quickly and can form dense mats that crowd out native species. Eurasian watermilfoil has been described as "CLP on steroids" (more).

To date, this infestation has been controlled by herbicides and hand-pulling, but extreme vigilance is needed to prevent the spread of this invasive.

Eurasian watermilfoil identification

 

LCO Aquatic Plant Management Plan

In 2011, the COLA aquatic plant committee finalized the LCO Aquatic Plant Management Plan and developed a strategy to effectively and efficiently reach specific goals. The goals include the following:

  • Goal 1) Curly leaf pondweed growth is kept at a minimum level.
  • Goal 2) Prevent the introduction and spread of other aquatic invasive species.
  • Goal 3) Preserve the lakes’ diverse native plant communities.
  • Goal 4) Lake residents and users are made aware of the importance of native aquatic plants, the means to protect them, and the threat of aquatic invasive species.
  • Goal 5) Restore native shoreline vegetation
  • Goal 6) Waterfront residents will protect lake water quality and plant communities by minimizing runoff of pollutants from their lake property.

 

How can you help?

Gary Pulford, COLA Vice-President, with a rake full of the invasive species curly leaf pondweed during our annual spring pre-survey.

Gary Pulford, COLA Vice-President, with a rake full of the invasive species curly leaf pondweed during our annual spring pre-survey.

Curly leaf pondweed. Seed pod "turions" in the center of of photo. Seed pods grow along the stem between the leaves and the stem anywhere along the entire column from roots to the surfacing plant. 

Curly leaf pondweed. Seed pod "turions" in the center of of photo. Seed pods grow along the stem between the leaves and the stem anywhere along the entire column from roots to the surfacing plant. 

Curly leaf pondweed. An invasive species infesting Lac Courte Oreilles. Invasive is slightly smaller than the native pondweed, a locally-occurring species. CLP has a reddish tint on the leaves and the stems. The leaves are smaller and the curl is tighter on the invasive than it is on the nativel. Note the size of plant as compared to the hands.  

Curly leaf pondweed. An invasive species infesting Lac Courte Oreilles. Invasive is slightly smaller than the native pondweed, a locally-occurring species. CLP has a reddish tint on the leaves and the stems. The leaves are smaller and the curl is tighter on the invasive than it is on the nativel. Note the size of plant as compared to the hands.

 

Related Stories in Short Ears, Long Tales

Issue 22  'Lac Courte Oreilles Boat Landings'