Curly-leaf Treatment information

The Pelican River Watershed District always uses the best scientific information available before applying for permits to treat aquatic invasive species.  Click on the links below to review some of the information we are using.

Factors affecting abundance and control of CLP

Evaluation of lakewide, early season herbicide treatments

Effects of repeated early season herbicide treatment of CLP on native macrophyte assemblages in MN Lakes.pdf

Curly-leaf Pondweed

Was first discovered in Minnesota in the early 1900's.  It was probably introduced to the state when common carp were intentionally brought to Minnesota.  It has been here so long that most people do not realize that it is not a native species.

In the spring, curly-leaf pondweed can form dense mats that may interfere with boating and recreation on lakes.  It can cause ecological problems because it can displace native aquatic plants.  In mid-summer, curly-leaf plants usually die back, which results in rafts of dying plants piling up on shorelines, and often is followed by an increase in phosphorous.

Location: Grows from the shore to depths of up to 15 feet.

Description: Leaves are somewhat stiff and crinkled, approximately 1/2-inch wide and 2 to 3 inches long; leaves are arranged alternately around the stem, and become more dense toward the end of branches; produces winter buds can be confused with claspingleaf pondweed.

Hints to identify: Has small "teeth" visible along edge of leaf; begins growing in early spring before most other pondweeds; dies back during midsummer; the flower stalks, when present, stick up above the water surface in June; appears reddish-brown in the water, but is actually green when pulled out of the water and examined closely. Easily confused with claspingleaf pondweed, which has leaves with no "teeth" around their edges. CLP pic.png


CLP harvest.jpg

The Pelican River Watershed District removed excessive curly-leaf pondweed through harvesting for many years.  You could often see the harvester working by the Holiday Inn area in May.  However, in 2016 and 2017 the District contracted with PLM to chemically treat the invasive plant.  In 2016, approximately 54 acres were treated in Big Detroit Lake and this amount increased slightly in 2017 to 60 acres.  There is an area near the south access that has become a problem and that area will more than likely be chemically treated in 2018 also.

There were much smaller areas on Sallie and Melissa that received chemical treatments in 2016 and 2017, also.

With the success of chemical treatments, the District sold the last aquatic weed harvester in the fall of 2017, thereby ending 50 years of harvesting plants from area lakes.



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Recent Water Levels
Detroit 1334.03 ft
Last Updated: 6/7/2018
Floyd(s) 1354.79 ft
Last Updated: 6/7/2018


Melissa 1328.40 ft
Last Updated: 6/7/2018
Sallie 1330.57 ft
Last Updated: 6/7/2018

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