Curly Leaf Pondweed
Note the alternate leaf arrangement on the stem and the wavy and serrated edges.
Note the alternate leaf arrangement on the stem and the wavy and serrated edges.
Treating curly leaf pondweed near the shoreline
Curly Leaf spreads by the turions. (hard cone-like seeds)
Problems: Mats made navigation and fishing impossible in some areas of the lake. Wind broke plants and blew them to shore in big rolls. Residents collected them by raking them up and hauling them away. The plants made excellent mulch and fertilizer though! Millions of green and brown cone-like turions blew in to shore forming piles near shore and under docks.
Treatment:
Aquacides used were Aquathol K and Hydrothol 191 in low concentration at 55-60F water temperature before native plants have started growth, but during an active growth period of curly leaf before turion formation. In 2006 the aquacide Reward was used instead of Aquathol K and Hydrothol 191 as it proved to be more effective, particularly in near shore areas. Low concentrations of these chemicals according to extensive studies, are not harmful to fish, fish fry or any other aquatic creatures.
The aquacides were applied either by a sprayer or injected under the water surface.
Cost of Treating Curly Leaf Pondweed in Portage Lake (Hubbard County)
In 2014 & 15 a free lakewide invasive specie treatment permit was utilized.
Chemicals Used: contact herbicides-guaranteed 90%control of whole plant
Usually Aquathol K for early treatments- but sometimes Reward, Hydrothol, Clipper or Tribune were used for near shore later treatments when CLP may regrow around docks and boatlifts. Native weed control permits @ $35each are required.
Year Cost Acres Treated
2003 $15,200 55 acres
2004 $ 6,370 20.5 acres
2005 $13,350 45 acres
2006 $11,950 40 acres
2007 $ 9,150 30 acres
2008 $11,950 40 acres
2009 $ 9,195.92 28.8 acres
2010 $ 7,597.40 23.5 acres
2011 949.00 (.69 acre of near shore CLP)
2012 $16,536.15 52.5 acres
- 7,875. grant
$8,661.15 -total cost
2013 $2,250 20 near shore frontages
2014 $1,642.32 3.7 near shore acres + retreating 3 places
-1,000.00 grant
$ 642.32--actual amount paid out
2015 $18,628.46 ( 53.43 acres @$339.20/acre +retreating 3 nearshore places
- 5,377.00 DNR grant costing $400 + 3 permits @$35 each=$505)
$13,251.46-actual amount paid out
$124,769.25----total cost
-14,252.00---total grants
$110,517.25---total actual amount paid out for CLP treatment 2003-2015.
For the past 12 years (2003-2015), the Portage Lake Association has paid for CLP treatment by requesting voluntary contributions each year from lake association members & property ownersl The suggested contribution amount is determined by dividing estimated total cost by probable number of contributors-usually 65-75 contributors out of approximately 110 property owners. Lake association members have already voted during their annual meeting on the contribution amount to be $175/property owner for 2016 as weather conditions and amount of CLP present in the future are unknown plus the total amount in the treatment fund has vastly decreased.
Over the years the suggested contribution has varied due to: 1) amount of CLP acreage; 2) Amount of money in the CLP treatment fund left over from the previous year; (3) Number of contributors. Suggested contribution amount has varied from $218/resident (the first 2 yrs.) to $30 in 2014 & 2015. Residents have been very supportive, contributing, and reaching or surpassing the goal each year of CLP treatment. Back in 2002 residents voted to financially support CLP treatment with 85.7% of the 84 returned ballots voting yes out of 106 ballots mailed out This was 67.9% of all possible votes.
Aquacides used were Aquathol K and Hydrothol 191 in low concentration at 55-60F water temperature before native plants have started growth, but during an active growth period of curly leaf before turion formation. In 2006 the aquacide Reward was used instead of Aquathol K and Hydrothol 191 as it proved to be more effective, particularly in near shore areas. Low concentrations of these chemicals according to extensive studies, are not harmful to fish, fish fry or any other aquatic creatures.
The aquacides were applied either by a sprayer or injected under the water surface.
Cost of Treating Curly Leaf Pondweed in Portage Lake (Hubbard County)
In 2014 & 15 a free lakewide invasive specie treatment permit was utilized.
Chemicals Used: contact herbicides-guaranteed 90%control of whole plant
Usually Aquathol K for early treatments- but sometimes Reward, Hydrothol, Clipper or Tribune were used for near shore later treatments when CLP may regrow around docks and boatlifts. Native weed control permits @ $35each are required.
Year Cost Acres Treated
2003 $15,200 55 acres
2004 $ 6,370 20.5 acres
2005 $13,350 45 acres
2006 $11,950 40 acres
2007 $ 9,150 30 acres
2008 $11,950 40 acres
2009 $ 9,195.92 28.8 acres
2010 $ 7,597.40 23.5 acres
2011 949.00 (.69 acre of near shore CLP)
2012 $16,536.15 52.5 acres
- 7,875. grant
$8,661.15 -total cost
2013 $2,250 20 near shore frontages
2014 $1,642.32 3.7 near shore acres + retreating 3 places
-1,000.00 grant
$ 642.32--actual amount paid out
2015 $18,628.46 ( 53.43 acres @$339.20/acre +retreating 3 nearshore places
- 5,377.00 DNR grant costing $400 + 3 permits @$35 each=$505)
$13,251.46-actual amount paid out
$124,769.25----total cost
-14,252.00---total grants
$110,517.25---total actual amount paid out for CLP treatment 2003-2015.
For the past 12 years (2003-2015), the Portage Lake Association has paid for CLP treatment by requesting voluntary contributions each year from lake association members & property ownersl The suggested contribution amount is determined by dividing estimated total cost by probable number of contributors-usually 65-75 contributors out of approximately 110 property owners. Lake association members have already voted during their annual meeting on the contribution amount to be $175/property owner for 2016 as weather conditions and amount of CLP present in the future are unknown plus the total amount in the treatment fund has vastly decreased.
Over the years the suggested contribution has varied due to: 1) amount of CLP acreage; 2) Amount of money in the CLP treatment fund left over from the previous year; (3) Number of contributors. Suggested contribution amount has varied from $218/resident (the first 2 yrs.) to $30 in 2014 & 2015. Residents have been very supportive, contributing, and reaching or surpassing the goal each year of CLP treatment. Back in 2002 residents voted to financially support CLP treatment with 85.7% of the 84 returned ballots voting yes out of 106 ballots mailed out This was 67.9% of all possible votes.
In 2011 the DNR didn't recommend treatment in open water as not enough CLP was found concentrated in large areas during the pre-treatment survey, just scattered plants. CLP as well as native weeds was late coming up. However, CLP did come up later during the summer and returned to hit us hard in 2012 with 52.5 acres, needing treatment. Winter 2014-15 brought very little snow, allowing lots of light to penetrate the ice and water, stimulating growth of 53.43 acres of CLP, needing treatment in 2015.
Click here to download curly leaf ID sheet
(pdf file-requires Adobe Acrobat Reader)
Almost everything you want to know about
Curly Leaf Pondweed
Curly Leaf Pondweed
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Curly leaf Pondweed (Potamogeton crispus)
Curly leaf is an exotic (not native to the U.S) plant specie introduced from Europe in the early 1900's. It is a rooted, submerged aquatic plant that grows aggressively in 4-10 ft. of water. Though it loves light, it is an opportunist; it can tolerate low light and can grow under algae blooms or ice.
Curly leaf affects lakes in several ways, making it a very obnoxious aquatic exotic plant. The plants grow rapidly in early spring, reaching its peak in early summer crowding out native plants. Its dense floating mats interfere with swimming, fishing, boating and recreational enjoyment of lakes. As it decays in early July, it releases nutrients fueling excessive algae blooms and produces difficult dead plant disposal as wind and waves deposit plants on shorelines.
Its life cycle gives it a competitive advantage over many other aquatic plants. Curly leaf begins a rapid growth period when the ice melts and water temperature warms-so rapid a growth that it crowds out later germinating native plants. In later spring, flower spikes are produced that emerge above the water surface. By June, the fruits are mature on the stalks and drop to the sediment. The seeds in these fruits have very low germination rates. Prior to dying back in mid-summer, curly leaf produces large numbers of small buds, called turions in leaf axes along its stem. These turions are the primary way the plant reproduces. These hard cone-like turions are dispersed by water movement, sink to the lake bottom, and lie dormant during the summer. As water cools in the fall, the turions sprout to form new plants, which remain alive under the ice waiting to proliferate again immediately when the ice melts. Ice fishermen have found curly leaf growing up into their fishing holes. When there is very little snow cover, a lot of light filters through the ice, causing winter growth giving curly leaf plants a head start.
The unique life cycle also makes curly leaf difficult to manage. Strategies must include stopping turion production, reducing plant biomass, and depleting the seed bank in the sediment. The most effective management is accomplished with herbicide treatment in early spring when water temperature is 55-60F and before turions have been produced. Treatment is necessary for several years to control turions that may remain in the sediment and sprout.
Portage Lake Curly leaf History
Infestation: early to mid 90's -perhaps on someone's boat motor propeller, trailer or in the water intake of a jet ski-nobody knows for sure
First mats observed: 48 acres of ugly brown mats on the water surface during late spring and early summer of 2002
Infestation: early to mid 90's -perhaps on someone's boat motor propeller, trailer or in the water intake of a jet ski-nobody knows for sure
First mats observed: 48 acres of ugly brown mats on the water surface during late spring and early summer of 2002
Curly leaf pondweed mats on Blueberry Lake between Park Rapids and Menahga in Wadena county
Close-up view of curly leaf mat on Portage Lake