An approximately 6 inch long sample of Curlyleaf Pondweed
What
is it?
Curlyleaf Pondweed,
(Potamogeton Crispus) is an introduced species of underwater plant that
can grow into thick surface mats. Although it looks similar to native
species of Pondweed such as White Stemmed Pondweed and Big Leaf Pondweed,
it is very different in its growth habit.
What
does it look like?
Unfortunately, Curlyleaf
Pondweed looks a lot like native pondweeds which are commonly called "cabbage"
by fishermen. If you have a piece of Pondweed in your hand, it is likely
to be Curlyleaf if ALL of the following are true.
- It has "wavy" or
"curly" leaves.
- It has a plastic-like
feel.
- It has serrated
(tiny saw tooth) leaf edges.
- It has alternate
leaves on the stems (the leaves do not occur at the same point on opposite
sides of the stem)
- It has reddish
stems.
An approximately 6 inch long sample of
Curlyleaf Pondweed
Where
did it come from?
It came to Minnesota
in the early nineteen hundreds along with Carp from the Orient. It is now
in most Minnesota lakes and left unchecked it can seriously degrade the
quality of a lake for recreation.
When
is it most visible in the lake?
Curlyleaf Pondweed
grows beneath the ice when there is little snow cover to block sunlight.
In spring the Curlyleaf grows rampantly and soon forms the dense surface
mats that cause problems. In summer, the Curlyleaf produces seed like structures
called turions which float to other locations on the lake and then
sink to the bottom where they germinate, thus spreading the unwanted plants.
After dropping their turions, the plants die back and seem to disappear,
only to begin growing again in the late fall and early winter. Curlyleaf
Pondweed can also be spread from pieces of stems and leaves that have floated
around the lake.
Why
is it a serious threat?
Curlyleaf Pondweed
can grow into surface mats so thick that boats and swimmers cannot get
through it. It crowds out native underwater plants and can be detrimental
to fish populations.
What uncontrolled Curlyleaf Pondweed can
do in a lake.
What is being done to combat Curlyleaf Pondweed in Lake Hubert?
There is no known way to eliminate Curlyleaf Pondweed once it is in a lake but it can be controlled.
Special chemical herbicides approved by the State of Minnesota and applied by licensed companies can control Curlyleaf when applied correctly and at the proper time of the year. The Lake Hubert Conservation Association contracted for and paid for spraying of a large patch of Curlyleaf in the northeast corner of the lake in 2003. This spraying, along with plenty of snow on top of the ice (which reduces or eliminates the light getting through the ice to the underwater plants) reduced the Curlyleaf Pondweed population to the point where we do not have to spray again in the spring of 2004.
We will continue to monitor the Curlyleaf Pondweed and will take appropriate measures when needed.
What can individual property owners do?
The association is not allowed to treat Curlyleaf Pondweed close to privately owned shoreline. If there is a large concentration of Curlyleaf Pondweed growing on the lake bottom directly out from your property and within 150 feet of your shore, you can apply to the DNR for a permit for spraying and contract with a professional spraying company to treat the Curlyleaf.
If you find large
patches (hundreds of plants) of Curlyleaf Pondweed growing in the lake,
note the exact location and let the association know where you found it.
(GPS coordinates would be wonderful if you can provide them). You can e-mail
your findings to us at LakeHubert@aol.com
or drop us a note at LHCA, P.O.
Box 1352, Lake Hubert, MN 56459.
Links to additional Curlyleaf Pondweed information.