PLM’s recent survey of Clark Lake revealed that the invasive weed, hybrid Eurasian water milfoil (HEWM), is under control, but is still showing up in small pockets.  For that reason, treatment will take place tomorrow, Wednesday, June 12, localized to the areas shaded green on this map – Eagle Point and three spots at the east end.

 

The product to be used is ProcellaCOR.  The notice shows “no-swim” for one day, and only in the areas of treatment (scroll down to see notice mailed to property owners this spring).

The PLM program defends Clark Lake against invasive species.  Lakes that didn’t (or don’t) deal with Hybrid Eurasian Water Milfoil (HEWM) and Starry Stonewort face the consequences.  Recreational, fishing, and habitat are threatened.  Some lakes waited too late, and that affected property values.

What follows is a brief history of the weed program at Clark Lake.

By 2014, something akin to an underwater jungle lurked below and was increasingly surfacing.  Clark Lakers recall having to pause raft rides to clear props.  That exotic growth likely began earlier than 2014, but had become painfully noticeable by then.   A group of Clark Lake residents stood up for the lake.  With overwhelming support form the Clark Lake community, a special assessment district (SAD) was formed, and PLM was contracted for treatments.

The photo was taken as the weed control project began.

Flashing back to their first survey, PLM stated that “Eurasian water milfoil was in approximately 32% of the 63 sites surveyed. In addition, genetic testing of the milfoil plants by Grand Valley State University found that many of the samples collected were of a hybrid milfoil, a cross between native milfoil and the exotic Eurasian watermilfoil. Hybrid milfoils tend to be more difficult to control and grow back rapidly following control efforts. Management efforts to date have focused on controlling this hybrid milfoil in Clark Lake.”

Fast forward to one year ago – June 2023.  PLM treated 4.6 acres of Clark Lake for HEWM.  “During the September 2022 survey, only two of the sixty-five survey sites contained Eurasian watermilfoil.  Both sites are in the northeast corner of the lake, adjacent to the County Park. Although the plants were clearly impacted by treatment, it appears as though some of the plants may survive.”  Clark Lake’s situation had improved significantly.

Clark Lake is also on the Starry Stonewort watch.  This plant masquerades as Chara. PLM says “Chara is a highly desired species because it is typically low growing, keeps the water clear and can slow down the invasion of exotic weed species. Starry stonewort also forms dense mats, but unlike Chara, it can grow from 5 to 7 feet tall. Starry stonewort can be very detrimental to a lake’s ecosystem and has the ability to kill off native plants and have a negative impact on a lake’s fisheries.”  The good news?  No Starry Stonewort was found in the September survey.  Previously Starry showed up near the County Park and Eagle Point.  You might say Clark Lake nipped it in the bud.

The control program targets only invasive species.  In some cases, non-invasive, native weeds can be bothersome.  Residents may take it upon themselves to eliminate them.  PLM makes the following comments about non-invasive weeds. “Aquatic plant management should preserve species diversity and cover of native plants sufficient to provide habitat for fish and other aquatic organisms. Native plants should be managed to encourage the growth of plants that support the Clark Lake fishery (by creating structure and habitat) provided that they do not excessively interfere with recreational uses of the lake (e.g., swimming and fishing) in high-use areas. Where they must be managed, management techniques that reduce the stature of native plants without killing them (e.g., harvesting, contact herbicides) should be used whenever possible. Specific areas should be set aside where native plants will not be managed, to provide habitat for fish and other aquatic organisms.”

The SAD cost to lakefront property owners is about $59 per year, and is included in the tax bill.  The program is under the auspices of Columbia Township, and the tax money collected can only be used to control Clark Lake’s invasive weeds.