BENTHIC BARRIER PILOT
VIDEOS
HISTORY
A small benthic mat was placed over dense milfoil in summer 2023. Essential to successful treatment of Eurasian watermilfoil with benthic burlap mats requires maintenance. In July 2024, a diver observed the mat and pulled the majority of milfoil. The mat was in good condition, remained in place, and several native plants were observed growing on it. The diver will return in August for final milfoil removal this summer. All equipment, boat time, dive labor, and videography provided free of charge by the Dahlstrom/Davidson family of Long Lake.
A native plant (slender naiad) settled on the mat. By pulling the milfoil each year and leaving the natives, the mat will hopefully be covered with natives before it naturally breaks down.
The mat and sandbags remain in place despte the log obstruction.
Another part of the project was “planting” natives in small burlap rolls. This is an example of a native pond weed successfully growing.
Before weeding, milfoil was growing along the edge of this mat. Now, native wild celery has light and room to grow. Note how mat and sandbags remain flat and in place.
Close up of wild celery.
PROJECT OVERVIEW
Long Lake Association and Long Lake Foundation Partner to Deploy Benthic Mat Pilot Project
The Long Lake Association and the Long Lake Foundation worked in partnership to deploy a benthic mat pilot project on Long Lake on Saturday, September 2. The Long Lake Foundation fully funded the project and the Long Lake Association contracted to have the project deployed. A benthic mat is a methodology used to control invasive aquatic plants like Eurasian Watermilfoil (EWM) that consists of laying a material such as biodegradable burlap on the lake bottom and weighing it down using sandbags to keep sunlight from getting to the invasive aquatic plants on the lake bottom. As part of this project, native plants were attached to the benthic mat including pondweed; slender naiad; and wild celery to help repopulate the area with native aquatic plants. This is a unique restoration technique that has only been tried on Long Lake, to our knowledge. This project is part of the Long Lake Association’s mission to continue to control the levels of Eurasian Watermilfoil (EWM) and evolve our treatment program to take advantage of all possible control measures to create a hybrid approach including benthic barriers, new treatment types, etc. As always, please remember to remove any plants attached to your boat and/or trailer before entering the lake and remind boat visitors that Long Lake has a brand-new boat wash station at the former fire hall located at 8870 N. Long Lake Road.
Please review the video provided below that provides an underwater survey of the benthic barrier site located at the north end of the peninsula in Long Lake.
Please note that the Eurasian Watermilfoil (EWM) shown growing from the edges of the benthic mat will be monitored in 2024. Any EWM that does re-grow will be hand-pulled or covered in 2024.