Aquatic Plant Management in 2015 – Update

The APM Committee has been working hard in the 2015 season to improve the weed conditions in the waterway using multiple approaches. These programs include prevention, monitoring and plant control.

Prevention

The Clean Boats, Clean Waters (CBCW) program consists of boat inspections at the Library Launch. Staffed with volunteers and paid interns, boats are inspected as they enter and leave the waterway. Transportation of aquatic plants on your boat or trailer is prohibited by the Wisconsin Department of Natural Resources (WDNR). When we hear about new species that invade Wisconsin lakes, such as Starry Stonewart, this is the best way to prevent the spread. Boaters are asked a series of questions and the boat and trailer are inspected for plant growth. All data collected is reported to the WDNR. This program is fully funded by a grant from the WDNR.

Monitoring

The Citizens Lake Monitoring Network (CLMN) is a program fully staffed with volunteers. Individuals monitor an area of the waterway and report on the plant growth found. This helps us monitor the health of the waterway and can identify new invasive species early before growth becomes pervasive.

Plant Control

The role most people identify with this Committee is that of controlling the ‘weeds’. When plant growth inhibits navigation or spoils the look of the waterway residents want something done. We currently have three programs in place to manage weed growth and are continuously exploring other avenues. Our programs are:

Herbicidal Treatments

The waterway is treated with herbicides to manage plant growth in very controlled ways. All treatments are monitored by the WDNR following permit approvals and survey. All treatments are applied under the water to minimize dispersal and only treat specific areas. Herbicides are no longer sprayed around and there is no chance of any application to the shore. Two types of treatments are done during the season:

Aquatic Invasive Species (AIS) Treatment
This treatment is done early in the season (Late April/Early May). The waterway is surveyed using specific GPS locations. The amount and type of growth is documented and treatment for AIS is allowed wherever it is found. This year we treated over 140 acres, one of our highest ever. No AIS treatments are permitted for the remainder of the season. The final step is a second survey of the same points done in July/August to track the effectiveness of the treatments.

Navigational Treatments
In addition to AIS, we have issues with abundant growth of indigenous plants. These include Coontail, Elodea, and Lily Pads. There are additional restrictions on the treatment of these. We cannot treat in broad areas of the water way, only treatments to allow navigation are permitted. This is defined as a 30ft wide channel to a pier head. NO treatment is allowed along the shore, or to a home that does not have a pier.

After three seasons of successful trials in small areas on our waterway, we were authorized to use a new herbicide, Clipper, on a broader basis. This season we used Clipper in all bays. Results from this have been positive. One challenging plant is Lily Pads. The herbicide we use has limited success and we can only treat navigational lanes. Residents in areas with Lily Pads are encouraged to remove these by hand if they are restricting access to the water. This is easiest to do when plants are first seen.

Diver Assisted Suction Harvesting – DASH

Often referred to as ‘Weed Sucking’, this method of weed harvesting uses specialized equipment and divers in the water. The plants are pulled and sucked up into the boat. They are collected in bags and the water returns to the lake. A small trial was done in 2014 and expanded this year. The area harvested in 2014 showed little regrowth in 2015 allowing for just maintenance of the area this season.

Manual Weed Pulling

We work with a Non-Profit organization (Venture Crew 519) that supplies 5-9 divers for the day. The divers are in the water manually pulling the weeds and bagging them. Volunteers transport the weeds to shore and to a disposal site. Volunteers also use boats/canoes to load weeds and transport them to shore. One area in Island View Bay was cleared in 2014 and regrowth this season was less. In 2015 we expanded the program to three areas – Elm Island Bay, NE Conservancy and a different area in Island View. This approach is very effective but relies on a large number of volunteers.

In addition to the these programs we have investigated and tried other approaches, these include the following:

  • Weed Cutting
  • Winter Drawdowns
  • Bugs and Beetles
  • Lake Blankets
  • Fish Species

The Committee will continue to investigate and explore other approaches that may be appropriate for our waterway.