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Ryerson Lake Aquatic Plant Control Program

Herbicide Treatments

Next survey: Week of June 17

Next treatment: Week of June 24

Survey date: May 20, 2024

Treatment dates: May 23 and 30

Click here for the treatment map

There will be a 24-hour swimming restriction from the time of treatment. Irrigation restrictions will be posted on a sign in your yard as applicable.

April 30, 2024 Treatment Map

Nuisance aquatic plant control is the primary focus of the Ryerson Lake Improvement Program. In managing aquatic plants, it is important to remember that most plants are beneficial to the lake. Plants in lakes produce oxygen during photosynthesis, help stabilize shoreline and bottom sediments, and provide cover and habitat for fish and other aquatic inhabitants.

The objective of a sound aquatic plant control program is to remove plants only from areas where nuisance growth is occurring. Excessive removal of aquatic plants can have negative consequences. For example, broad-spectrum herbicide treatments can result in algae blooms and reduced water clarity which, in turn, can be detrimental to the fishery. Maintaining a diversity of beneficial plants is as important as controlling nuisance and exotic species.

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Exotic plant species that are potentially a threat to the Ryerson Lake include Eurasian milfoil, starry stonewort, and curly-leaf pondweed. Early detection and rapid response are key to effective control of invasive aquatic plant species. Each year, biologists from Progressive AE conduct multiple surveys of the lake to identify exotic plant locations and targeted herbicide treatments are carried out to control nuisance plant growth. The herbicide treatments require a permit from the Michigan Department of Environment, Great Lakes, and Energy.

The above "heat map" shows where aquatic plants typically grow in Ryerson Lake. Red areas show where plants occupy the entire water column, green and yellow areas depict areas of low and moderate growth, respectively, and blue areas depict areas where no vegetation typically grows.

Frequently Asked Questions

Who oversees the plant control program?

Plant control activities are coordinated under the direction of the lake board's environmental consultant, Progressive AE. Beginning in May and continuing through August, biologists from Progressive AE conduct GPS-guided surveys of the entire lake to identify problem areas, and detailed plan control maps are provided to our plant control contractors. Progressive then conducts follow-up surveys to evaluate contractor performance, and provide status reports to the lake board.

Who conducts the herbicide treatment and mechanical harvesting work?

The Ryerson Lake plant control program includes herbicide treatments. Herbicide treatments are conducted by Savin Lake Services. Both the herbicide and mechanical harvesting contracts are competitively bid and performance based. The contractors are only compensated for work that is performed satisfactorily.

Who determines when and where treatments occur?

When and where treatments are conducted is determined by the weather and where nuisance plants are found when biologists from Progressive AE conduct their surveys. Also, the EGLE Aquatic Nuisance Control permit dictates where and when treatments can occur and what herbicides can be used.

Why are there still plants in the lake following treatments and mechanical harvesting?

Not all plants are treated with herbicides. The goal of the program is to strike a balance by controlling invasive plant species and maintaining beneficial species. We do not want to remove all the plants in the lake. This would be bad for the fishery and cause a host of other problems, such as massive algae blooms.

Is there a permanent fix to the problem?

If conditions are favorable, aquatic plants will grow. However, there are things property owners can do to help minimize the amount of plants in the lake such as limiting the use of lawn fertilizers and maintaining natural vegetation along the shoreline to act as a filter for nutrients that wash into the lake. For more information on how to protect Ryerson Lake over the long term, click on the Watershed tab above.

Are herbicide treatments safe?

The aquatic herbicides that are permitted by the Michigan Department of Environment, Great Lakes, and Energy (EGLE), are registered by the United States Environmental Protection Agency (EPA) and the Michigan Department of Agriculture and Rural Development (MDARD). Before herbicides are approved for use in public trust waters, they also undergo toxicological review by EGLE. In Michigan, aquatic herbicide use requires an EGLE permit. The permit lists herbicides approved for use in the lake, respective dose rates, and shows the specific areas in the lake where treatments are allowed. If herbicides are applied according to label instructions and permit requirements, they should pose no danger to public health and the environment.

How will I know about use restrictions?

All lake residents receive a written notice in the spring regarding pending treatment. The written notice will list all potential herbicides that may be used and what the resultant use restrictions would be. The day before treatment, the state required treatment sign will be posted in all areas within 100 feet of treatment areas complete with a list of herbicides used and the associated use restrictions. If there is no sign posted along your property, it means that your area was not treated and there are no use restrictions.

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