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Aquatic Plant Control

Managing and controlling invasive aquatic species is a primary objective of the Paw Paw Lake management plan.

 

In attempting to manage aquatic plants, it is important to note that aquatic plants are an important ecological component of lakes. They produce oxygen from photosynthesis, provide food and habitat for fish, and help stabilize shoreline and bottom sediments. The goal of the plant control program on Paw Paw Lake is to control invasive plant species while preserving beneficial plants.

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Plant Control Information

Next treatment:

Tentatively June 18 pending weather

The distribution and abundance of aquatic plants are dependent on several variables including light penetration, bottom type, temperature, water levels, and the availability of plant nutrients. The term aquatic plants" includes both the algae and the larger aquatic plants or macrophytes. The macrophytes can be categorized into four groups: emergent, floating-leaved, submersed, and free floating. Each plant group provides unique habitat essential for a healthy fishery.

Paw Paw Lake has a diverse aquatic plant community consisting of a variety of plant types. Of primary concern in Paw Paw Lake are the invasive species Eurasian milfoil and starry stonewort. Both plants have the potential to spread rapidly in the lake if not controlled.

The control of invasive plants in Paw Paw Lake is accomplished through the select use of aquatic herbicides. In Michigan, herbicide treatments require a permit from the Michigan Department of Environment, Great Lakes, and Energy. The permit dictates herbicides that are allowed, dose rates, plants targeted for treatment, and specific areas of the lake where treatments are permissible.

Plant control activities in Paw Paw Lake are coordinated under the direction of biologists from Progressive Companies, the environmental consultant employed by Watervliet and Coloma Townships. Biologists from Progressive conduct GPS-guided surveys of the lake to identify problem areas, and detailed treatment maps are provided to the plant control contractor, PLM Lake and Land Management. Follow-up surveys are conducted throughout the growing season to evaluate results and the need for additional treatments.

2024 Activity:

May 15 Plant Survey

May 22/29 Treatment

June 10 Plant Survey

June 18 Treatment

July 16 Plant Survey

Late July Treatment

August 27 Survey

Who oversees the plant control program?

Plant control activities are coordinated under the direction of the Townships’ environmental consultant, Progressive Companies. Biologists from Progressive Companies conduct GPS-guided surveys of the lake to identify problem areas, and detailed treatment maps are provided to the plant control contractor. Follow-up surveys are then conducted throughout the growing season to evaluate treatment effectiveness and the need for additional treatments.

 

Who conducts the herbicide treatments?

Herbicide treatments in Paw Paw Lake are conducted b PLM Lake and Land Management.

 

Who determines when and where treatments will occur?

The timing and scope of treatments is based on where nuisance plants are found when biologists from Progressive AE conduct their surveys.

 

What plants are targeted for control?

The plant control program on Paw Paw Lake focuses on invasive plants, such as Eurasian milfoil and starry stonewort. Invasive plant species have the potential to spread quickly if left unchecked.

 

How about a pre-emptive strike?

To be effective, aquatic herbicides must be applied directly to the plant beds when the plants are actively growing. There are no pre-emergence aquatic herbicides like there are for agriculture.

 

Why are there still plants in the lake following treatments?

In managing aquatic plants, it is important to recognize that most plants are beneficial. Aquatic plants produce oxygen during photosynthesis, help stabilize shoreline and bottom sediments, and provide cover and habit for a variety of fish. The main objective of the plant control program on Paw Paw Lake is to control nuisance, invasive species while maintaining beneficial plants. We do not want to remove all plants from the lake. This would negatively impact the fishery and cause many other problems such as algae blooms.

 

Is a permit required?

In Michigan, a permit must be acquired from the Department of Environment, Great Lakes, and Energy (EGLE, formerly the DEQ), before herbicides are applied to inland lakes. The permit lists the herbicides that are approved for use, dose rates, use restrictions, and indicates specific areas of the lake where treatments are allowed. Permit requirements are designed to protect public health and the environment.

 

Can I apply herbicides myself?

If you have a permit from EGLE, you can treat your own shoreline, but we don’t recommend it. In most cases, it is best to have herbicides applied by a licensed professional applicator rather than attempting to apply herbicides yourself. If applied improperly, herbicides can do more harm than good.

How do herbicide treatments impact swimming and fishing?

All herbicides, except algaecides, have a 24-hour swimming restriction, but only in the area where treatment has occurred as indicated by state-required posting signs. If there are no posting signs, or the sign indicates that only algaecides were applied, there are no swimming restrictions. There are no fishing restrictions for any herbicide treatments.

 

When can I water my lawn following a treatment?

If you draw water from the lake for irrigation, be sure to read the sign posted along your shoreline at the time of treatment. Most irrigation restrictions do not apply to established lawns. However, it you water flowers or a garden, you should adhere to the irrigation restrictions posted on the sign.

 

Why didn’t my property get a treatment notice sign?

If there is no sign posted along your property, it means your area was not treated and there are no use restrictions. State regulations require that areas within 100 feet of treatment areas be posted with a sign that lists herbicides applied and the associated use restrictions. Not every property gets treated every time; which properties get treatment depends on where the plants are found during lake surveys.

 

Is there a permanent fix to the problem?

If conditions are favorable, aquatic plants will grow. However, there are steps property owners can take to help minimize plant growth in the lake such as limiting the use of lawn fertilizers and maintaining natural vegetation along the shoreline to prevent nutrients from washing into the lake.

 

What can I do to prevent the spread of aquatic invasive species in Paw Paw Lake?

To help prevent the spread of invasive species, a new state law requires drain plugs to be pulled, water to be drained, and plants and debris to be removed from boats and trailers before trailering. If you trailer your boat to other lakes, be sure to thoroughly wash your boat, motor, and trailer before launching back into Paw Paw Lake. With invasive species, an ounce of prevention is worth a pound of cure!

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