Recreational use impacts

The number of motorized watercraft and the size of their engines has dramatically increased in recent years. Watercraft can have multiple effects on a lake's ecosystem including:

• Churning up sediments (resuspension) which can cloud water and release nutrients (such as phosphorus) stored in sediment back into the water.
• Eroding shorelines when waves created by watercraft hit shorelines (this can be more severe in shallow lakes). Erosion further clouds water.
• Impacting plant communities. Motor propellers can chop or uproot plants, and waves can damage them and limit growth of some species. Cloudy water caused by churned up sediments limits light available for plants and where they can grow. Watercraft can also transport invasive species from one lake to another.
• Contributing to water pollution by discharging unburned fuel (up to 25 to 30%) into the lake and lowering oxygen levels due to carbon monoxide in exhaust.

In addition to the physical impact of watercraft on lakes, watercraft also impact how we use our lakes. Recreational use conflicts such as crowding, safety, air quality, and noise are concerns for a growing number of lake users. Many local governments and lake groups have passed boating ordinances for specific lakes.