Impacts of Motorized Watercraft on The Environment


Based on research by Tim Asplund, WDNR Limnologist


Excerpts from report:

While the effects of boats on aquatic systems are complex and depend on a number of factors, a few general observations can be made:

First, the physical effects of propeller, waves, and turbulence appear to be more of an issue than engine fuel discharge. Water clarity, aquatic plant disturbance, and shoreline erosion are all serious issues that can be accelerated by boat traffic.

Second, most of the impacts of boats are felt directly in shallow waters (less than 10 feet deep) and along the shoreline.

Third, these effects can have repercussions for other features of the aquatic ecosystem, including the fish and wildlife community and nutrient status.

These observations all indicate that the most important area of a lake to protect is the shallow water, near shore habitat known as the littoral zone.

Boats that operate in deep waters with large surface areas are not likely to be impacting the aquatic ecosystem.

What can we do?

1. Establish No-Wake Zones.

Given that most impacts of boats are exhibited in shallow-water, near-shore areas, protecting these areas with no wake zones would be the most effective way of reducing impacts. No-wake zones have a dual benefit of both slowing boats down and directing traffic elsewhere. Extending a no-wake zone to 200 or even 300 feet has the most potential to protect the littoral zone and help reduce shoreline erosion.