Aquatic Vegetation Surveys

As part of the Breakwall Evaluation Study, staff from the Winnebago Waterways Program at Fox-Wolf Watershed Alliance completed aquatic plant surveys at Scott’s Bay, Samer’s Bay, and Terrell’s Island in August 2022.

With the help of one of our dedicated volunteers (Tom Bett), we sampled over 900 locations. We used a standardized point-intercept (PI) aquatic plant survey protocol that was developed by the WI DNR to ensure consistency in sampling over time and space in a way that allows for quantitative analysis of aquatic plant communities. A formula is applied to a GIS polygon of the area of interest to determine the number of sampling locations in a regularly-spaced grid pattern. The calculation takes the size, depth, and shape of the area into consideration. This allows us to accurately assess the aquatic plant community in a lake and compare results among locations and across years.

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Breakwall Evaluation Project Webpage

Maps of the sampling grids:

To conduct the survey, we travelled by boat to the pre-determined locations within the PI grid using a GPS. At each point, a double-headed rake was used to pull plants up from under the water. Depth, sediment type, rake fullness, and visual sightings were recorded. The plants on the rake were identified and vouchered (if needed). This was repeated at each sampling location on the sampling grid for the three study sites being evaluated as part of this project.

Results from the surveys will be shared once data entry is completed and statistics reviewed. Some interesting preliminary findings:

The first known finding of brittle naiad in the Winnebago System. Brittle naiad is an aquatic invasive species. More to come on this species in future blog posts!
High plant diversity in Scott’s Bay. We found over 25 different species!
Very few plants and diversity in Terrell’s Island and Samer’s Bay. We hope this changes as the restoration projects progress.

We very much appreciate the help from our partners at Fond du Lac County Land and Water and Winnebago County Land and Water as well as Tom Bett, our dedicated volunteer, for your help completing the surveys!