HomeMy WebLinkAbout2025 Otto Lake POI Survey Report2025 Otto Lake (DOW: 27067800, Hennepin County)
Aquatic Vegetation Point Intercept Survey Report
4/26/2025
An aquatic vegetation point intercept survey was completed in Otto Lake on 4/26/2025 for the City
of Edina. The point intercept survey consisted of 67 points. A meandering delineation was also
performed to detect any additional curlyleaf pondweed not in the proximity of a site. At each site
depth was recorded and vegetation was sampled with a double-sided rake. For every species
sampled, an abundance rating was assigned based on how much was sampled on the rake. The
ratings are as follows:
0. Plant species absent
1. Plant species covers <25% of the rake
2. Plant species covers 25-75% of the rake
3. Plant species covers >75% of the rake
This rating scale was taken out of the Minnesota Department of Natural Resources Guidance for
Delineating Aquatic Plants for Management.
1 2 3 Frequency Avg. Rake Abundance
Curlyleaf Pondweed 0 0 0 0 0
Northern Watermilfoil 7 8 14 43 2.2
Common Waterweed 6 0 0 9 1
Coontail 8 1 0 13 1.1
Flatstem Pondweed 5 0 0 7 1
Curlyleaf pondweed was not sampled or observed during the survey.
Northern watermilfoil was the most abundant species sampled at 43% of sites. The average rake
abundance was 2.2. Identiflcation to northern watermilfoil was performed by leafiet count, however
there was a hybrid quality to plants sampled.
Coontail, common waterweed, and fiatstem pondweed were also sampled during the survey. All
three species were sampled below 15% of the sites, with average rake abundances of 1 or 1.1.
Also during the survey, Chinese mystery snail was observed at multiple sites.
Figure 1: 2025 Otto Lake northern watermilfoil distribution and abundance
Figure 2: 2025 Otto Lake common waterweed distribution and abundance
Figure 3: 2025 Otto Lake coontail distribution and abundance
Figure 4: 2025 Otto Lake flatstem pondweed distribution and abundance