HomeMy WebLinkAbout2024 Indianhead Lake POI Survey Report Revised2024 Indianhead Lake (DOW: 2700400, Hennepin County) Aquatic Vegetation Point Intercept Survey Report
4/5/2024 & 4/18/2024
An aquatic vegetation point intercept survey was completed in Indianhead Lake on 4/5/2024 for the City of Edina. Two species of vegetation were sampled during the survey:
Curlyleaf pondweed
Chara spp.
The point intercept survey consisted of 100 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:
Plant species absent
Plant species covers <25% of the rake
Plant species covers 25-75% of the rake
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.
Curlyleaf pondweed was not abundant in Indianhead Lake (See figure 1). It was only found at 6 sites (frequency of occurrence: 6%) with an average rake abundance of 1.16 at sites where
it was collected. The sites where curlyleaf pondweed was found ranged in depth from 2 - 5ft with the most abundant site being 2 feet. Extensive searching in shallow areas did not find
other stands of curlyleaf pondweed. A follow up survey was completed on 4/18/2024 to examine further curlyleaf pondweed growth after the initial survey. It was found at 2 sites during
this survey, one of which had curlyleaf pondweed surveyed on 4/5/2023. Curlyleaf pondweed had a frequency of occurrence of 2% and had an average abundance rating of 1 during the 4/18/2024
survey. Figure 3 shows the comparison of the two surveys regarding curlyleaf pondweed distribution and abundance.
Chara spp was the most abundant plant species in Indianhead Lake (See figure 3). It was found at 96 sites (frequency of occurrence: 96%) with an average rake abundance of 1.58 at the
sites where it was collected. The sites where chara was found ranged from 1 - 7ft but was more abundant in shallow areas of the lake. Similar results were collected during the 4/18/2024
survey. Chara was sampled at 89 sites (frequency of occurrence: 89%) with an average rake abundance of 1.7 at the sites where it was collected.
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Figure 1: Indianhead Lake CLP distribution and abundance
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Figure 2. Curlyleaf pondweed distribution and abundance comparison of 4/5 and 4/18/2024 surveys
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Figure 3: Indianhead Lake Chara distribution and abundance