Lake Mgmt Plan Goal and Action Steps: Aquatic Vegetation

Starting around 2017, a concern was raised that Clearwater Lake was loosing native vegetation. 
First hand observation is an important part of managing a potential problem.    However, it is hard to quantity and comparing spring vegetation to summer or fall vegetation will result in very different observations.
Monitoring through aquatic surveys
The MN DNR produced a report in 1995 and 2015.  The Clearwater Lake Conservancy decided supplement this with an aquatic plant survey every three years.   This will allow us to see any trends.

Clearwater Lake Conservancy contracted with RMB Environmental Laboratories to do a Vegetation Point intercept Survey in 2018 and 2021.   They were unavailable in 2024.   See the survey results on Survey Results and Comparison.

At this time,  the board is working with Limnopro to do a survey in 2024 or 2025.  The previous surveys were 1 point per acre, the 2024/2025 survey will be increased to 1 survey point per 1/2 acre for more refined results.
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Our 2021 and 2018 survey results show very similar findings.    The surveys show no significant change in our native vegetation.   There were signs that some plants were doing better, however this could be the difference between a July and August survey or even the summer climate.    Gladly no decline was reported between 2018 and 2021.
This is good news.   Either the decline has stopped or it it was a misinterpretation.   We are hoping the 2024/25 survey shows increased plant growth.
Determine Root Cause
Since the decline was perceived by many lake residents the Clearwater Lake Conservancy board has been working with experts to determine WHY we might have had this issue.

The first concern was the chemical treatment for the invasive aquatic plants.  Given that the chemical treatment is designed to kill aquatic plants, the board has worked with the experts to determine if this could be the root cause.

The other culprit they explored is the invasive Rusty Crayfish.
Minimize chemicals that could harm native vegetation
We explored hand pulling and talked to the experts about the best chemical solution that will our target our invasives and minimize impact to our natives.  

We used hand pulling, in specific areas in one year and on the whole lake the next year.  The hand pulling turned out to be a non-viable option for our lake and may even have aggravated the problem.

The MN DNR, Freshwater Scientific Surveys and PLM Lake and Land Management were contacted and all agreed that our current treatment of ProcellaCOR is the best option.   A
Determine impact of Rusty Crayfish
Virginia Cooperative Extension, Virginia Tech, 2020
Sustaining America’s Aquatic Biodiversity Crayfish Biodiversity and Conservation
Nonnative crayfish cause declines of native aquatic plants and animals through the spread of diseases, such as crayfish plague, to native crayfish; by predation on eggs, young fish, amphibians, and native crayfish; by out-
competing or preying on native crayfish; and by the elimination of native water plants and habitats. The rusty crayfish (which is native to four states, but has been introduced into 24 states) is an aggressive crayfish that has been linked with the decline of native crayfish and other aquatic species in states where it has been introduced.