Volunteers monitored Lake Fenwick in 1994 -1995, 2001, 2003-2004 and again beginning in 2021.
The key takeaways from the 2023 monitoring season are:
• Lake Fenwick continued to have fairly clear water, high algal growth, and high nutrient concentrations. • An algal bloom was sampled for toxin testing in October. Toxin testing found very low concentrations of algal toxins, well below the Washington State Recreational Guidelines. • Lake Fenwick has an infestation of Brazilian elodea (Egeria densa), a class B Noxious Weed, however because it is widely established around the lake, there is no requirement to control.
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The average of these three TSI indicators during the growing season can be used to place lakes in one of three broad categories: <40 = oligotrophic (low productivity), 40 to 50 = mesotrophic (moderate productivity) >50 = eutrophic (highly productive).