The key takeaways from the 2023 monitoring season are:
• Lake Killarney continues to have fairly clear water, moderate nutrient concentrations and moderate algal growth. • Long-term trends suggest that water quality in Lake Killarney has been improving over time, with decreasing nitrogen, phosphorus, and chlorophyll concentrations. Secchi depth has gotten shallower over time, although decreasing nutrient concentrations would be expected to lead to deeper Secchi depths instead. Secchi depth readings can vary considerably depending on the weather, time of day, or the individual observer. Further analysis is needed to determine if the observed trend is due to these factors, or if water clarity has actually decreased over time. • No algal blooms were reported for toxin testing in 2023. • Continue to monitor nearshore plants to catch purple loosestrife, a regulated Class B noxious weed that has been identified near Lake Killarney. If spotted, notify the King County Noxious Weeds Progr
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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).
