Water Quality of Lake Marcel
The data collected between 1998 and 2008 indicate that Lake Marcel is relatively high in primary productivity (mesotrophic to
eutrophic) with fair to good water quality that has remained relatively stable over time. This means that algae blooms may occasionally cloud the water, but in general the lake is in good condition for recreational use and there is enough algae produced to support the tiny animals (zooplankton) that feed the fish. Similar conditions are very commonly found in shallow
lakes, especially those created from beaver ponds or wetlands that are naturally very productive water bodies with lots of
Data from different depths in the lake suggest that thermal stratification (warm temperatures on top, cool temperatures in deep water) is not stable through summer, and the water will mix with windiness or summer storms. Therefore, phosphorus concentrations do not build up in deep water and algae generally have nutrients available to them through the whole water column. The nitrogen to phosphorus ratio drops below 20:1 in late summer, which indicates that bluegreen algae may be favored over other algae at that time period. However, for most of the growing season, phosphorus remains the nutrient that is least available to algae, thus it limits their growth and managing the phosphorus levels will allow the community to control algae growth to some degree.
2021 Lake Stewardship Report
Here is a link to the full report: 2021 Lake Marcel Stewardship Report
The key takeaways from the 2021 monitoring season are:
- Lake Marcel had fairly clear water, with high nutrient concentrations and high algal growth.
- Lake Marcel had a prolonged algal bloom with samples collected and tested for toxins in July, August and September.
- Toxin testing found elevated microcystin concentrations in July: 9.83 μg/L, above the Washington State Recreational Guideline of 8.0 μg/L.
- Toxin testing also found anatoxin concentrations ranging from 0.015 - 0.129 μg/L, well below the Washington State Recreational Guideline of 1.0 μg/L.
The Lake Stewardship Program recommends:
- Stay alert for toxic algae blooms in Lake Marcel – increase people’s awareness of toxic algae, and their ability to identify which algae are potentially toxic.
- Any potentially toxic blooms should be reported to the King County Lake Stewardship Program and sampled for toxin analysis.