Our lake temperature is higher than last year at this time due to the very warm and dry May weather. Temperature has not changed much over the past week and hopefully the upcoming mild weather will allow it to cool.
Lake temperature readings at 1 meter (epilimnion) and 14 meter (hypolimnion) depths. Dark lines are the current year and light lines are last year.
Water clarity has decreased since mid-May, down to 10 feet as of June 12th. This summers peak was 20 feet when we were in the “clear water phase” typical of spring when zooplankton are actively grazing on phytoplankton. Our best Secchi reading was 30 feet several years ago.
Secchi readings for 2023. Lake surface is represented by the top of the y-axis, with higher Secchi readings reaching deeper into the lake.
Phytoplankton biomass in Lakewood Bay and the Main Lake was very low in early May, but has increased over the past month as indicated by a reduced Secchi visibility. Diatoms were high earlier this spring but we are likely shifting to other species better adapted to warmer water. We typically run a few weeks behind on getting our most recent data due to the analyst caseload, but we should see increased numbers with the next samples.
Lakewood Bay saw a decline in phytoplankton biovolume in May. Three groups made up almost all the biovolume, as represented by light blue, dark blue and green stacked bars. Interestingly we had more cyanbacteria in January than May, but that was held over from the high biomass last fall.
Phytoplankton in Main Lake showing almost complete dominance by diatoms earlier this spring. It will be interesting to see what it shifts to as more data come in for late May and early June.
West bay always has high phytoplankton biomass, made up almost entirely of diatoms. Even when the Main Lake is shifting towards cyanobacteria West Bay will still be growing lost of diatoms. Please note the scale on the West Bay chart is an order of magnitude higher than the Main Lake and Lakewood Bay charts.