After a cool week the lake surface temperature dropped to near what it was last year at this time. The lake will start warming again as we approach mid-90 degree temperatures this coming holiday weekend.
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 increased the past two weeks as a result of low phytoplankton biomass. Low biomass is not the case everywhere as you will see in the phytoplankton graphs below, but in Main Lake it is looking very good.
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 has been very low all spring. I only included the most common groups, but there is a bit of a gap under the orange “Total Biomass” line on May eight and June 19. These are filled in by green algae, dinoflagellates and cryptophytes, species that are not that abundant compared to the biomass of diatoms and cyanobacteria. But since there is a small overall biovolume these make up a larger percentage of biomass.
Lakewood Bay phytoplankton biomass. Orange line represents the total biomass from the sampling day. Only the most numerous groups are included.
Phytoplankton in Main Lake continue to decline, and the population has been dominated by diatoms all spring. This is typical this time of year since diatoms reproduce very rapidly this time of year, only to get fed upon by zooplankton.
Phytoplankton in Main Lake showing almost complete dominance by diatoms earlier this spring.
West Bay is an amazing generator of diatoms, with a peak of over 25 million um^3/ml in late May. This will persist throughout the year with diatoms dominating, but at a reduced overall biovolume.
West bay always has high phytoplankton biomass, made up almost entirely of diatoms.