Fig. 3.

Water column profiles for years 2019, 2020, and 2021: biochemical properties. a, d, g Dissolved oxygen (DO; mg L⁻¹). b, e, h Turbidity (Tu; FTU), an ad hoc proxy for the bacterial layer (BL). c, f, i Blue–green algae in terms of phycocyanin (BGA-PC; ppb). The black and white continuous lines tagged with 10 and 5 represent isothermal depths at 10 °C (highest line) and 5 °C (lowest line), respectively. White contours on BGA-PC graphs (c, f, i) depict the turbidity peak and show that blue–green was often concentrated above the BL. White bars on the upper part of each plot indicate the sampling date. The missing DO and BGA-PC profiles in 2019 are due to broken sensors at the time of the sampling