Lake morphometry underlies physical and chemical parameters affecting the distribution of phytoplankton functional groups in lakes of the Sakarya River Basin (Turkey)

To test the effects of lake morphometry (lake size and depth) on water quality parameters which affect the phytoplankton functional groups (FG) distribution, phytoplankton and some environmental parameters were sampled in November 2017 and May 2018 at the two or three monitoring stations in nine Lakes of Sakarya River Basin (Turkey). Lake size and depth affected phytoplankton FG distribution in both large-sized and small-sized lakes by affecting light availability which was mainly driven by the mixing events during the studied period. Although PO4-P and alkalinity were the other main environmental constraints influencing phytoplankton distribution, they were not directly affected by lake morphometry. Codon Lo was mainly found in small-sized and shallow lakes, whereas coda B, C, D, J, R, and T, which do not have active buoyancy regulation and adapt to high Zmix/Zeu conditions, occurred with high relative biovolwne in large-sized water bodies.