Case study: Nutrients distribution and assessment of the current trophic status of Plastiras lake in Thessaly (central Greece) after tropical storm Daniel

Based on the interactions of three water quality variables, chlorophyll-a (Chl-a), secchi depth (SD – water transparency) and total phosphorus (TP), this study was aimed to assess the trophic state of Plastiras Lake through the modified method of Carlson's trophic state index (CTSI). Eutrophication is one of the most serious problems for water quality and CTSI is an important index for monitoring water quality status and eutrophication assessment. The classification scale for Trophic State Index (TSI) fluctuates from 0 to 100 and the results of this study showed that the mean TSI for Chl-a was 42.95, for SD was 45.50 and for TP was 75.15. The overall CTSI finally was 54.53. These show that Plastiras Lake is presently classified as mesotrophic to eutrophic which reflects the current levels of nutrients in the lake.