Total organic carbon as a new index for monitoring trophic states in lakes

Total organic carbon (TOC) can be one of the parameters used to determine trophic state in lakes, as shown by the statistically significant correlation between TOC and chlorophyll, total phosphorus and Secchi disk transparency. Calculation of the TSI index based on TOC according to the formula TSI(TOC) = 20.59 + 15.71 ln(TOC) and its introduction as an additional index to the classification by Carlson may optimize the comparative analysis of lakes and allow a measurable assessment of lakes with respect to the trophic gradient.