EVALUATION OF EUTROPHICATION STATUS OF POOVAR ESTUARY, SOUTHERN KERALA, INDIA

Abstract

In the present study, the Poovar estuary (PV) of southern Kerala was selected for the evaluation of eutrophication status using Carlson’s Trophic State Index (CTSI). This study is based on Secchi disk transparency- TSI(SD), the concentration of total phosphorus- TSI(TP) and chlorophyll a- TSI (Chl.a) using CTSI. The results of TSI showed that, based on TSI(SD), the PV estuary is under the eutrophic category characterised by high productivity. Season-wise values of TSI (SD) are greater (>60) than TSI(Chl.a), indicating non-algal suspended particles responsible for light attenuation as turbidity is dominated by runoff containing wastewater than algae emanating from canals adjoining the estuary. The TSI(Chl.a) is greater than TSI(TP), which indicates total phosphorus limiting the algal growth. The CTSI Index of PV estuary reveals that all sampling stations fall under the eutrophic condition.