Seasonal variations in Physico-Chemical parameters of Thengapattanam estuary

ABSTRACT Thengapattanam estuary is located in the South west coast of India 10 Km from Marthandam. It is one of the minor estuary in Kanyakumari District formed by the confluence of Tampirabarani River (locally known as Kuzhithuraiar) with Arabian sea in between Thengapattanam and Eraiummanthurai (7 o 53' N latitude and 77 o 07' E longitude) .The present study has been undertaken to enlighten the influence of domestic sewage, agricultural run off and coconut retting wastes on the water quality parameters of this estuary during October 2011 to August 2012. The study area recorded maximum rainfall during northeast monsoon and minimum during summer season. Air and surface temperature showed summer peaks and monsoonal troughs. Temperature variations were associated with the seasonal changes of other physicochemical parameters. Salinity was high during summer season and low during monsoon season. But maximum salinity was recorded at mouth region (station 5).pH remained alkaline throughout the study period in all the stations. DO concentration showed a wide range of variation. It reached its peak during the monsoon season BOD was high during summer season and low during monsoon. Concentration of nutrients nitrite, nitrate, phosphate etc showed significant spatial and temporal variations and high values were observed at the polluted stations