Seasonal variations in physico-chemical characteristics of Tuticorin coastal waters, southeast coast of India

Physico-chemical parameters were determined along the Vellapatti, Tharuvaikulam and Threspuram coastal waters, southeast coast of India. All the physico-chemical parameters such as sea surface temperature, salinity, pH, total alkalinity, total suspended solids, dissolved oxygen and nutrients like nitrate, nitrite, inorganic phosphate and reactive silicate were studied for a period of 12 months (June 2014–May 2015). Sea surface temperature varied from 26.4 to 29.7 °C. Salinity varied from 26.1 and 36.2 ‰, hydrogen ion concentration ranged between 8.0 and 8.5. Variation in dissolved oxygen content was from 4.125 to 4.963 mg l −1 . Total alkalinity ranged from 64 to 99 mg/l. Total suspended solids ranged from 24 to 97 mg/l. Concentrations of nutrients, viz. nitrates (2.047–4.007 μM/l), nitrites (0.215–0.840 μM/l), phosphates (0.167–0.904 µM/l), total phosphorus (1.039–3.479 μM/l), reactive silicates (3.737–8.876 μM/l) ammonia (0.078–0.526 μM/l) and also varied independently.