Spatial and temporal variations in hydrrographical parameters in Talapady lagoon, southwest coast of India

Spatial and temporal variabilities in hydrographical parameters were studied in Talapady lagoon, a tropical coastal lagoon located on the southwest coast of India. The lagoon was influenced by two adjoining water bodies, the Talapady river during the southwest monsoon (June-September) and the Arabian Sea during the rest of the year. Temperature, during this study, varied between 26.18 to 34.50°C, salinity from 0.2 to 18.5 × 10 -3 , dissolved oxygen from 3.90 to 6.20 ml.l -1 . suspended particulate matter from 3.8 to 744.3 mg.l -1 and particulate organic carbon from 0.22 to 3.96 mg.l -1 . The nutrients studied included NH 3 -N (6.79 - 24.72 μg-at.l -1 ), NO 2 -N (0.1-9.8 μg-at.l -1 ), NO 3 -N (2.5-16.1 μg-at.l -1 ), PO 4 -P (3.4-6.5 μg-at.l -1 ), and SiO 3 -Si (15.3-132.9 μg-at.l -1 ). Temporal variations in the parameters studied were quite distinct with most parameters following a trimodal pattern, with peaks during premonsoon, monsoon and postmonsoon.