A brief description on spatial variability in nutrient-phytoplankton relationship in a shallow tidal creek-Thane Creek, India

Abstract

Anthropogenic influence on nutrient-phytoplanktonrelationship was studied in Thane Creek. The upper creek was highly loaded with N-forms through anthropogenic inputs. The elevated level of nutrients enhanced the chlorophyll a and phytoplankton density. A huge disparity was observed in the distribution of nitrate in the upper creek which can be linked to the 10 times higher density by Skeletonema costatum. CCA analysis carried out on species-environment parameters implied that phytoplankton species which were found in ascendancy (Thalassiosira sp. Skeletonema sp.,>Leptocylindrus sp.,>Plagioselmis sp.,>Chaetoceros sp.,>Cylindrotheca sp.,>Teleaulax sp.,>Alexandrium sp.,>Nitzschia sp.,>Gyrodinium sp.,>Surirella sp.>Guinardia sp., and Pyramimonas sp.) were more correlated to environmental variables like nitrate, ammonia, phosphate and salinity. The correlation between nitrate, ammonia and the phytoplankton showed that they were the essential nutrients responsible for their high density and distribution along the creek.