An evaluation of phytoplankton assemblage in relation to environmental variables of Narmada Estuarine Region of Gulf of Khambhat, Gujarat, India

Abstract

A study on the relationship between physicochemical parameters and phytoplankton assemblage in Narmada estuarine region (21◦40’05.19”N and 72◦34’26.90”E) of the Gulf of Khambhat, Gujarat, India was carried out from July 2009 June 2010. Principal Component Analysis with environmental variables like pH, dissolved oxygen, salinity, ammonia, phosphate, nitrate, silicate and chlorophyll-a reveled two factors influencing variability in the water nutrient composition up to 72% during the whole study period. Canonical Correlation Analysis between environmental variables and 31 dominant taxa of phytoplankton showed the freshwater influence on phytoplankton distribution in the estuarine zone. The maximum diversity in phytoplankton assemblage was observed during the postmonsoon (November, December, January, February) and post-monsoon (March, April, May, June) period. The same period reported a high load of inorganic nutrients at the middle and upper reaches of the estuary due to anthropogenic influence and low freshwater flow in this zone.