Effects Of Tidal Events On The Composition And Distribution Of Phytoplankton In Merbok River Estuary Kedah, Malaysia

Abstract

The impact of tidal events on water quality and on the species composition and distribution of phytoplankton at three stations along Merbok river estuary, Malaysia were investigated. Bacillariophyta was the most dominant group, followed by, in decreasing order, Dinophyta, Chlorophyta, Euglenophyta, Cyanophyta and Cryptophyta. Spring tides had higher total cell number and richness but neap tides had higher diversity (except Station 2) and evenness of phytoplankton at all stations. Spring tides also led to higher salinity, conductivity, total suspended solids, nitrate and orthophosphate but lower pH, dissolved oxygen, transparency, chlorophyll-a and nitrite. No significant effects of tidal changes were observed on temperature, light intensity and ammonia.