No abstract

The distribution of the phytoplankton community in different zones of Putrajaya Lake, Malaysia was analyzed from October 2009 to September 2010 to examine the zonal-distribution relationship. Three stations representing three different lake zones namely Station 1 (littoral zone), Station 2 (sub-littoral zone) and Station 3 (limnetic zone) were selected. Water transparency, temperature, pH, dissolved oxygen and conductivity were found to be important factors characterizing each zone. A total of 148 species from 77 genera were recorded throughout the sampling duration from October 2009 until September 2010. During this period, Chlorophyta was the most abundant group (59% of the total phytoplankton), followed by Pyrrhophyta (15%), Cyanobacteria (11%), Bacillariophyceae (9%), Chrysophyceae (3%), Cryptophyta (2%) and Euglenophyta (1%). The highest mean density of phytoplankton was recorded in the limnetic zone (433.94 ± 18.29 cells ml-1), followed by sub-littoral (292.94 ± 18.61 cells ml-1) and littoral zone (199.58 ± 13.56 cells ml-1). There was a significant difference in the Shannon-Wiener diversity index for phytoplankton diversity and abundance in all three zones (p<0.05) with limnetic zone demonstrating the highest species diversity. 150 Asma' Jamal et al. Species commonly found in the sub-littoral area also dominated both littoral and limnetic phytoplankton communities suggesting that sub-littoral zone acted as an interphase for phytoplankton adaptation and migration between the two different zones. The findings suggest that spatial distribution and diversity of the phytoplankton community can be affected significantly by local lake zonation characterized by environmental variations.