A comparative study of phytoplankton populations in two Malaysian lakes

Abstract

Phytoplankton composition and production in two Malaysian lakes were studied between February and December 1988. Lake Aman is a shallow (mean depth 0.3 m) nutrient-rich water body, whilst Lake Titiwangsa is comparatively deep (mean depth 3.4 m) and poor in nutrients. Phytoplankton taxa in Lake Aman consisted of four phyla with 19 genera, and Lake Titiwangsa had five phyla with 33 genera. The euglenoids were the most abundant group in Lake Aman throughout the study period, comprising 85.4% of the total phytoplankton population. The second largest group of phytoplankton in this lake was chlorophytes (13.8%), followed by cyanobacteria (0.6%) and diatoms (0.2%). The order of phytoplankton abundance in Lake Titiwangsa was cyanobacteria (45.7%), followed by chlorophytes (28.4%), dinoflagellates (11%), chrysophytes (10%), diatoms (4.3%), and euglenoids (0.6%). Chlorophyll a concentrations in Lake Aman ranged from 60.0 mu g/l to 969.41 mu g/l. Chlorophyll a concentrations in Lake Titiwangsa were comparatively low, ranging from 0.5 mu g/l to 6.3l mu g/l. The composition and biomass of phytoplankton populations in the two lakes indicated that the study lakes were of different trophic status: i.e. Lake Aman was hypertrophic and Lake Titiwangsa was mesotrophic. The physicochemical characteristics of the lake water supported this hypothesis. (DBO)