Publication Details

Investigating factors influencing algal bloom development – A preliminary case study of Putrajaya lake inlet, Malaysia

Algal bloom phenomena are increasingly occurring in many urban lakes worldwide. To enhance understanding of how environmental factors influence the development of harmful algal bloom (HAB), a preliminary study was carried out at one of the inlets in Putrajaya Lake. Physicochemical variables, nutrients, weather conditions, chlorophyll-a, and phycocyanin were measured over two weeks. Algal indicators, namely chlorophyll-a values, were strongly correlated to dissolved oxygen (DO), pH, conductivity, turbidity and nitrate. There is no correlation recorded between chlorophylla with phosphate and total phosphorus. This preliminary study showed the complex relationship influencing algal development and bloom formation. Blue-green algae (BGA) was the most dominant phytoplankton assemblages during the study. A positive correlation was also observed between chlorophyll-a and solar radiation, temperature, and wind speed. Despite no strong correlation between chlorophyll-a and rainfall amount, a strong relationship between chlorophyll-a and turbidity indicated other environmental factors contributing to algal bloom occurrence. BGA density was correlated to DO, pH, turbidity, air temperature and nitrate. Management measures recommended to reduce algal bloom development include external nutrient reduction through the constructed wetland. Artificial mixing is also recommended to improve vertical mixing and circulation pattern.