Limnological Analysis of Laguna de Bay Lake at Binangonan Freshwater Station: Its Implication to Plankton Diversity

Abstract

Geographically located southeast of Manila, Laguna Lake is used for multiple resources such as fishery, irrigation, power generation and navigation. Recently, the lake has been considered as a source of potable water for Metro Manila. A Limnological study of the Lake was conducted to assess its present status and potential. Three sampling sites were considered in the identification of the plankton community. Plankton samples were examined at the University of Santo Tomas Biological laboratory. Plankton species were identified using the taxonomic key of Needham and Needham. The physicochemical characteristics of the water at the different sites were assessed. Temperature and pH were measured using an analytical radiometer, dissolved oxygen (DO) was computed, transparency was determined sing the secchi disc with a diameter of 26 cm; chemical oxygen demand (COD) was computed using the standard method. The results showed that sampling site 2 had the highest DO and COD. The phytoplankton Cyanobacteria like Spirullina major and Lyngbya limnetica dominated the lake. The green algae Chlorella vulgaris and Pediastrum spp. Were found to be distinct in the lake. Copepods (Copepoda spp.) are the zooplanktons observed. Laguna Lake (Binangonan Freshwater Station) has slightly basic water still suitable for aquaculture, recreation and industrial use. The lake is eutrophic. Keywords - algae, copepods, Laguna lake, limnological study, Physicochemical analysis, phytoplanktons, zooplanktons