Phytoplankton Composition and Water Quality of Lake Palakpakin, San Pablo City, Laguna

The richness of the phytoplankton community is evidence of changes in the physical, chemical, and biological parameters of a lake. Nitrates and phosphates are essential for the growthof living organisms in the water. Nevertheless, excessive levels lead to eutrophication. The objective of the study focuses on the assessment of nutrients and richness of phytoplankton in LakePalakpakin, one of the Seven Crater Lakes of San Pablo, Laguna. Specifically, this study aims to (1) assess the richness of phytoplankton in the lake and (2) determine the effect of the lake’snitrate and phosphate levels on phytoplankton richness. Results show that green algae were the richest group with 21 genera (44%), followed by diatoms with 13 genera (27%) and blue-greenalgae with 9 genera (19%). Among the sampling stations, the outlet was the richest with 36 genera, followed by the center (26 genera), inlet (22 genera), and fish pen (19 genera). There was noobserved effect between phytoplankton richness and nitrate and phosphate levels among the different study sites.