Phytoplankton assessment on the tributaries of the Makiling freshwater system

Abstract

The Makiling Freshwater system (MFS) consisted of Molawin Creek, Cambantoc River, and Dampalit River located in the Mount Makiling Forest Reserve supplies the residential water in Calamba, Los Baños, Bay, and Calauan in Laguna. This study aims to assess the water quality of the three tributary rivers of MFS. Grab water samples were subjected through (1) physico-chemical analyses (temperature, pH, conductivity, total dissolved solids (TDS), dissolved oxygen (DO), nitrate-nitrogen and orthophosphate) and (2) phytoplankton assessment. Results have shown that the physico-chemical parameters tested in MFS, except for the DO measured in Molawin Creek, were within the DENR standards. Physico-chemical parameters such as conductivity, TDS, and DO were observed to be significantly different across the three river systems of the MFS (P < 0.05). The upstream region of Molawin Creek had the most phytoplankton mean±SEM count of 2011.50±67.50. The midstream of Molawin Creek and the upstream of Cambantoc River were the most diverse and least diverse regions, respectively. Using the Palmer’s Pollution Index, the upstream and midstream regions of Molawin Creek were found to be affected by organic pollution. Continuous monitoring of these tributaries is necessary as this safeguards the water quality of the MFS where a number of residents are dependent.