Assessment and Local Community Perception on the Water Quality of the Seven Crater Lakes of San Pablo City, Philippines

Abstract

 The Seven Lakes of San Pablo in the Philippines provide various ecosystem services including aquaculture and ecotourism which can degrade the lake’s condition. The water quality of the lakes was assessed and the perception of the locals on this and on the impacts of aquaculture and ecotourism on water quality were determined. Water quality was assessed in August and November 2019 and May 2021 to determine the condition of the lakes. Aquaculture lakes had lower dissolved oxygen (DO) levels, higher biochemical oxygen demand (BOD) and chlorophyll-a indicating eutrophic condition. Participatory Rural Appraisal (PRA) was conducted to elicit the perception of locals on the historical water quality. Locals perceived that there is a relationship between degraded water quality and anthropogenic activities in the lake. The PRA result is a verification that water quality has been degrading since the establishment of fish cages and settlements around the lake. The condition of the Seven Lakes in terms of water quality is being threatened due to these factors. These results will be useful for the local government unit in crafting strategies for the protection and sustainable management of the Seven Lakes.

Keywords: Seven Lakes of San Pablo, water quality assessment, participatory rural appraisal (PRA), aquaculture, ecotourism