LOS BAÑOS, Philippines – Laguna de Bay marches on to its “ecological doom,” according to a recent study on water quality of the Southern Tagalog lake.
“The water quality in Laguna Lake has seriously deteriorated due to pollution from effluents from chemical industries, agricultural household discharges, and soil erosion,” a study titled “Environmental Risks to Food and Health Security in the Laguna Watershed” said.
The Research Institute for Humanity and Nature and Yokohama National University in Japan, University of the Philippines Los Baños (UPLB) and UP Manila, and the Laguna Lake Development Authority were part of the project focusing on food and health security in Asian watersheds.
The research was drawn from the presentation titled “Ecology-related Risks on Water, Food Safety, and Security” by professor Ryohei Kada of the Yokohama National University. A synthesis of the study was published by the Philippine government-hosted, UPLB-based Southeast Asian Regional Center for Graduate Study and Research in Agriculture under its “Agriculture and Development Notes.”
Researchers aimed mainly to document the current levels and pathways of heavy metals pollution in the aquatic resources of the 90,000-hectare Laguna de Bay and to investigate the health condition of residents and their perception of local risks.
It also analyzed the ecological effects of agri-chemical inputs and their cumulative impact on food production and relation to subsequent ecosystem deterioration. Moreover, it described land use change in the lake area and its impact on water and material cycles, including impacts on sedimentation and groundwater level and quality.
The research was primarily done in the Sta. Rosa sub-watershed, which was identified to have noticeable primary and complex drivers of change in the lake’s ecosystem. The factors considered included population expansion, rapid economic development, industrial and commercial development, widespread urban sprawl, land use conversion, exotic and invasive species, and under-coordinated and conflicting policies.
In the study, the researchers collaborated with local residents and worked in five sub-teams to conduct socioeconomic evaluation, environmental risk assessment, health risk evaluation, payment for ecosystems services analysis, and geographic information system risk analysis.
Among other things, the researchers developed water quality maps for Laguna de Bay and its watershed that showed the high presence of heavy metals in the lake’s western region. They also evaluated individual willingness to pay for enhanced ecosystem services and provided estimates of the farmers’ decision-making in agroforestry.
The study showed that Laguna de Bay, the country’s biggest inland freshwater lake, is faced with declining agriculture and fisheries productivity, increasing domestic wastes and health issues, pollution and environmental degradation, and household food insecurity and health risks.
“Laguna Lake has become more vulnerable to food-health insecurities due to environmental deterioration,” the study stated.