VOLUME 19 NUMBER 1 (January to June 2026)

Stream benthic macroinvertebrates of Pansipit River, Batangas, Philippines: Does protection status influence a highly urbanized river ecosystem?

The impact of protection efforts in streams situated in urban settings remains unclear in Philippine lotic ecosystems. Despite the ecosystem services provided, urban lotic environments are exposed to pollution and overexploitation. In this study, we aimed to examine whether the establishment of freshwater protected areas has a significant impact on aquatic environments and biodiversity using benthic macroinvertebrates as biological indicators. Benthic macroinvertebrates and physicochemical parameters were sampled across four sites of Pansipit River categorized by their land use. Multivariate analyses highlighted the variations in water quality of protected areas and their impact on benthic macroinvertebrate communities. Biotic and diversity indices (e.g., EPTC index, Shannon diversity index, and evenness) were calculated to assess macroinvertebrate community structures. The streams with lower dissolved oxygen, higher total dissolved solids and conductivity were correlated with the abundance of pollution-tolerant species, such as Chironomus sp. and Lamprodrilus sp. Moreover, the streams were observed to have degrading water quality, increased nutrient inputs (i.e., ammonia, phosphate), and low macroinvertebrate diversity from upstream to downstream reaches. Despite its protected status, freshwater protected areas in Batangas revealed poor stream ecosystem conditions, affected by anthropogenic activities. This study highlights the need for immediate and targeted measures to address the issues in Philippine freshwater protected areas, as well as the implementation of mitigation and management strategies to enhance watershed governance and rehabilitation.