Oral Presentation Freshwater Sciences 2023

Benthic macroinvertebrates as biological indicators: their sensitivity to water quality in a tropical river basin (#449)

Sedney S Mendoza 1 2 , Ashemir B Velasco 1 , Francis S Magbanua 1
  1. Institute of Biology, University of the Philippines Diliman, Quezon City, NCR, Philippines
  2. Graduate School, University of the Philippines , Los BaƱos, Laguna, Philippines

Evaluation of freshwater ecosystems using the combination of physical, chemical, and biological indicators is now becoming a prerequisite. In the Philippines, however, the use of organisms such as aquatic macroinvertebrates is not yet a part of the assessment and monitoring framework of its water resources. To contribute to addressing this gap, this study aimed to test the sensitivity of macroinvertebrates and their associated metrics calculated at the family and genus levels. A suite of water quality parameters was examined with the macroinvertebrate data collected from the Cagayan River Basin, Luzon Island, Philippines. Canonical correspondence analysis (CCA), principal component analysis (PCA), and correlation analysis were used to reveal the association of the water quality with macroinvertebrate communities. A total of 4,108 individuals were collected, comprising 75 taxa belonging to 47 families under 17 orders. The CCA revealed that the water quality affected the macroinvertebrate community found in the river basin. The first three principal components greatly explained the relationship between variables and the metrics as water quality indicators. Each macroinvertebrate-based metric calculated was sensitive to at least one of the water quality parameters considered in this study. The findings highlight the sensitivity of macroinvertebrates and their potential as part of the water quality assessment and monitoring program in the Philippines.