2026 IJRSE – Volume 15 Issue 11
Available Online: 9 May 2026
Author/s:
Reyes, Kathleen B.*
Central Bicol State University of Agriculture, Philippines (kathleen.reyes@cbsua.edu.ph)
Estremera, Rey Ann Joy B.
Repia, Princess Grace B.
Dela Cruz, Cazy L.
Delos Santos, V-jay O.
Papa, John Alfred L.
Felezmiño, Jasper Ian U.
Nolaco, Michael N.
Abstract:
This study assessed phytoplankton diversity as a bio-indicator of water quality in the Caranan River, Pasacao, Camarines Sur. Specifically, it aimed to: (1) identify phytoplankton species at surface and sub-surface layers; (2) determine the river’s physico-chemical characteristics using physical parameters (color, odor, turbidity, salinity, temperature, total dissolved solids (TDS), total suspended solids (TSS) and chemical parameters (biochemical oxygen demand (BOD), dissolved oxygen (DO), pH, nitrate (NO₃⁻), phosphate (PO₄³⁻); (3) assess phytoplankton diversity in surface and sub-surface layers; and (4) determine the significance of phytoplankton diversity in evaluating water quality. Water samples and phytoplankton were collected from three stations along the river. A total of 774 individual phytoplankton belonging to Dinoflagellates, Diatoms, Cyanobacteria, and Chlorophytes were identified. Diatoms were the most abundant group, with Pseudo-nitzchia species the most abundant across all stations. Physico-chemical analysis revealed that most parameters, such as water temperature (25.11 °C average) and pH (8.32), were within standard limits, while nitrate (NO₃⁻, 25.9 ppm) and phosphate (PO₄³⁻, 4.62 ppm) concentrations exceeded permissible levels. Dissolved oxygen (DO) levels were above the minimum standard, and total suspended solids (TSS) and biochemical oxygen demand (BOD) were below the limits. Results indicated that phytoplankton diversity reflected water quality conditions, where high nutrient concentrations favored opportunistic species, potentially signaling early eutrophication. This study concluded that Caranan River’s water quality was moderately impacted by nutrient enrichment, and phytoplankton diversity served as an effective bio-indicator for environmental monitoring. Future studies were recommended to include seasonal variations, more sampling stations, and additional bio-indicator organisms for comprehensive water quality assessment.
Keywords: phytoplankton, species diversity, water quality, bio-indicator, Caranan River
DOI: https://doi.org/10.5861/ijrse.2026.26171
Cite this article:
Reyes, K. B., Estremera, R. A. J. B., Repia, P. G. B., Dela Cruz, C. L., Delos Santos, V. O., Papa, J. A. L., Felezmiño, J. I. U., & Nolaco, M. N. (2026). Phytoplankton diversity as bio-indicator of water quality in Caranan River, Pasacao, Camarines Sur. International Journal of Research Studies in Education, 15(11), 101-116. https://doi.org/10.5861/ijrse.2026.26171
* Corresponding Author