2026 IJRSE – Volume 15 Issue 11
Available Online: 11 May 2026
Author/s:
Aguilan, Maria Denise Lou C.*
Ilocos Sur Polytechnic State College, Philippines (aguilandenise43@gmail.com)
Olarte, Elizabeth I.
Don Mariano Marcos Memorial State University – South La Union Campus, Philippines
Abstract:
This study assessed the physicochemical and biological water quality of selected beach resort areas in Northwestern Philippines. Sampling was conducted in four beach resort stations (Ilocos Norte, Ilocos Sur, La Union, and Pangasinan) from July to December 2018. Water quality was evaluated in terms of physical parameters (temperature, salinity, turbidity, total suspended solids), chemical parameters (pH, dissolved oxygen, nitrate, phosphate), and biological parameters (chlorophyll a, total coliform, and fecal coliform). Descriptive statistics and the Kruskal-Wallis H test were employed to determine spatial variations among sampling stations. Results revealed significant differences in several physical parameters, particularly salinity (p = .022), turbidity (p = .007), total suspended solids (p = .002), and temperature (p = .027). Among chemical parameters, only nitrate showed significant variation (p = .007), while pH, dissolved oxygen, and phosphate showed no significant differences. Likewise, biological parameters (chlorophyll a, total coliform, and fecal coliform) showed no statistically significant spatial differences among sampling stations (p > .05). Overall, the findings indicate that physical parameters are the most variable components of coastal water quality in the study area, while chemical and biological parameters were relatively stable, except for nitrates and localized coliform presence. Although most parameters remained within generally acceptable environmental limits, elevated turbidity and coliform levels in some stations suggest localized anthropogenic influence. These results highlight the need for continuous monitoring and strengthened coastal management in tourism-based marine environments.
Keywords: coastal water quality, salinity, turbidity, dissolved oxygen, chlorophyll a, coliform bacteria, Northwestern Philippines
DOI: https://doi.org/10.5861/ijrse.2026.26161
Cite this article:
Aguilan, M. D. L. C., & Olarte, E. I. (2026). Physicochemical and biological assessment of coastal water quality in selected beach resort areas of Northwestern Philippines. International Journal of Research Studies in Education, 15(11), 233-241. https://doi.org/10.5861/ijrse.2026.26161
* Corresponding Author