Distribution pattern and multivariate analyses for anthropogenic apportionment of selected coastal water in Macajalar Bay, Philippines

Macajalar Bay in the southern Philippines has become an attractive thoroughfare with recent developments, rendering anthropogenic input to the coastal waters. Expediting coastal resource management strategies necessitates the present study on coastal water characteristics. This was aided with distribution pattern and multivariate analyses for apportioning possible anthropogenic inputs. A total of 15 biophysicochemical characteristics were studied covering two municipalities (Opol and Jasaan) with six subcoastal communities in 2017. Data were all processed for Q test to eliminate outliers before distribution analyses using univariate (descriptive), inferential (t test, one-way ANOVA, Pearson correlation), and multivariate statistics (hierarchal cluster analysis (HCA) and principal component analysis (PCA)). Overall, higher concentrations were determined in the ecotourism site (Opol) than in the industrial site (Jasaan) as sampling months progressed except for oil and grease. Results for total coliform, fecal coliform, heterotrophic plate count (HPC), total suspended solids (TSS), chemical oxygen demand (COD), and oil and grease regardless of spatial-temporal variations exceeded the standards. Distribution pattern revealed variations selectively for pH, temperature, dissolved oxygen (DO), and oil and grease, indicating site-specific distribution. HCA and PCA results corroborated correlation matrices showing elevated concentrations in an ecotourism site (Opol) apportioned anthropogenic input mainly due to rural development and ecotourism. Likewise, in the industrial site (Jasaan), HCA and PCA results reflected possible anthropogenic input from rural development and industries. Overall, anthropogenic apportionment in the bay was influenced by rural development, ecotourism, and industries.