Diatoms in the rivers of Calamba Misamis Occidental, Philippines

Abstract

Diatoms are good indicators of the environmental integrity of lotic ecosystems. This study aims to identify the genera of diatoms present in the rivers of Calamba, Misamis Occidental, Philippines and their corresponding abundance. Sixteen genera of diatoms were identified in the rivers where the majority of the genera favor intermediate to the high nutrient concentration. The species of Fragilaria and Navicula were most abundant upstream while the species of Amphora was the most abundant downstream. The following genera were present in all the rivers sampled and most of these have high cell densities: Amphora, Cymbella, Epithemia, Fragilaria, Gomphonema, Navicula, and Nitzschia. Based on the assemblage of diatom genera, the rivers sampled at Calamba Misamis Oriental are already showing signs of nutrient enrichment. Using probes to measure the concentrations of nutrients in the rivers can further validate this finding.