Diatom ecological guilds as environmental indicators for biomonitoring in a tropical river basin of Southeast Asia

Abstract

Functional traits are widely used in ecological studies to better understand diatom assemblages. This study examined the relationship between diatom ecological guilds (low-profile, high-profile, motile, and planktonic) and environmental parameters across 28 rivers and streams in the Tagoloan River Basin, Northern Mindanao, Philippines. The aim was to assess whether these guilds serve as effective indicators for biomonitoring. Canonical correspondence analysis (CCA) revealed a significant relationship (p=0.015), indicating that phosphate (PO₄³⁻), nitrate (NO₃⁻), nitrite (NO₂⁻), ammonium (NH₄⁺), turbidity, pH, temperature, total dissolved solids (TDS), total suspended solids (TSS), conductivity, dissolved oxygen (DO), and flow influence diatom ecological guilds. The CCA explained 98.27% of the variance in two axes, demonstrating that diatom ecological guilds respond to environmental variables and may serve as useful indicators for river basin biomonitoring, which is useful for tropical countries like the Philippines where physicochemical analyses can be costly.