Benthic Fauna and Environmental Quality Assessment of Water Bodies in Phra Nakhon Si Ayutthaya Province: A Synthetic Review from Natural Waters, Community Areas, and Aquaculture Systems

Abstract

Benthic fauna are important components of aquatic ecosystems. They can be used as biological indicators of the environmental quality of water bodies because they are closely associated with bottom substrates and sediments, have limited mobility, and exhibit different tolerance levels to environmental changes. This academic article aims to synthesize knowledge on the application of benthic fauna for assessing the environmental quality of water bodies in Phra Nakhon Si Ayutthaya Province, Thailand, based on case studies from three major groups of water bodies: natural waters, community areas, and aquaculture systems. These groups covered major subtypes of water bodies, including main rivers, urban community waters, agricultural canals, retention areas, river cage aquaculture, earthen ponds and aquaculture areas, and local community ponds and water bodies. The synthesis indicates that different types of water bodies are exposed to different environmental pressures, resulting in distinct patterns of benthic faunal composition, abundance, and roles in indicating environmental quality. Pollution-tolerant benthic fauna, particularly aquatic oligochaetes in the families Tubificidae and Naididae, together with chironomid larvae in the family Chironomidae, tend to dominate areas affected by domestic wastewater, agricultural activities, and aquaculture systems. In contrast, some freshwater mollusks, freshwater shrimps, and aquatic insect larvae may indicate habitats that remain suitable for several groups of aquatic organisms or moderate water quality. The integration of benthic fauna with benthic fauna indices, specifically the BMWPthai Score and ASPTthai, together with water quality data, sediment characteristics, and community participation, can provide a practical and low-cost biomonitoring tool suitable for local communities and systematically support local-scale water body management. This approach should be further developed as part of provincial-level environmental monitoring to identify risk areas and guide continuous water body management planning.