Abstract

The aim of this study was to identify appropriate biometric candidates for assessing the environmental quality of wetlands in northeastern Thailand. Field sampling was conducted in 13 wetlands during the cool season of 2009 and hot season of 2010. Macroinvertebrates were collected based on the proportion of multi-habitats using a 500 µm D-frame dip net within a 500 m reach. Fourteen physicochemical parameters of the environmental quality were measured. The total scores of the human disturbance score for the reference sites were lower than those for the test sites, and the number of total taxa of macroinvertebrates in the reference sites was higher than the numbers of taxa in the test sites in both seasons. The BOD₅, PO4^3-, conductivity and turbidity were significantly different between the reference and test sites (p < 0.05). The 63 test metrics, only 7 core metrics for the biological index score were included in the biotic index. The results revealed that the index can be used for all three wetland types in northeastern Thailand. However, the score must be tested and calibrated for other ecoregions.

Key words: Benthic macroinvertebrates, biotic index, bioassessment, multi-metric index, wetland, Northeastern Thailand.