A correlation study of Bio-Index and Water Quality Index in upstream of Forest Eco Park Soga Perdana, Johor, Malaysia.

Abstract Monitoring water quality is essential in the recreation sector to ensure the safety of tourists engaging in activities that involve contact with water bodies. According to the Water Quality Index (WQI) established by the Department of Environment (DOE), Class II water is deemed suitable for recreational use involving human contact. However, assessing the WQI typically requires expensive reagents and equipment. This study aims to evaluate water quality using macroinvertebrates as a more economical indicator and to establish a correlation with the WQI. The research was conducted at the Forest Eco Park Soga Perdana, a recreational forest in Batu Pahat, Johor, which is renowned for its water park, forest adventure activities, and popularity as a tourist destination. To assess water quality, we utilized macroinvertebrate data alongside various physical-chemical indicators. The evaluation was performed using the Biological Monitoring Working Party and Average Score Per Taxon (BMWP-ASPT) Index for biological indicators, and the WQI for physical-chemical indicators (pH, DO, COD, BOD, TSS and AN). Three stations were included in the water quality assessments. Station 1 recorded the highest ASPT Index of 7.63, indicating an “almost clean” stream. Stations 2 and 3 followed with ASPT Index values of 7.44 and 6.84, respectively. The physical-chemical analyses revealed that Station 1 achieved the highest WQI value of 87.02, categorizing it as clean water. Stations 2 and 3 also registered WQI values of 86.47 and 85.99, respectively, thus classifying them as clean water, consistent with the same Class II designation as Station 1. This study demonstrated a strong positive correlation between the ASPT Index and the WQI method, with an R-value of 0.9825.