author(s)
Mohd SI Shafie, Andrew BH Wong, Sahana Harun and Arman Hadi Fikri

abstract
A study was conducted to investigate the water quality in the Liwagu River, Sabah using aquatic insects as biological indicators. Sampling was carried out at different land use of the Liwagu River (forest, agricultural and urban settlement). Aquatic insects were sampled using a Surber net from August to October 2015. YSI Multiparameter was utilized to measure in situ parameters including dissolved oxygen (DO), salinity, conductivity, temperature and pH. Ex situ measurements were undertaken for Total Suspended Solid (TSS), ammonia nitrogen, phosphate and nitrate. A total of 44 genera, 34 families, eight orders and 3,126 individuals of aquatic insects were collected. Kruskal-Wallis test showed that most of the physico-chemical parameters have significant difference between the land uses of the river (p<0.05). Interim National Water Quality Standard for Malaysia (INWQS) showed that physico-chemical parameters in three types of land use were categorized as Class I – Class V. Biotic indices showed similar results where both forest and agricultural areas have good water quality while the human settlement area had scored moderate water quality. Pearson’s correlation showed that aquatic insect abundance and taxa richness had significant relationships (P<0.05 or 0.01) with all physico-chemical water quality parameters except for pH and phosphate.