Macrozoobenthic diversity and heavy metals (Pb and Hg) accumulation in Bone River Gorontalo Indonesia

The heavy metal pollution on benthic macroinvertebrate communities in Bone River has not been studied. This present study determined to investigate the diversity of the macrozoobenthic trough the length of Bone River concerning the heavy metals leads and mercury at eight sampling stations. The samples were taken in July 2021. A sample of four representative macro zoobenthic families (Hydropsychidae, Baetidae and Elmidae) was also used to analyze metal bioaccumulation. The macrozoobenthic recorded in this study comprise of ten orders and 35 families with a total of 3146 individuals. Diptera, Ephemeroptera, Coleoptera, and Trichoptera dominate the population size of benthic. The diversity indices show the low and medium categories but favour a better macrozoobenthic development. Monitoring studies show that the concentration of Pb in sediments is much higher than that of mercury. Metal accumulation in sediments showed fluctuations but did not reflect macrozoobenthic metal concentrations. The bioconcentration factor (BCF) value generally indicates that the three taxa are categorized in the low accumulative category.