Bioaccumulation of Heavy Metals in Catfish (Hemibagrus nemurus) at the Downstream of Citarum River, Indonesia

Rivers are highly dynamic systems. Rapid population growth and the development of industrial areas around rivers significantly influence water quality. This research aims to analyze the heavy metal content in both water and catfish in the lower reaches of the Citarum River. Five locations were purposively selected: Station 1 (26.87 m asl), Station 2 (18.35 m asl), Station 3 (22.5 m asl), Station 4 (22.5 m asl), and Station 5 (22.5 m asl). At each site, physical and chemical water parameters (temperature, pH, depth, brightness, current speed, and DO), as well as concentrations of heavy metals (Hg, Pb, and Cd), were measured. Catfish were collected using stocking nets and fishing rods from the five stations, with assistance from local fishermen. Sampling was conducted over 14 consecutive days, from June 20 to July 4, 2022. The bioaccumulation of metals in both water and catfish was analyzed and calculated using the bioaccumulation factor (BAF) formula. The results showed that the accumulation of Hg in catfish was higher than that of Pb and Cd. Spatially, Pb accumulation was highest at Station 5 (4 times that of the water concentration) and lowest at Station 2 (2 times that of the water). Cd accumulation was highest at Station 5 (5 times that of the water) and lowest at Station 2 (3 times that of the water). Hg accumulation was highest at Station 1 (6 times that of the water) and lowest at Station 4 (2 times that of the water).