Assessment and Bioaccumulation of Heavy Metals in Fish Feeds, Water, and Some Tissues of Cyprinus carpio Cultured in Different Environments (Biofloc Technology and Earthen Pond System).

Fish feed quality is the main determinant of fish flesh quality, so it is important for successful aquaculture. The current study determines the concentration of heavy metals in fish feeds (A and B), water, and their bioaccumulation in gills, liver, and muscle of C. carpio cultured in different environments (biofloc technology and earthen pond systems). In addition, the correlation between heavy metals in fish feeds with bioaccumulated metals in fish tissues was also determined. Results revealed that most heavy metal concentration was significantly greater (P < 0.05) in feed B than in feed A but in permissible range, while all the heavy metal concentration was notably higher in earthen ponds than in biofloc technology. Result from the bioaccumulation factor and concentration of the metals showed that heavy metals were highly accumulated in the fish liver followed by gills. The metal concentration in fish feeds and fish edible parts (muscle) was lower than the WHO standard level; however, the amount of Pb was higher in the fish muscle, liver, and gills, which is harmful for human consumption and also for fish health. Though the correlation test revealed that all of the metals from the feeds were positively correlated to the metals in fish tissues, but most of the estimated correlation was significant and linearly correlated. It can be concluded that producers must measure feed quality correctly to avoid heavy metal contamination because it may assimilate and accumulate in the food chain.