Heavy Metal Contamination in Sediments and Its Potential Ecological Risks in Youtefa Bay, Papua Province, Indonesia

This study aimed to analyze the heavy metal contamination in sediments and their potential ecological risks. The sediment samples were collected using PVC pipes and grab samplers at nine study sites in Youtefa Bay, namely five sites in the mangrove ecosystem, two sites in the estuary, and two sites in the middle of the bay. The heavy metal content was analyzed using Atomic Absorption Spectrophotometry. The results of the analysis of the heavy metal content in the sediment were in the following order: Zn > Cu > Pb > Ni > Cr > Cd > As > Hg (106.077±98.857, 28.553±30.505, 19.798±11.541, 17.665±11.457, 12.103±0.124, 2.996±1.235, 0.149±0.124, and 0.082±0.047 mg kg-1, respectively). Only the Cd content has exceeded the Threshold Effect Level (TEL) at all study sites. On the other hand, the As and Cr content has not exceeded TEL at any study site. The content of Hg, Cr, Pb, Zn, and Ni has exceeded TEL only at a few study sites. The heavy metal content in estuary sites is higher than in mid-bay and mangrove sites, which can provide the information on the sources of heavy metal contaminants. There is a significant correlation for the content of Cu, As, Pb, Cd, Zn, and Ni which can indicate that the sources of these heavy metals are relatively the same (r = 0.569 to r = 0.950). The CF and Igeo values indicate that there has been contamination of several heavy metals studied. Further analysis (ERI) showed that the heavy metal content in the sediments poses a potentially serious ecological risk. Most of the potential ecological risks are the contribution of Cd and Hg which have high toxicity factors and this should receive special attention from local governments and stakeholders to prevent higher contamination