From Sediment to Food: Heavy Metal Contamination in Fish of Lake Sentani, Indonesia

Heavy metal contamination in freshwater ecosystems has become an increasing concern due to its ecological consequences and potential risks to human health through aquatic food consumption. This study investigated heavy metal accumulation in fish and sediments of Lake Sentani, a tropical freshwater lake in Papua, Indonesia, between June and August 2024. Three commonly consumed fish species—Sentani Gudgeon (Oxyeleotris heterodon), Mozambique Tilapia (Oreochromis mossambicus), and Red Devil (Amphilophus sp.)—together with surface sediments collected from nine locations were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Concentrations of manganese (Mn), arsenic (As), mercury (Hg), cadmium (Cd), and lead (Pb) were compared against Indonesian food safety standards and Canadian sediment quality guidelines. Heavy metals were detected in both fish and sediments, although contamination patterns varied among species and locations. Arsenic and mercury were detected primarily in Tilapia and Red Devil from Jembatan 2 and Yoboi, while cadmium and lead were absent in fish tissues. Sediments contained all five metals, with arsenic and mercury reaching or exceeding thresholds at several sites, particularly Jembatan 2. Correlation analysis between metal concentrations in sediments and fish tissues indicated positive relationships, suggesting that sediment-mediated exposure pathways. Although fish contamination levels remained below the Indonesian regulatory limits, sediment contamination indicates ongoing environmental pressure and potential long-term ecological risks. The findings highlight the importance of continuous environmental monitoring, pollution mitigation, and habitat management to protect biodiversity, fisheries resources, and communities dependent on Lake Sentani.