Mesel gold mine, Ratatotok Sub-district, North Sulawesi, Indonesia deposited about 4.5 million m3 of detoxified tailings containing arsenic (As) and mercury (Hg) via a submarine pipeline into Buyat Bay. As and Hg analysis of 216 fish muscle tissue composites from subsistence fishermen, local markets and a reference market confirmed that mean As levels were comparable between locations (range 1.71 to 2.12 mg/kg wet weight (ww)) and < 10% of the Australia New Zealand standard. Mean Hg concentrations were highest for the artisanal fishermen group (0.23 mg/kg ww), similar between the local markets (0.11–0.14 mg/kg ww) and lower at the reference market (0.04 mg/kg ww). A 12-month fish availability study identified that the results were due to the different coral and deep ocean species assemblages. All mean values were < 50% of the FAO/WHO/Codex standard for Hg. The results confirmed that there was no contamination from the deposited submarine tailings.
- Health effects
- Submarine tailings disposal