Buyat Bay, submarine tailings of the Mesel gold mine

The Mesel mine, in Ratatotok sub-district, was operated by PT Newmont Minahasa Raya, 80% owned by the US company Newmont. The tailings, finely ground rock left after gold recovery, were piped out to sea. The environmental organisation WALHI claimed the discharge was 2,000 tonnes a day (Wikipedia).

In mid-2004 fishermen reported fish deaths and ailments such as skin disease, tremors and swellings. In November 2004 a report by WALHI and other Indonesian organisations gave up to 666 mg/kg arsenic in seabed sediment and on average over 1,000 µg/kg mercury, attributing them to the tailings (Wikipedia). In August 2004 the Ministry of Environment sued for 133.6 million US dollars; the suit was dismissed in 2005 on procedural grounds and closed in 2006 with a settlement of 30 million dollars over ten years, plus scientific monitoring and community programmes. In 2007 the executive Richard Ness was acquitted in the criminal trial.

The scientific literature gives a less clear-cut picture than either side. Coral skeletons in the area record metals from both the industrial tailings and small-scale mercury-amalgamation mining, but arsenic does not differ between sites (Edinger et al. 2008). A dietary exposure study finds that at Buyat Pantai mercury intake from fish exceeds the FAO/WHO weekly limit for methylmercury, and attributes this to the coastal communities' high fish consumption rather than to elevated levels in fish (Bentley and Soebandrio 2017).