Simandou Biodiversity Offset Strategy — Pic de Fon Classified Forest (Guinea)

Since 2007, Rio Tinto Simfer — a joint venture of Rio Tinto, Chalco Iron Ore Holdings and the Republic of Guinea — has surveyed western chimpanzee populations in the roughly 25,000-hectare Pic de Fon Classified Forest, part of the Simandou mountain range in south-eastern Guinea, to inform a Biodiversity Offsets Strategy aligned with IFC Performance Standard 6's mitigation hierarchy (avoid, minimise, restore, offset) and its goal of a 'Net Positive Impact' for critical-habitat species.

Surveys have recorded between roughly 36 and 75 chimpanzees directly in the affected area and over 700 across the wider Simandou range, alongside 2,750 chimpanzee nests along the planned rail corridor. The mine and its associated 670-km railway are projected to permanently destroy around 50 km² of chimpanzee range, 12 km² of it inside Pic de Fon itself. A Simandou Offsets Working Group involving Simfer, Guinea's Environment Ministry and the NGO Guinée Écologie has been tasked with identifying compensation sites, but as of the mid-2020s these remained under suitability assessment rather than secured or actively managed.

A 2014 peer-reviewed study in PLOS ONE singled out Simandou as a test case for why voluntary, project-by-project biodiversity offsetting is unlikely to hold up without a national offset framework, cumulative-impact accounting, or guaranteed long-term financing — Guinea, like other West and Central African range states, has no policy requiring or guiding offsets. Independent journalism in 2024 and 2025 reported primatologists and Guinean civil-society voices questioning whether offsetting can succeed when mining occurs inside a classified forest at all, and describing on-the-ground implementation as difficult to verify. This practice is included as an honest, cautionary case: it demonstrates rigorous baseline biodiversity monitoring but no independently confirmed net-positive outcome.

Read the full analysis: https://www.riotinto.com/en/operations/africa/simandou