La mine, élément de la controverse écologique dans le Pacifique Sud

Abstract

Mines: an element of the ecological debate in the South Pacific. — The island of Nauru, Grande Terre in New Caledonia and Bougainville in Papua-New Guinea have open air mines ranking among the most extensive world-wide, of phosphates, nickel and copper respectively. The exploitation of the mines has caused major disturbances in the natural and social environment of neighbouring populations. In two cases out of three, such disturbances, in the late 1960s and early 1970s, stemmed from the fact that natural, human and environmental factors had not been sufficiently taken into account. Two decades later — a length of time which (by sheer coincidence?) corresponds exactly to the duration of the debate about nuclear trials in the region — there remain ecological imbalances. Mining companies and public authorities have begun however to draw lessons from the deteriorations which local populations are denouncing with increasing determination. Techniques have been devised for the extraction of ore and the processing and stocking of waste, which aim at preserving the environment. Discussions with all parties concerned have also developed.

Reconstructing the impact of nickel mining activities on sediment supply to the rivers and the lagoon of South Pacific Islands: Lessons learnt from the Thio early mining site (New Caledonia)

“…Moreover, visual observations, colorimetric and geochemical analyses indicated a modification of sediment composition during this phase resulting in the dominance of red-coloured, nickel and goethite/hematite-enriched sediment. This red coloration of sediment described in the studies (Bird et al, 1984;Iltis, 1992) but also observed in the sediment core could correspond to the release of laterites initially stored on the foothills.…”

“…Indeed, the rapid increase of nickel ore production was accompanied by a sharp increase in mining waste (i.e. 2.1 tons per tons of nickel ore mined; Iltis (1992); Figure 5), resulting in an increase of sediment inputs to the New Caledonian rivers (Bird et al, 1984;Iltis, 1992).…”

“…This rapid increase of nickel ore production was accompanied by a sharp increase in bare soil areas (i.e. mining sites, mining prospection areas and mining roads) and mining waste (Iltis, 1992). In the absence of environmental legislation, 200 million tons of mining waste have been stored on the foothills exposed to rainfall.…”

“…degradation of coral reef systems). The mining sector, although having contributed largely to New Caledonia's economic growth, is considered to be the main driver of environmental degradation (Bird et al, 1984;Iltis, 1992). This awareness of the environmental impacts of mining activities led to the implementation of the first environmental regulations as early as in 1975 (e.g.…”

Combining colour parameters and geochemical tracers to improve sediment source discrimination in a mining catchment (New Caledonia, South Pacific Islands)

“…New Caledonia, an island located in the south-western Pacific Ocean and currently the world's sixth-largest producer of nickel, is in particular challenged with the problems of hyper-sedimentation and over-burden of its river systems. Several studies outline how mining activities, which started in 1875, are generally responsible for these deleterious river morphological changes (Bird et al, 1984;Iltis, 1992;Garcin et al, 2017). The excessive sediment inputs transferred mainly during extreme rainfall events (e.g.…”