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)

Open-cast mining has strongly increased soil erosion and the subsequent downstream transfer of sediments in river systems. New Caledonia, a French island located in the south-west Pacific Ocean and currently the world's 6th largest nickel producer, is confronted in particular to unprecedented sediment pollution of river systems: hyper-sedimentation. A significant fraction of this sediment is likely originating from tributaries draining nickel mining sites. Nevertheless, the contribution of this sediment source has not been quantified and this estimation is required to guide the implementation of efficient management measurements to mitigate fine sediment supply to New Caledonian river systems and lagoons. To this end, a pilot sediment tracing study has been conducted in one of the first areas exploited for nickel mining, the 397-km&#178; Thio River catchment.Sediment deposits were collected after two major floods (~10 yr return period): the tropical depression of February 25, 2015 and Cyclone Cook on April 10, 2017. Sources (n=25) were sampled on (i) tributaries draining mines, and (ii) tributaries draining &#8216;natural&#8217; areas affected by landslides occurring frequently in the region, and sediment (n=19) on (iii) the main stem of the Thio River. In addition, (iv) a 1.60 m long sediment core was collected in the Thio river deltaic floodplain in April 2016. Six sediment tracing techniques were tested based on the following properties: fallout radionuclides, geogenic radionuclides, elemental geochemistry, colorimetric parameters and reflectance spectra.Several of these methods were identified as relevant to the New Caledonian context and allowed to estimate the contributions of both mining and non-mining sources according to their variations both in space and time. In particular, the sedimentary contributions of mining sources were estimated between 65-68 % for the 2015 flood and 83-88 % for the 2017 flood. The impact of the spatial variability of precipitation was highlighted to explain the variations in the spatial contributions of the sources. The temporal variations in the contributions of the sources deduced from the analysis of the sediment core were interpreted at the light of the mining history in the Thio River catchment (pre-mechanization, mechanization, post-mechanization of mining activity). The contributions of mining sources were again dominant with an average contribution along the sedimentary profile of 74 &#177; 13 %.In the future, similar studies should be carried out in other catchments draining mines in New Caledonia and potentially across similar South Pacific and other tropical islands.

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Phosphorus sorption and desorption in oxide-rich Ferralsols of New Caledonia

Soil Research ◽

10.1071/sr00003 ◽

2001 ◽

Vol 39 (2) ◽

pp. 403 ◽

Cited By ~ 32

Author(s):

I. G. Dubus ◽

T. Becquer

Keyword(s):

Organic Matter ◽

Crop Production ◽

Pacific Islands ◽

New Caledonia ◽

Clay Fraction ◽

South Pacific ◽

Limiting Factors ◽

P Availability ◽

P Sorption ◽

South Pacific Islands

Phosphorus (P) availability in soils is one of the main limiting factors for crop production in Ferralsols that contain high amounts of aluminium and iron oxides. Highly weathered Geric Ferralsols cover large surface areas of south Pacific islands, some of which are required for agricultural development. Sorption and desorption of P in Geric Ferralsols of the island of Maré (New Caledonia) were investigated. The soils contain large quantities of oxides, especially of aluminium. The clay fraction consisted exclusively of fine, discrete oxide particles. Both Freundlich and Langmuir equations provided a good fit to the data for equilibrium P concentrations ranging from 0.05 to 850 mg P/L. The extremely high P sorption capacities of New Caledonian Geric Ferralsols were exemplified by the large Langmuir sorption maxima which ranged from 6400 to 9250 mg P/kg. A strong negative correlation between P sorption and organic matter was noted, resulting in a larger P availability in topsoils. This relationship can be used to provide a first assessment of P sorption capacities of Geric Ferralsols across the island. Management of organic matter is likely to be of major importance in the control of P availability in Geric Ferralsols of south Pacific islands.

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A monograph of Entodon (Entodontaceae) in Australia, eastern Melanesia and southern Oceania

Australian Systematic Botany ◽

10.1071/sb9900701 ◽

1990 ◽

Vol 3 (4) ◽

pp. 701 ◽

Cited By ~ 1

Author(s):

WR Buck

Keyword(s):

Pacific Islands ◽

New Caledonia ◽

South Pacific ◽

The Philippines ◽

Pacific Basin ◽

The South ◽

South Pacific Islands

The moss genus Entodon C. Müll. (Entodontaceae) is revised for Australia, eastern Melanesia (New Caledonia and Fiji) and the South Pacific islands. The nine validly described species and 10 nomina nuda are reduced to two species, E. mackaviensis C. Müll. and E. plicatus C. Müll. Entodon mackaviensis, with terete branches and extensive alar development is confined to the region treated. Entodon plicatus, with complanate branches and significantly fewer alar cells, ranges from India to the far reaches of the South Pacific basin, and from Tasmania to the Philippines. Both species are described and illustrated. Some extra-limital synonymy is provided.

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Doctor William Gunn (1804–1890): From the South Pacific Islands to Chatham Royal Dockyard

Journal of Medical Biography ◽

10.1177/0967772016657702 ◽

2016 ◽

Vol 27 (1) ◽

pp. 55-61

Author(s):

Richard Biddle

Keyword(s):

Pacific Islands ◽

South Pacific ◽

Health Issues ◽

Influenza Epidemic ◽

Royal Navy ◽

The South ◽

Medical Department ◽

Victorian Era ◽

South Pacific Islands ◽

The Impact

Doctor William Gunn had a long and varied career in the Royal Navy. After spending time on anti-slavery patrols along the west coast of Africa, he was posted to the south Pacific. At Pitcairn Island, he treated the inhabitants during an influenza epidemic, proving himself to be a determined and dedicated practitioner. Subsequently, he was appointed head of the medical department at Chatham Royal Dockyard (1859–1865), an appointment that coincided with the final stages of the Royal Navy's transition from sail and wood to steam and iron. The impact of these changes on the health of dockworkers was quickly felt at Chatham, and Gunn found himself in charge during the building of the first iron warship in a royal dockyard. His story thus offers a window through which to observe a practitioner confronting the health issues and medical uncertainties thrown up by technological change in the Victorian era.

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Decolonisation Processes in the South Pacific Islands: A Comparative Analysis between Metropolitan Powers

Victoria University of Wellington Law Review ◽

10.26686/vuwlr.v26i2.6172 ◽

1996 ◽

Vol 26 (2) ◽

pp. 355

Author(s):

Paul De Deckker

Keyword(s):

New Zealand ◽

Great Britain ◽

Pacific Islands ◽

New Caledonia ◽

Free Association ◽

South Pacific ◽

French Polynesia ◽

The South ◽

The Pacific ◽

South Pacific Islands

The South Pacific islands came late, by comparison with Asia and Africa, to undertake the decolonising process. France was the first colonial power in the region to start off this process in accordance with the decision taken in Paris to pave the way to independence for African colonies. The Loi-cadre Defferre in 1957, voted in Parliament, was applied to French Polynesia and New Caledonia as it was to French Africa. Territorial governments were elected in both these Pacific colonies in 1957. They were abolished in 1963 after the return to power of General de Gaulle who decided to use Moruroa for French atomic testing. The status quo ante was then to prevail in New Caledonia and French Polynesia up to today amidst statutory crises. The political evolution of the French Pacific, including Wallis and Futuna, is analysed in this article. Great Britain, New Zealand and Australia were to conform to the 1960 United Nations' recommendations to either decolonise, integrate or provide to Pacific colonies self-government in free association with the metropolitan power. Great Britain granted constitutional independence to all of its colonies in the Pacific except Pitcairn. The facts underlying this drastic move are analysed in the British context of the 1970's, culminating in the difficult independence of Vanuatu in July 1980. New Zealand and Australia followed the UN recommendations and granted independence or self-government to their colonial territories. In the meantime, they reinforced their potential to dominate the South Pacific in the difficult geopolitical context of the 1980s. American Micronesia undertook statutory evolution within a strategic framework. What is at stake today within the Pacific Islands is no longer of a political nature; it is financial.

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