The rapid emergence and spread of pathogenic bacteria (multi)resistant to antimicrobials is a priority health issue. Despite its insularity, New Caledonia has not been spared from this pandemic: the territory was the host country of the first French isolate carrying the plasmid gene mcr-1 (conferring resistance to colistin). Other resistances are of increasing concern because they cause significant public health problems in the territory. For example, methicillin-resistant Staphylococcus aureus is spreading in the community with highly virulent strains and Carbapenem Resistant Enterobacteriaceae (CRE) are involved in epidemics in the Territorial Hospital.

The selection and transmission of these resistances are frequently investigated through clinical studies and it is only recently that the role of the environment as a source and pathway for the diffusion of antibiotic resistance has been recognized. Indeed, effluents from hospitals, industry, livestock or veterinary structures, wastewater treatment plants and urban/agricultural runoff are all potential sources of new contaminants (antibiotics, biocides, metals, resistance genes, resistant bacteria) that can be discharged into receiving environments. In addition to anthropogenic inputs, the high concentrations of metals found naturally can also add factors favoring the emergence and/or selection of antibiotic-resistant bacteria. Indeed, the genes for resistance to metals and antibiotics may be located on the same mobile genetic elements (co-resistance), or an identical mechanism may be involved in resistance to antibiotics and metals (cross-resistance).

Among the techniques aimed at highlighting these sources of contaminants and the risks to human health, epidemiology based on wastewater analysis via metagenomic approaches has been developed in recent years. These innovative approaches make it possible to identify bacterial species but also to quantify and describe thousands of genes (e.g. resistance or virulence) in a given sample.

In New Caledonia, no study aimed at identifying resistant bacteria in wastewater, runoff or the receiving environment has been conducted to date. However, there is a real need in the territory since, during heavy rains for example, it is not uncommon to see bacterial contamination of bathing areas. Sanitary monitoring of bathing waters is carried out annually during the summer period (from December to April) by the New Caledonian Government's Department of Health and Social Affairs throughout the territory. In some municipalities , additional analyses are also carried out. This monitoring focuses on the enumeration of Escherichia coli and intestinal enterococci without assessing antibiotic resistance.

In this context, the objectives of the ARCANE project are to evaluate the dissemination of resistance genes and antibiotic-resistant bacteria in the environment, with an innovative integrated environmental approach. Thanks to the development of an innovative technology for monitoring metal and antibiotic concentrations, this project will also identify possible factors of anthropic or environmental origin likely to promote the selection, development and dissemination of resistant bacterial strains.

This project includes three CRESICA partners: Institut Pasteur of New Caledonia, New Caledonia Central Hospital CHT, and French National Research Institute for Sustainable Development IRD.The metagenomic part will be carried out in partnership with the Institut Pasteur in Paris and the assays of metals and antibiotics will involve the private company AEL. This project also involves the New Caledonian authorities and institutions responsible for health (DASS, DAVAR, Noumea municipality, Dumbéa municipality, SIVOM-VKP), as well as the Environment (South Province and North Province) for the different sampling sites, the health care institutions concerned by the study and the managers of the wastewater treatment systems selected.

1. Sampling

The monitoring will be carried out longitudinally during a 14-month sampling campaign (sampling every other month). The targeted sampling sites follow the path of wastewater: from the effluents of the healthcare structures to the receiving environment. Punctual water sampling as well as 24-hour sampling will be carried out on certain sites.

2. Culture

Concerning the isolations, a selection of environmental isolates, with a particular focus on Enterobacteriaceae producing (i) carbapenemases, (ii) extended spectrum beta-lactamases and (iii) high level of cephalosporinsase is carried out. The technique is based on direct plating on culture medium or filtration of water samples and deposition of membranes on selective agars to isolate β-lactam resistant Enterobacteriaceae. An identification by MALDI-ToF is performed and synergy tests allow to identify the resistance mechanism involved. These isolations will provide an overview of the resistance mechanisms found in cultivable bacteria in the environment. Some isolates will be subjected to whole genome sequencing to identify the repertoire of genes and mobile genetic elements involved in resistance to serve as a reference repertoire for metagenomics analyses. In parallel, complete genomes of clinical and hospital isolates of interest will be added to the database.

3. Metagenomic

For metagenomics, the proposed approach consists in collecting organisms and debris (from organisms) present in water by filtration at 0.22 µm. The DNA will be extracted and subjected to shotgun sequencing. This approach allows to gain a global view of the microbiome as well as its functional potential by identifying the genes and mobile genetic elements represented. The consensus sequences obtained after assembly of the sequencing reads will be aligned with referenced genomes for the identification of the species forming the microbiome. Comparisons of bacterial communities sampled in different environments as well as resistance profiles and their variations in time and space will be performed. The longitudinal approach from the source to the coastal waters will allow a detailed description of the circulation of resistant bacteria and resistance genes and to inform the possible sanitary risks.

4. Integrative monitoring of metals and antibiotics

An integrative technique for the analysis of trace metals and trace and ultra-trace antibiotics on thin film resin (Diffusive Gradient in Thin film; DGT) will be used in addition to classical assays on waters.

Les 28 et 29 mars 2022, le CRESICA organisait le séminaire "Au fil de l'eau" qui a permis de présenter l'état d'avancement du projet.

Visionnez la présentation fait lors du séminaire grâce à la vidéo du projet du projet ARCANE par A. Bourles.

Le 29 août 2023, le CRESICA organisait le séminaire de restitution "Au fil de l'eau" qui a permis de présenter les résultats du projet.

Brochure : "Des projets de recherche sur la thématique de l'eau en Nouvelle-Calédonie."

Visionnez la présentation faite lors du séminaire grâce à la vidéo du projet ARCANE par A.Bourles

Rapport final : projet ARCANE

     On a global scale, the increase in population and its needs has aggravated the problems of water contamination. In industrialized countries and in New Caledonia in particular, these contaminations mainly concern metallic trace elements (ETM) and they have their origin both in anthropogenic activities (industry, mines, domestic discharges) and in the natural erosion of landforms. Due to the multiple impacts of MTEs on terrestrial and marine ecosystems, as well as on human health, these contaminations directly threaten the water supply. Indeed, among the MTEs encountered in New Caledonia, some are known to be moderately or significantly toxic to humans and the environment. This is particularly the case for chromium (in particular Cr6+), nickel (Ni2+), zinc (Zn2+), copper (Cu2+), lead (Pb2+), cadmium (Cd2+), arsenic (As3+ and As5+), mercury (Hg2+) or scandium (Sc3+).

    Faced with this global problem, current water purification techniques (chemical precipitation, ion exchange, reverse osmosis, electrodialysis and ultrafiltration) are unsatisfactory because they are too expensive, slow or generate toxic waste. In addition, they do not respond to the context of the territory which requires the use of light installations adapted to a very local scale (scale of AEP collection (Drinking Water Supply) for example). Thus, there is an urgent need to develop in New Caledonia more selective, inexpensive and effective alternatives to reduce the concentrations of ETM in wastewater or runoff, to acceptable levels for the environment and human health.

    The use of natural filters with a high adsorption capacity seems to us a particularly relevant way for the territory. Indeed, these filters would make it possible, on the one hand, to retain the ETMs trapped in dissolved or particulate forms, then to recover them for potential reuse downstream. On the other hand, the environmental impact of processes based on the use of such natural filters would be negligible. However, preliminary research work is necessary to identify the biomaterials possessing the necessary bio-physico-chemical properties and to develop new methods using them to lower the ETM contamination of the effluents downstream of the ultrabasic massifs and/or at high industrial pressure. or anthropogenic.

    It is in this perspective that we are currently running this research project to CRESICA today. We consider that the work proposed here is fully in line with the theme "Drinking water for all and at all times", and particularly with the objective of "identifying or developing technological solutions for treatment (drinking water) on a small scale ". However, we would like to point out that, although this project is developed in New Caledonia, the techniques it proposes to develop will be easily transferable to other countries; this project is more broadly part of the global issue of water pollution control and metal capture.

    In this project, we propose to test different methods, based on the use of original microorganisms from New Caledonian biodiversity (figures 1 and 2), or the biomolecules they produce, to develop innovative biotechnologies for the depollution of ETM contaminated waters or environments.

Les 28 et 29 mars 2022, le CRESICA organisait le séminaire "Au fil de l'eau" qui a permis de présenter l'état d'avancement du projet.

Visionnez la présentation fait lors du séminaire grâce à la vidéo du projet DEPOLEAU par V. Burtet.

Le 29 août 2023, le CRESICA organisait le séminaire de restitution "Au fil de l'eau" qui a permis de présenter les résultats du projet.

 Brochure: "Des projets de recherche sur la thématique de l'eau en Nouvelle-Calédonie."

Visionnez la présentation faite lors du séminaire grâce à la vidéo du projet DEPOLEAU par V. Burtet. 

Outcrops of asbestos minerals expose populations to significant health risks. Natural (erosion, leaching) or anthropogenic (mining, quarrying, road works, land use planning, etc.) mechanical stresses favor the fractionation of asbestos-type minerals. The dispersion in the environment of fibres and fibrils is likely to trigger serious pathologies when they penetrate the organism (lung cancers, mesothelioma, etc.). However, the risks associated with exposure to environmental fibre emissions are still not well known. The protocols required to link the probability of exposure (occurrence/emissivity) and the associated health impact (in vitro and in vivo toxicological tests) remain to be defined in order to better assess and manage the risk.

Exposure types to elongated mineral fibres and particles are diverse. Research on natural occurrences of asbestos (NOA) focuses on exposure by dispersal of contaminated aerosols. Similarly, health studies focus mainly on pathologies related to inhalation of fibres. However, like any mineral particle, fibres present in outcrops are likely to be eroded and then transported during runoff to infiltrate deep groundwater or contribute to the suspended matter in watercourses. Water is a transport agent that can disperse particles over very long distances and thus generate new asbestos outcrops after deposition. While a rock outcrop easily reveals the presence of asbestos minerals to geologists or trained persons, the mass of transported sediments may hide the presence of easily mobilized fibres in sedimentary deposits. A better assessment of the health risk from natural occurrences of asbestiform minerals requires consideration of freshwater transport to population exposure to pathogenic fibres.

In New Caledonia, the island of “Grande Terre” , has potentially asbestos lands over more than half of its area. Exposure to natural occurring of asbestos is a major public health issue in the territory. The presence of asbestiform minerals not recognized as asbestos, but presenting toxic effects, as well as the potential increase in the capacity to release pathogenic fibres and fibrils under the influence of the tropical climate, contribute to increasing the health risk incurred by the Caledonian population. In the context of better prevention of NOA-related health risks, it is therefore important to understand the capacity of fibres dispersions by freshwater through the example of New Caledonia.

The SAFE project is highly multidisciplinary, as demonstrated by the project's scientific consortium. The field part is the responsibility of the team's geologists. The aim is to ensure that the sampling, which is limited in quantity, is sufficiently representative of the outcrops of asbestiform minerals and sediments transported by fresh water. Sampling will mainly concern surface water and sediments. Drinking water will also be sampled during periods of high flooding. The sampling missions and geochemical analyses will be capitalized as much as possible with the ECOMINE project, led by Hugues Lemonnier (CRESICA, au fil de l'eau). The SAFE project will mainly consist on sampling ultrabasic catchments influenced of current or past mining activity. This choice is also consistent with the expertise acquired by the SAFE project's scientific consortium, whose members have participated in previous CRESICA (SEARSE) and CNRT (Amiante et Bonnes Pratiques, DYNAMINE) projects. The SAFE project consortium members are also collaborating in a project funded by the Italian government whose objective is, among other things, to develop a methodology for assessing the health risk linked to the presence of NOA, based on outcrop. The SAFE project will be able to draw on the results acquired during the Italian programme at the Tontouta mining site in New Caledonia.

A continuum from upstream to downstream will draw an initial assessment of the dispersal capacity of freshwater. The SAFE project will provide the first elements of a response, but these will have to be confirmed later, as the number of samples cannot be increased within the framework of the CRESSICA calls for projects.

The X-ray diffraction and Raman spectrometry analyzes will access to all samples mineralogy. At first binoculars and then by electron microscopy visualizations will confirm or not the presence of fibrous forms. In accordance with the NF-X 43050 standard, applied in the CRESICA P2M lab, transmission electron microscopy will quantify of the fibres. EDX analyzes will evaluate the surface geochemistry of the isolated fibres. In the continuity of the work previously initiated by the SAFE project's scientific team, a very innovative approach using machine learning methodologies applied to microscopy images for automated fibre recognition will be developed.

The LAC (Laboratory under controlled atmosphere) of the UNC, will host experiments under controlled conditions that simulate the natural environment as closely as possible. The objectives are to better constrain the evolution of the morphological and physico-chemical properties of the fibres during their transport or residence in fresh waters.

Antigorite is an asbestiform mineral, not listed as an asbestos in European legislation. This mineral is widely found in Caledonian ultrabasic units, particularly on mining sites. Initial in vitro toxicology analyses carried out in the “Amiantes et bonnes pratiques” program highlighted that there may be a correlation between increasing supergene alteration and the reactivity of antigorite samples to toxicity tests. The SAFE program proposes to extend these experiments in order to consolidate these very first results from the scientific community on the toxicity of Caledonian antigorite.

The SAFE project will spread out over 2 years, which is necessary to complete the sampling during the different annual seasons and to finalize the particularly time-consuming analyses.

Le 29 août 2023, le CRESICA organisait le séminaire de restitution "Au fil de l'eau" qui a permis de présenter les résultats du projet.

 Brochure: "Des projets de recherche sur la thématique de l'eau en Nouvelle-Calédonie."

Visionnez la présentation faite lors du séminaire grâce à la vidéo du projet SAFE par C.Laporte-Magoni

Rapport final : projet SAFE

New Caledonia has exceptional terrestrial and marine biodiversity that must be preserved in the face of environmental pressures associated with land development and global warming. By increasing the inputs of contaminants, nutrients and organic matter into hydrosystems, human activities pose a threat to this biodiversity and the associated ecosystem services.

According to the "one health" concept, the resulting degradation is also a source of risk for human health and more particularly in terms of epidemics. The implementation of a regulation to protect and / or restore these hydrosystems requires defining their ecological states. About 300 methods have been developed around the world to characterize the state of environments, whether associated with fresh, brackish and marine waters. For example, the diatomaceous index is used today in the territory to characterize the ecological quality of watercourses. However, the tools developed so far remain expensive and their implementation sometimes takes a long time. However, in the context of climate change, it is important to put in place rapid tools to improve our ability to detect changes early in order to provide solutions to maintain the integrity (function and service) of ecosystems. .

In recent years, a new generation of tools with the ability to provide more complete information and in a faster manner has emerged through the characterization of communities by environmental DNA sequencing (eDNA). These tools are particularly well suited to monitoring microbial communities which are considered to be early indicators of environmental variations.

By combining environmental genomics (eDNA) and geochemistry approaches, this project will aim to (i) understand the impacts of mining activity on microbial communities at different time scales (annual, decadal, centennial) along the earth continuum - sea and (ii) to develop biotic indicators of the health of hydrosystems and coastal ecosystems and (iii) of health risks. Mining activity is targeted here because it is considered the main source of metal contaminants in ecosystems located downstream. The analyzes will be carried out to dissociate two types of impacts associated with this activity: deforestation which modifies the cycle of organic matter and the contribution of metals favored by the erosion of the zones put into exploitation. This work should make it possible to assess the capacity of ecosystems to absorb mining pressures through the analysis of the spatio-temporal variability of their structure and to identify new tools sensitive enough to detect changes at an early stage.

To carry out this study, three zones will be targeted in order to cover the different ultrabasic contexts of New Caledonia: the VKP zone made up of the Koniambo watersheds, the one south of Nouméa made up of the watersheds of the pirogues river and the river. Coulée and an area on the east coast made up of the Thio watershed. These study areas will allow us to take advantage of the achievements of research projects led by CRESICA (Tremor and Searsé) and CNRT (ADIIP, Dynamine, IMMILA, Quavar, Chronick) in geochemistry and sedimentology. The work will be carried out in two phases.

In the first phase, we will collect surface sediment samples, describe them and analyze them both in terms of eDNA and geochemistry. A minimum of five sites will be sampled per zone in the dry season and in the wet season, for a total of 30 samples for this phase. They will be positioned along the land - sea continuum. The second phase of the project will aim to reconstruct changes in microbial communities in parallel with the development of the mining industry, via the analysis of sedimentary archives by harvesting three sedimentary cores. about 1 to 2 meters deep. The choice of site will depend on the siltation conditions observed during the first sampling phase. About 40 samples will be selected for analysis of their ancient DNA content and chemical properties.

Les 28 et 29 mars 2022, le CRESICA organisait le séminaire "Au fil de l'eau" qui a permis de présenter l'état d'avancement du projet.

Visionnez la présentation fait lors du séminaire grâce à la vidéo du projet ECOMINE par H. Lemonnier.

Le 29 août 2023, le CRESICA organisait le séminaire de restitution "Au fil de l'eau" qui a permis de présenter les résultats du projet.

 Brochure: "Des projets de recherche sur la thématique de l'eau en Nouvelle-Calédonie."

Visionnez la présentation faite lors du séminaire grâce à la vidéo du projet ECOMINE par H. Lemonnier

The coastal ecosystems of New Caledonia are complex systems which are governed by multiple interactions. The mining industry and urbanization impact these habitats and increase terrigenous inputs, in particular metals, by rivers which are important vectors for the transport of sediments and dissolved elements. In addition, natural erosion, subject to climatic hazards, leads to inputs of sediments loaded with a number of MTE from mineralized massifs to hydrographic networks and coastal areas. These metallic inputs are essential for primary production and the functioning of tropical coastal ecosystems, but can also be toxic in excess amount. This metallic constraint is increasingly strong today due to anthropogenic pressures and there are no data evaluating the impact of these terrigenous inputs on the physiological, metabolomic and genetic response of phytoplankton.

Some metals are essential at nanomolar concentrations in physiological processes such as photosynthesis and antioxidant defenses. For example, manganese (Mn) and iron (Fe) are key components of photosystems. At high concentrations, metallic elements can however induce the production of reactive oxygen species (ROS) which will oxidize biomolecules such as proteins, lipids and nucleic acids, thus causing oxidative stress and also inducing membrane damage. Some microalgae have great metal absorption capacities. The metal will be captured either by bioadsorption at the cell surface, or by bioaccumulation. This exposure can also limit growth and modify the molecular composition (fatty acids, phenolic compounds, carotenoids) in order to protect algae against ROS generated by metals thanks to the antioxidant activity of these molecules.

Dinoflagellates of the genus Heterocapsa are able to transfer dissolved TMEs to bivalve organisms (oysters and clams), thus allowing bioaccumulation to higher trophic compartments which are subject to consumption by local populations. The genus Heterocapsa is known to be able to grow at high concentrations of metallic trace elements. In New Caledonia, species of Heterocapsa have been isolated during red tides in shrimp ponds, and internationally, the genus is recognized for its strong blooms that can have a toxic impact, especially in bivalves and rotifers. The limitation or the stress induced by an excess of metal inputs has a strong capacity to impact the physiological response and in particular the metabolome of microalgae.

These terrigenous inputs of metallic elements are naturally present in the coastal ecosystems of New Caledonia and may have played a decisive evolutionary role in certain groups of microalgae. The objective of the MICROCOMET project is therefore to study the influence of the metallic stress on the mechanisms of chemical and biological diversification of phytoplankton using a multidisciplinary approach. Comparative studies coupling physiology, metabolomics and transcriptomics on the same genus of dinoflagellates (Heterocapsa spp.) will be set up in order to update the responses induced by a contrasted environment in metallic trace elements which possibly impact food webs.

An approach coupling ecophysiology, metabolomics and genomics will be developed within the framework of this project in order to study the effect of an impact of TMEs on different strains of Heterocapsa spp.

(i) Ecophysiological studies of the influence of metal concentration on the metabolome, oxidative stress and photophysiology of different strains of Heterocapsa spp. The objective here is to characterize the link between the concentrations of certain metals, especially when mixed so as to approximate environmental conditions, with the physiological responses of phytoplankton. Growth monitoring will be carried out and coupled with photophysiology measurements by PAM (Pulse-Amplitude-Modulated fluorimetry) (Fv / Fm, RLC, NPQ) to define the effects of different metal concentrations on photosynthetic capacities, photoprotection of microalgae, as well as on their elemental (CHN) and metallic content.

(ii) Extraction, description of the metabolome of different strains of Heterocapsa spp. and construction of molecular networks. The untargeted study of the metabolome will be conducted on liquid chromatography systems coupled with high resolution mass spectrometry (LC-MS2). This study will be completed by targeted approaches of certain families of metabolites which will be analyzed on UV-visible liquid chromatography systems (pigments) and FID-MS gas chromatography (fatty acids). It will make it possible to identify the metabolites most expressed during a metallic stress.

(iii) Coupled study of ecophysiology (i), metabolomics (ii) and transcriptomics during a continuous culture experiment (Caledonian seawater and seawater "very" enriched in Fe then in a mixture of ETM). The comparison of the transcriptomes from a species of Heterocapsa exposed to environments more or less rich in metals should make it possible 1/ to update the cellular pathways involved in the response to metallic stress and thus possibly corroborate the results of ecophysiology and metabolomics. 2/ to potentially reveal pathways for acclimatization to water rich in metals.

Les 28 et 29 mars 2022, le CRESICA organisait le séminaire "Au fil de l'eau" qui a permis de présenter l'état d'avancement du projet.

Retrouver toutes les informations sur la vidéo de présentation du projet  MICROCOMET par N. Lebouvier.

Le 29 août 2023, le CRESICA organisait le séminaire de restitution "Au fil de l'eau" qui a permis de présenter les résultats du projet.

 Brochure: "Des projets de recherche sur la thématique de l'eau en Nouvelle-Calédonie."

Visionnez la présentation faite lors du séminaire grâce à la vidéo du projet MICROCOMET par N.Lebouvier.

The METEXPO program, funded by the National Centre for Technological Research (CNRT), has identified high concentrations of nickel and chromium in urine samples from New Caledonian residents, particularly in young people aged under 18 and older people aged over 60, with geographic and seasonal variations also recorded.

 

Urinary concentrations of chromium exceeded reference values in the case of 47% of adults and 90% of children.

The most affected regions were: Kouaoua, Houaïlou, Poya, Hienghène, Touho and, unexpectedly, Lifou (no ultramafic massifs).

Urinary concentrations of nickel exceeded reference values in the case of 9% of adults and 13% of children. The most affected areas were the Isle of Pines, Belep, Houaïlou and Yaté.

In the findings set out by the METEXPO program, urinary concentrations of nickel or chromium were not explained by the proximity of mining operations. Data included in the prediction models - socio-economic and dietary data -, did not provide a satisfactory explanation of urinary trace metal concentrations.

Drinking water appeared to constitute one possible source of contamination affecting residents; contamination levels and links to urinary concentrations of nickel and chromium indicated that further study was necessary.

The main objectives of the Nickel-Chrome projects are to :

•    assess, as regards the general population, levels of exposure to nickel and chromium and, in particular, Cr6, in drinking water, together with any geographic and climatic variations.

•    analyse nickel and chromium concentrations in urine samples, according to gender, age, and geographic location;

•    study the correlation between nickel and chromium levels in drinking water and in urine samples.

Following the results of the Metexpo program four research sites were selected for the purposes of the Nickel-Chromium project: the Isle of Pines, Houaïlou, Poya and Lifou. The choice was based on the high levels of nickel or chromium in these municipalities as recorded by the METEXPO study, and the fact that they represent each of the three Provinces, as well as the East and West coasts of the Main Island.

Sampling and analysis will be carried out at each site:

•    samples of drinking water will be taken from each water catchment located in each of the sites, and from water taps belonging to each person taking part in the study of urinary concentrations of nickel and chromium;

•    urinary analyses will be performed in clinics on samples provided by children or adults with a doctor’s appointment, subject to their informed consent.

This work, undertaken as part of the Nickel-Chromium project, will serve as preliminary research for a study the CNRT decided to conduct during the course of 2018. The CNRT research focus will be to achieve a better understanding of the factors involved in mobilisation of nickel (Ni) and chromium, including Cr6, in water, and to target areas where water plays a role in the presence of nickel and chromium trace metals in human urine. Public health authorities will be able to leverage the results to implement protective measures.

Four research sites were selected: Isle of Pines, Houaïlou, Poya and Lifou. Sampling began in 2018 at two sites (Houaïlou and the Isle of Pines) and will continue at two other sites in 2019 (Poya and Lifou). Given that research work began half way through 2018, sampling is scheduled to end half way through 2020.

At each research site, the Nickel-Chromium project will carry out

--   Sampling and analysis of drinking water. Samples will be taken from each water catchment within the site area and from water taps belonging to each person taking part in the study of urinary concentrations of nickel and chromium.

Samples from each catchment will be studied to determine:

 

o    the impact of weather events in levels of trace metals in the water. A sample will be taken during the dry season and another after a heavy rainfall episode. An estimated 150 samples per research site will be collected by an environmental epidemiologist

o    analysis of total dissolved nickel and chromium content (filtration at 0.45 μm) and dissolved hexavalent chromium (particularly toxic), carried out at LAMA-IRD under the supervision of a specialist in the analysis of water for trace metals.

o    concentrations of nickel and chromium, carried out by the ICP-MS

o    concentrations of chromium, Cr6, carried out using polarography.

--  Sampling and analysis of urinary concentrations of nickel and chromium

Research participants will be recruited at dispensaries, from amongst children or adults with a doctor’s appointment, and subject to their informed consent.

The following will be recruited at each centre :

•    30 children (3-17 years old)

•    40 adults aged 18-59 (20 men and 20 women)

•    30 people aged 60 or over.

Clinic staff will get people to fill in a general and dietary questionnaire to provide information on

•    Sociodemographic characteristics

•    Place of residence

•    Place of work or education,

•    Sources of drinking water and foods likely to contain trace metals.

Urine samples will be collected and transported to the Noumea CHT (hospital complex) via standard sample transfer channels.

An external laboratory will be in charge of assays to measure nickel and chromium levels in urine samples. The same laboratory will perform urinary creatinine assays, to ensure measurements of urinary trace metal concentrations are standardised.

Statistical analyses will be performed by environmental epidemiology consultants.

Median and quartile values for concentrations in water will be provided per site for each metal, and seasonal variations will be analysed. Concentrations in samples of tap water will be compared with samples from corresponding water catchments. Analyses of urinary concentrations of Ni and Cr will be performed and compared per research site, sex and age group. Finally, multivariate linear regression analyses will be performed to calculate the statistical relationship between nickel and chromium in tap water and in urine samples, using sociodemographic, dietary and environmental data as covariates.

Perspectives

Public health authorities will be able to leverage the results to implement protective measures. Furthermore, this study will form the basis for CHT-CNRS-IRD-BRGM DIMENC collaborative research work on the mobilisation of Ni and Cr6 trace metals in water, the research topic chosen for the next CNRT call for projects, and for targeting specific areas for advance field work.

The workshop of the programm "Au fil de l'eau" took place on 17 and 18 September 2019, at the UNC.

Tuesday 18 September was dedicated to the intermediate results of the "Au fil de l'eau" program (whose presentation is available on the french's page of the project). This restitution day was an opportunity to exchange on the various projects that make up the program, between research professionals, actors from the public, private and associative sectors working on these themes.

Les 28 et 29 mars 2022, le CRESICA organisait le séminaire "Au fil de l'eau" qui a permis de présenter les résultats du projet.

Brochure : "Quel bilan après trois années de projets de recherche sur la thématique de l'eau en Nouvelle-Calédonie ? "

Rapport final : projet NICKEL-CHROME

Visionnez la présentation faite lors du séminaire grâce à la video du projet NICKEL CHROME par F. Baumann.

The composition of New Caledonia’s coastal soils is characterised by a high lateritic content due to decades of laterite mining, laterites being valued for their concentration of trace metals such as nickel, chromium, cobalt and manganese.

Due to the dispersal and potential toxicity of these trace metals, mining could have a permanent impact on coastal ecosystems and affect their biodiversity (pelagic and benthic macro and micro organisms).

Since mangroves are located at the land-sea interface, they may act as a filter between the mining massifs and coastal ecosystems, including New Caledonia's lagoon, a substantial part of which is listed as a UNESCO World Heritage Site.

Mangroves contribute significant quantities of organic matter and therefore constitute a key reservoir for dissolved organic matter (DOM) which can be transported over considerable distances into the ocean.

DOM plays a key role in the oceanic carbon cycle, representing a significant fraction of terrestrial carbon. The coloured part of the dissolved organic matter (known as coloured dissolved organic matter or CDOM) is composed of fractions of carbon chains contained in a fraction smaller than 0.2 μm. Fractions which strongly absorb radiation at UV wavelengths.

Due to this optical property, CDOM acts as a solar umbrella for tropical corals and means that satellite remote sensing (water colour) can be used for large-scale quantification.

The complexation of heavy metals with dissolved organic matter can facilitate their dispersal into the lagoon. However, following complexation, heavy metal trace elements are less easily assimilated by living organisms; this reduces bioaccumulation and can endow DOM with detoxifying properties in the lagoon area.

The TREMOR project aims to round out research work recently initiated by MIO in New Caledonia, with a thesis on the “Dynamics of coloured and fluorescent dissolved organic matter in tropical lagoon areas in the South Pacific - New Caledonia: climatic and anthropogenic influences” (Martias, 2018) dealing with FDOM in the waters of New Caledonia’s lagoon, as part of the INSU EC2CO TREMOLO  project  (2012-2015), and as part of the CNRT DYNAMINE project (2015-2018).

Characterisation of FDOM components in river waters and their fate in the lagoon will be of use in:

•    specifying the origin of FDOM and how it makes its way from massifs to lagoon, using PARAFAC - a tool for the decomposition of complex signals;

•    achieving a clearer understanding of the influence of bacterial degradation processes during transit and early diagenesis of FDOM;

•    assessing the complexing abilities of the various FDOM constituents as regards heavy metal trace elements, for a more accurate estimate of the respective contributions of FDOM constituents in the dispersal and toxicity of trace metals along New Caledonia’s coastline.

Samples studied as part of the TREMOR project will be taken along river continua - mangroves - lagoon area, i.e. along 3 transects in the Koné lagoon:

•    the first transect follows the Témala river which flows into Chasseloup Bay. This first transect is associated with low mining-related impacts;

•    the second transect follows the Coco river which flows into Vavouto Bay. This second transect is associated with high mining-related impacts, with the KNS industrial site as a potential additional contributory factor;

By comparison with these affected sites, the MOISE permanent observation station, located at Basse Caui opposite Maa Bay in the southwestern lagoon, has been regularly monitored by the IRD (monthly) for several years.

Other research sites can also be considered, including in connection with other projects funded by the CRESICA Au fil de l’eau Program (SEARSE project (Ifremer), for example).

The TREMOR project will have the advantage of a new-generation high sensitivity spectrofluorometer recently put into operation (October 2017) in New Caledonia (UMR IRD MIO). This instrument will perform analyses of FDOM and heavy metal trace element complexation experiments on fresh specimens (no preservation-related bias).

Furthermore, the recent commissioning of an ICP-MS device at LAMA (US IMAGO IRD) means that these spectrofluorimetric analyses can be locally coupled with analyses of heavy metal trace element concentrations in samples from waters under study.

Two factors will be taken into account during sampling campaigns.

• seasons: slow dynamics

The dry season corresponds to low outflows into the lagoon and the rainy season corresponds to high outflows into the lagoon. By taking this into account, observations relating to FDOM source tracking and dynamics, and also complexing abilities as regards heavy metal trace elements, can be repositioned in line with typical annual seasonal variations.

• tides: rapid dynamics

Tidal influence will be appraised through hourly sampling over 12 or 24 hours at an upstream mangrove station and a downstream mangrove station for each transect (Mounier et al, 2018). Comparison of findings from these series of timed samples will enable day-night effects to be separated from tide-related effects.

The TREMOR project sampling plan will require analysis of around 120 samples, including fifteen samples representative of habitats passed through, which will be used for heavy metal trace element complexation experiments.

Experiments testing the potential of spectrofluorimetric analysis in the identification of FDOM constituents have already been carried out:

•    in January 2018 in the Koné lagoon during a one-month assignment carried out by MIO aboard the vessel ALIS, as part of the UECOCOT project (monitoring cross-reef exchanges between lagoon and ocean at barrier reef breaks);
•    in March 2018 on sediments in the Koné lagoon sampled as part of the DYNAMINE project.
•    in July 2018, when Stéphane Mounier arrived for spectrofluorimetry training, an assignment targeting the same sites was carried out, concluding the series of analyses. These initial analyses were later supplemented by analyses carried out between March and June 2018 on samples collected along Coco and Témala river transects as part of Laura Boher’s  and as part of Marie Bessard’s Master 2 fieldwork course.
•    In July 2019 on the 2  Coco and Temala mangroves points with a 24h automatic sampler during a CRESICA mission of Stephane Mounier (48 samples)
•    The last mission will be in March 2020 during a CRESICA mission by Stephane Mounier in Coco and Temala rivers.

The process of interpreting findings from all these campaigns is underway. Works were presented at international symposiums WOMS 2018 in Toulon) and next at EGU 2020 in Vienna, Austria).

The workshop of the programm "Au fil de l'eau" took place on 17 and 18 September 2019, at the UNC.

Tuesday 18 September was dedicated to the intermediate results of the "Au fil de l'eau" program (whose presentation is available on the french's page of the project). This restitution day was an opportunity to exchange on the various projects that make up the program, between research professionals, actors from the public, private and associative sectors working on these themes.

Découvrez la publication "Tropical mangrove forests as a source of dissolved rare earth elements and yttrium to the ocean" dans la revue Chemical Geology

https://www.sciencedirect.com/science/article/pii/S0009254121002229?via%3Dihub

Les 28 et 29 mars 2022, le CRESICA organisait le séminaire "Au fil de l'eau" qui a permis de présenter les résultats du projet.

Brochure : "Quel bilan après trois années de projets de recherche sur la thématique de l'eau en Nouvelle-Calédonie ? "

Rapport final : projet TREMOR

Visionnez la présentation faite lors du séminaire grâce à la vidéo du projet TREMOR par F. Juillot.

In New Caledonia, mining operations (recent or historic) play a key role in heightening the natural erosion process. This phenomenon, known as “red waters”, is characterised by a significant increase in sediment transport along rivers, particularly notable during rain events. This transport of suspended mineral solids such as iron oxide is responsible for downstream accumulations of silt in watersheds.

 

To mitigate the impact of suspended solids sedimentation at confluences of rivers and the lagoon, depending on salinity levels, tailings ponds are located on mining massifs along the river to facilitate the sedimentation process.

Since suspended solids associated with some substrates settle very slowly, such tailings ponds do not always prove effective. Flocculants and coagulants are therefore used to accelerate the sedimentation process. However, these have a greater or lesser effect depending on substrate characteristics and the physico-chemical conditions of the environment.

The aim of the MECAFLOC project is to obtain a clearer understanding of flocculation and suspended mineral solids sedimentation mechanisms in accordance with mineral characteristics and environmental physico-chemical properties (salinity, pH, etc.).

These sedimentation mechanisms vary depending on the environment and tend to significantly impact coastal areas. Today, we need to achieve greater control over related costs and impacts.

The MECAFLOC project aims to identify scientific responses targeting:
•    a better understanding of the dynamics of suspended solids sedimentation, according to the variable nature of soils and the physico-chemical environment of tailings ponds or areas where rivers and lagoon meet;
•    a knowledge of flocculant/suspended solids interactions according to mineral characteristics, taking into account the specific geological context of New Caledonia;
T

his project is being developed in line with the National Centre for Technical Research (CNRT) projects “Functioning of small mining catchments” and “Dynamine”, in which issues relating to the dynamics of suspended solids sedimentation are addressed.
SEARSE, a parallel project led by the IRD/UNC/IFREMER/AEL consortium since 2017, has been studying the behaviour of suspended solids in New Caledonia’s lagoon and assessing the impacts of mechanisms of aggregation/flocculation with organic matter.

The MECAFLOC project is based on laboratory research into in situ devices to monitor flocculation phenomena using optical measurements and filming of sedimentation fronts.

Tests will be carried out on various flocculant products to assess their effectiveness. There will be a strong focus on new natural molecules such as bioflocculants, which have a lower environmental impact than conventional chemical flocculants.

Test results will be used to model aggregation/flocculation mechanisms using the latest methods for simulation of nonlinear phenomena.
The ultimate aim of the project could be to propose methods for:
•    improving estimates of suspended solids sedimentation rates depending on mineral characteristics
•    improving tailings pond design

With, as a final goal: to come up with a flocculant use methodology suited to New Caledonia’s natural environments.

The workshop of the programm "Au fil de l'eau" took place on 17 and 18 September 2019, at the UNC.

Tuesday 18 September was dedicated to the intermediate results of the "Au fil de l'eau" program (whose presentation is available on the french's page of the project). This restitution day was an opportunity to exchange on the various projects that make up the program, between research professionals, actors from the public, private and associative sectors working on these themes.

Les 28 et 29 mars 2022, le CRESICA organisait le séminaire "Au fil de l'eau" qui a permis de présenter les résultats du projet.

Brochure : "Quel bilan après trois années de projets de recherche sur la thématique de l'eau en Nouvelle-Calédonie ? "

Visionnez la présentation faite lors du séminaire grâce à la vidéo du projet MECAFLOC par M. Meyer.

New Caledonia is a vast territory possessing an exclusive economic zone (EEZ). Its maritime area comprises a variety of coral reef formations, lagoon areas, mangroves and very extensive expanses of ocean and seas.

New Caledonia’s exceptionally preserved marine biodiversity was recognised by the 2008 inscription of a majority of the lagoon and reef systems as a World Heritage Site (UNESCO).

For over a century, the mining industry has played a significant role in shaping the country’s landscapes and coastlines but there is an increasingly strong commitment to diversifying the economy and developing tourism and other sectors by leveraging factors such as the country’s attractiveness.

The vulnerability of these tropical ecosystems is a key issue both in terms of research and in terms of the challenges of achieving sustainable management (Territorial Innovation Strategy, 2015).

Any assessment of the environmental status of marine ecosystems must take into account the various human-induced pressures on the environment.

The fact that there is currently no quantification of human-induced pressures makes it very difficult to reach a clear understanding of the structuring processes which affect the integrity of this natural heritage and the related ecosystem services.

Adopting an ecosystem approach is vital to the implementation of an Integrated Coastal Ecosystems Management (ICZM) system.

Ultimately, the SEARSE project should make it possible to:

•    model the fate of dissolved compounds in the marine environment;

•    analyze the fate of some contaminants in the marine environment;

•    provide data allowing hydrologic landscapes in the lagoon around Greater Noumea to be defined and mapped.

With the goal of reaching a clearer understanding of:

•    ecosystem functioning in New Caledonia’s lagoon;

•    connectivity between lagoon fish communities;

•    initial sources of trace metal accumulation in the food chain.

The SEARSE project aims to conduct:

•    analyses of concentrations of dissolved and particulate matter at 4 outflows: the Dumbea, La Coulée, Rivière des Pirogues and Tontouta rivers;

•    monitoring of sediment plumes in the lagoon environment around Greater Noumea.

Analyses will identify essential characteristics for each river and quantify sedimentary loads carried by rivers into New Caledonia’s lagoon:

•    total suspended solids (TSS)

•    nutrients (ammonium, nitrates, phosphates and silicates)

•    metals (Cr, Ni, Fe, Mn, Cu, Zn and Al),

•    nitrogen, carbon and phosphorus,

•    organic material in dissolved and particulate form (including COD, CDOM and FDOM),

•    biological particles (bacteria and phytoplankton).

The monitoring process aims to:

•    establish maps of hydrological landscapes;

•    estimate the influence of fluvial loads on these landscapes.

The SEARSE project will conduct analyses based on the deterministic GR4J rainfall-runoff model to quantify sediment exports of dissolved and particulate matter from rivers.

This model, developed in 2017 by the IFREMER LEAD team, is designed to estimate river flows on an hourly time-step, from rain data.

These analyses were conducted in four Greater Noumea catchments (Desclaux et al., 2018).

A 300-m hydrodynamic model was developed around the Greater Noumea area to analyse the fate of river outflow waters.

Analyses will be linked to data rates from the GR4H model, with water characteristics at the 4 outflows (Dumbea, La Coulée, Rivière des Pirogues, La Tontouta).

The purchase of drifting buoys will allow tracking of the fate of the plumes and various materials that make up the lagoon.

There will be a special focus on the fate of genetic and functional diversity in microorganisms, excellent markers of environmental changes in the plumes.

This research work will be carried out as part of the assignment of an IFREMER expert from France.

Progress report on the monitoring of rivers at outflows in the south of New Caledonia, available at: https://archimer.ifremer.fr  

Boher L., Coignot E., Lopez E., Royer F., Lemonnier H., 2018. Monitoring fluorescent organic materials upstream from estuaries in the south of New Caledonia. End of contract report CSD IFREMER-LEAD. p. 38

Mot-Clé(s): Rivières, Matière organique fluorescente, dynamique

The workshop of the programm "Au fil de l'eau" took place on 17 and 18 September 2019, at the UNC.

Tuesday 18 September was dedicated to the intermediate results of the "Au fil de l'eau" program (whose presentation is available on the french's page of the project). This restitution day was an opportunity to exchange on the various projects that make up the program, between research professionals, actors from the public, private and associative sectors working on these themes.

Les 28 et 29 mars 2022, le CRESICA organisait le séminaire "Au fil de l'eau" qui a permis de présenter les résultats du projet.

Brochure : "Quel bilan après trois années de projets de recherche sur la thématique de l'eau en Nouvelle-Calédonie ? "

Rapport final : projet SEARSE

Visionnez la présentation faite lors du séminaire grâce à la vidéo du projet SEARSE par H. Lemonnier.

Leptospirosis is a zoonosis estimated to cause over one million cases and nearly 60,000 deaths worldwide each year, with an average annual incidence of 45 cases per 100,000 pop. in New Caledonia.

In rural and urban areas, in subtropical, tropical or temperate climate conditions, leptospirosis presents with symptoms which are difficult to distinguish from infections such as dengue fever or flu.

Transmission to humans occurs when Leptospira enter the human body via skin lesions or mucous membranes :

• through direct contact with animals or their tissues, mainly rodents. Pathogenic Leptospira colonise the renal tubules of mammals and are excreted into the environment via urine;
• In contaminated freshwater environments.

Leptospirosis outbreaks occur after heavy rainfall.

Rainwater leaches through the soil surface and carries Leptospira to water sources, thus leading to human exposure. Most cases of human infections are attributable to indirect exposure via surface water, soil and mud. Such exposure may be work-related, such as people working in water-irrigated rice or taro fields or banana plantations, or may be related to leisure activities or subsistence farming, e.g. swimming or freshwater, fishing, etc.

Outbreaks of leptospirosis tend to occur during periods of heavy rainfall, and seasonal peaks are noted. There is an uneven spatial distribution of cases in New Caledonia, with, however, the highest incidence recorded on the northern East Coast of the Main Island.

Currently, there is a scarcity of data concerning:

• the conditions for survival of pathogenic Leptospira in water and soil environments;
• the resuspension of Leptospira during heavy rainfall;
• freshwater contamination dynamics and the resulting health risk.

The ASSURPLUHYT project therefore involves collaborative work between microbiology, geochemistry, hydrology and hydro-geochemistry experts. Consequently, the project will be carried out in close collaboration with the University of New Caledonia ISEA laboratory and the Institute for Research and Development (IRD).

Targeting the Touho region, which presents a high incidence of leptospirosis, the project focus is the characterisation of physico-chemical conditions favouring the survival of pathogenic Leptospira in soils.

The impact of such physico-chemical conditions will then be tested in controlled laboratory conditions.

Based on the expertise developed to study mining-related materials transfer, the characterisation of Leptospira resuspension and transport dynamics during flooding will provide a better understanding of the infection risk linked to heavy rainfall, a risk recognised worldwide.

The project may well find evidence that this risk is related to hydrology, and such findings will allow an estimation of the risk timeframe after water levels fall.

By adopting a multidisciplinary approach, the impact of parameters such as vegetation and soil stability can be addressed, thereby providing additional data on the dispersion of Leptospira in the environment.

These findings will form the basis for a clearer understanding of leptospirosis infection risks, and ultimately the implementation of hydrology and soil properties-related infection risk mapping.

Thus, the ASSURPLUHYT project aims to

• Accurately determine the physico-chemical composition

     - of soils;

     - of run-off water;

     - of Total Suspended Solids (TSS) when flooding occurs.

• Quantify Leptospira in complex matrices (soil, water, TSS during flooding);
• Determine optimal physico-chemical parameters for the environmental survival of pathogenic Leptospira
• Determine the dynamics of Leptospira resuspension during the rise and fall of floodwaters so that health risks may be more accurately assessed.

The Institut Pasteur in New Caledonia (IPNC) UREL laboratory has already identified contaminated sites in Touho, the location for the field study.

Ascertaining, as part of this project, the physico-chemical properties of soils found in these sites – an historic and possible future source of cases of human infection with leptospirosis -, will lead to a more accurate characterisation of the soil as an environmental reservoir of pathogenic Leptospira. The technology required for the detection of viable Leptospira from environmental samples has been validated by the IPNC.

Experimental soil erosion plots already fitted with measurement devices will be used to:

• Characterise the physical and chemical properties

      - of soils;

      - of run-off water, to obtain a clearer picture of how this compartment contributes to soil-related Leptospira dispersion subject to varying rainfall patterns.

Analyses will be made quarterly so possible seasonal variations can be assessed.

• Determine the impact of environmental parameters on suspended solids and Leptospira numbers in run-off water, based on the presence of different vegetation covers representative of individual ecosystems on various erosion plots;
• Characterise suspended solids and quantify Leptospira in order to determine the role of soil/river connectivity in Leptospira dispersion;

During various rainfall events, water samples will be taken from rivers fed by water from the watershed which also includes the experimental erosion plots.

Detailed analysis of suspended solids in these two fluid compartments (runoff waters and river waters) will elucidate the way(s) in which Leptospira are dispersed, directly in water or attached to the surface of suspended solids.

This research will draw on P. Genthon’s (IRD) expert knowledge in the field of hydrology, and on work using a comparable methodological approach undertaken at UNC (P. Gunkel-Grillon and C. Laporte-Magoni) and at the IRD (F. Juillot) as part of the CNRT projects (DMML and DYNAMINE), and the doctoral thesis by A. Boula (directed by Nazha Selmaoui-Folcher and co-supervised by P. Gunkel-Grillon and C. Laporte-Magoni).

The workshop of the programm "Au fil de l'eau" took place on 17 and 18 September 2019, at the UNC.

Tuesday 18 September was dedicated to the intermediate results of the "Au fil de l'eau" program (whose presentation is available on the french's page of the project). This restitution day was an opportunity to exchange on the various projects that make up the program, between research professionals, actors from the public, private and associative sectors working on these themes

Les 28 et 29 mars 2022, le CRESICA organisait le séminaire "Au fil de l'eau" qui a permis de présenter les résultats du projet.

Brochure : "Quel bilan après trois années de projets de recherche sur la thématique de l'eau en Nouvelle-Calédonie ? "

Rapport final : projet ASSURPLUHYT

Visionnez la présentation faite lors du séminaire grâce à la vidéo du projet ASSURPLHUYT par C. Goarant.

Building on a Pacific Fund project
The Goutte project has been developed to build on a Pacific Fund project undertaken between 2014 and 2016 and entitled “Fresh water supply and the land-water nexus in the Pacific: competing uses, complex regulations, conflictive political issues”.
This project was led by the Australian National University (ANU) and involved New Caledonia (IAC in association with the North Province), the Kiribati Islands, the Solomon Islands and Tonga.

The ANU project focused on water-related collaborative issues and aimed to
•    Promote “water-social science” research collaboration and networks in the Pacific;
•    Identify research themes with promising and inclusive reach and appeal throughout the Pacific.

The issue of water governance on customary land emerged as a key topic both for researchers and communities involved in the project (Bouard et al, 2017; Daniell et al, 2016; Bouteloup, 2015; Lejars et al, 2016).

2017, launch of exploratory research
In the wake of this initial project, IAC, CIRAD and IRD launched an exploratory study in 2017, focusing on the topic and funded by the Montpellier Institute of Water and the Environment (IM2E) in New Caledonia (Nekiriai, 2017; Lejars et al, 2017) in association with researchers from the “Eau-SHS” network set in place by the Pacific Fund project.

Indigenous peoples' rights of access to water - an issue frequently discussed in existing literature
The issue of water governance on customary land occupies a whole field of the existing literature on “indigenous peoples’ rights” of access to water, which often highlights the interconnections between political, land and environmental claims and water resource ownership claims made by indigenous peoples (see for example: Hidalgo et al, 2017; Boelens and Seeman 2016 as regards South America; Tripod, Trepied, 2011 & Trepied, 2004 as regards New Caledonia).

Another section of existing literature focuses on repercussions deriving from divergences in institutional systems regulating access to safe drinking water (Chambre des communes, 2005, Penn, 2016)  

A topic also addressed in the Pacific Region
In New Zealand; the sacred and symbolic nature of water is reflected in practical terms in innovative methods of water resource management (Jackson and Altman, 2009; Hsiao, 2012).
In the Pacific Region, while issues relating to water on customary lands have been identified, there has been little research focussing on the central issue at stake (Daniell et al, 2016).

Against this background, New Caledonia can serve as a model for the development of innovative modes of water governance which factor in local knowledge and practices (Bouard et al, 2017; Lejars et al, 2017).

GOUTTE is a multidisciplinary project. Water governance on customary lands involves several disciplines (law, water management, anthropology, geography...) and thus requires cooperation and discussion between researchers and key players in these fields.

     The project is therefore structured around 5 major work packages spread over 3 years, with specific         contributors assigned to each package.

To ensure that diversity of practices, knowledge and languages is taken into account, research work will mainly be conducted in three common land areas: ideally, the North Province, the South Province and the Loyalty Islands Province.

The GOUTTE project aims to:

Improve knowledge of water-related know-how and practices on customary land, including perception of risks associated with water shortage or flooding;

Facilitate awareness raising and the sharing of new practices and management rules, including water saving and water pricing issues;

Support consolidation of the legal framework regulating water and aquatic environments, with a view to adapting it to reflect the legal fragmentation of rivers and groundwater;

Clarify the social feasibility of introducing new

•    hydraulic structures (e.g. dams)

•    Systems for:

o    management and sharing of water (e.g. river contracts)

o    water pricing

At New Caledonia level

The GOUTTE project should help to consolidate and broaden existing partnerships, by

•    setting up local workshops

•    joint training of a civic service volunteer (VSC)

•    joint work by researchers on common lands

•    Involving researchers from other disciplines and institutions like the ADCK and IANCP.

Moreover, the project will be carried out, wherever possible, in interaction with other research projects led by CRESICA, for the purposes of which knowledge of water-related practices and know-how could serve as complementary or supporting factors.

At community level

The GOUTTE project will be carried out in coordination with research on water policy in New Caledonia led by MISE. Debates and discussions on program progress and findings will be scheduled in conjunction with the DGRAC/DAVAR/START, the Customary Senate/North Province/South Province/Loyalty Islands Province.

At Pacific Region level

Funding from bodies such as the Pacific Fund or IM2E could strengthen existing collaborations, particularly with the ANU in Australia, with Vanuatu, Tonga and the Kiribati Islands.

The GOUTTE project mobilises tools and methodologies drawn from the various disciplines within the project scope: water management, geography, anthropology, linguistics.

Each social science discipline will use its own methodological tools, such as

•    Direct or participant observation

•    Historic data from analysis of public and/or private archives

•    Conducting open and semi-structured interviews

•    Survey analysis, regulatory frameworks

•    Studies, spatial data

•    Children's drawings...

 

This will involve

•    Listening to elders talking about the changes they have observed and experienced

•    Asking young people about their knowledge, practices and representations/protests and contrasting them with those of older generations

Given the diverse range of disciplines and methodologies, the GOUTTE project plans to make common and shared lands are central focus for research work. The choice of lands, still to be defined, will be designed to ensure that case studies in the North Province, South Province and Loyalty Islands Province are covered.

Having researchers work on common lands will promote

•    Scientific discussion between researchers from different disciplines

•    Discussion with local stakeholders.

Work groups and project monitoring involving the DGRAC and community water services will also be put in place.

Finally, depending on available resources, an international seminar addressing the issue of water on customary lands could be scheduled.

The workshop of the programm "Au fil de l'eau" took place on 17 and 18 September 2019, at the UNC.

Tuesday 18 September was dedicated to the intermediate results of the "Au fil de l'eau" program (whose presentation is available on the french's page of the project). This restitution day was an opportunity to exchange on the various projects that make up the program, between research professionals, actors from the public, private and associative sectors working on these themes.

Les 28 et 29 mars 2022, le CRESICA organisait le séminaire "Au fil de l'eau" qui a permis de présenter les résultats du projet.

Brochure : "Quel bilan après trois années de projets de recherche sur la thématique de l'eau en Nouvelle-Calédonie ? "

Rapport final : projet GOUTTE

Visionnez la présentation faite lors du séminaire grâce à la vidèo du projet GOUTTE par S. Bouard

To date, there has been no research into emerging pollutants in the tropics; they have only been studied in temperate environments in highly developed countries. The focus has so far been mainly on freshwater ecosystems.
Although contamination due to emerging pollutants has not been of crucial interest in recent years, coral ecosystems are subject to increasing anthropogenic pressures, and it is therefore conceivable that marine environments could be affected by this type of pollutant.
Natural or mining-related sedimentation acts as the carrier of a whole range of heavy metals (Ni, Co, Cr, Mn, etc.) and/or pesticides, which could impact marine ecosystems and fish caught by traditional fishing methods.
The urban development of “Greater Noumea” also means that wastewater requires increased attention and that wastewater evacuation into the receiving environment (such as coral ecosystems) must be assessed.
Population growth also drives agricultural development to meet rising demand for food. Many pesticides are used, sometimes in poorly controlled or uncontrolled quantities. This raises the question of their fate and effects in the receiving environments, including fish and sea food consumed by the population.

The marine environment is the ultimate repository of freshwater sources throughout New Caledonia, be they underground (percolation, infiltration, etc.) or on the surface (rivers, runoff), or derived from urban waste (drains, discharge from wastewater treatment plants, etc.).

As a consequence, reef and lagoon environments are directly affected by such freshwater inflows and subject to variability in quantitative and qualitative, and also spatial and temporal terms.

The species inhabiting these ecosystems are also liable to ingest and absorb into their tissues all or part of the elements carried by water bodies, either directly (food) or indirectly (phenomena of dissemination or osmotic transport, etc.)

The PEMPOM project aims to analyse:

•    the sources of emerging, organic and heavy metals pollutants;

•    concentrations in various biological compartments in the coral ecosystem, and in humans who consume fish and seafood.

To this end, various research sites have been identified, such as freshwater “vectors”, including wastewater treatment plants (traditional activated sludge process and microfiltration membrane process), the lagoon and estuaries receiving water from septic tanks and household-level sanitation systems, such as the La Foa river, the area of corals opposite the estuaries.

Given the total lack of prior knowledge as regards emerging pollutants in the tropics, during a preliminary phase, research will be carried out on only a few biological compartments located in the immediate vicinity of these receiving areas, to test for possible contamination of the coral ecosystem (e.g. algal turfs, territorial herbivorous fish).

The PEMPOM project will carry out targeted sampling on key species constituting “food chains”, aiming at a spatial vision in order to:

•    understand how contaminants (pesticides, metals, emerging pollutants) become absorbed (or not) into these key species;

•    assess health implications in the event of high concentrations of pollutants in a few iconic species of commercial interest, which are representative of the dietary habits of New Caledonians;

•    assess, for the first time in New Caledonia:

o    whether so-called emerging pollutants have a significant impact on the reef environment and whether there are grounds for suspecting an accumulation in food webs.

o    the potential contamination sensitivity of seabirds (exclusively fish-eating), species of major heritage significance (biomonitoring, etc.)

•    study various sectors characterised by dissimilar potential pollutant inputs into coral systems (reefs not impacted by humans, reefs subject to agricultural inputs, reefs subject to inputs from treatment plants).

This project is therefore designed to provide answers to key questions about contamination rates and the diversity of compartments studied, with a view to assessing how contaminants are absorbed into food webs ending with focal species.

Spinoffs from the PEMPOM project could:

•    Enable findings from several Pacific islands to be transposed, at least in general terms. The project is already being conducted in close collaboration with similar projects in Wallis, Futuna, Vanuatu and Fiji;

•    provide clarification on other aspects of basic research which will focus, significantly on physiological processes;

•    have implications in terms of:

o    management and protection of sensitive species (protected areas, raising awareness and regulatory framework, etc.)

o    management of fisheries resources (traditional fishing, etc.) and development of regulations targeting fish, seafood and public health (contaminant levels and potential health risks, etc.)

o    management of natural areas and species.

The PEMPOM project aims to promote collaborative work between key CRESICA consortium partners who are active in this field, i.e. the UNC, the CHT and the IRD, together with universities in France (La Rochelle and Aix-Marseille) and abroad (New Zealand), while involving Calédonienne des Eaux water company, a key player in the local economy, and also New Caledonia’s provincial government authorities.
This method of collaborative work aims to bring in partner-colleagues who have done work and/or are currently working in this area, with a view to optimising the effectiveness of work undertaken as part of the PEMPOM research project.
Furthermore, the involvement of colleagues from Noumea CHT, in close contact with medical circles, will mean that the project, according to the results achieved, could set a clear benchmark in terms of social significance.
Research work will be rooted in an approach based on dynamic predictive mathematical models and multidimensional data analysis, which will take into account the spatial variability of contaminant levels for several compartments in the food web, thereby enabling the assessment and prediction of potential contaminant accumulation phenomena.
Theoretical and digital simulation studies will also be carried out on the properties of models and estimators.
The project will also build on research recently conducted on issues directly affecting New Caledonia (thesis by M.Briand, master 2 internships by P.Fey and J.Liétar).

The workshop of the programm "Au fil de l'eau" took place on 17 and 18 September 2019, at the UNC.

Tuesday 18 September was dedicated to the intermediate results of the "Au fil de l'eau" program (whose presentation is available on the french's page of the project). This restitution day was an opportunity to exchange on the various projects that make up the program, between research professionals, actors from the public, private and associative sectors working on these themes.

Les 28 et 29 mars 2022, le CRESICA organisait le séminaire "Au fil de l'eau" qui a permis de présenter les résultats du projet.

Brochure : "Quel bilan après trois années de projets de recherche sur la thématique de l'eau en Nouvelle-Calédonie ? "

Rapport final :  projet PEMPOM

Visionnez la présentation faite lors du séminaire grâce à la vidéo du projet PEMPOM par Y. Letourneur.