HAL Collection UNC (Univ. de la Nouvelle Calédonie)
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Remote sensing and spatial modelling. Applications to the surveillance and control of mosquito-borne diseases
No full textSource Agritrop Cirad (https://agritrop.cirad.fr/615033/)International audienceMosquitoes are vectors of many disease-causing pathogens, including malaria, dengue, chikungunya, and yellow fever. According to the World Health Organization, these vector-borne diseases account for several hundred thousand deaths annually. They also cause zoonoses, such as Rift Valley fever and West Nile fever. In this context, the development of operational tools to support surveillance and control strategies is essential—not only in countries of the Global South, where mosquito-borne diseases are most prevalent in tropical and subtropical regions, but also in the countries of the North, where the establishment of invasive species such as the tiger mosquito is increasing the risk of disease emergence. To address these challenges, Earth observation imagery offers valuable potential: the spatial distribution and seasonal dynamics of mosquito populations are closely linked to climatic factors (such as temperatures, rainfall, and humidity) and environmental variables (such as the presence of water bodies and vegetation), many of which can be monitored through satellite data. Numerous recent studies have led to the development of innovative methods that combine remote sensing with spatial modelling to predict the spatial and temporal dynamics of vector mosquitoes and associated diseases. Moving beyond proof-of-concept, some of these approaches have given rise to operational tools and processing chains that are now actively used by public health authorities and vector control agencies. This book, intended for students, researchers, and public health professionals, offers a synthesis of current research and operational tools in the field
Nest Exposure to Marine Flooding and Impacts on Green Turtle (Chelonia Mydas) Embryos Under Rapid Sea Level Rise: The Role of Beach Geomorphology and Hydrodynamics
No full textInternational audienceClimate change-induced sea-level rise increases the risk of sea turtles' nests being flooded which could threaten their populations. However, impacts on embryonic development remain limited, and the mechanisms driving nest flooding are still poorly understood. Our multidisciplinary study aimed to determine the geomorphological and hydrodynamic factors exposing nests to flooding, and to better understand the effects of flooding on embryonic development under natural conditions. The research was conducted on Mayotte Island (France, Indian Ocean), where a seismic crisis between 2018 and 2020 caused subsidence, resulting in a relative rise in sea level. Thirty green turtle nests on a primary nesting reef beach were monitored from March to June 2022 using pressure sensors to measure flooding. The hydrodynamics were measured, and the beach morphology was mapped. Approximately 30% of the nests were flooded, mainly due to their relatively low position on the beach, with the flooding likely to have been influenced by water level fluctuations related to the tidal cycle. The early and late incubation phases were particularly sensitive to flooding. Emergence success was 1% for flooded nests, significantly lower than 85% for non-flooded nests. This study provides new insights and reveals that under natural conditions, nests are more sensitive to flooding than previously reported in controlled laboratory studies. However, flooding does not always directly impact embryonic mortality; other related factors may be involved, requiring further research
Snapshots of Coral Reef Biodiversity
No full textInternational audienceCoral reefs are sanctuaries for a large portion of our planet’s biodiversity, but their rapid decline begs critical questions about what exactly is being lost, what driving forces determine decline or resilience, and what implications for life on Earth. To help address these questions, this chapter synthesizes the state of knowledge on the diversity of coral reef life forms at different scales of biological and ecological organization, encompassing variability in genes, biomolecules, cells, organs, organisms, populations, communities, ecosystems, socio-ecosystems, and biogeoclimatic systems, with a particular focus on French tropical overseas. We discuss research pathways to address knowledge gaps in various scientific disciplines, covering genetics (genomics, transcriptomics, proteomics, metabolomics), morphology, ethology, bioacoustics, demography, functional ecology, macro-ecology, landscape ecology, human and social sciences, bioclimatology, and their cross-disciplinary interactions. Based on contributions from coral reef experts working in different coral reef regions around the world, our synthesis supports a better understanding of the various dimensions of coral reef biodiversity and proposes future research orientations for improving knowledge and conservation. Given the rapid disappearance of coral reefs and how much is still unknown, this chapter underscores the urgency of cross-scale biodiversity assessments for a systemic understanding of the distribution and dynamics of biodiversity
Publication de conversations téléphoniques entre Claude Guéant et sa fille : la liberté d’informer pouvait primer sur le respect de la vie privée: CEDH 11 sept. 2025, Charki c. France, n<sup>o</sup> 28473/22
No full textInternational audienceLa Cour européenne des droits de l’homme estime, à une très courte majorité, qu’il résulte de la mise en balance des différents intérêts en jeu, valablement effectuée par les juridictions internes, que les motifs retenus par ces dernières pour justifier la primauté de la liberté d’information étaient suffisants et pertinents pour justifier l’ingérence litigieuse et qu’il n’y a pas eu violation de l’article 8 de la Convention
Artificial light at night during early development directly affects embryonic but not larval quality in a wild coral reef fish
No full textInternational audienceArtificial light at night (ALAN) is an emergent yet already global form of sensory pollution. However, its effects on marine environments remain poorly understood compared to those on terrestrial ecosystems. Low-latitude ecosystems such as shallow coral reefs might be at greater risk as they experience little change in annual day length and reef organisms rely on moonlight illumination as a zeitgeber for critical biological processes. Moreover, many coral reef fish are demersal spawners, making them vulnerable to the effects of ALAN from early life. We performed a field experiment to determine whether artificial light affects the quality of fish embryos and newly hatched larvae by exposing wild nests of the orange-fin anemonefish (Amphiprion chrysopterus) to white light emitting diode (LED) light (22 ± 2.0 lx; 4000 K) throughout the 6-day embryonic development period. We also explored whether light pollution indirectly influences offspring traits by measuring parental care investment. Exposure to ALAN altered embryo quality, leading to a reduction in egg volume (2.40%) and yolk reserves (6.11%) alongside an increase in heart rate (7.42%) a few hours before hatching. These changes reflect higher metabolic demands of embryos developing under light-polluted conditions. As parental care investment was unaffected by light pollution, our results suggest that these effects are more likely the consequence of a direct effect of ALAN on embryogenesis. In contrast, there was no influence of artificial light on the larval morphology or swimming performance, suggesting that the direct effects of ALAN on fish embryos do not cascade onto the larval stage immediately after hatching. These results may suggest that embryos compensated for ALAN exposure to maintain their early post-hatching larval performance. Further studies are needed to investigate whether light pollution exposure during embryonic development has delayed effects on larval performance during the dispersal phase or on larval survival
Renforcer la résilience juridique des savoirs autochtones dans le Pacifique : une étude comparative d'étudiants calédoniens et vanuatais
No full textInternational audienceDans le cadre du projet de recherche SPAR-Pacific, une enquête a été menée auprès d’étudiants calédoniens et vanuatais afin d’évaluer leur perception du rôle du droit dans la préservation des savoirs et pratiques autochtones. Si la résilience est généralement abordée sous le prisme social et culturel, elle peut également être envisagée comme un outil juridique, en particulier pour préserver des savoirs menacés par la modernisation et la globalisation. Or, la perception du droit diffère selon les contextes : en Nouvelle-Calédonie, seuls 11 % des étudiants interrogés déclarent connaître l’organisation administrative et politique du territoire, et parmi eux, à peine la moitié considèrent que le droit protège effectivement les savoirs traditionnels. À l’inverse, au Vanuatu, 30 % des étudiants affirment connaître leur cadre politico-administratif, et parmi ceux-ci, 80 % estiment que les dispositifs existants sont suffisants pour assurer cette protection. Ce contraste interroge sur la relation entre droit et résilience : pourquoi les étudiants calédoniens semblent-ils moins sensibilisés aux outils juridiques de protection des savoirs autochtones ? Comment renforcer leur appropriation du droit en tant que levier d’adaptation face aux risques de perte culturelle ? Cette contribution vise à analyser ces différences et à mettre en lumière les propositions formulées par les étudiants pour faire du droit un vecteur de résilience juridique au service de la transmission et de la préservation des savoirs autochtones dans le Pacifique
Beyond Ecology: Land–Sea Governance, Policy, and Research in Réunion Island (2000–2024)
No full textInternational audienceCoastal areas are increasingly exposed and vulnerable to environmental degradation and climate change, requiring adaptive governance approaches that integrate the climate-environment-health nexus. In Réunion Island, a French overseas department and EU region, two decades of science-policy initiatives have aimed to improve coastal governance through stakeholder engagement, scientific knowledge integration, and deliberative processes. Building on the evolutionary governance theory framework, this study analyzes a body of 281 scientific research articles (2000-2024), 4 participatory projects (2005-2020), and 12 expert insights to identify land-sea governance challenges and opportunities. Scientific articles remain focused on diagnosing environmental problems rather than elaborating systemic solutions, with a predominance of ecological and conservation science. Participatory governance and long-term strategic foresight are underdeveloped, and while digital tools are widely used for environmental monitoring, their integration into decision-making remains insufficient. Key barriers include administrative fragmentation, weak institutional coordination, and difficulties in integrating scientific knowledge into policy processes. Four enablers emerge: strong political leadership, long-term institutional support, a shared strategic vision, and regional cooperation aligned with European and international frameworks. Additionally, Réunion's hybrid sociability, shaped by its colonial history, presents both challenges and opportunities for governance. While it may foster exclusivity, it can also facilitate trust-based collaboration. A dedicated land-sea governance structure could enhance multi-scale and multi-level coordination among stakeholders
Adolescent financial literacy: viewing peers as good financial role models
No full textInternational audiencePurpose This study aims to develop a peer financial modelling scale to ascertain any correlations between the role modelling of peers and the financial literacy of adolescents. The theoretical foundation for this aim lies in Social Learning Theory. This study also examines the reliability of the recently developed short and minimal versions of the Parent Financial Socialisation Scale. Design/methodology/approach Using a survey administered through Qualtrics, data were collected from a sample of 382 15- to 19-year-olds. Confirmatory factor analysis was used to measure model fit of any proposed scale, with Cronbach’s alpha calculated to assess for internal consistency reliability. An ordinary least squares regression was then run to assess any correlation between the scale developed and financial literacy, incorporating control variables for gender and socioeconomic status. Findings A Peer Financial Modelling Scale is developed and found to be negatively correlated with financial literacy levels. Adolescents with lower financial literacy are more likely to view their peers as good financial role models. All three versions of the Parent Financial Socialisation Scale were found to be positively correlated with financial literacy knowledge. Research limitations/implications Limitations include the lack of a general cognitive ability measure and personality measure in the ordinary least squares regressions. Practical implications A previously undiscovered advantage of higher financial literacy levels among adolescents is a lower likelihood to see peers as appropriate financial role models. Originality/value To the best of the authors’ knowledge, this study is the first to develop a scale to capture the socialising effect of peers in the context of financial literacy
Impact of the 2023 coral bleaching event in Martinique, Eastern Caribbean
No full textInternational audienceMass coral bleaching events are increasing in severity and frequency globally. In 2023, the wider Caribbean region experienced the longest period of marine heatwave ever recorded. Twelve sites around Martinique island, Eastern Caribbean, were surveyed in October 2023, during the peak of this intense bleaching event, in February 2024, one month after the end of the bleaching heat stress with risk of mortality, and in May 2024, seven months after exposure to the maximum heat stress. Point intercept transects and belt transects were used to evaluate affected coral cover and colonies. The main objectives were to quantify the spatial distribution and level of impact of bleaching on the coral assemblages and to identify the most vulnerable species. Thermal stress during the 2023 event exceeded any previous record, with the present study describing one of the worst bleaching prevalence (86% in October 2023) ever observed in the region and a 35% decline of coral cover. Among the species most vulnerable to bleaching are some of the coral taxa that had shown most resistance to the Stony Coral Tissue Loss Disease, another major driver of coral mortality in the Caribbean region. We discuss the consequences of this bleaching event in the current context of coral decline in the Caribbean region, which suggests a concerning future in a warming climate. The reduction of greenhouse gas emissions together with efficient local management is urgently needed to limit further climate and human impacts on corals and support any chances of recovery.En 2023, la région Caraïbe a subi la plus longue et la plus intense canicule marine jamais enregistrée. Douze stations coralliennes ont été suivies autour de la Martinique, à l'Est des Caraïbes, pendant le pic de stress thermique (octobre 2023), un mois après la fin du stress thermique entrainant un risque de mortalité corallienne (février 2024) et sept mois après le pic de stress thermique (mai 2024). Deux types de transects ont été réalisés afin d'évaluer l'impact sur la couverture corallienne et les colonies. Cette étude a pour objectifs de quantifier l'intensité du blanchissement sur les communautés coralliennes et sa distribution spatiale ainsi que d'identifier les espèces les plus vulnérables. Le stress thermique de l'épisode de 2023 se traduit en Martinique par un blanchissement corallien avec 86% de prévalence en octobre 2023 et une perte de couverture corallienne de 35%. Parmi les espèces les plus vulnérables au blanchissement corallien se trouvent des espèces connues pour être résistantes à la maladie corallienne « Stony Coral Tissue Loss Disease», une des autres causes importantes de mortalité dans la région. Les effets de cet épisode majeur de blanchissement sur les communautés coralliennes déjà en déclin dans la région Caraïbe sont discutés et mettent en avant un futur alarmant dans le contexte d'épisodes de blanchissement corallien de plus en plus intenses et fréquents. La réduction des gaz à effet de serre combinée à une gestion locale efficace sont nécessaires et urgentes afin de limiter au maximum les impacts climatiques et humains sur les coraux et de leur donner un espoir de résilience face aux pressions subie
Toward a spatialized index of the “benthic ecological state” using a new Coral Reef Rapid Assessment Method (CORRAM): case study at Reunion Island
No full textInternational audienceThe development of a spatial index that can be used to represent the benthic ecological state of coral reefs is essential for guiding public conservation policies. We propose the spatialization of a new index of "benthic ecological state" using the Coral Reef Rapid Assessment Method (CORRAM). Eight benthic biodiversity indicators selected from the literature that reflect key resistance and resilience mechanisms were assessed in 786 circular plots on the Saint-Pierre reef flat of Reunion Island. The "benthic ecological state" index was constructed from the eight benthic biodiversity indicators and spatialized using ordinary kriging. To better assess functional mechanisms with respect to environmental pressures, the "benthic ecological state" index can be sub-divided into two indexes. By establishing the associations between these indexes and abiotic environmental variables, the "coral community structure" and "benthic community vitality" showed a differential response sensibility including interaction with abiotic environmental variables studied. Our large dataset enabled us to propose a "benthic ecological state" of reference based on habitat type for the Saint-Pierre reef flat in 2021. These indexes highlight areas of high socio-ecological issues and contribute to quantifying the deviation between the "reference ecological state" and the "benthic ecological state" at a given spatio-temporal point. This proof of concept provides a methodological framework that can be replicated at multiple scales (from local to global) in other reefs. Using a field-based method with spatial indexing and pressure data, it is now possible to accurately locate and quantify areas of coral reef are vulnerability and of major concern