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Based on extensive ethnographic research on Mayotte (Indian Ocean), this article presents a case study on how environmentalism manifests in one of the world's richest biodiversity sites. It illustrates how Mayotte, the last and poorest French overseas department, is shaped by ‘hyper-environmentalism’ – where residents are forced to be ‘hyper-aware’, ‘hyper-educated’, and ‘hyper-committed’ to environmental issues. The paper discusses how Mayotte is constructed by the Wazungu ("white people") as a tropical ‘otherness’ and describes the process of ‘eco-infantilisation’, where the Maorais people are paternalistically portrayed as ‘children’ who need to be taught to ‘see’, ‘read’, and protect their environment. Finally, it shows how this effort to ‘change mindsets’ fails because it doesn't integrate new scientific knowledge with local expertises, which are often not recognised. The aim of this paper is to provide insights into the diverse manifestations of environmentalism in a post-colonial, tropical, insular, and ‘southern’ territory like Mayotte. [ABSTRACT FROM AUTHOR]

In May 2018, an unprecedented long and intense seismic-volcanic crisis broke out off the island of Mayotte (Indian Ocean) and was associated with the birth of an underwater volcano (Fani Maoré). Since then, an integrated observation network has been created (REVOSIMA), with the given objective of monitoring and better understanding underwater volcanic phenomena. Recently, an unmanned submarine glider (SeaExplorer glider) has been deployed to supplement the data obtained during a series of oceanographic surveys (MAYOBS) carried out on an annual basis. Operated by ALSEAMAR, the glider performed a continuous monitoring of 30 months of the water column from the sea surface to 1250 meters water depth with the objective to acquire hydrological properties, water currents and dissolved gas concentrations. This monitoring already showed that it is feasible and valuable to measure autonomously, continuously and at a high spatio-temporal scale, physical (temperature, salinity, ocean current) and biogeochemical parameters (O 2, CH 4, CO 2, bubbles/droplets, vertical speeds anomalies related to droplets) over several months from a glider. In particular, innovating sensing capabilities (e.g., MINICO2, ADCP) have shown a great potential in the context of the Mayotte seismic volcano crisis, despite technical challenges (complex algorithms, sensor capabilities, etc.). [ABSTRACT FROM AUTHOR]

Seamount eruptions alter the bathymetry and can occur undetected due to lack of explosive character. We review documented eruptions to define whether they could be detected by a future satellite gravity mission. We adopt the noise level in acquisitions of multi-satellite constellations as in the MOCAST+ study, with a proposed payload of a quantum technology gradiometer and clock. The review of underwater volcanoes includes the Hunga Tonga Hunga Ha'apai (HTHH) islands for which the exposed surface changed during volcanic unrests of 2014/2015 and 2021/2022. The Fani Maoré submarine volcanic eruption of 2018–2021 produced a new seamount 800 m high, emerging from a depth of 3500 m, and therefore not seen above sea surface. We review further documented submarine eruptions and estimate the upper limit of the expected gravity changes. We find that a MOCAST+ type mission should allow us to detect the subsurface mass changes generated by deep ocean submarine volcanic activity for volume changes of 6.5 km3 upwards, with latency of 1 year. This change is met by the HTHH and Fani Maoré volcanoes. [ABSTRACT FROM AUTHOR]

The oriental fruit fly (Bactrocera dorsalis) is one of the world's most invasive and polyphagous fruit pests. It causes severe damage throughout its range and can devastate the entire fruit harvest in unprotected orchards. In 2007, B. dorsalis was detected in Mayotte, where it now ranks ninth on the list of fruit fly species of economic importance. This tropical island is a good study area to analyse the host range of B. dorsalis and its interactions with other resident fruit fly species.Two field campaigns were carried out from 2012 to 2014 and from 2019 to 2021. We collected fruit from all over the island in cultivated and non‐cultivated areas and compared the infestation rates between the two periods.We detected six fruit fly species, including the common species Dacus ciliatus, Neoceratitis cyanescens, Ceratitis capitata, B. dorsalis and two rarer species, Dacus etiennellus and Trirhithrum nigerrimum.The most surprising result was the low occurrence of B. dorsalis, with only seven host plant species identified out of a total of 84 plant species. Infestation rates were low for these host plant species, even in the case of mango (11.71 flies/kg) and Indian almond (0.97 fly/kg), which are considered to be major host plants of B. dorsalis.Bactrocera dorsalis seems to have a lower impact in Mayotte than in other parts of the world. We discuss the possible causes of the weak infestation rates observed, which could provide the key to regulating the species on the island. [ABSTRACT FROM AUTHOR]

Citizen-driven approaches are promising to overcome the challenges in the energy transition of geographical islands. However, the economic profitability of related activities must be ensured to achieve the intrinsic and sustainable uptake of related solutions in an island's communities. Here, we investigate the long-term (2020–2054) economic profitability of solar-based prosumption on islands belonging to the European Union (EU), soft-linking energy system modelling and actor-related cash-flow analysis. This combination considerably extends common assessments of the profitability of renewable energy technology and long-term projections of island energy systems. We base our case study on the French overseas territory of Mayotte, discussing household affordability and the socio-economic impact of prosumerism. These topics are relevant to transferability on non-EU islands. The profitability of investments in PV depends on (i) the size of the PV system, with larger systems (>9 kWp) profiting from lower specific investment costs compared to smaller systems; (ii) the time of investment, with more profitable investments to be expected in early periods; (iii) the level of decarbonization of the entire energy sector, with an ongoing decarbonization reducing the compensation or energy-saving possibilities; and (iv) the market behavior, with the practice of feeding in all electricity produced rather than self-consuming energy offering a higher expected return on investment under current feed-in-tariff (FiT) compensation schemes. We introduce various policy measures to improve solar rooftop PV profitability and discuss their trade-offs and effectiveness. While indirect subsidies via FiT are generally effective in improving PV profitability, they undermine efforts to incentivize decentralized self-consumption. From the perspective of harmonizing efforts in the energy transition of African and European islands, we recommend a careful evaluation of the trade-offs in relevant regulations required for the economic incentivization of prosumers to achieve compatibility with the principles of a citizen-driven and just energy transition. Particular attention must be paid to context-specific socio-economic characteristics, including low access to financial resources and non-financial access barriers, including legal status. [ABSTRACT FROM AUTHOR]

This article examines the postcolonial politics of migration control in Mayotte, an overseas French department, and argues that these bear necropolitical consequences. It sheds light on the gendered dimension of this necropolitical power by focusing on the life and border-crossing experiences of undocumented Comorian women. Entrenched barriers to the regularization of their administrative status endanger their access to healthcare and degrade the conditions for life long-term. The constant risk of arrest and massive forced removals furthermore engender dangerous border crossings, each instance exposing the passengers to the risk of death. The article also foregrounds that these necropolitics are exacerbated as a result of the postcolonial conundrum in which Mahoran elites find themselves, with the increasing support of Black and Muslim elites for the French far-right political party. [ABSTRACT FROM AUTHOR]

Submarine volcanoes are more challenging to monitor than subaerial volcanoes. Yet, the large eruption of the Hunga Tonga-Hunga Ha'apai volcano in the Tonga archipelago in 2022 was a reminder of their hazardous nature and hence demonstrated the need to study them. In October 2020, four autonomous hydrophones were moored in the sound fixing and ranging channel 50 km offshore Mayotte Island, in the North Mozambique Channel, to monitor the Fani Maoré 2018–2020 submarine eruption. Between their deployment and July 2022, this network of hydrophones, named MAHY, recorded sounds generated by the recent volcanic activity, along with earthquakes, submarine landslides, marine mammals calls, and marine traffic. Among the sounds generated by the volcanic activity, impulsive signals have been evidenced and interpreted as proxy for lava flow emplacements. The characteristics and the spatio-temporal evolution of these hydroacoustic signals allowed the estimation of effusion and flow rates, key parameters for volcano monitoring. These sounds are related to the non-explosive quenching of pillow lavas due to the rapid heat transfer between hot lava and cold seawater, with this process releasing an energy equivalent to an airgun source as used for active seismic exploration. Volcano observatories could hence use autonomous hydrophones in the water column to detect and monitor active submarine eruptions in the absence of regular on-site seafloor survey. [ABSTRACT FROM AUTHOR]

Mayotte Island, a French department located in the Mozambique Channel, has for several years been faced with the consumption of "La Chimique" (LC), reputed (but extremely poorly documented) to be a mixture of tobacco and synthetic cannabinoid receptor agonists (SCRAs). One of the objectives of the CHASSE‐MAREE protocol is to assess the composition and heterogeneity of LC products through successive LC sample collection campaigns among users. Currently underway, we present here the first analytical results (samples collected in 2022). Between September and December 2022, 80 samples were collected throughout the island over three periods: 70 in the usual form of LC (small folded papers containing a plant‐like sample, mostly tobacco), 6 powders, and 4 cigarettes. Analysis was performed using liquid chromatography with high‐resolution mass spectrometry. The detected substances (number of detections) included SCRAs (MDMB‐4en‐PINACA [35], ADB‐FUBIATA [25], MDMB‐INACA [16], ADB‐BUTINACA [15], AFUBIATA [11], 4F‐MDMD‐BICA [7], CH‐PIATA [14], 5C‐APINACA [3], BZO‐HEXOXIZID [2], and 4F‐ABINACA [1]), nicotine (68), tetrahydrocannabinol (THC), cannabinol (CBN), and cannabidiol (CBD) (2), medications (amantadine [11], cyamemazine [6], and acetaminophen [3]), and a designer benzodiazepine (bromazolam [4]). The SCRAs currently in use are varied, and the market for "cooks" (those who prepare LC) is dispersed according to where and when samples are collected. These preliminary results will be supplemented by analysis of samples collected in the first half of 2023 and by an improved description of the current panorama of consumption of LC in Mayotte (mapping, effects felt and dependence, etc.). [ABSTRACT FROM AUTHOR]

During the last 10 kyr, significant subsidence and uplift occurred on Mayotte Island in the Comoros archipelago (Indian Ocean), but the role of volcanic processes in Holocene vertical movements has been neglected in the research so far. Here, we show that an abrupt subsidence of 6–10 m occurred between 9.4 and 10 kyr ago, followed by an uplift of the same amplitude at a rate of 9 mm/yr from 8.1 to 7 kyr ago. A comparison of the relative sea level of Mayotte and a reference sea level curve for the global ocean has been conducted using a modeling approach. This shows that an increasing and decreasing pressure at depth, equivalent to the process caused by a deep magma reservoir (50–70 km), was responsible for ~6–10 m subsidence and 6–10 m uplift, whereas loading by new volcanic edifices caused subsidence during the last few thousand years. Surface movements and deep pressure variations may be caused by pulses from the deep mantle, related to superplume activity, but uncertainties and unknowns about these phenomena are still present and further studies are needed. A better understanding of the volcano-tectonic cycle may improve assessments of volcanic hazards. [ABSTRACT FROM AUTHOR]

Background: Dengue is a major public health concern in Reunion Island, marked by recurrent epidemics, including successive outbreaks of dengue virus serotypes 1 and 2 (DENV1 and DENV2) with over 70,000 cases confirmed since 2017. Methodology/Principal findings: In this study, we used Oxford Nanopore NGS technology for sequencing virologically-confirmed samples and clinical isolates collected between 2012 and 2022 to investigate the molecular epidemiology and evolution of DENV in Reunion Island. Here, we generated and analyzed a total of 499 DENV1, 360 DENV2, and 18 DENV3 sequences. By phylogenetic analysis, we show that different genotypes and variants of DENV have circulated in the past decade that likely originated from Seychelles, Mayotte and Southeast Asia and highly affected areas in Asia and Africa. Conclusions/Significance: DENV sequences from Reunion Island exhibit a high genetic diversity which suggests regular introductions of new viral lineages from various Indian Ocean islands. The insights from our phylogenetic analysis may inform local health authorities about the endemicity of DENV variants circulating in Reunion Island and may improve dengue management and surveillance. This work emphasizes the importance of strong local coordination and collaboration to inform public health stakeholders in Reunion Island, neighboring areas, and mainland France. Author summary: This study, conducted from 2012 to 2022, aimed at understanding the dynamics and genetic diversity of dengue virus on Reunion Island, a French overseas department located in the southwestern Indian Ocean, which is regularly affected by dengue epidemics. Several thousand clinical isolates and patient samples were collected from across the island and sequenced, resulting in 877 new genetic sequences of dengue virus. Our results show significant genetic diversity among dengue virus variants that circulated on the island over the past decade. This diversity indicates the simultaneous presence of multiple lineages and closely related viruses, which may have resulted from regular introductions of new variants. Our phylogenetic analyses show that the sequences detected in Reunion Island may have originated from other Indian Ocean islands, such as Seychelles and Mayotte, as well as from Asian regions where dengue virus circulates. [ABSTRACT FROM AUTHOR]

While many ecology studies require estimations of species abundance, doing so for mobile animals in an accurate, non‐invasive manner remains a challenge. One popular stopgap method involves the use of remote video‐based surveys using several cameras, but abundance estimates derived from this method are computed with conservative metrics (e.g., maxN computed as the maximum number of individuals seen simultaneously on a single video). We propose a novel methodological framework based on a remote‐camera network characterized by known positions and non‐overlapping field‐of‐views. This approach involves a temporal synchronization of videos and a maximal speed estimate for studied species. Such a design allows computing a new abundance metric called Synchronized maxN (SmaxN). We provide a proof‐of‐concept of this approach with a network of nine remote underwater cameras that recorded fish for three periods of 1 h on a fringing reef in Mayotte (Western Indian Ocean). We found that abundance estimation with SmaxN yielded up to four times higher values than maxN among the six fish species studied. SmaxN performed better with an increasing number of cameras or longer recordings. We also found that using a network of synchronized cameras for a short time period performed better than using a few cameras for a long duration. The SmaxN algorithm can be applied to many video‐based approaches. We built an open‐sourced R package to encourage its use by ecologists and managers using video‐based censuses, as well as to allow for replicability with SmaxN metric. [ABSTRACT FROM AUTHOR]

Aethozoid ctenostome bryozoans are an unusual, small group of solitary ctenostome bryozoans, occurring almost exclusively in deep-sea habitats. Currently, there are only five species belonging to four, still insufficiently known genera, which have been reported from the Atlantic and Pacific Oceans. Recent examination of sediment core samples from an active volcanic area near Mayotte revealed a high abundance of aethozoids, recorded for the first time in the Indian Ocean. A comparative approach identified the specimens as belonging to a new species, Aethozoon flavum sp. nov. There are particular characters diagnostic of this new species, such as basally oriented duplicature bands, a highly denticulate proximal vestibular wall, and a highly elongated anal tube terminating in an almost vestibular anus. This species is the first ctenostome observed at depths of over 3.000 m in the Indian Ocean. Morphological characters are compared among all aethozoids, but still require more detailed analyses in most species. Aethozoids appear to be globally distributed and often occur in high numbers, which indicates that additional efforts will increase their distribution and species range. Ultimately, additional studies will be able to show the ecological importance of these bryozoans and molecular studies should reveal more about their diversity and phylogenetic affinities. [ABSTRACT FROM AUTHOR]

Fluid‐filled cracks sustain a slow guided wave (Krauklis wave or crack wave) whose resonant frequencies are widely used for interpreting long period (LP) and very long period (VLP) seismic signals at active volcanoes. Significant efforts have been made to model this process using analytical developments along an infinite crack or numerical methods on simple crack geometries. In this work, we develop an efficient hybrid numerical method for computing resonant frequencies of complex‐shaped fluid‐filled cracks and networks of cracks and apply it to explain the ratio of spectral peaks in the VLP signals from the Fani Maoré submarine volcano that formed in Mayotte in 2018. By coupling triangular boundary elements and the finite volume method, we successfully handle complex geometries and achieve computational efficiency by discretizing solely the crack surfaces. The resonant frequencies are directly determined through eigenvalue analysis. After proper verification, we systematically analyze the resonant frequencies of rectangular and elliptical cracks, quantifying the effect of aspect ratio and crack stiffness. We then discuss theoretically the contribution of fluid viscosity and seismic radiation to energy dissipation. Finally, we obtain a crack geometry that successfully explains the characteristic ratio between the first two modes of the VLP seismic signals from the Fani Maoré submarine volcano in Mayotte. Our work not only reveals rich eigenmodes in complex‐shaped cracks but also contributes to illuminating the subsurface plumbing system of active volcanoes. The developed model is readily applicable to crack wave resonances in other geological settings, such as glacier hydrology and hydrocarbon reservoirs. Plain Language Summary: Just as sound trapped in organ pipes, vibrating waves in fluid‐filled cracks produce different tunes, called resonant frequencies, which are useful for inferring crack geometries and fluid properties as a larger and narrower crack produces a lower tune. Previous works have primarily studied simple crack geometries while cracks in the natural world normally have complex shapes. In this study, we develop a new method to compute the resonant frequencies of fluid‐filled cracks of complex geometry. This method relies on solving equations only on the crack surface and thus very efficient. We then study vibrations in rectangular and elliptical cracks and evaluate the effect of crack aspect ratio and stiffness. Rich vibrational patterns exist in a crack network, some isolated in a single segment and others involving the entire network. We then discuss the effect of fluid friction and seismic waves on the energy loss of these vibrations. Finally, we show that the crack in Fani Maoré submarine volcano in Mayotte that produced the seismic signal may be dumbbell‐shaped. Overall, our method is applicable for simulating fluid‐filled cracks in wide geological environments, such as active volcanos, glaciers, and oil reservoirs. Key Points: Hybrid boundary element and finite volume method efficiently computes resonant frequencies of complex‐shaped fluid‐filled cracksElliptical crack shares similar modes with rectangular crack but a crack network produces more complex resonancesA dumbbell‐shaped crack explains ratio of first two modes (∼2.5) in the very long period seismic signal at Mayotte submarine volcano [ABSTRACT FROM AUTHOR]

Microbial carbonates are common components of Quaternary tropical coral reefs. Previous studies revealed that sulfate-reducing bacteria trigger microbial carbonate precipitation in supposedly cryptic reef environments. Here, using petrography, lipid biomarker analysis, and stable isotope data, we aim to understand the formation mechanism of microbial carbonate enclosed in deep fore reef limestones from Mayotte and Mohéli, Comoro Islands, which differ from other reefal microbial carbonates in that they contain less microbial carbonate and are dominated by numerous sponges. To discern sponge-derived lipids from lipids enclosed in microbial carbonate, lipid biomarker inventories of diverse sponges from the Mayotte and Mohéli reef systems were examined. Abundant peloidal, laminated, and clotted textures point to a microbial origin of the authigenic carbonates, which is supported by ample amounts of mono-O-alkyl glycerol monoethers (MAGEs) and terminally branched fatty acids; both groups of compounds are attributed to sulfate-reducing bacteria. Sponges revealed a greater variety of alkyl chains in MAGEs, including new, previously unknown, mid-chain monomethyl- and dimethyl-branched MAGEs, suggesting a diverse community of sulfate reducers different from the sulfate-reducers favoring microbialite formation. Aside from biomarkers specific for sulfate-reducing bacteria, lipids attributed to demosponges (i.e., demospongic acids) are also present in some of the sponges and the reefal carbonates. Fatty acids attributed to demosponges show a higher diversity and a higher proportion in microbial carbonate compared to sponge tissue. Such pattern reflects significant taphonomic bias associated with the preservation of demospongic acids, with preservation apparently favored by carbonate authigenesis. [ABSTRACT FROM AUTHOR]

We studied four Quaternary volcanic phonolitic explosive edifices on Petite-Terre Island (Mayotte, Comoros Archipelago, Western Indian Ocean) to quantify magma fragmentation processes and eruptive dynamics. Petite-Terre explosive volcanism is the westernmost subaerial expression of a 60-km-long volcanic chain, whose eastern tip was the site of the 2018–2020 submarine eruption of the new Fani Maoré volcano. The persistence of deep seismic activity and magmatic degassing along the volcanic chain poses the question of a possible reactivation on land. Through geomorphology, stratigraphy, grain size, and componentry data, we show that Petite-Terre "maars" are actually tuff rings and tuff cones likely formed by several closely spaced eruptions. The eruptive sequences of each edifice are composed of thin (cm–dm), coarse, lithic-poor pumice fallout layers containing abundant ballistic clasts, and fine ash-rich deposits mostly emplaced by dilute pyroclastic density currents (PDCs). Deposits are composed of vesiculated, juvenile fragments (pumice clasts, dense clasts, and obsidian), and non-juvenile clasts (from older mafic scoria cones, coral reef, the volcanic shield of Mayotte, as well as occasional mantle xenoliths). We conclude that phonolitic magma ascended directly and rapidly from depth (around 17 km) and experienced a first, purely magmatic fragmentation, at depth (≈ 1 km in depth). The fragmented pyroclasts then underwent a second shallower hydromagmatic fragmentation when they interacted with water, producing fine ash and building the tuff rings and tuff cones. [ABSTRACT FROM AUTHOR]

With over a million described species, insects are the most diverse group of animals on Earth. Insects, particularly those responsible for pollination, play a major ecological role that is often overlooked or even ignored. Indeed, apart from honeybees, many species are not recognized for the services they provide. What is more, all pollinating insects do not attract the same affection. Some, such as butterflies, enjoy a very positive image, while others are feared or hated, often because they can sting. During a semi-structured interview study (N = 35) on the island of Mayotte, we confirmed these views. On the other hand, butterflies and one species of carpenter bee were the subject of many children's play and games, which have now been abandoned. Those who played with them in the past, and more simply enjoyed watching children play, seem to bitterly regret it. [ABSTRACT FROM AUTHOR]

Charroux, S.; Jeanson, M.; Morisseau, S., and Pennober, G., 2024. Seasonal morphodynamics of fringing reef pocket beaches and responses to rapid vertical tectonic movements. Journal of Coastal Research, 40(1), 31–50. Charlotte (North Carolina), ISSN 0749-0208. Determining the morphological response of coastal environments to a general rise in sea level constitutes one of this century's greatest challenges. In 2018–19, Mayotte, a coral reef–fringed island in the Indian Ocean, underwent a volcanic crisis that resulted in island subsidence of up to 0.2 m. This seismo-volcanic crisis made the island an ideal workshop site to observe the response of pocket beaches to sea-level variations. Morphodynamic analyses were carried out on three beaches located on different sides of the island on a biannual basis between 2019 and 2022. Analysis of these survey data showed that the alternation between monsoon and trade winds led to a seasonal rotation of the beaches. Furthermore, the central profiles did not appear to be affected by seasonal variations. As result, they were used to characterize subsidence-related impacts. When the pre- and postsubsidence profiles were compared, morphological changes were not noticeable. However, the rise in the sea level caused by subsidence led to an increase in the frequency of spring flooding at high tide in certain areas of low-lying beaches and roads on the densely populated NE coast of the archipelago, the area most affected by this tectonic movement. [ABSTRACT FROM AUTHOR]

Implosive consonants have drawn the attention of researchers over time, partially due to their relative rarity in the world's languages, and partially due to their unique ingressive air flow. This sound category has varying complex features from an articulatory and acoustic perspective. This study explores the sound category by analyzing the acoustic features of a language whose implosives have yet to be acoustically considered: Shimaore, a Bantu-Sabaki language spoken in Mayotte. Specifically, it compares the bilabial plosive /b/ and the bilabial implosive /ɓ/ in terms of Voice Onset Time (VOT), fundamental frequency, amplitude, and voice quality via H1*–H2*, harmonics-to-noise ratios (HNR), and cepstral peak prominence (CPP). Analyses show that VOT is shorter for implosives than for plosives. At oral closure and vowel onset, amplitude and f0 are higher than plosives. H1*–H2* values read alongside HNR and CPP values suggest that implosives in Shimaore have glottal constriction. Some individual differences are explored for question of variation in implosives. Implications regarding sociophonetic studies in Mayotte as well as general implications for implosives are discussed. [ABSTRACT FROM AUTHOR]

The 2nd french Marine Protected Area was officially created in Mayotte in January 2010, thanks both to a swift procedure and to a strong determined policy. It clearly shows the will of France to manage a broad area in south-west of the Indian Ocean even if its means of action are still to settle. Beyond environemental protection, the park is seen as a useful tool for an island still considered as emergent. From fishing to tourism, many activities hope to take advantage from the dynamic set in motion.

Since 2018 an unexpected number of earthquakes have been occurring offshore Mayotte, in the Mozambique Channel. They are linked to the eruption of the Fani Maoré submarine volcano. Using a recently-developed comprehensive automatic catalog, we explore two years of volcano-tectonic (VT) seismicity between March 2019 and March 2021 and analyse in detail the active structures of the magmatic plumbing system using ~33,000 events. The VT earthquakes highlight three magma storage zones and two aseismic conduits that had never been observed before. The temporal evolution of the seismicity reveals a probable regime change in March 2020. While before, the plumbing system reacted to the drainage of magma from a deep reservoir and to the migration of magma towards the seafloor, it is now responding to new migrations of fluids and to the redistribution of the stress-load across the system's pre-existing faults. This analysis is key to better understand long-term volcanism worldwide.

Introduction: A high incidence of human leptospirosis is recorded on Mayotte, an oceanic island located in southwestern Indian Ocean, but the severity of the disease appears relatively mild in terms of mortality rate and admission to the intensive care unit. It has been proposed that mild leptospirosis may result from a limited virulence of some of the occurring Leptospira species to which the population is exposed. Methods: Clinical and biological data of patients admitted to the Centre Hospitalier de Mayotte were collected and the infecting Leptospira species were determined through molecular typing. Results: Leptospira interrogans was detected in the minority of admitted patients but most of these patients suffered from severe forms, with 50% admitted to intensive care unit and suffering from organ failures. Nineteen percent of patients infected with Leptospira borgpetersenii were admitted to the intensive care, with 13% displaying organ failures, and one patient died. Leptospira mayottensis was found in 28% of the patients and not a single severe case was observed. Discussion: The distribution of Leptospira species in patients was not different from that reported 10-15 years ago and bacterial genotypes were very closely related to those previously reported. These results highlight the importance of the diversity of pathogenic Leptospira circulating on Mayotte island and are in keeping with distinct outcome of the disease depending on the infecting Leptospira. Altogether, presented data support that the infecting Leptospira species is an important driver of disease severity in humans. [ABSTRACT FROM AUTHOR]

Due to their life cycle shared between rivers and oceans, amphidromous organisms serve as intriguing models for studying biogeography. To investigate the implications of their unique life history, we examined the population structure of the amphidromous shrimp Caridina natalensis across its known range in the South Western Indian Ocean. A total of 118 specimens were collected from 7 islands (Mayotte, Mohéli, Mahé, Praslin, Silhouette, Mauritius and Madagascar) and the African mainland (South Africa), and their 16S rRNA and Cox1 mitochondrial genes were sequenced. Our findings reveal significant regional structure among archipelagos, suggesting complex patterns of dispersal involving successive events of extinction-recolonization. By conducting a comparative analysis with six other amphidromous species from the South Western Indian Ocean, based on literature sources, we were able to draw conclusions regarding the amphidromous biogeography of the area. Furthermore, we propose a novel classification of amphidromous species, considering their population structure and life history traits. We defined four categories of increasing dispersal abilities and decreasing genetic population structure: 1. Land-locked species; 2. Species with reduced or facultative amphidromy; 3. Species with common amphidromy; and 4. Super-amphidromous species. Lastly, we identified the Comoros Islands (namely Mayotte and Mohéli) as a critical area for the dispersal of amphidromous species, emphasizing the need for prioritizing conservation efforts in this region. [ABSTRACT FROM AUTHOR]

Two specimens of large blackish chimaeras of the genus Hydrolagus were caught, one off Reunion Island and the other off Mayotte in the southwestern Indian Ocean. The specimens, an adult male of 710 mm BDL and a female of 870 m BDL, are described, compared to similar species (i.e., having a large size, over 110 cm TL, dark blackish colour, and rather long conical snout), and tentatively identified to the small-eyed rabbitfish Hydrolagus affinis, pending a taxonomic revision of the large blackish chimaeras is completed. [ABSTRACT FROM AUTHOR]

IntroductionA high incidence of human leptospirosis is recorded on Mayotte, an oceanic island located in southwestern Indian Ocean, but the severity of the disease appears relatively mild in terms of mortality rate and admission to the intensive care unit. It has been proposed that mild leptospirosis may result from a limited virulence of some of the occurring Leptospira species to which the population is exposed.MethodsClinical and biological data of patients admitted to the Centre Hospitalier de Mayotte were collected and the infecting Leptospira species were determined through molecular typing.ResultsLeptospira interrogans was detected in the minority of admitted patients but most of these patients suffered from severe forms, with 50% admitted to intensive care unit and suffering from organ failures. Nineteen percent of patients infected with Leptospira borgpetersenii were admitted to the intensive care, with 13% displaying organ failures, and one patient died. Leptospira mayottensis was found in 28% of the patients and not a single severe case was observed.DiscussionThe distribution of Leptospira species in patients was not different from that reported 10-15 years ago and bacterial genotypes were very closely related to those previously reported. These results highlight the importance of the diversity of pathogenic Leptospira circulating on Mayotte island and are in keeping with distinct outcome of the disease depending on the infecting Leptospira. Altogether, presented data support that the infecting Leptospira species is an important driver of disease severity in humans.

The name Bulimus ovoideus Bruguière, 1789 is in current use for two different species, one from East Africa and one from the Philippines. The name has also been declared as the type species of both Edentulina Pfeiffer, 1856 (Streptaxidae) and Cochlostyla Férussac, 1821 (Camaenidae). We demonstrate that the use of this name for a Philippine camaenid is based on an early misidentification. To clarify the situation, we invoke Article 70.3 of the Code of Zoological Nomenclature, concerning misidentified type species, to select the taxonomic species actually involved, Bulinus luzonicus Sowerby I, 1833, as the type species of Cochlostyla. Cochlostyla thus becomes a senior objective synonym of Canistrum Mörch, 1852. Under Article 40.2 of the Code, Helicostylinae Ihering, 1909 takes precedence of Cochlostylinae Möllendorff, 1890. We further show that the Philippine camaenids Orthostylus Beck, 1837 and Dryocochlias Möllendorff, 1898 are objective synonyms with the former name having priority. Finally, we designate a neotype for Bulimus ovoideus to stabilise its taxonomy. These actions permit the current nomenclature to be maintained with a minimum of disruption. The currently accepted name of the taxon in question is Edentulina ovoidea (Bruguière, 1789). [ABSTRACT FROM AUTHOR]

Environmental parameters drive seasonal soil CO2 efflux toward the atmosphere. However, their influence is not fully understood in contexts of high CO2 fluxes where CO2 accumulates in the subsurface. A prime example are volcanoes subject to continuous CO2 diffuse degassing rising from deep magmatic reservoirs, through the subsurface and up to the atmosphere. For many of these volcanoes where soil CO2 is monitored, a seasonal influence of the atmosphere and water table is observed but not characterized. Here, we compare variations of air temperature, atmospheric pressure, rainfall and water table level with near‐surface soil CO2 concentration by performing a time‐lagged detrended cross‐correlation analysis on years‐long time series from the volcanoes of Piton de la Fournaise and Mayotte. At Piton de la Fournaise, soil CO2 variations correlate best with air temperature variations (0.81) and water table variations (0.74). In Mayotte, soil CO2 variations correlate best with atmospheric pressure variations (−0.95). We propose that at Piton de la Fournaise, the thick vadose zone and high permeability favor CO2 transfer by thermal convection. Additionally, energy transfer is decoupled from mass transfer. Slow heat transfer from the atmosphere down to the accumulated CO2 layers in the subsurface results in a delayed influence of air temperature and of the water table level on the thermal gradient between the subsurface and the atmosphere, and consequently on the efficiency of the CO2 transfer. In Mayotte, we propose that the thin vadose zone and the presence of a network of large fractures favor CO2 transfer by barometric pumping. Plain Language Summary: The soil is a major reservoir of gaseous CO2 at the scale of the planet. This soil CO2 is mobile and can escape to the atmosphere and contribute to global warming. It thus important to understand what controls its mobility. In contexts of high soil CO2 contents, environmental parameters can drive soil CO2 transfers toward the atmosphere, but their influence is still poorly understood at timescales beyond a few days. To address this issue, we studied how air temperature, atmospheric pressure, rainfall, and water table level affect soil CO2 efflux in volcanic environments where the soil CO2 content is naturally high due to magmatic degassing. Our study sites are the volcanoes of Piton de la Fournaise and Mayotte. We performed a time‐lagged detrended cross‐correlation analysis which compares the similarity between different time series. We find that air temperature, atmospheric pressure and water table level variations can cause soil CO2 to move toward the surface. The magnitude of their influence and the type of transfers depend on the geological properties of the study sites. We also find that these influences can occur with significant delays of over a hundred days. Key Points: Air temperature, atmospheric pressure, and water table level influence soil CO2 concentrations at a seasonal scaleThe decoupling of heat and mass transfer in the subsurface induces a delayed response of soil CO2 concentrations to environmental forcingCO2 mass transport at high flux is driven by thermal convection or barometric pumping depending on site properties [ABSTRACT FROM AUTHOR]

Since May 2018 till the end of 2021, Mayotte island has been the locus of a major submarine volcanic eruption characterized by the offshore emission of more than 6.5 km$^{3}$ of basanitic magma. The eruption occurred along a WNW–ESE trending submarine ridge on the east flank of the island where, in addition, several seemingly recent phonolitic bodies were also identified close to the island. To define realistic scenarios of magma ascent and potentially predict the style of an upcoming event, it is crucial to have a precise understanding on the plumbing system operating below volcanoes. The putative relationships between basanites emitted by the new volcano and these recent phonolites have been experimentally explored by performing crystallization experiments on a representative basanite over a large range of pressures (up to 400 MPa). The results show that the crystallization of basanite at crustal levels (${\le }$12–15 km) yields a phonolitic residual liquid containing up to 3–4 wt% $\mathrm{H}_{2}\mathrm{O}$ after ${\ge }$65 wt% of an assemblage of olivine$+$plagioclase$+$amphibole$+$clinopyroxene$+$biotite$+$magnetite$+$ilmenite$+$apatite. The final iron content of the residual phonolitic liquids is strongly controlled by the depth/pressure of fractionation. Fe-rich phonolites from the submarine ridge are produced at 6–8 km depth, while a shallower differentiation (${\le }$4–5 km) results in the production of liquids with trachyte–benmoreite affinities. If the fractionation process occurs at depths higher than 8 km, the resulting phonolitic melts are progressively enriched in $\mathrm{SiO}_{2}$–$\mathrm{Al}_{2}\mathrm{O}_{3}$ but depleted in FeO*, ie unlike those erupted. We therefore conclude that phonolitic magma production and storage at Mayotte is a rather shallow process.

From 10 May 2018 to 1 November 2022 (time of writing), an unprecedented seismic activity is observed east of Mayotte Island (France), related to the largest submarine eruption ever recorded with offshore geophysical studies. Using signals from regional and local seismic stations, we build a comprehensive catalog of the local seismicity for the first ten months of the sequence. This catalog includes a total of 2874 events of magnitude (Mlv) ranging from 2.4 to 6.0, with 77% of them relocated using a double difference location procedure. The hypocentral locations over this period are highly dependent on the small seismic network available. Therefore we compare the locations of later events using a similar network and those estimated from a local ocean bottom seismometer (OBS) network installed since March 2019. Based on the time space evolution and characteristics of the seismicity, five distinct phases can be identified, corresponding to the successive activation of two deep seismic swarms, related to the lithospheric-scale magma ascent up to the seafloor, along with progressive deepening of the seismicity interpreted as decompression of a 40 km deep reservoir.

(1) The island of Mayotte, located in the Indian Ocean, possesses remarkable biodiversity. In a previous ethnobotanical study, we already highlighted 69 different plant species used in traditional medicine. Among those, 21 were traditionally employed for skin care by the local populations. The present study aimed to better understand the traditional use of those plants by investigating their in vitro biological activities and, more specifically, their anti-lipoxygenase, antioxidant and anti-tyrosinase properties. (2) These three activities were, respectively, determined by lipoxygenase inhibition, DPPH-reducing potency, and anti-tyrosinase activity assays. (3) Results revealed high biological activities for several plant species, with some of them displaying one strong single activity, while others had at the same time anti-lipoxygenase, antioxidant and anti-tyrosinase effects. (4) Those in vitro biological activities agreed with the traditional use of those plants by the local population. It also highlights the high potential of those species from Mayotte in the development of new cosmetic ingredients for the treatment of many skin affections, such as eczema.

Unlike subaerial volcanic activity, deep submarine eruptions are difficult to detect, observe and monitor. The objective of this paper is to describe a large and complex volcanic region, named the Horseshoe area, recently discovered at ${\sim }$1500 m below sea level on the eastern upper submarine slope of Mayotte Island. The area is crucial because, since 2018, it has experienced an exceptionally deep seismic activity associated with the ongoing submarine eruption that formed a new volcanic edifice, Fani Maoré, about 40 km to the east. We present the results of a multiscale study, based on high-resolution bathymetry and in-situ seafloor observations carried out with autonomous underwater vehicles (AUVs) and deep-towed camera systems. In-situ imagery provides ground-truth for the geological interpretation of seafloor textures mapped with the bathymetry. The combination of both datasets allows us to discuss the nature of the volcanic structures and to propose a relative chronology of previous eruptive events in the Horseshoe area. Based on our analyses, we propose the following chronology: (a) the emplacement of a large explosive volcanic cone, the Horseshoe edifice, (b) the later collapse of this edifice that resulted in the formation of an elongated, 2 km wide horseshoe-shaped depression, crosscutting older hummocky lava flows, (c) the development of an E–W eruptive fissure associated with numerous explosive craters, east of the Horseshoe edifice, and (d) late volcanism emanating from the rim of the horseshoe-shaped depression that fed elongated thin lava flows both towards and away from the depression. While all volcanic features mapped at the Horseshoe area were emplaced prior to the 2018 eruption, our study shows that this region has still been volcanically active in the recent past. Our results thus document a complex geological history at small spatial scales involved in the construction of major submarine edifices, and that are controlled by volcano-tectonic processes at larger scales.

A new marine volcano is erupting offshore Mayotte since May 2018, generating numerous earthquakes. The population felt many of them and the stronger shaking of the ongoing sequence caused slight damage to buildings. Historical records also confirm that damaging earthquakes had occurred in the past in this region. Seismic damage scenarios are a key tool for supporting the decision-making process, the preparedness, and for designing appropriate emergency responses. This paper provides the outcomes of a work consisting in improving the seismic risk assessment as a part of disaster risk governance and exposes the scientific background of this workflow. It illustrates its use with two earthquakes. Related post-seismic surveys provide observations that are useful to check the validity of the reference dataset. The paper also discusses the main characteristics of the rapid loss assessment tool that has been developed to provide operational information for crisis management.

A multichannel seismic reflection profile acquired during the SISMAORE cruise (2021) provides the first in-depth image of the submarine volcanic edifice, named Fani Maore, that formed 50 km east of Mayotte Island (Comoros Archipelago) in 2018–2019. This new edifice sits on a ${\sim }$140 m thick sedimentary layer, which is above a major, volcanic layer up to ${\sim }$1 km thick and extends over 120 km along the profile. This volcanic unit is made of several distinct seismic facies that indicate successive volcanic phases. We interpret this volcanic layer as witnessing the main phase of construction of the Mayotte Island volcanic edifice. A ${\sim }$2.2–2.5 km thick sedimentary unit is present between this volcanic layer and the top of the crust. A complex magmatic feeder system is observed within this unit, composed of saucer-shape sills and seal bypass systems. The deepest tip of this volcanic layer lies below the top-Oligocene seismic horizon, indicating that the volcanism of Mayotte Island likely began around 26.5 Ma, earlier than previously assumed.

The “Fani Maoré” eruption off the coasts of Mayotte has been intensively monitored by applying methods similar to those used for subaerial eruptions. Repeated high-resolution bathymetric surveys and dredging, coupled with petrological analyses of time-constrained samples, allowed tracking the evolution of magma over the whole submarine eruptive sequence. Indeed, after one year of direct ascent (Phase 1), basanitic magma switched to a different pathway that sampled a tephri-phonolitic subcrustal reservoir (Phase 2). Later, the magma pathway shifted again in the crust resulting in a new eruption site located 6 km northwest of the main edifice (Phase 3). The petrological signature of lava flows reveals both an evolution by fractional crystallization and syn-eruptive mixing with a tephri-phonolitic magma.We demonstrate that high-flux eruption of large volumes of basanitic magma from a deep-seated reservoir can interact with shallower reservoirs and remobilize eruptible magma. This has significant hazards implications with respect to the capacity of such large eruptions to reactivate shallow-seated inactive reservoirs from a transcrustal magmatic system that could be located potentially at a distance from the high-flux eruptive site.

Since the 2000s, local seismic hazard studies have shown that Mayotte Island presented superficial geological formations prone to lithological site effects. The seismic sequence initiated in May 2018 confirmed the importance of such effects, both in terms of intensity and spatial extension. The analysis of the recorded strong motions showed that weathered volcanic formations are prone to significant site effects with mean amplification factors for peak ground acceleration (PGA) between 1.4 and 4.9 and that a complex combination of lithological and topographic site effects is in action. We thus implement a regional scale map of site effects for the fast calculation of strong motion and damage maps for crisis management purposes. We also provide a first estimate of key site parameters for eight stations: surface geology, resonance frequency, an amplification factor proxy for PGA, a ${V}_{{S},30}$ value, if available, and an estimated EC8 soil class.

In May 2018, the Mayotte island, located in the Indian Ocean, was affected by an unprecedented seismic crisis, followed by anomalous on-land surface displacements in July 2018. Cumulatively from July 1, 2018 to December 31, 2021, the horizontal displacements were approximately 21 to 25 cm eastward, and subsidence was approximately 10 to 19 cm. The study of data recorded by the on-land GNSS network, and their modeling coupled with data from ocean bottom pressure gauges, allowed us to propose a magmatic origin of the seismic crisis with the deflation of a deep source east of Mayotte, that was confirmed in May 2019 by the discovery of a submarine eruption, 50 km offshore of Mayotte ([Feuillet et al., 2021]). Despite a non-optimal network geometry and receivers located far from the source, the GNSS data allowed following the deep dynamics of magma transfer, via the volume flow monitoring, throughout the eruption.

Teleseismic receiver-functions and Rayleigh-wave dispersion curves are jointly inverted for quantifying $S$-wave velocity profiles beneath the active volcanic zone off Mayotte. We show that the lithosphere in the east-northeast quadrant is composed of four main layers, interpreted as the volcanic edifice, the crust with underplating, the lithospheric mantle, and the asthenosphere, the latter two presenting a main low-velocity zone. The depths of the old (10–11 km) and new Moho (28–31 km) coincide with the two magma reservoirs evidenced by recent seismological and petrological methods. We propose that the main magma reservoir composed of mush with an increasing amount of liquid extends down to 54 km depth. This magma storage develops from a rheological contrast between the ductile lower and brittle upper lithospheric mantle and accounts for most of the volcanic eruption-related seismicity. Finally, the abnormally small thickness of the lithospheric mantle (33 km) is likely a result of a thermal thinning since the onset of Cenozoic magmatism.

Since May 2018, an unexpected long and intense seismic crisis started offshore Mayotte (Indian Ocean, France). This ongoing seismic sequence is associated with the birth of a newly discovered submarine volcano 50 km east of Petite Terre. Here, we investigate the indirect impact of this crisis on the stability of an atypical ecosystem located in Mayotte, the Dziani Dzaha Lake. This lacustrine system presented physical, chemical and biogeochemical characteristics that were distinct from those classically observed in modern lakes or seawater, e.g. high salinity (up to 70 psu), lack of nitrate, sulfate content below 3 mM, and permanent water column anoxia below ca. 1.5 m depth (2012–2017 period). Based on three surveys conducted in 2020 and 2021, we documented an episode of water column oxygenation, a significant pH decrease and an impressive change in the carbon isotope signatures. These preliminary data suggest that the functioning of biogeochemical cycles in the Dziani Dzaha Lake is impacted by increased CO2 inputs and the changes in the lake mixing dynamics, which is an indirect consequence of the ongoing seismo-volcanic crisis.

Mayotte’s seismo-volcanic crisis gave rise to extensive media coverage in the local, regional and national daily press. Analyzing the news narratives allows us to bring to light the representations that readers are confronted with when they try to inform themselves about the situation. This article brings together the sciences of risk, language and communication in order to analyse these pluri-vocal narratives, in which the scientific community is given pride of place. It shows how the voices of the main actors (the inhabitants, the administrative and scientific authorities) are put on the stage, conveying differing representations, differing forms of explanation and contributing to an effect of “enunciatory muddling”. It aims to provide food for thought for people called upon to intervene in the media, in Mayotte or elsewhere.

The archipelago of Comoros was generally considered a moderately seismic region. However, since May 2018, unusual seismicity has been observed off the east coast of Mayotte Island. Following this increase of seismic activity, oceanographic campaigns led to the discovery of a new submarine volcano, indicating that the observed seismicity had a volcanic origin. In this study, we estimate Centroid Moment Tensor (CMT) solutions of $M_w\ge 5$ earthquakes of this sequence using 3D Green’s functions and analyze their non-double-couple (non-DC) components. Consistently with previous reports, our results indicate that seismicity migrated upward in May–June 2018 with an increasing number of non-DC events. We show that non-DC components observed in our solutions and previously published catalogs cannot correspond to dike opening or closing as the observed rupture durations suggest unrealistically large magma flow rates. Given that waveforms can be relatively well explained with pure-shear sources, we postulate that non-DC components are most likely artifacts due to unmodeled shallow structural heterogeneities. Most $M_w\ge 5$ earthquakes have a strike-slip mechanism consistent with the rupture of pre-existing faults loaded by the regional stress regime and triggered by the increment of stress produced by the upward magma transfer.

The Comoros archipelago is an active geodynamic region located in the Mozambique Channel between East continental Africa and Madagascar. The archipelago results from intra-plate volcanism, the most recent eruptions having occurred on the youngest island of Grande Comore and on the oldest one of Mayotte. Since 2018, the eastern submarine flank of Mayotte has been the site of one of the largest recent eruptive events on Earth in terms of erupted lava volume. On land, the most recent volcanic activity occurred in Holocene on the eastern side of Mayotte, corresponding to the small Petite Terre Island, where two main and persistent gas seep areas are present (Airport Beach, namely BAS, and Dziani Dzaha intracrateric lake). The large submarine eruption at the feet of Mayotte (50 km offshore; 3.5 km b.s.l.) is associated with deep (mantle level) seismic activity closer to the coast (5–15 km offshore) possibly corresponding to a single and large magmatic plumbing system. Our study aims at characterizing the chemical and isotopic composition of gas seeps on land and assesses their potential link with the magmatic plumbing system feeding the Mayotte volcanic ridge and the recent submarine activity. Data from bubbling gases collected between 2018 and 2021 are discussed and compared with older datasets acquired between 2005 and 2016 from different research teams. The relation between $\mbox {}^{3}\mathrm{He}/\mbox {}^{4}\mathrm{He}$ and $\delta ^{13}\mathrm{C}$-$\mathrm{CO}_{2}$ shows a clear magmatic origin for Mayotte bubbling gases, while the variable proportions and isotopic signature of $\mathrm{CH}_{4}$ is related to the occurrence of both biogenic and abiogenic sources of methane. Our new dataset points to a time-decreasing influence of the recent seismo-volcanic activity at Mayotte on the composition of hydrothermal fluids on land, whose equilibrium temperature steadily decreases since 2018. The increased knowledge on the gas-geochemistry at Mayotte makes the results of this work of potential support for volcanic and environmental monitoring programs.

Chikungunya is an arboviral disease causing arthralgia which may develop into a debilitating chronic arthritis. In Mayotte, a French overseas department in the Indian Ocean, a chikungunya outbreak was reported in 2006, affecting a third of the population. We aimed at assessing the chikungunya seroprevalence in this population, after over a decade from that epidemic. A multi-stage cross sectional household-based study exploring socio-demographic factors, and knowledge and attitude towards mosquito-borne disease prevention was carried out in 2019. Blood samples from participants aged 15–69 years were taken for chikungunya IgG serological testing. We analyzed associations between chikungunya serological status and selected factors using Poisson regression models, and estimated weighted and adjusted prevalence ratios (w/a PR). The weighted seroprevalence of chikungunya was 34.75% (n = 2853). Seropositivity for IgG anti-chikungunya virus was found associated with living in Mamoudzou (w/a PR = 1.49, 95%CI: 1.21–1.83) and North (w/a PR = 1.41, 95%CI: 1.08–1.84) sectors, being born in the Comoros islands (w/a PR = 1.30, 95%CI: 1.03–1.61), being a student or unpaid trainee (w/a PR = 1.35, 95%CI: 1.01–1.81), living in precarious housing (w/a PR = 1.30, 95%CI: 1.02–1.67), accessing water streams for bathing (w/a PR = 1.72, 95%CI: 1.1–2.7) and knowing that malaria is a mosquito-borne disease (w/a PR = 1.42, 95%CI: 1.21–1.83). Seropositivity was found inversely associated with high education level (w/a PR = 0.50, 95%CI: 0.29–0.86) and living in households with access to running water and toilets (w/a PR = 0.64, 95%CI: 0.51–0.80) (n = 1438). Our results indicate a long-lasting immunity from chikungunya exposure. However, the current population seroprevalence is not enough to protect from future outbreaks. Individuals naïve to chikungunya and living in precarious socio-economic conditions are likely to be at high risk of infection in future outbreaks. To prevent and prepare for future chikungunya epidemics, it is essential to address socio-economic inequalities as a priority, and to strengthen chikungunya surveillance in Mayotte. [ABSTRACT FROM AUTHOR]

by accompanying the eutocial birth at the technical, relational, and symbolic levels, the midwife mediates knowledge to support the bond between baby and mother. A co-adjustment operates by weaving together identities in a given context, specifically in Réunion and Mayotte. The qualitative analysis of clinical interviews shows a mobilization of anthropological, psychological, and epistemological knowledge. Diversified in its adaptations, the alliance around well-being varies with each birth: recursively, the midwife's view is modified, allowing the construction of a transcultural expertise. [ABSTRACT FROM AUTHOR]

Understanding and quantifying the hazards related to earthquake-induced submarine liquefaction and landslides are particularly significant offshore of tropical volcanic-carbonate islands, where carbonate production competes with volcanism to create highly contrasted lithological successions. To improve the detection of liquefaction-prone layers, we analyzed physical properties and mineralogy and performed 70 dynamic triaxial tests on 25 sediment cores offshore of the eastern side of Mayotte (Comoros archipelago in the western Indian Ocean) in an area that has experienced significant seismicity since 2018. We found that the main parameter controlling the liquefaction potential offshore of Mayotte is the presence of low-density layers with high calcite content accumulating along the slope during lowstands. This phasing with sea-level fluctuations implies a significant recurrent geohazard for tropical volcanic-carbonate islands worldwide. Furthermore, the relationship we found between the cyclic resistance of sediment and its density and magnetic susceptibility represents a timeeffective approach for identifying the hazards related to earthquake-induced liquefaction. [ABSTRACT FROM AUTHOR]

Bats have received considerable recent attention for infectious disease research because of their potential to host and transmit viruses, including Ebola, Hendra, Nipah, and multiple coronaviruses. These pathogens are occasionally transmitted from bats to wildlife, livestock, and to humans, directly or through other bridging (intermediate) hosts. Due to their public health relevance, zoonotic viruses are a primary focus of research attention. In contrast, other emerging pathogens of bats, such as bacteria, are vastly understudied despite their ubiquity and diversity. Here, we describe the currently known host ranges and geographic distributional patterns of potentially zoonotic bacterial genera in bats, using published presence-absence data of pathogen occurrence. We identify apparent gaps in our understanding of the distribution of these pathogens on a global scale. The most frequently detected bacterial genera in bats are Bartonella, Leptospira, and Mycoplasma. However, a wide variety of other potentially zoonotic bacterial genera are also occasionally found in bats, such as Anaplasma, Brucella, Borrelia, Coxiella, Ehrlichia, Francisella, Neorickettsia, and Rickettsia. The bat families Phyllostomidae, Vespertilionidae, and Pteropodidae are most frequently reported as hosts of bacterial pathogens; however, the presence of at least one bacterial genus was confirmed in all 15 bat families tested. On a spatial scale, molecular diagnostics of samples from 58 countries and four overseas departments and island states (French Guiana, Mayotte, New Caledonia, and Réunion Island) reported testing for at least one bacterial pathogen in bats. We also identified geographical areas that have been mostly neglected during bacterial pathogen research in bats, such as the Afrotropical region and Southern Asia. Current knowledge on the distribution of potentially zoonotic bacterial genera in bats is strongly biased by research effort towards certain taxonomic groups and geographic regions. Identifying these biases can guide future surveillance efforts, contributing to a better understanding of the ecoepidemiology of zoonotic pathogens in bats. [ABSTRACT FROM AUTHOR]

Background: Toxoplasmosis is an infection caused by an intracellular protozoan, Toxoplasma gondii. It is usually asymptomatic, but toxoplasmosis acquired during pregnancy can cause congenital toxoplasmosis, potentially resulting in fetal damage. Epidemiological information is lacking for toxoplasmosis in Mayotte (a French overseas territory). We evaluated (1) the prevalence of maternal toxoplasmosis, (2) the incidence of maternal and congenital toxoplasmosis, and (3) the management of congenital toxoplasmosis in Mayotte. Methodology / Principal Findings: We collected all the available data for toxoplasmosis serological screening during pregnancy and maternal and congenital cases of toxoplasmosis obtained between January 2017 and August 2019 at the central public laboratory of Mayotte (Mamoudzou). Using toxoplasmosis serological data from samples collected from 16,952 pregnant women we estimated the prevalence of toxoplasmosis in Mayotte at 67.19%. Minimum maternal toxoplasmosis incidence was estimated at 0.29% (49/16,952, 95% CI (0.0022–0.0038)), based on confirmed cases of maternal primary infection only. The estimated incidence of congenital toxoplasmosis was 0.09% (16/16,952, 95% CI (0.0005–0.0015). Missing data made it difficult to evaluate management, but follow-up was better for mothers with confirmed primary infection and their infants. Conclusions / Significance: The seroprevalence of toxoplasmosis among pregnant women and the incidence of toxoplasmosis are higher in Mayotte than in mainland France. There is a need to improve the antenatal toxoplasmosis screening and prevention programme, providing better information to physicians and the population, to improve management and epidemiological monitoring. Author summary: Toxoplasmosis, a zoonotic disease caused by a ubiquitous protozoan parasite Toxoplasma gondii is usually asymptomatic. However, maternal infection during pregnancy can cause congenital toxoplasmosis with potentially severe neurologic or ophthalmological sequelae. Prevalence varies from country to country depending on socio-economic conditions, dietary habits and hygiene and the prevalence is higher in resource-poor countries. In Mayotte (a French overseas territory), recommendations for toxoplasmosis prevention and screening are partially applied. Indeed, many women don't speak French, serological follow up is generally irregular and responsible for delayed introduction of treatment and consequently more congenital toxoplasmosis cases. To our knowledge, few published data were available on maternal and congenital toxoplasmosis for this territory. A better understanding of the epidemiology of this parasite would allow surveillance, information and limitation of maternal-fetal transmission to reduce the number of congenital toxoplasmosis cases and improve the management of toxoplasmosis in Mayotte. [ABSTRACT FROM AUTHOR]

Islands face unique challenges on their journey towards achieving carbon neutrality by the mid-century, due to the lack of energy interconnections, limited domestic energy resources, extensive fossil fuel dependence, and high load variance requiring new technologies to balance demand and supply. At the same time, these challenges can be turned into a great opportunity for economic growth and the creation of jobs with non-interconnected islands having the potential to become transition frontrunners by adopting sustainable technologies and implementing innovative solutions. This paper uses an advanced energy–economy system modeling tool (IntE3-ISL) accompanied by plausible decarbonization scenarios to assess the medium- and long-term impacts of energy transition on the energy system, emissions, economy, and society of the island of Mayotte. The model-based analysis adequately captures the specificities of Mayotte and examines the complexity, challenges, and opportunities to decarbonize the island's non-interconnected energy system. The energy transition necessitates the adoption of ambitious climate policy measures and the extensive deployment of low- and zero-carbon technologies both in the demand and supply sides of the energy system, accounting for the unique characteristics of each individual sector, while sectoral integration is also important. To reduce emissions from hard-to-abate sectors, such as transportation and industry, the measures and technologies can include the installation and use of highly efficient equipment, the electrification of end uses (such as the widespread adoption of electric vehicles), the large roll-out of renewable energy sources, as well as the production and use of green hydrogen and synthetic fuels. [ABSTRACT FROM AUTHOR]

Assessment methods have been developed to estimate a preliminary conservation status for species and subsequently to facilitate the building of Red Lists. Such pre-assessment methods could be particularly useful in the French Overseas Territories (FOTs) where Red Lists tend to be out-dated or absent and where a high number of endemic species face detrimental anthropogenic pressures. We first aimed to conduct a preliminary assessment (hereafter, pre-assessment) of the conservation status of endemic plants from Guadeloupe, Martinique, Réunion, Mayotte, French sub-Antarctic islands, New Caledonia, and Scattered Islands. We then compared the various methods used in conducting the pre-assessment and discussed ways to adapt these methods to small territories. We compiled occurrence data of endemic species identified thanks to a previous taxonomic work and pre-assessed their conservation status under Red List criteria A and B and the use of a Random Forest algorithm. We then measured the accuracy, specificity, and sensitivity of each method based on existing Red Lists. The Random Forest algorithm and a method based on range-size performed best at correctly attributing conservation status. Using these pre-assessment methods, we estimated that up to 60% of the endemic flora of the FOTs is potentially threatened. Range restriction but also anthropogenic pressures were key factors that explained these risks. Pre-assessment methods are useful tools to get a first measure of species conservation status. These methods should be adapted to the territories considered and their conservation issues in order to reach a good performance. [ABSTRACT FROM AUTHOR]