Assessment of river ecological status in the French West Indies based on diatom flora.

The Water Framework Directive (WFD) requires member states to routinely assess the river ecological status using community-based indices. However, there is still a lack of published WFD-compliant methods for the French West Indies, especially using diatom-based indices. Martinique and Guadeloupe exhibit diverse landscapes shaped by their complex geological history and tropical climatic conditions. These strong particularities make the existing indices developed for the European mainland unusable. Based on diatom sampling from to 2013 (607 samples) and through multivariate analyses, we developed the Indice Diatomique des Antilles (IDA). We first identified the key abiotic factors influencing diatom communities on both islands, and then characterized taxon sensitivity by considering their presence probability along a pressure gradient.. The index was based on the presence and relative abundance of these taxa in each sample. The last step consisted of using new data from the 2014-2022 sampling surveys (457 samples) as a validation dataset to verify IDA accuracy. Our results suggest that the IDA methodology is well designed to assess the ecological status of rivers in the West Indies.

[Sargassum seaweed assaults the French West Indies]. / Algues sargasses à l'assaut des Antilles.

SARGASSUM SEAWEED AS SAULTS THE FRENCH WEST INDIES. Since 2011, Martinique and the islands of Guadeloupe have been affected by repeated groundings, culminating in an exceptional wave in 2018. While the sargassum ( Sargassum natans and S. fluitans ) involved in these phenomena are neither toxic nor urticating, indirect toxicity linked to the presence of microorganisms and heavy metals (arsenic, mercury, etc.) in sargassum clusters has been described. Similarly, after a 24 to 48 hours stay on the shore, sargassum algae enter a putrefaction cycle responsible to produce hydrogen sulfide (H2S) and ammonia (NH3). The acute toxicity of these gases is well known. However, very few data are available on the clinical effects of prolonged exposure to low doses of H2S and NH3. Our team has recently described the syndromic features of chronic exposure, supposing for deleterious effects on the cardiovascular, respiratory and neurological systems.

ALGUES SARGASSES À L'ASSAUT DES ANTILLES. Depuis 2011, la Martinique et les îles de la Guadeloupe sont touchées par des échouements à répétition d'algues sargasses qui ont culminé avec une vague exceptionnelle en 2018. Si les sargasses (Sargassum natans et S. fluitans) impliquées dans ces phénomènes ne sont ni toxiques ni urticantes, une toxicité indirecte liée à la présence de micro-organismes et de métaux lourds (arsenic, mercure…) dans les amas de sargasses est décrite. De même, après un séjour de vingt-quatre à quarante-huit heures sur le littoral, les algues sargasses entrent dans un cycle de putréfaction responsable de la production d'hydrogène sulfuré (H2S) et d'ammoniac (NH3). La toxicité aiguë de ces gaz est bien connue. Il existe en revanche très peu de données disponibles sur les effets cliniques d'une exposition prolongée à de faibles doses d'H2S ou NH3. Notre équipe a récemment décrit le tableau syndromique de l'exposition chronique et suppose des effets délétères sur le système cardiovasculaire, respiratoire et neurologique.

Achieving healthy and profitable production through collective action? The case of vegetable farmers in the French West Indies.

Given the multiple challenges that agriculture faces, collective action is a potential pathway towards more sustainable agriculture. This article aims to contribute to the literature by assessing the extent to which collective action can meet the objective of both healthy and profitable production in the French West Indies. To do so, we call on the theory of collective action and emphasise the role of formal and informal collectives in achieving the objectives of improving income and implementing agroecological practices. We use original data collected in 2022 from 409 vegetable farmers in Martinique and Guadeloupe. We consider the interdependence between farmers' economic and environmental objectives through a simultaneous equations model. We characterise the diversity of collectives according to their degree of formalisation and to the adequacy between the objectives pursued by these collectives and the individual objectives of their members. Our results show that the achievement of an individual objective is fostered by its adequacy with the objective set by the collective and also, to a certain extent, by the degree of formalisation of this collective. It appears that achieving individual objectives is based on sharing common objectives as well as having collective rules. More particularly, we find that producer organisations - collectives considered to be the most formal - best meet the objectives of improving income and adopting agroecological practices. However, in the French West Indies, the instability of such collectives and the organisational deficiencies of the sector call into question their real long-term impact. These findings contribute to a better understanding of farmers' decision-making and provide relevant policy implications for supporting agricultural collectives in managing and federating producers towards achieving a more healthy and profitable production.

Temporal fluctuation of metallic trace elements concentrations in three morphotypes of floating holopelagic Sargassum from the Caribbean coast (Guadeloupe, French West Indies).

Since 2011, the Caribbean coasts have unprecedented stranding of a pelagic brown macroalgae Sargassum inducing damages for coastal ecosystems and economy. This study evaluated the temporal fluctuations of metallic trace elements (MTE) in Sargassum freshly arrived on the Caribbean coast. From May 2020 to September 2021, 12 floating samples of three morphotypes (S. fluitans III and S. natans I and VIII) were regularly collected in the Petit Cul-de-Sac Marin (Guadeloupe, French West Indies). Measured concentrations of 28 metal(loid)s trace elements reveal i) an absence of seasonal patterns in MTE concentrations except for metals Fe and Al during 2020 summer ii) a regular and high As content during the entire survey iii) a similar trend of contamination for each morphotype. The constant and high amount of As implies that stranding management policy and valorization processes of Sargassum must consider As contamination and that this vigilance must be constantly along the year.

Phylosymbiosis and metabolomics resolve phenotypically plastic and cryptic sponge species in the genus Agelas across the Caribbean basin.

Fundamental to holobiont biology is recognising how variation in microbial composition and function relates to host phenotypic variation. Sponges often exhibit considerable phenotypic plasticity and also harbour dense microbial communities that function to protect and nourish hosts. One of the most prominent sponge genera on Caribbean coral reefs is Agelas. Using a comprehensive set of morphological (growth form, spicule), chemical and molecular data on 13 recognised species of Agelas in the Caribbean basin, we were able to define only five species (=clades) and found that many morphospecies designations were incongruent with phylogenomic and population genetic analyses. Microbial communities were also strongly differentiated between phylogenetic species, showing little evidence of cryptic divergence and relatively low correlation with morphospecies assignment. Metagenomic analyses also showed strong correspondence to phylogenetic species, and to a lesser extent, geographical and morphological characters. Surprisingly, the variation in secondary metabolites produced by sponge holobionts was explained by geography and morphospecies assignment, in addition to phylogenetic species, and covaried significantly with a subset of microbial symbionts. Spicule characteristics were highly plastic, under greater impact from geographical location than phylogeny. Our results suggest that while phenotypic plasticity is rampant in Agelas, morphological differences within phylogenetic species affect functionally important ecological traits, including the composition of the symbiotic microbial communities and metabolomic profiles.

Molecular epidemiology identifies the expansion of the DENV2 epidemic lineage from the French Caribbean Islands to French Guiana and mainland France, 2023 to 2024.

In 2023, dengue virus serotype 2 (DENV2) affected most French overseas territories. In the French Caribbean Islands, viral circulation continues with > 30,000 suspected infections by March 2024. Genome sequence analysis reveals that the epidemic lineage in the French Caribbean islands has also become established in French Guiana but not Réunion. It has moreover seeded autochthonous circulation events in mainland France. To guide prevention of further inter-territorial spread and DENV introduction in non-endemic settings, continued molecular surveillance and mosquito control are essential.

Evaluating vector competence for Yellow fever in the Caribbean.

The mosquito-borne disease, Yellow fever (YF), has been largely controlled via mass delivery of an effective vaccine and mosquito control interventions. However, there are warning signs that YF is re-emerging in both Sub-Saharan Africa and South America. Imported from Africa in slave ships, YF was responsible for devastating outbreaks in the Caribbean. In Martinique, the last YF outbreak was reported in 1908 and the mosquito Aedes aegypti was incriminated as the main vector. We evaluated the vector competence of fifteen Ae. aegypti populations for five YFV genotypes (Bolivia, Ghana, Nigeria, Sudan, and Uganda). Here we show that mosquito populations from the Caribbean and the Americas were able to transmit the five YFV genotypes, with YFV strains for Uganda and Bolivia having higher transmission success. We also observed that Ae. aegypti populations from Martinique were more susceptible to YFV infection than other populations from neighboring Caribbean islands, as well as North and South America. Our vector competence data suggest that the threat of re-emergence of YF in Martinique and the subsequent spread to Caribbean nations and beyond is plausible.

Microwave-enhanced thermal removal of organochlorine pesticide (chlordecone) from contaminated soils.

Soil contamination with chlordecone, an organochlorine pesticide, is causing serious health problems, affecting crop production and local livestock valorization in the French West Indies. In-situ chemical reduction (ISCR) processes for soil remediation have shown promise but need improvement in terms of time, cost and effective treatment, particularly for andosol soil types. Our study shows that a 10-min microwave treatment significantly reduces chlordecone concentrations (50-90%) in contaminated andosol and nitisol soils. Dry andosol soils show the highest removal yields and reach a higher final temperature (350 °C). Microwave treatment is in all cases more effective or at least as effective as 60 min of conventional heating at a target temperature of 200 °C. The thermal response of andosol and nitisol to microwave exposure is different, as the former is likely to undergo thermal runaway, reaching high temperatures in a short time, resulting in highly efficient thermal removal of chlordecone. These results encourage further scale-up, particularly for the treatment of andosol soils due to their strong microwave response.

Flood exposure and pregnancy loss in 33 developing countries.

Floods have affected billions worldwide. Yet, the indirect health impacts of floods on vulnerable groups, particularly women in the developing world, remain underexplored. Here, we evaluated the risk of pregnancy loss for women exposed to floods. We analyzed 90,465 individual pregnancy loss records from 33 developing countries, cross-referencing each with spatial-temporal flood databases. We found that gestational flood exposure is associated with increased pregnancy loss with an odds ratio of 1.08 (95% confidence interval: 1.04 - 1.11). This risk is pronounced for women outside the peak reproductive age range (<21 or >35) or during the mid and late-stage of pregnancy. The risk escalated for women dependent on surface water, with lower income or education levels. We estimated that, over the 2010s, gestational flood events might be responsible for approximately 107,888 (CIs: 53,944 - 148,345) excess pregnancy losses annually across 33 developing countries. Notably, there is a consistent upward trend in annual excess pregnancy losses from 2010 to 2020, and was more prominent over Central America, the Caribbean, South America, and South Asia. Our findings underscore the disparities in maternal and child health aggravated by flood events in an evolving climate.

Early exposure to mercury and cardiovascular function of seven-year old children in Guadeloupe (French West Indies).

BACKGROUND: The cardiotoxicity of prenatal exposure to mercury has been suggested in populations having regular contaminated seafood intake, though replications in the literature are inconsistent. METHODS: The Timoun Mother-Child Cohort Study was set up in Guadeloupe, an island in the Caribbean Sea where seafood consumption is regular. At seven years of age, 592 children underwent a medical examination, including cardiac function assessment. Blood pressure (BP) was taken using an automated blood pressure monitor, heart rate variability (HRV, 9 parameters) and electrocardiogram (ECG) characteristics (QT, T-wave parameters) were measured using Holter cardiac monitoring during the examination. Total mercury concentrations were measured in cord blood at birth (median = 6.6 µg/L, N = 399) and in the children's blood at age 7 (median = 1.7 µg/L, N = 310). Adjusted linear and non-linear modelling was used to study the association of each cardiac parameter with prenatal and childhood exposures. Sensitivity analyses included co-exposures to lead and cadmium, adjustment for maternal seafood consumption, selenium and polyunsaturated fatty acids (n3-PUFAs), and for sporting activity. RESULTS: Higher prenatal mercury was associated with higher systolic BP at 7 years of age (ßlog2 = 1.02; 95% Confidence Interval (CI) = 0.10, 1.19). In boys, intermediate prenatal exposure was associated with reduced overall HRV and parasympathetic activity, and longer QT was observed with increasing prenatal mercury (ßlog2 = 4.02; CI = 0.48, 7.56). In girls, HRV tended to increase linearly with prenatal exposure, and no association was observed with QT-wave related parameters. Mercury exposure at 7 years was associated with decreased BP in girls (ßlog2 = -1.13; CI = -2.22, -0.004 for diastolic BP). In boys, the low/high-frequency (LF/HF) ratio increased for intermediate levels of exposure. CONCLUSION: Our study suggests sex-specific and non-monotonic modifications in some cardiac health parameters following prenatal exposure to mercury in pre-pubertal children from an insular fish-consuming population.

A population-based analysis of hematological malignancies from a French-West-Indies cancer registry's data (2009-2018).

BACKGROUND: A worldwide increased incidence of HM has been marked in recent decades. Therefore, to update epidemiological characteristics of HM in a French West Indies territory, we have performed analysis through Martinique's population-based cancer registry database. METHODS: We included cancer case data, from 2009-2018, coded in strict compliance with international standards set by International Agency for Research on Cancer. We calculated standardized incidence rates, cumulative rate (ages 0-74), and temporal trends for cases and deaths using the global population standard, by sex and five age group. Mortality rates were obtained from the French Epidemiology Center on Medical Causes of Death (CépiDc). RESULTS: One thousand forty seven new cases and 674 deaths from HM were recorded, of which 501 MM (47.8%), 377 LMNH (36%), 123 LAM (11.8%), and 46 LH (4.4%) were reported in both sexes. MM is one of the hematological malignancies with the highest incidence in Martinique among men. Temporal trends of incidence rates for all HM decreased overall in both sexes, except for MM in men. There is significant variability in mortality rates for both sexes. In addition, over the period, the temporal trends of mortality rates for all HMs has decreased overall. Gender-specific rates, between 2009 and 2018, showed that all lymphoid HM have a multimodal distribution curve that increased with age. CONCLUSIONS: Characteristics of HM in Martinique over the reporting periods differ from mainland France. Higher incidences have been observed, particularly for MM, and non-significant sub-mortality is observed compared to mainland France. Moreover, temporal distribution of mortality and incidence trends had decreased over the reporting periods except for MM. Our results showed similarities with African-Americans groups in United States and in particular an equivalence in the frequency distribution of diagnosed HM. However, SMR remains lower compared to US black ethnic groups. Our results contributed to expanding knowledge on the epidemiology of HM with Caribbean data.

Safeguarding the Caribbean's future: making the case to research the direct and indirect impacts of climate change on youth mental health and wellbeing.

This article makes a call for attention to paid on the development of a research agenda for studying the impact of climatic events on youth mental health in the Caribbean. It details the climate injustices that the region faces and the potential mental health problem which can arise from climatic events. It makes a call for interdisciplinary research and a multi stakeholder approach to dealing with this potential issue.

Promoting Access to Dental Care in a Developing Caribbean Nation, Post-disaster.

In September 2017, Hurricane Irma struck several Caribbean islands, which suffered catastrophic damage. Anguilla, the most northerly of the Caribbean's Leeward Islands, a developing nation, experienced devastating damage to its social, physical, political, and economic infrastructures. Anguilla's longstanding Dental Unit, a public sector health care facility, was among the services that suffered irreparable destruction. Hurricane Irma's debilitating impact on a developing nation and its citizens' livelihoods exacerbated existing challenges in dental care, and created barriers to access. As part of the rehabilitation process, it was essential to promote access to dental care. This commentary shares examples of some practical and economical approaches that were employed: providing direct access to dental therapists, offering dedicated emergency and routine care appointments, delivering oral health campaigns, partaking in community health fairs, and social media engagement. The commentary also considers future approaches that could be beneficial.

Individual residency behaviours and seasonal long-distance movements in acoustically tagged Caribbean reef sharks in the Cayman Islands.

Understanding how reef-associated sharks use coastal waters through their ontogeny is important for their effective conservation and management. This study used the horizontal movements of acoustically tagged Caribbean reef sharks (Carcharhinus perezi) to examine their use of coastal space around the Cayman Islands between 2009 and 2019. A total of 39 (59.1%) tagged sharks (male = 22, female = 17, immature = 18, mature = 21) were detected on the islands wide network of acoustic receivers. The detection data were used to calculate values of Residency Index (RI), Site-Fidelity Index (SFI) and minimum linear displacement (MLD), as well as for network analysis of individual shark movements to test for differences between demographics, seasons, and diel periods. Sharks were detected for up to 1,598 days post-tagging and some individuals showed resident behaviour but the majority of tagged individuals appear to have been one-off or only occasional transient visitors to the area. Generally, individuals showed strong site-fidelity to different areas displaying linear home ranges of < 20 km. The evidence indicates that there was no pattern of diel behaviour. Tagged sharks generally showed increased movements within and between islands during the summer (April-September), which may be related to breeding activity. Some individuals even made occasional excursions across 110 km of open water > 2,000 m deep between Grand Cayman and Little Cayman. One mature female shark showed a displacement of 148.21 km, the greatest distance reported for this species. The data shows that the distances over which some sharks moved, greatly exceeded the extent of any one of the islands' marine protected areas indicating that this species may be more mobile and dispersive than previously thought. This study provides support for the blanket protection to all sharks throughout Cayman waters, which was incorporated within the National Conservation Act in 2015.

Geographic range size and species morphology determines the organization of sponge host-guest interaction networks across tropical coral reefs.

Sponges are widely spread organisms in the tropical reefs of the American Northwest-Atlantic Ocean, they structure ecosystems and provide services such as shelter, protection from predators, and food sources to a wide diversity of both vertebrates and invertebrates species. The high diversity of sponge-associated fauna can generate complex networks of species interactions over small and large spatial-temporal gradients. One way to start uncovering the organization of the sponge host-guest complex networks is to understand how the accumulated geographic area, the sponge morphology and, sponge taxonomy contributes to the connectivity of sponge species within such networks. This study is a meta-analysis based on previous sponge host-guest literature obtained in 65 scientific publications, yielding a total of 745 host-guest interactions between sponges and their associated fauna across the Caribbean Sea and the Gulf of Mexico. We analyzed the sponge species contribution to network organization in the Northwest Tropical Atlantic coral reefs by using the combination of seven complementary species-level descriptors and related this importance with three main traits, sponge-accumulated geographic area, functional sponge morphology, and sponges' taxonomy bias. In general, we observed that sponges with a widespread distribution and a higher accumulated geographic area had a greater network structural contribution. Similarly, we also found that Cup-like and Massive functional morphologies trend to be shapes with a greater contribution to the interaction network organization compared to the Erect and Crust-like morphos. Lastly, we did not detect a taxonomy bias between interaction network organization and sponges' orders. These results highlight the importance of a specific combination of sponge traits to promote the diversity of association between reef sponges and their guest species.

Juvenile Dermatomyositis in Afro-Caribbean children: a cohort study in the French West Indies.

INTRODUCTION: The epidemiology of Juvenile Dermatomyositis (JDM) in non-Caucasian population is poorly described. We performed a study of patients followed up in the French West Indies for JDM. We aimed to describe clinical and biological specificities during childhood. METHODS: Retrospective study covering the period from Januarys 2000-2023. Listings of patients were obtained from multiple sources, namely computerized hospital archives, registry of referent pediatricians and adult specialists in internal medicine and the French National Registry for rare diseases. JDM and organ involvement were defined according to the international ILAR criteria. RESULTS: Twenty-one patients were included over a 23 year-period. Median age at onset was 8.1 years (Range: 2.5-13.9) with a median follow up of 8 years (Range: 2-19). Two-thirds (14/21) had dysphagia at onset and 33% had respiratory involvement. Thirteen had specific autoantibodies (58%), most frequently anti-Mi-2. The median number of flares during childhood was three (1-9). During childhood, 76% had calcinosis lesions. Clinical evolution seemed to be more aggressive for boys than girls (respectively 4.2 versus 2.2 flares (p = 0.04) and 50% vs 18% needing more than one background therapy, p = 0.03). CONCLUSION: This retrospective study is the largest cohort of pediatric patients of Afro-Caribbean and Black African descent treated for JDM in a high-income health system, and the first to describe the incidence and immunological profile in a population of African descent. They had higher rate of calcinosis and similar respiratory involvement. Overall outcomes during childhood were similar to North America and European countries.

Changes in parrot diversity after human arrival to the Caribbean.

Humans did not arrive on most of the world's islands until relatively recently, making islands favorable places for disentangling the timing and magnitude of natural and anthropogenic impacts on species diversity and distributions. Here, we focus on Amazona parrots in the Caribbean, which have close relationships with humans (e.g., as pets as well as sources of meat and colorful feathers). Caribbean parrots also have substantial fossil and archaeological records that span the Holocene. We leverage this exemplary record to showcase how combining ancient and modern DNA, along with radiometric dating, can shed light on diversification and extinction dynamics and answer long-standing questions about the magnitude of human impacts in the region. Our results reveal a striking loss of parrot diversity, much of which took place during human occupation of the islands. The most widespread species, the Cuban Parrot, exhibits interisland divergences throughout the Pleistocene. Within this radiation, we identified an extinct, genetically distinct lineage that survived on the Turks and Caicos until Indigenous human settlement of the islands. We also found that the narrowly distributed Hispaniolan Parrot had a natural range that once included The Bahamas; it thus became "endemic" to Hispaniola during the late Holocene. The Hispaniolan Parrot also likely was introduced by Indigenous people to Grand Turk and Montserrat, two islands where it is now also extirpated. Our research demonstrates that genetic information spanning paleontological, archaeological, and modern contexts is essential to understand the role of humans in altering the diversity and distribution of biota.

Kinetics of metal and metalloid concentrations in holopelagic Sargassum reaching coastal environments.

Since 2011, the Caribbean Islands have experienced unprecedented stranding of a pelagic brown macroalgae Sargassum inducing damages for coastal ecosystems and economy. This study measures the kinetics of metal trace elements (MTE) in Sargassum reaching different coastal environments. In July 2021, over a period of 25 days, fixed experimental floating cages containing the three Sargassum morphotypes (S. fluitans III and S. natans I and VIII) were placed in three different coastal habitats (coral reef, seagrass, and mangrove) in Guadeloupe (French West Indies). Evolution of biomasses and their total phenolic content of Sargassum reveals that environmental conditions of caging were stressful and end up to the death of algae. Concentrations of 19 metal(loid) trace elements were analyzed and three shapes of kinetics were identified with the MTE that either concentrate, depurate, or remains stable. In the mangrove, evolution of MTE was more rapid than the two other habitats a decrease of the As between 70 and 50 µg g-1 in the mangrove. Sargassum natans I presented a different metal composition than the two other morphotypes, with higher contents of As and Zn. All Sargassum morphotype are rapidly releasing the metal(oid)s arsenic (As) when they arrive in studied coastal habitats. In order to avoid the transfer of As from Sargassum to coastal environments, Sargassum stranding should be avoided and their valorization must take into account their As contents.