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From Organizational Resilience to Social-Ecological Resilience : Adaptive dynamics of tourism SMEs facing sargassum strandings
No full textInternational audienceThis article examines the mutual dependency between organizational and social-ecological resilience. We argue for the importance of moving beyond a firm-level perspective on resilience to account for potentially significant cross-scale interactions (Linnenluecke, 2015; A. Williams et al., 2017; T. A. Williams et al., 2017). In line with Clement and Riviera (2017) we define organizational resilience “as a dynamic firm property that integrates processes of both adaptation and transformation and that is longer term and intersystemic in nature” (Clement and Riviera, 2017: 15). We suggest that when organizations fail to consider the social-ecological environment in which they operate, their resilience strategies risk not only failing to contribute to the resilience of the broader socio-ecological system but potentially undermining it. For instance, a narrow focus on optimizing resilience from the perspective of a single firm may compromise social-ecological functioning, ultimately jeopardizing long-term organizational survival. We examine cross-scale interactions between organizational and social-ecological resilience through the case of the sargassum crisis in Martinique. Since 2011, massive Sargassum landings have caused serious ecological, economic, and social harm in the Caribbean and along African coasts, affecting marine life and human health. In Martinique, popular sites like the islets of Le François and Le Robert bays accessible only by water, face significant disruptions due to the accumulation of Sargassum, posing major challenges for the local authorities, populations, businesses and ecosystem. We study the adaptive dynamics of economic actors, focusing in particular on local tour operators operating in the bays of Le François and Le Robert. Our research aims to explore how these adaptive strategies impact the overall resilience of the social-ecological system. We focus on the adaptation and transformation strategies of tourism SMEs and assess their short- and medium-term impacts on the social ecological system and their potential feedback relationships. We regard social ecological systems as complex adaptive systems and use a social-ecological resilience approach as a lens to address and understand these dynamics. We conducted a longitudinal study focusing on small and medium-sized tourism enterprises in Martinique affected by the Sargassum crisis. As part of this research, we carried out 35 semi-structured interviews between April 2023 and March 2025 primarily with economic actors, but also with residents and institutional stakeholders who were affected by the Sargassum crisis and involved in its management
The Role of Barrier Reef Protection to Storm Surge During Tropical Cyclones in a Narrow Lagoon, New Caledonia, South West Pacific
No full textInternational audiencePacific islands are exposed to coastal hazards, particularly storm surges resulting from low pressure, extreme winds, and waves. While coral reefs naturally protect shorelines from incident waves, the diversity of reef geomorphologies induce various coastal responses, complicating hazard prediction based on offshore conditions. Understanding lagoon storm surge dynamics is therefore crucial for developing adaptation strategies to address global warming and sea-level rise. This study investigates the storm surge response of the narrow and shallow lagoon of Poe in New Caledonia using the SCHISM-SWAN coupled circulation-wave numerical model under tropical cyclone conditions. A retrospective of the 2019 cyclonic season shows that maximum storm surge is concentrated in the narrowest part of the lagoon, where human infrastructures are located, increasing exposure to extreme water levels. Modifying the reef structure to a more irregular form reveals that macro-scale reef features can mitigate wave setup intensity. Additionally, water depth variations over the reef crest significantly affect wave setup, with up to 30% difference between high and low tides. A broader generalization based on 258 synthetic cyclone tracks highlights that within the lagoon, wave setup accounts for approximately 70% of the storm surge, rising to 90% during the most extreme event. These results showing that the wave contribution is essential for accurate storm surge prediction. The findings provide critical insights for improving coastal hazard assessment, land use planning, and resilience strategies in reef island environments facing climate change
Environmental preferences of green sea turtles (Chelonia mydas) for egg-laying on a fringing reef pocket beach, Mayotte Island
No full textInternational audienceUnderstanding the spatial ecology of sea turtles is essential to ensure their long-term conservation by the preservation of their environment. The distribution and environmental preferences for egg-laying by the green turtle ( Chelonia mydas ) were studied on Grande Saziley beach in Mayotte (north of the Mozambique Channel). Green turtle nesting activity was geolocated during night patrols and the depth of specific nests was measured during two field campaigns in 2021 and 2022. Various original environmental parameters related to vegetation and beach morphology were extracted in a GIS environment based on this geolocated data using orthophotography and digital elevation models (DEMs) created by drones prior to field deployments. Sediment samples were also collected from the beach. Thanks to the combination of fieldwork and GIS analysis, this study makes it possible to examine a set of variables, which until now have rarely been studied simultaneously. The results showed that the Grande Saziley beach is a heterogeneous site with the distribution of egg-laying being concentrated in two hotspots. After principal component and GLMM statistical analysis, it appeared that gravid females preferentially lay in a low proportion of coarse sand at the bottom of the nest, at higher elevation and predominantly in surface sand with a low calcium carbonate content. This preference seems to be linked more to elevation, where black sand is mainly found at the top of the beach, rather than an intentional choice based on sand composition. No significant egg-laying site-related variables were found to explain the variations in nest depth. Our study was based on a new approach combining GIS techniques and drone surveys, enabling the collection of environmental parameters, a methodology that can easily be reproduced on other nesting beaches, reducing field workload. However, this work should be continued to assess the viability of sites for clutch survival while considering the spatial and temporal heterogeneity of the environment
Family involvement in business and the rise of online sales: insights from the covid-19 context
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Diving deep into kelp forest food webs using dietary DNA metabarcoding
No full textInternational audienceKelp forests are iconic coastal ecosystems, harbouring highly diverse communities of algae, meiofauna, and macrofauna, valued for their ecological, economic, and cultural significance. These ecosystems confront multiple threats including pollution, overfishing, seaweed harvesting, over-grazing events, and temperature anomalies linked to climate change. Understanding the intricate interaction network within these communities is critical for predicting the cascading effects of such pressures. Kelp forests have been the subject of numerous studies on their level of primary production, their genetic characteristics and the associated communities. However, precise knowledge regarding their structure and trophic functioning remains lacking. For example, traditional methods such as stable isotope analyses provide insights on dominant trophic pathways, but they do not provide adequate taxonomic resolution to assign species-specific interactions. In this study, we used a multi-marker metabarcoding approach to reconstruct food webs within kelp forests in two protected areas in Britany. We examined the diet of twenty keystone species including seals, cormorants, fish and invertebrates such as urchins, starfish, and crabs. Our findings revealed a remarkable diversity of prey with the vast majority identified at the species level. We also uncovered cryptic dietary niche partitioning in fish that likely contributes to stabilizing species coexistence. Additionally, dietary DNA metabarcoding data provided information on the trophic dependency levels of the studied species on kelp forests, offering valuable insights for conservation efforts
California Amphibians and Reptiles
No full textInternational audienceAnalyse de l'ouvrage California Amphibians and Reptiles, de Robert W. Hansen et Jackson D. Shedd. 202
Thromboinflammatory complications of Bothrops snakebite envenoming: the case of B. lanceolatus endemic to the Caribbean Island of Martinique
No full textInternational audienceSnakebite envenoming remains a predominant neglected disease in tropical and subtropical regions, with high rates of morbidity and mortality worldwide. Bothrops snakebite envenoming. is characterized by severe injuries at the site of venom injection, which include tissue necrosis, hemorrhage, blistering, and edema. Haemotoxicity is typically attributed to the strong procoagulant state induced by the majority Bothrops venoms leading to coagulation factor consumption and incoagulable blood. Concomitantly with this procoagulant state, a complex host response develops in the affected tissues, accompanied by the recruitment of inflammatory and immunocompetent cells, along with the activation of resident cells, and the synthesis of a plethora of pro-inflammatory mediators and damage-associated molecular patterns from injured tissue. An increasing body of evidence suggests that this intricate response is, in fact, related to the well-documented immunothrombosis and thromboinflammation integrated features. Of note, thrombotic complications are extremely rare in Bothrops snakebite envenoming. However, in the case of Bothrops lanceolatus and B. caribbaeus , which are respectively endemic to Martinique and St. Lucia, the absence of overt consumption coagulopathy due to their weak procoagulant effects may be related to the thrombotic effects, as clotting factors are present in the bloodstream by the time the thrombogenic and inflammatory mechanisms are operating in blood vessels. Prior to the era of immunotherapy, B. lanceolatus envenoming was associated with thrombotic complications in 25% of cases and was fatal in approximately 10% of cases. This review examines the potential role of thromboinflammation as a mechanism of thrombotic accidents in B. lanceolatus snakebite envenoming
Monitoring reef metabolism for a better management – case study of Reunion Island
No full textInternational audienceMonitoring carbon budget is a major challenge to improve coral reefs management (protection, conservation or restoration), including predictions about their fates by 2100. It requires sensors deployment, a collection of seawater samples and consideration of local factors such as tide, wind and benthic cover. This study assessed the benthic metabolic processes (organic production, respiration, calcification and calcium carbonate -CaCO3- dissolution) at three sites on the main shallow fringing reef of La Reunion Island. Autonomous sensors (current speed, temperature, salinity, PAR, dissolved oxygen -DO- and pH) were deployed during the warm and cold seasons between 2020 and 2022 and were complemented by discrete sampling of seawater for DO, pH and total alkalinity (TA) analysis. Metabolic budgets were calculated using a one-dimensional Eulerian approach of flow respirometry (study of changes in seawater chemistry along an axis, between two points, using fixed moored sensors). Due to the reef geomorphology, the variation in current orientation and its unidirectionality, spatio-temporal variability of metabolic budgets could not be related to benthic cover (Pleiades satellite images). Those factors strongly influenced variations of seawater chemistry and our ability to estimate the seawater residence time. We will show here, for instance, that reef geomorphology creates conditions for a flow re-entrainment of TA-depleted seawater (due to reef calcification activity) exiting the reef. Such TA-depleted seawater is immediately redirected towards the reef flat leading to an overestimation of daily reef net calcification rates (Gnet). At one site (33% of coral cover), Gnet was estimated at 283 mmolCaCO3.m-2.d-1. Such rate characterizes reefs with a coral cover up to 60%. Gnet accounted for 40% of reef gross primary production GPP (GPP = 726 mmolC.m-2.d-1, similar to the Indo-Pacific median) while calcification usually corresponds to 15-20% of GPP for typical coral/algal reef flats. The Eulerian method that was used in our study is a punctual approach and can be a powerful tool for monitoring coral reefs metabolism, mainly through the use of autonomous sensors. However, accurate estimations on a large spatio-temporal scale need long-term surveys and may be limited due by the difficulty of integrating the specific hydrodynamic conditions of each coral reef studied
Study on Copper Protection in H2S-rich Marine Environments using SAMs from Sargassum Extract
No full textInternational audienceCorrosion is a complex and progressive degradation process that occurs when an aggressive external agent attacks a metal and is known to cause significant harm to materials, the environment, and metals. One important factor in these physicochemical phenomena is the atmosphere. Factors like temperature, humidity, and salinity are relevant. For most materials, the marine environment is the ideal example of an environment that is naturally aggressive. Because few metals can resist it, they must be protected. For instance, when copper corrodes in an alkaline environment, copper oxide forms a protective film on the metal's surface, reducing its ability to attack. Nevertheless, the metal eventually deteriorates because of the instability of the surrounding environment, so this solution is only temporary. These days, plants-based inhibitors represent a real source of robust, long-lasting protection. They can function as natural inhibitors of metals and their alloys due to their very beneficial natural characteristics. Therefore, the focus of this work is on how Sargassum fluitans III self-assembled monolayers (SAMs) inhibit copper corrosion in coastal environments. When copper is submerged directly in the inhibiting solution, the extract successfully prevents copper corrosion, according to the findings of surface analysis and electrochemistry. In this article, for example, it was demonstrated that sargassum extract halves the loss of copper thickness, reducing it from 8.00±0.61 mm to 4.76±0.52 mm on a site heavily exposed to sea salts
Restaurer la forêt marécageuse pour contrer le Typha, une espèce exotique envahissante
No full texthttps://guadeloupe-parcnational.fr/frFor the past ten years, the Parc national de la Guadeloupe has supported scientific studies on the archipelago's wetlands. In this context, the work carried out at the University of the West Indies (UA) plays an essential role in optimizing the management of these natural environments, which are largely under the Park's responsibility. The following is a summary of a recent UA study highlighting the rapid invasion of Typha domingensis in Guadeloupe and an effective control technique based on swamp forest restoration.Le Parc national de la Guadeloupe soutient depuis une dizaine d’années les études scientifiques portant sur les zones humides de l’archipel. Dans ce contexte, les travaux menés à l’Université des Antilles (UA) jouent un rôle essentiel pour optimiser la gestion de ces milieux naturels, en grande partie placés sous la responsabilité du Parc. Voici le résumé d’une étude récente de l’UA mettant en évidence l’invasion fulgurante de Typha domingensis en Guadeloupe et une technique de contrôle efficace basée sur la restauration de la forêt marécageuse