HAL Portal UPF (Université de la Polynésie française)
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Prokaryotic communities of the French Polynesian sponge Dactylospongia metachromia display a site-specific and stable diversity during an aquaculture trial
No full textInternational audienceDynamics of microbiomes through time are fundamental regarding survival and resilience of their hosts when facing environmental alterations. As for marine species with commercial applications, such as marine sponges, assessing the temporal change of prokaryotic communities allows us to better consider the adaptation of sponges to aquaculture designs. The present study aims to investigate the factors shaping the microbiome of the sponge Dactylospongia metachromia , in a context of aquaculture development in French Polynesia, Rangiroa, Tuamotu archipelago. A temporal approach targeting explants collected during farming trials revealed a relative high stability of the prokaryotic diversity, meanwhile a complementary biogeographical study confirmed a spatial specificity amongst samples at different longitudinal scales. Results from this additional spatial analysis confirmed that differences in prokaryotic communities might first be explained by environmental changes (mainly temperature and salinity), while no significant effect of the host phylogeny was observed. The core community of D. metachromia is thus characterized by a high spatiotemporal constancy, which is a good prospect for the sustainable exploitation of this species towards drug development. Indeed, a microbiome stability across locations and throughout the farming process, as evidenced by our results, should go against a negative influence of sponge translocation during in situ aquaculture
Studying sea snakes through citizen science
No full textInternational audienceThe contribution of citizen scientists to herpetology programs has been increasing during the last few years, thanks to digital technologies. In New Caledonia, a program involving grandmothers to study sea snakes was launched in 2017. Since then, it has been very successful, allowing us to collect valuable data on sea snake populations and spatial ecology. As for many other citizen science programs, data collecting is not the only outcome of this program.Due to its unusual combination of grandmothers and venomous snakes, our program attracted strong media’s interest. This mediatization in turn raised public and stakeholder’s awareness about sea snakes and their importance in New Caledonia’s marine ecosystems. It gives us opportunities to educate public and positively change attitude and behaviour towards sea snakes
Coral recruitment in the Toliara region of southwest Madagascar: Spatio‐temporal variability and implications for reef conservation
No full textInternational audienceInvestigating coral recruitment is critical to better understand replenishment and resilience capacities of coral reef ecosystems and to improve their conservation. Here, we examined the spatio‐temporal patterns of coral recruitment and the influence of confamilial adult coral cover in the region of Toliara, southwest Madagascar. Terracotta tiles were immersed from October to late January over a 3‐year period (2018–2021) at 10 stations located on major reef habitats. Overall recruitment rates were relatively high compared to those of other reefs in the Southwestern Indian Ocean, ranging from 219.20 recruits.m −2 in 2018–2019 to 156.30 recruits.m −2 in 2020–2021. Recruit assemblages were dominated by Acroporidae (45.5%) and Pocilloporidae (45.0%), whereas Poritidae (1.9%) and “other” recruits (3.6%) were rarely recorded. Recruitment patterns varied among stations and habitats, with higher rates in patch reef (187.06 recruits.m −2 ) and outer slope stations (156.99 recruits.m −2 ) compared to inner slope stations (108.04 recruits.m −2 ). With the exception of “other” recruits, recruitment rates decreased between 2018 and 2019 and 2019 and 2020, followed by an increase in 2020–2021 that reached or even exceeded initial values at some stations. The abundance of Pocilloporidae recruits was positively correlated with the cover of confamilial adult corals, highlighting potential stock–recruitment or recruitment–limitation relationships, or an aggregative settlement of young stages near the established adult colonies, whereas no such relationships were recorded for other coral family categories. This study identified sites on the outer slope and patch reefs to consider prioritizing for protection as recruitment hotspots, as well as degraded inner slope sites that could benefit from restoration, with the important caveat that any measures should be accompanied by alternative income‐generating activities through local involvement that suits the Malagasy context, such as locally marine managed areas
Study of the coastal reef fishery pressure in a South Pacific Island (Bora-Bora, French Polynesia)
No full textInternational audienceIn the context of the general overexploitation of South Pacific reef fisheries, there is a global push to precisely define fishery parameters such as fishing effort, annual landings, and exploitation levels. In Bora-Bora, several surveys were performed to define the fishing grounds and the fishing effort of the reef fishery for the first time. Maps of the fishing grounds under different fishing pressures were created for the Bora-Bora reef fishery. The average fishing effort throughout the lagoon was 40 trips week−1 km−2. Annual landings were estimated following two different methods: school participatory surveys and landing based on the catch per unit effort. These estimations were used to determine that the maximum sustainable yield of the island's fisheries was 6.5 tons km−2 year−1. the reported annual yield in 2022 was 5.35 tons km−2 year−1, under the estimated maximum sustainable yield. The level of exploitation of the fisheries was also estimated based on the catch size composition of the ten most fished species. This revealed that fishing is responsible for more than 50% of fish mortality in six of the ten studied species, and that catch length could be increased to optimize both catches and biomass. Overall, the Bora-Bora reef fishery may be experiencing growth overfishing (i.e., the catching of fish that are too small to maximise biological sustainability and economical yield), which can endanger stock recruitment in the future if no actions are taken
Le tourisme sportif en Polynésie française et sa dépendance au transport aérien
No full textInternational audienceIn French Polynesia, tourism and sport represent two sets of social, economic and cultural practices which overlap (or merge) very marginally. This is the case in particular in the more frequented islands where tourists tend to go hiking, canyoning, paragliding, and then mostly to marine activities such as diving, canoeing, paddling, sailing, fishing... These nature sports do not appear to be a significant vector of tourist attraction, but rather a niche product offered by the hotel complexes (resorts) to local and international tourists. On the other hand, the most popular sports are part of a more specific environment, that of the South Oceanic hemisphere, in terms of competition (the Pacific Games since 1963). Consequently, tourists are the athletes who travel to these events. There is therefore very little hybridization between popular sports, which concerns as much the mā’ohi disciplines, as those imported by the tutelary powers, up to those introduced more recently in French Polynesia, from the United States, such as beach soccer, stretching, pole dancing... and this with the exception of golf and diving. Concerning surfing, whose origin is Polynesian, some tourists travel to the islands to take part in competitions, such as those organised on the mythical Teahupo’o wave, selected as a venue for the 2024 Paris Olympic Games. The few connections between the two areas described, tourism and sport, are part of the fallout of the remoteness between the islands of French Polynesia and the rest of the world. This extreme isolation induces a total dependence on air transport, which invariably results in high costs of stay and questions for the long term on the viability and sustainability of the product.En Polynésie française, le tourisme et le sport représentent deux ensembles de pratiques sociales, économiques et culturelles qui se superposent (ou se confondent) très marginalement. C'est le cas notamment dans les îles les plus fréquentées où les touristes ont tendance à faire de la randonnée, du canyoning, du parapente, puis surtout des activités marines telles que la plongée, le canoë-kayak, le paddle, la voile, la pêche.... Ces sports de nature ne semblent pas être un vecteur important d'attraction touristique, mais plutôt un produit de niche offert par les complexes hôteliers (resorts) aux touristes locaux et internationaux. En revanche, les sports les plus populaires s'inscrivent dans un environnement plus spécifique, celui de l'hémisphère sud océanique, en termes de compétition (Jeux du Pacifique depuis 1963). Par conséquent, les touristes sont les athlètes qui se rendent à ces événements. Il y a donc très peu d'hybridation entre les sports populaires, ce qui concerne aussi bien les disciplines mā'ohi, que celles importées par les puissances tutélaires, jusqu'à celles introduites plus récemment en Polynésie française, en provenance des Etats-Unis, comme le beach soccer, le stretching, la pole dance... et ce à l'exception du golf et de la plongée. Concernant le surf, dont l'origine est polynésienne, certains touristes se rendent dans les îles pour participer à des compétitions, comme celles organisées sur la mythique vague de Teahupo'o, sélectionnée pour les Jeux olympiques de Paris en 2024. Les quelques liens entre les deux domaines décrits, le tourisme et le sport, font partie des conséquences de l'éloignement des îles de la Polynésie française du reste du monde. Cet isolement extrême induit une dépendance totale au transport aérien, ce qui se traduit invariablement par des coûts de séjour élevés et des interrogations à long terme sur la viabilité et la durabilité du produit
Buw! Inter islands trade and cultural significance of betel nut in Micronesia.: Inter island trade and cultural significance of betel nut in Micronesia. A comparative ethnographic project on supply chains in Palau and Yap.
No full textInternational audienceBetel nut consumption is widely spread around the Asia-Pacific area as well as among the austronesian speaking societies from Madagascar to Micronesia.It is one of the most popular drug, used on a daily basis by over 600 millions of people around the world. It is also widely involved in religious offerings, indigenous medicine and magic.Chewing the nut of the areca palm tree (areca catechu) requires several adjuvants in order to increase its psychoactive effect and its taste. Most common of these adjuvants are betel leaves (piper betle) and slaked lime, along with tobacco and a wide range of different spices. While most previous researches focus on health issues and addiction, anthropological approaches to betel nut use and trade remain either marginal or, in the case of Micronesia non-existent
L'apport des jeunes chercheurs à l'étude de l'écosystème éducatif antillais [Allocution d'ouverture]
No full textNational audienceCette allocution d'ouverture présente le cadre théorique de cette deuxième édition de la journée d'études des jeunes chercheurs en éducation (JCE2024), consacrée aux travaux réalisés dans l'écosystème éducatif de la Martinique. Un état de l'art des recherches réalisées dans les contextes éducatifs ultramarins nous montre que, très souvent, ces travaux sont réalisés par des jeunes chercheurs. Certes, il s'agit de terrains d'études très exigeants, en termes de logistique et de programmation d'une recherche, au vu de certaines contraintes géographiques, des limites imposés par l'infrastructure locale mais aussi de certaines habitudes liées à l'héritage colonial (qui compliquent le travail d'enquête). Cependant (et heureusement), la plupart de ces travaux proposent aussi des pistes pour améliorer la situation et corriger certaines défaillances systémiques
Introduced rat assemblage affects feral cat threat to biodiversity in French Polynesian islands
No full textInternational audienceContext Invasive feral cats strongly threaten native fauna on islands worldwide. The impact of feral cat populations is assumed to be higher in the presence of introduced rodents and may also vary according to an island’s rodent species assemblage. Aims This study assessed feral cat impacts on island biodiversity in French Polynesian islands harbouring differing assemblages of rat species, by investigating their abundance and trophic ecology. Methods We focused on the following six human-inhabited islands of three archipelagos in French Polynesia (South Pacific) with differing rat species assemblages: Tahiti and Moorea, Ua Huka and Tahuata, Rurutu and Rimatara. We studied (1) cat abundance, by setting up camera traps during 15 consecutive days to provide an abundance index, the general index (GI) or mean number of virtual captures per camera per occasion, and (2) cat diet, by performing macroscopic analyses of scat samples to determine the frequency of occurrence (FO) of prey categories. Key results Our study showed previously unreported patterns of cat-abundance index for the Society archipelago, with a GI of 0.30 ± 0.12 in Tahiti and 0.02 ± 0.02 in Moorea; for the Marquesas, with a GI of 0.75 ± 0.20 in Ua Huka and 0.20 ± 0.06 in Tahuata; and for the Austral, with a GI of 0.06 ± 0.04 in Rurutu and 0.19 ± 0.05 in Rimatara. Feral cats are shown to prey strongly on introduced rodents (FO = 91.3%), arthropods (37.8%), squamates (18.6%) and birds (13.3%) in our study sites. FO of birds are particularly high in Rimatara (31.9%) and Ua Huka (16.8%). Conclusions We demonstrated that feral cats represent a serious threat to biodiversity in French Polynesian islands, with 15 species preyed on, including eight endemic birds, four of them being considered threatened by the IUCN Red List. Surprisingly, relative abundances of feral cats were higher both on islands harbouring only one rat species (Ua Huka, with only Rattus exulans) and on islands free of black rats. This finding raises questions regarding the ‘hyperpredation’ hypothesis for multi-invaded island ecosystems. Implications This study on islands with differing assemblages of introduced rodents demonstrated the need for invasive predator studies in multi-invaded ecosystems, so as to improve bird conservation and guide management strategies and site prioritisation
De la « dérogation » coloniale à « l’adaptation » postcoloniale: Retour sur la peine et son exécution dans les collectivités du Pacifique français (Nouvelle Calédonie, Polynésie française)
No full textIn New Caledonia as in French Polynesia, the colonial legacy is often used to account for the contemporary particularities of criminal justice. While, on the one hand, numerous historical works have been devoted to the penal colony and to this form of repressive justice specific to the colonial context which is the indigenous regime, on the other hand, the prison has remained a blind spot in historiography. The research target was to identify a possible sui generis model for the execution of sentences, shaped as much by representations of the specificities of the colonized population as by the representations of colonial public order in their local variations. Insofar as they focus on the colonial period stricto sensu, historians’ work does not fill the gap concerning the immediate post[1]colonial period, when these territories became Overseas Territories (TOM) in the aftermath of the Second World War. Our research aims to understand what happened – and what didn’t happen – from the 1950s to the 1990s, the years of transition to the state-run prison services. It looks at the disappearance of special treatment for former colonized subjects who had become full French citizens concerning the enforcement of sentences. From colonial to post-colonial times, it identifies the turning points in the history of custodial sentence in these two archipelagos, showing that the moments of rupture are dependent on the major institutional changes affecting these territories, but also have dynamics specific to the prison system. The project lies at the crossroads of several disciplinary fields: colonial and imperial history, history of decolonization, history of penitentiary institutions, political anthropology of Pacific islands societies. It draws on various types of sources: academic bibliographical references and grey literature, administrative archives preserved in mainland France and in the Pacific, the local press of the time, and a corpus of interviews conducted in situ in New Caledonia and French Polynesia. A first step consists in situating the prison within the range of main sanctions, both criminal and extra-judicial, to which the indigenous populations of the two territories were subjected: capital punishment, deportation, confinement. A second part presents the period which follows that of a “prison of conquest”, with the opening of civil prisons that continued to largely escape the major reforms that punctuated the history of Metropolitan French prisons, and bear witness to original trajectories. The third section develops the difficult transformation of a prison environment marked by colonial history into a prison compatible with the formal equality of citizens, in the context of a protest against nuclear tests and demands for independence.En Nouvelle-Calédonie comme en Polynésie française, le legs colonial est souvent mobilisé pour rendre compte des particularités contemporaines de la justice pénale. Si de nombreux travaux historiques ont été consacrés au bagne d’une part, et à cette forme de justice répressive propre au contexte colonial, le régime de l’indigénat, d’autre part, la prison y est restée un angle mort de l’historiographie. La recherche avait pour ambition de dégager un éventuel modèle de l’exécution des peines sui generis, façonné tant par les représentations des spécificités de la population colonisée que par les représentations de l’ordre public colonial dans leur déclinaison locale. En tant qu’ils sont centrés sur la période coloniale stricto sensu, les travaux des historiens ne permettent pas de combler un vide concernant la période immédiatement post-coloniale, quand ces territoires deviennent des Territoires d’Outre-mer (TOM) au lendemain de la Seconde Guerre mondiale. La recherche vise à comprendre ce qui se passe – et ce qui ne se passe pas – des années 1950 aux années 1990, années de transition vers l’étatisation des services pénitentiaires. Elle envisage la disparition d’un traitement particulier des anciens sujets colonisés devenus citoyens français à part entière en matière d’application des peines. Du colonial au post-colonial, elle identifie les tournants de l’histoire de la privation de liberté dans ces deux archipels, en montrant que les moments de rupture sont tributaires des grands changements institutionnels qui affectent ces territoires, mais ont aussi des dynamiques propres au système carcéral. Le projet se situe à la croisée de plusieurs champs disciplinaires : histoire coloniale et impériale, histoire de la décolonisation, histoire des institutions pénitentiaires, anthropologie politique des sociétés du Pacifique insulaire. Il mobilise différents types de sources : des références bibliographiques académiques et de la littérature grise, des archives administratives conservées en France hexagonale et dans le Pacifique, la presse locale d’époque, et un corpus d’entretiens réalisés in situ en Nouvelle-Calédonie et en Polynésie française.Un premier temps consiste à situer la prison dans l’ensemble des principales sanctions, tant pénales qu’extra-judiciaires, auxquelles ont été soumises les populations indigènes des deux territoires : la peine capitale, la déportation, les enfermements.Un second temps présente la période qui succède à celle d’un « carcéral de conquête », avec l’ouverture de prisons civiles qui continuent d’échapper largement aux grandes réformes qui jalonnent l’histoire pénitentiaire hexagonale et témoignent de trajectoires originales.Le troisième temps développe la difficile transformation d’un univers carcéral marqué par l’histoire coloniale en une prison compatible avec l’égalité formelle des citoyens, dans le contexte d’une protestation contre les essais nucléaires et de revendication indépendantiste