Éditeur(s) : HAL CCSD Frontiers Media
Résumé : International audience
Coral reef fisheries support the development of local and national economies and are the basis of important cultural practices and worldviews. Transitioning economies, human development, and environmental stress can harm this livelihood. Here we focus on a transitioning social-ecological system as a case study (Moorea, French Polynesia). We review fishing practices and three decades of effort and landing estimates with the broader goal of informing management. Fishery activities in Moorea are quite challenging to quantify because of the diversity of gears used, the lack of centralized access points or markets, the high participation rates of the population in the fishery, and the overlapping cultural and economic motivations to catch fish. Compounding this challenging diversity, we lack a basic understanding of the complex interplay between the cultural, subsistence, and commercial use of Moorea's reefs. In Moorea, we found an order of magnitude gap between estimates of fishery yield produced by catch monitoring methods (2 t km −2 ∼ year −1) and estimates produced using consumption or participatory socioeconomic consumer surveys (∼24 t km −2 year −1). Several lines of evidence suggest reef resources may be overexploited and stakeholders have a diversity of opinions as to whether trends in the stocks are a cause for concern. The reefs, however, remain ecologically resilient. The relative health of the reef is striking given the socioeconomic context. Moorea has a relatively high population density, a modern economic system linked into global flows of trade and travel, and the fishery has little remaining traditional or customary management. Other islands in the Pacific in similar contexts in Polynesia such as Hawaii, that continue to develop economically, may have small-scale fisheries that increasingly resemble Moorea. Therefore, understanding Moorea's reef fisheries may provide insight into their future.
ISSN: 2296-7745

Droits : http://creativecommons.org/licenses/by/
hal-01325804
https://hal-univ-perp.archives-ouvertes.fr/hal-01325804
https://hal-univ-perp.archives-ouvertes.fr/hal-01325804/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01325804/file/fmars-03-00070.pdf
DOI : 10.3389/fmars.2016.00070

Éditeur(s) : HAL CCSD Paris : Muséum national d'histoire naturelle
Résumé : International audience
Coral reefs are one of the most diverse ecosystems on Earth and sustain millions of people worldwide.However, coral reefs are temporally dynamic and fragile systems subject to ever increasing disturbancesof anthoropogenic and natural origins. Understanding the patterns and trajectories of changes through time isurgently needed to estimate the resilience of coral reefs. To ascertain these patterns, we depend on the availabilityof long-term datasets, which are seldom available. In this study, we present the data set which allowed us to analysethe long-term trends of coral and fish assemblages for the island of Moorea (French Polynesia) from 1983to 2014, a dataset spanning 32 years, comprising two Acanthaster planci outbreaks (1987 and 2006) and severalhurricanes (1982, 1983, 1991 and 2010), on three permanent monitoring sites (quadrats of 50 × 2 m2) located onboth fringing and barrier reefs as well as on the outer slope. Coral cover oscillated significantly over time, particularlyon the outer slope where it suffered greatly from the effects of A. planci outbreaks and hurricanes. Totalfish and commercial fish abundances varied significantly across the three habitats. Prior to 2000, both total fishand herbivorous fish abundances increased on the barrier reef while after this time, numbers began to drop significantlyalong the outer slope. Species richness for total, commercialized and herbivorous fish increased over thesampling period for all three habitats. There were varied responses amongst species to disturbances on the outerslope over the sampling period: while some tended to disappear for a while before reappearing, others showed apeak in abundance in the middle of the sampling period, and still others increased or decreased continuously orwere stable over time. Our results support the view that coral reefs are highly dynamic systems and that differentfunctional groups show different temporal trajectories. While disturbance is probably the major driver for coralcover dynamics, its impact is less obvious for fish, possibly due to their mobility and population dynamics whichmay mask the effect of disturbance.
Les récifs coralliens sont des systèmes dynamiques et diversifiés régulièrement soumis à des perturbationsnaturelles et anthropiques, sources d’hétérogénéité spatiale et temporelle dans la structure et la dynamique deces communautés d’organismes que sont, entre autres, les poissons et les coraux. Récemment, il a été démontréque les activités humaines pouvaient modifier les régimes naturels de perturbations des récifs coralliens en transformantles événements ponctuels en perturbations persistantes ou en stress chronique, soit en introduisant denouveaux types de perturbations, soit en ajoutant ou altérant certaines perturbations naturelles nécessaires au bonmaintien de la dynamique inhérente aux récifs. Dans cette étude, nous présentons la base de données qui nouspermettra d’analyser les tendances à long-terme des assemblages de poissons et de coraux de l’île de Moorea(Polynésie française) entre 1983 et 2014 sur une période de 32 ans, comprenant deux proliférations d’Acanthasterplanci (1987 et 2006) et plusieurs cyclones (1982, 1983, 1991 et 2010), sur trois sites de suivi permanents(quadrats de 50 × 2 m2) sur les récifs barrière et frangeant ainsi que sur la pente externe. La couverture corallienneprésente de fortes oscillations, en particulier sur la pente externe où elle a répondu fortement à la proliférationd’A. planci et des cyclones. Les abondances des poissons totaux et des poissons commercialisés montrent destendances contrastées sur les trois habitats, avec, plus particulièrement, une augmentation sur le récif barrière etune diminution sur la pente externe après 2000. Ces tendances se retrouvent chez les poissons herbivores dansces deux habitats. La richesse spécifique des poissons totaux, commerciaux et herbivores, augmente de façoncontinue au cours de la période d’étude dans les trois habitats. Des groupes particuliers d’espèces répondentdifféremment aux perturbations de la pente externe au cours du suivi : alors que certaines espèces ont tendanceà disparaître pendant quelques années avant de réapparaître, d’autres présentent un pic en terme d’abondanceen milieu de suivi ; d’autres espèces ont des abondances qui augmentent ou diminuent de façon continue, etd’autres encore montrent des abondances stables. Ceci indique que les récifs coralliens sont des systèmes trèsdynamiques dans lesquels les perturbations naturelles peuvent affecter les espèces de façon différente. Alors quele régime de perturbations naturelles semble être important pour la dynamique de la couverture corallienne danscertains habitats, cela se retrouve beaucoup moins pour les poissons. Cette atténuation des fluctuations spatialeset temporelles peut être due aux aptitudes de dispersion de nombreuses espèces de poissons, capables de chercherun autre habitat favorable en cas de perturbation de l’habitat corallien d’origine.
ISSN: 0399-0974

hal-01282378
https://hal-univ-perp.archives-ouvertes.fr/hal-01282378

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Ciguatera Fish Poisoning (CFP) is a non-bacterial seafood poisoning well characterized in the remote archipelagos of French Polynesia, yet poorly documented in the Society archipelago, most notably on Moorea, the second most populated island in French Polynesia, which counts a high proportion of fishermen fishing on a regular basis. To address this knowledge gap, a holistic study of the ciguatera issue was conducted on Moorea. First, ciguatera risk was analysed in terms of incidence rate, fish species most commonly involved and risk stratification in Moorea lagoon based on 2007–2013 epidemiological data. A mean incidence rate of 8 cases per 10,000 inhabitants for the study period and an average under-reporting rate of 54% were found. Taking into account hospitalization and medication fees, and loss of productive days, the health-related costs due to CFP were estimated to be USD $1613 and $749 for each reported and unreported case, respectively, with an overall cost of USD $241,847 for the study period. Comparison of the present status of CFP on Moorea with a risk map established in the late 1970’s showed that the spatial distribution of the risk has stayed relatively stable in time, with the north shore of the island remaining the most prone to ciguatera. Evaluation of the current knowledge on CFP among different populations groups, i.e. fishermen, residents and visitors, was also conducted through direct and indirect interviews. About half of the fishermen interviewed were actually able to identify risky fishing areas. While, overall, the CFP risk perception in the fishing community of Moorea seemed accurate, although not scientifically complete, it was sufficient for the safe practice of their fishing activities. This may be due in part to adaptive responses adopted by 36% of the fishermen interviewed, such as the avoidance of either high-risk fishing sites or toxic species. At the residents and visitors’ level, the study points out a striking lack of awareness of the CFP issue among visitors, as compared to local residents. Indeed, less than 25% of Moorea visitors vs. an average of 98% in residents were aware of CFP or of its presence on the island. Interestingly, evaluation of the fish consumption preferences showed that 70% of visitors do not consume lagoon fish during their stay, not for fear of CFP, but mainly due to the lack of availability of these species in recreational facilities or because they have nutritional preference for pelagic fish. This lack of awareness, along with the report by several CFP patients of the consumption of fish species yet banned for sale, stress the need for improved communication efforts on this critical issue among both residents and visitors on Moorea. The implementation of a public outreach strategy is proposed, based on both existing information networks and low-cost communication actions through information displays at various strategic locations, e.g. Tahiti-Faa’a international airport, the ferry boat station, recreational facilities, as well as the major trading points on Moorea Island.
ISSN: 1568-9883

hal-01391648
https://hal-univ-perp.archives-ouvertes.fr/hal-01391648
DOI : 10.1016/j.hal.2016.10.003

Éditeur(s) : HAL CCSD Springer Verlag (Germany)
Résumé : International audience
Mass bleaching events resulting in coral mortality are among the greatest threats to coral reefs, and are projected to increase in frequency and intensity with global warming. Achieving a better understanding of the consistency of the response of coral assemblages to thermal stress, both spatially and temporally, is essential to determine which reefs are more able to tolerate climate change. We compared variations in spatial and taxonomic patterns between two bleaching events at the scale of an island (Moorea Island, French Polynesia). Despite similar thermal stress and light conditions, bleaching intensity was significantly lower in 2007 (approximately 37 % of colonies showed signs of bleaching) than in 2002, when 55 % of the colonies bleached. Variations in the spatial patterns of bleaching intensity were consistent between the two events. Among nine sampling stations at three locations and three depths, the stations at which the bleaching response was lowest in 2002 were those that showed the lowest levels of bleaching in 2007. The taxonomic patterns of susceptibility to bleaching were also consistent between the two events. These findings have important implications for conservation because they indicate that corals are capable of acclimatization and/or adaptation and that, even at small spatial scales, some areas are consistently more susceptible to bleaching than others.
ISSN: 0167-6369

hal-00905944
https://hal.archives-ouvertes.fr/hal-00905944
DOI : 10.1007/s10661-012-2923-3

Éditeur(s) : HAL CCSD Société nationale de protection de la nature
Résumé : International audience
The island of Moorea in French Polynesia is representative of a relatively well preserved small tropical oceanic island but both its terrestrial and marine ecosystems are currently under strong anthropogenic pressures. The terrestrial ecosystems are facing an increasing urbanization, and the destruction and modification of their natural habitats by cultivation and forestry plantations, accidental or intentional fires, and particularly by the invasion of alien plant and animal species. Coastal areas and reef ecosystems are threatened by shoreline artificialization, sedimentation due to soil erosion, increasing uses of marine and lagoon resources and frequency of coral bleaching events. A significant erosion of terrestrial and marine biodiversity is observed on the island since the last decades. In the context of the Land Management Plan (PGA) and Marine Area Management Plan (PGEM) recently set up in the island by local authorities, scientific surveys and inventories were made in 2006 in order to assess the status of terrestrial biodiversity (vascular plants) and marine biodiversity (reef fishes) and compare areas with different anthropogenic pressures. Studies conducted on the flora and the vegetation at low and middle elevation along altitudinal transects show that the plant invasion process is related to climatic and topographic factors, and species autoecology. The marine study aims to compare the protected areas with control areas in order to test the effectiveness of protection measures and to propose a streamlined monitoring protocol. A methodological study in both terrestrial and marine ecosystems was conducted in order to propose biodiversity indicators which are crucial for decision making in conservation and sustainable development of island biodiversity. We used Geographic Information System (GIS) as a fast and intuitive tool for mapping indicators and their variability. This methodological approach developed on the island of Moorea could be used as a model for other tropical islands
Moorea est une petite île océanique tropicale de la Polynésie française relativement bien préservée, mais dont les écosystèmes terrestres et marins sont actuellement soumis à de fortes pressions anthropiques. Le milieu terrestre est confronté à une urbanisation croissante, à la destruction ou à la modification des habitats naturels pour l’extension des cultures ou des plantations forestières, aux incendies volontaires ou accidentels, et particulièrement à l’invasion d’espèces végétales et animales introduites. Les zones côtières et les récifs coralliens sont menacés par de multiples perturbations telles que l’artificialisation des lignes de rivage, l’apport de sédiments dus à l’érosion des sols, l’augmentation des usages des ressources marines et lagonaires et de la fréquence des phénomènes de blanchissement du corail. Une érosion sensible de la biodiversité terrestre et marine de l’île est observée depuis les dernières décennies. Dans le cadre du Plan Général d’Aménagement (PGA) et du Plan de Gestion de l’Espace Maritime (PGEM) mis en place par les autorités locales, des inventaires scientifiques ont été réalisés en 2006 dans le but d’évaluer l’état de la biodiversité terrestre (plantes vasculaires) et marine (poissons récifaux) et de comparer des zones soumises à différentes perturbations. Les études réalisées sur la flore et la végétation de basse et moyenne altitude le long de transects altitudinaux montrent des processus d’invasion végétale différents en relation avec les facteurs climatiques, topographiques et autoécologiques des espèces. Les études en milieu marin visent à comparer des aires protégées à des aires témoins afin de suivre l’efficacité des mesures de gestion. La réflexion méthodologique menée parallèlement sur les deux écosystèmes a pour but d’illustrer différents indices de biodiversité nécessaires à la prise de décision en matière de conservation ou de développement durable de la biodiversité insulaire et de réaliser un état de référence pour établir un diagnostic sur l’état de la biodiversité. La représentation cartographique des indices à l’aide d’un SIG, illustrée dans cette étude avec la richesse spécifique terrestre et marine, permet une lecture intuitive et rapide de la variabilité de cet indice dont la restitution est basée sur une standardisation du nombre d’espèces. Cette approche méthodologique développée sur l’île de Moorea pourrait servir de modèle pour d’autres îles tropicales
EISSN: 2429-6422

hal-01306285
https://hal-univ-perp.archives-ouvertes.fr/hal-01306285

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
Symbioses with the dinoflagellate Symbiodinium are widespread among marine invertebrates and protists, especially in nutritionally demanding habitats, such as tropical coral reefs, where they play a major role in ecosystem survival. Moreover, apart from corals and sea anemones, many of the Symbiodinium species and clades involved in these partnerships remain to be characterized. This study provides new insights into nudibranch and sponge associations with Symbiodinium by sequencing regions of the Symbiodinium 28S rDNA and the host mitochondrial COI oxidase. Specimens were sampled between 2011 and 2013 from locations around the islands of Moorea and Tahiti, French Polynesia. Our results revealed that some of the sponges and nudibranchs harbored typical Symbiodinium from clade B or C while others harbored new, undescribed Symbiodinium-like dinoflagellates. A detailed analysis of the different life stages of the nudibranch Phestilla lugubris and of its specific coral prey, Porites rus, suggests a prey-predator horizontal transfer of the symbiont and its vertical inheritance from the parent to the eggs.
Les symbioses à zooxanthelles, dinoflagellés du genre Symbiodinium, sont largement répandues chez les invertébrés marins et les protozoaires, notamment dans les eaux oligotrophes, où ils jouent un rôle important dans la survie des récifs coralliens. De plus, excepté chez les coraux et les anémones, les différentes espèces et clades de Symbiodinium impliqués dans ces associations restent à être caractérisés. Notre étude, grâce à l’utilisation des marqueurs génétiques 28S ADNr des Symbiodinium et la sous-unité 1 de la cytochrome oxydase mitochondriale (COI) de l’hôte, procure de nouvelles données quant aux associations des éponges et des nudibranches avec les Symbiodinium. L’échantillonnage a eu lieu autour de Moorea et de Tahiti (Polynésie française), entre 2011 et 2013. Nos résultats révèlent que certaines espèces d’éponges et de nudibranches possèdent les clades B et C communément retrouvés, chez les coraux notamment, alors que d’autres présentent de nouveaux dinoflagellés « Symbiodinium-like ». Une analyses détaillée des Symbiodinium à différents stades du cycle de vie du nudibranche corallivore Phestilla lugubris et de son corail hôte Porites rus suggèrent l’existence d’un transfert horizontal de Symbiodinium proie–prédateur et un transfert vertical du parent P. lugubris à ses œufs.
ISSN: 1631-0691

hal-01145518
https://hal.archives-ouvertes.fr/hal-01145518
DOI : 10.1016/j.crvi.2015.01.005

Éditeur(s) : HAL CCSD Consejo Superior de Investigaciones Científicas
Résumé : International audience
The temporal variation in carbon and nitrogen isotopic compositions (noted as δ 13 C and δ 15 N) was investigated in the convict surgeonfish (Acanthurus triostegus) at Moorea (French Polynesia). Over a period of 24 days, juveniles were reared in aquaria and subjected to two different feeding treatments: granules or algae. The dynamics of δ 13 C and δ 15 N in two muscles (the adductor mandibulae complex and the epaxial musculature) having different functions were compared. At the end of experiments, a steady-state isotopic system in each muscle tissue was not reached. Especially for the algal treatment, we found different patterns of variation in isotopic compositions over time between the two muscles. The turnovers of δ 13 C showed opposite trends for each muscle but differences are mitigated by starvation and by the metamorphosis. Our study highlighted that the metabolism of coral reef fish may be subjected to catabolism or anabolism of non-protein precursors at settlement, inducing variation in isotopic compositions that are not linked to diet change. Comparación de la dinámica de variación isotópica en dos músculos de un pez de arrecife de coral durante la fase de asentamiento Resumen: La variación temporal en la composiciones isotópicas del carbono y nitrógeno (δ 13 C y δ 15 N) fue investigada en el pez cirujano Acanthurus triostegus en Moorea (Polinesia Francesa). Durante un período de 24 días, peces juveniles se mantuvieron en acuarios y se sometieron a dos tratamientos de alimentación: gránulos o algas. Se compararon las dinámicas de cambio δ 13 C y δ 15 N en dos músculos con diferentes funciones (complejo aductor mandibular y musculatura epiaxial). Al final de los experimentos, no se alcanzó un sistema isotópico de estado estacionario en ningún tejido. Especialmente para el tratamiento de algas, encontramos distintos patrones de variación en composiciones isotópicas en el tiempo entre los dos músculos. Las variaciones en δ 13 C mostraron tendencias opuestas para cada músculo, pero las diferencias fueron mitigadas por la inanición y la metamorfosis. Nuestro estudio destaca que el metabolismo de los peces de arrecife puede ser sometido a catabolismo o anabolismo por los precursores no proteicos durante el asentamiento, induciendo variación en las composi-ciones isotópicas que no están vinculados al cambio de dieta.
ISSN: 0214-8358

Droits : http://creativecommons.org/licenses/by-nc/
hal-01212253
https://hal-univ-perp.archives-ouvertes.fr/hal-01212253
https://hal-univ-perp.archives-ouvertes.fr/hal-01212253/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01212253/file/1598-3145-1-PB.pdf
DOI : 10.3989/scimar.04225.31A

Éditeur(s) : Société Nationale de Protection de la Nature
Résumé : Monitoring of French Polynesia coral reefs and their recent development.-French Polynesia, consisting of 118 islands in the centre of the Pacific Ocean, has more than 15 000 km(2) of reefs and lagoons managed by the local government. Tourism and pearl culture are the two main economic resources of the country. Polynesian coral reefs are extremely diverse and are among those for which we have thorough knowledge. The exploitation of local resources has been recorded for multiple decades and includes : coral materials, fishing, harvest and export of mother-of-pearl molluscs, pearl production, and ornamental fish. All over the country, many monitoring programmes have been launched to measure the health of reefs and the natural and anthropogenic perturbations that they suffer : hurricanes and seismic events, water quality, health of benthic and fish communities, pearl oyster pathology and radiobiology. These data, collected over the last few decades, allowed to define the relative importance of natural and anthropogenic degradation on reefs and lagoons, and to explain the present status of reefs at different spatial scales. Devastating hurricanes are rare (1903-1906, 1982-1983 and occasionally at other times), but they may annihilate outer slope coral communities on some islands. Bleaching events with considerable coral mortality at different geographical scales occurred mainly in 1991, 1994 and 2003. Outbreaks of Acanthaster destroyed numerous reefs (lagoons and outer slopes) from 1978-1982 and a new demographic wave began in 2006 at many Society islands. Eutrophication events only occurred occasionally and only in some lagoons. Whereas natural catastrophic events degrade the coral reef ecosystem across many islands, at the archipelago or even regional scale, anthropogenic degradation is limited to a few Society Islands, occurring rarely on atolls and not at all on those (one third) which are uninhabited. The main causes of reef degradation in some areas of Tahiti and Moorea include the embankment of fringing zones, coral mining, overfishing, absence of urban sewage treatment and the development of leisure and tourism activities. Because of its large geographical extent, one may conclude that major reef degradation in French Polynesia is caused by catastrophic natural events. On the other hand, anthropogenic degradation is more localized. Unfortunately, the synergistic effects of these causes of degradation prevent reefs from recovering. Optimum coral cover on French Polynesian outer reef slopes is between 50-60%. After a major destructive impact (hurricane, bleaching, Acanthaster) a reef is reduced to less than 10% coral cover, however if no more major disturbance events occur a reef will recover in about 12 years. Most of the 15 000 km(2) of reefs and lagoons in French Polynesia are in good health, and along with their neighbouring reefs in East and Central Pacific they are considered as the least degraded reefs worldwide and at a low risk of becoming degraded in the few next decades. However, we are more and more anxious about the future of reefs in the world particularly because present simulations predict that major impacts of climate change would include : elevation of sea surface temperatures, increase in the strength of hurricanes and acidification of seawater which will affect the formation of coral structures.
La Polynésie française, 118 îles au coeur du Pacifique, possède une surface de plus de 15 000 km2 de récifs et lagons gérés par le gouvernement polynésien. Le tourisme et la perliculture représentent les deux ressources économiques majeures du Pays. Les formations récifales très diversifiées sont parmi les mieux connues. Plusieurs suivis d'exploitation des ressources sont opérationnels depuis des décennies : granulats coralliens, pêche pour l'alimentation, collecte et exportation de mollusques nacriers, production de perles, poissons d'ornement. À l'échelle du Pays de très nombreux programmes de surveillance de l'état des récifs et des perturbations qu'ils subissent, naturelles et anthropiques, ont été mis en place : perturbations cycloniques et sismiques, qualité des eaux, état de santé des peuplements benthiques et ichtyologiques, pathologie des nacres, radiobiologie. Toutes ces données recueillies au fi l des décennies ont permis d'établir l'importance relative des dégradations naturelles et anthropiques sur les récifs et lagons polynésiens et d'expliquer leur état de santé actuel en considérant différentes échelles spatiales. Les périodes cycloniques dévastatrices pour les récifs sont rares (1903-1906, 1982-1983 et épisodiquement) mais les cyclones ont parfois anéanti les communautés coralliennes de pentes externes dans certaines îles. Les blanchissements suivis de mortalités importantes à des échelles spatiales diverses, ont été surtout ceux de 1991, 1994 et 2003. Les explosions démographiques d'Acanthaster ont détruit de nombreux récifs (lagons et pentes externes) en 1978-1982 et une nouvelle pullulation s'amplifie depuis 2006 dans plusieurs îles de la Société. Les crises dystrophiques n'ont perturbé qu'épisodiquement certains lagons. [...]
Revue d'Ecologie de la Terre et de la Vie (0249-7395) (Société Nationale de Protection de la Nature), 2008 , Vol. 63 , N. 1-2 , P. 145-177

Droits : 2008 Société Nationale de Protection de la Nature
http://archimer.ifremer.fr/doc/2008/publication-4558.pdf
http://archimer.ifremer.fr/doc/00000/4558/

Éditeur(s) : HAL CCSD Wiley/Blackwell
Résumé : International audience
Marine fishes exhibit spectacular phenotypic changes during their ontogeny, and the identification of their early stages is challenging due to the paucity of diagnostic morphological characters at the species level. Meanwhile, the importance of early life stages in dispersal and connectivity has recently experienced an increasing interest in conservation programmes for coral reef fishes. This study aims at assessing the effectiveness of DNA barcoding for the automated identification of coral reef fish larvae through large-scale ecosystemic sampling. Fish larvae were mainly collected using bongo nets and light traps around Moorea between September 2008 and August 2010 in 10 sites distributed in open waters. Fish larvae ranged from 2 to 100 mm of total length, with the most abundant individuals being <5 mm. Among the 505 individuals DNA barcoded, 373 larvae (i.e. 75%) were identified to the species level. A total of 106 species were detected, among which 11 corresponded to pelagic and bathypelagic species, while 95 corresponded to species observed at the adult stage on neighbouring reefs. This study highlights the benefits and pitfalls of using standardized molecular systems for species identification and illustrates the new possibilities enabled by DNA barcoding for future work on coral reef fish larval ecology.
ISSN: 1755-098X

hal-01342973
https://hal-univ-perp.archives-ouvertes.fr/hal-01342973
DOI : 10.1111/1755-0998.12293

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
Marine biological invasions threaten biodiversity worldwide. Here we explore how Marine Protected areas, by reducing human use of the coast, confer resilience against the introduction of non-indigenous species (NIS), using two very different Pacific islands as case studies for developing and testing mathematical models. We quantified NIS vectors and promoters on Vancouver (Canada) and Moorea (French Polynesia) islands, sampled and barcoded NIS, and tested models at different spatial scales with different types of interaction among vectors and between marine protection and NIS frequency. In our results NIS were negatively correlated with the dimension of the protected areas and the intensity of the protection. Small to medium geographical scale protection seemed to be efficient against NIS introductions. The likely benefit of MPAs was by exclusion of aquaculture, principally in Canada. These results emphasize the importance of marine protected areas for biodiversity conservation, and suggest that small or medium protected zones would confer efficient protection against NIS introduction.
ISSN: 2045-2322

hal-01381251
https://hal-univ-perp.archives-ouvertes.fr/hal-01381251
https://hal-univ-perp.archives-ouvertes.fr/hal-01381251/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01381251/file/rate%20of%20biological%20invasions.pdf
DOI : 10.1038/srep33013

Éditeur(s) : HAL CCSD EDP Sciences
Résumé : International audience
In order to ensure a sustainable management of reef fisheries, data need to be collected regularly on the effect of these fisheries on both fish resources and the ecosystems that sustain them. Habitat and resources monitoring programs can provide such information, but are difficult to implement as they involve a range of technical, financial and human resources. Regarding these problems, the involvement of the local population in monitoring programs, called participatory monitoring, seems to offer solutions. Indeed, participatory monitoring has the potential of increasing the number of data collected at low cost, while taking advantage of the traditional ecological knowledge available locally. Some questions need clarifying, however: which methods can bring relevant information for the monitoring of reef fisheries while being appropriate to the motivations and skills of the local population? Is the degree of participation of the local population sufficient to make the monitoring program work, particularly over the long term? To answer these questions, participatory monitoring methods commonly used for coral reef ecosystems have been implemented to assess reef fisheries at three different sites: Moorea island and Tikehau atoll in French Polynesia, and the Bay of Tulear in Madagascar. While highlighting the relevance of some participatory monitoring programs for snapshot and large-scale surveys, the results of this study also show their lesser interest for regular data gathering on long-time scales. In any case, strong coordination and supervision by scientists are considered essential.
La gestion durable des écosystèmes coralliens nécessite de disposer d’informations régulières concernant l’impact des pêcheries sur les ressources récifales et sur les écosystèmes dont elles dépendent. Les suivis intégrés des ressources, des habitats et des espèces associées qui visent à fournir ce type d’informations sont difficiles à mettre en œuvre, car ils impliquent de nombreuses ressources humaines, techniques et financières. Face à ces problèmes, la participation de la société civile dans les programmes de suivi semble en mesure d’apporter des solutions. Dans le but de tester cette hypothèse, des méthodes de suivi participatif ont été mises en œuvre afin de caractériser des pêcheries récifales sur trois socio-écosystèmes contrastés : l’île de Moorea et l’atoll de Tikehau en Polynésie française, et le littoral de Tuléar à Madagascar. Les résultats de cette étude soulignent la pertinence de certains suivis participatifs pour fournir une vision écosystémique dans le cas de collecte de données ponctuelles et de large envergure, et leur intérêt moindre pour la collecte continue de données sur de longues échelles de temps. Dans tous les cas, une structure de coordination et l’implication de scientifiques s’avèrent primordiales pour assurer pérennité et fiabilité au système de suivi.
ISSN: 1240-1307

hal-01302983
https://hal-univ-perp.archives-ouvertes.fr/hal-01302983
DOI : 10.1051/nss/2013109

Éditeur(s) : HAL CCSD PeerJ
Résumé : International audience
The adaptative bleaching hypothesis (ABH) states that, depending on the symbiotic flexibility of coral hosts (i.e., the ability of corals to ''switch'' or ''shuffle'' their algal symbionts), coral bleaching can lead to a change in the composition of their associated Symbiodinium community and, thus, contribute to the coral's overall survival. In order to determine the flexibility of corals, molecular tools are required to provide accurate species delineations and to detect low levels of coral-associated Symbiodinium. Here, we used highly sensitive quantitative (real-time) PCR (qPCR) technology to analyse five common coral species from Moorea (French Polynesia), previously screened using only traditional molecular methods, to assess the presence of low-abundance (background) Symbiodinium spp. Similar to other studies, each coral species exhibited a strong specificity to a particular clade, irrespective of the environment. In addition, however, each of the five species harboured at least one additional Symbiodinium clade, among clades A–D, at background levels. Unexpectedly, and for the first time in French Polynesia, clade B was detected as a coral symbiont. These results increase the number of known coral-Symbiodinium associations from corals found in French Polynesia, and likely indicate an underestimation of the ability of the corals in this region to associate with and/or ''shuffle'' different Symbiodinium clades. Altogether our data suggest that corals from French Polynesia may favor a trade-off between optimizing symbioses with a specific Symbiodinium clade(s), maintaining associations with particular background clades that may play a role in the ability of corals to respond to environmental change. How to cite this article Rouzé et al. (2017), An updated assessment of Symbiodinium spp. that associate with common scleractinian corals from Moorea (French Polynesia) reveals high diversity among background symbionts and a novel finding of clade B.
ISSN: 2167-8359

Droits : info:eu-repo/semantics/OpenAccess
hal-01430294
https://hal-sde.archives-ouvertes.fr/hal-01430294
https://hal-sde.archives-ouvertes.fr/hal-01430294/document
https://hal-sde.archives-ouvertes.fr/hal-01430294/file/Rouze-2017-PeerJ-Updated.pdf
DOI : 10.7717/peerj.2856

Éditeur(s) : HAL CCSD Annex Publishers
Résumé : International audience
Introduction: Shark-based ecotourism is significantly developing around the world, often without appropriate management of risk. This activity involves a risk of accidental bites on divers that can be quite severe or even fatal. Objectives: To determine if ecotourism companies' liability can be engaged in the context of bites on scuba divers in presence of hand-feeding practices, supporting the legitimacy of financial compensation for the victims. Methods: We analyzed the development from the mid-eighties to 2010 of shark-based ecotourism through artificial provisioning practices in Moorea Island (French Polynesia) and more specifically the features and motivation of two bites on divers by Sicklefin Lemon sharks. Results: The specific practice of hand-feeding can be considered as a facilitating factor for accidental bites on divers, potentially involving the diving operator's responsibility. Conclusions: Our findings should support the technical work of experts that might be called in such cases.
ISSN: 2348-9804

hal-01238771
https://hal-univ-perp.archives-ouvertes.fr/hal-01238771
https://hal-univ-perp.archives-ouvertes.fr/hal-01238771/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01238771/file/3502-Determining-the-Role-of-Hand-Feeding-Practices-in-Accidental-Shark-Bites-on-Scuba-Divers.pdf

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
The present study tested different sounds that could disturb eagle rays (Aetobatus ocellatus) during their foraging activities at Moorea, French Polynesia. Results showed that artificial white sound and single-frequency tones (40 Hz, 600 Hz or 1 kHz) did not have an effect on rays (at least 90% of rays continued to forage over sand), while playbacks of boat motor sound significantly disturbed rays during foraging activity (60% exhibited an escape behaviour). Overall, our study highlighted the negative effect of boat noises on the foraging activity of eagle rays. These noises produced by boat traffic could, however, have some positive effects for marine aquaculture if they could be used as a deterrent to repel the eagle rays, main predators of the pearl oysters.
Notre étude teste différents types de sons qui pourraient perturber les raies-aigles (Aetobatus ocellatus) pendant leur prise de nourriture dans le lagon de Moorea, en Polynésie française. Les résultats montrent que le bruit artificiel blanc ou des fréquences uniques (40 Hz, 600 Hz ou 1 kHz) n’ont aucun effet sur les raies (au moins 90 % des raies continuent de se nourrir dans le sable), tandis que l’enregistrement d’un moteur de bateau les perturbe significativement dans cette activité (60 % des individus ont un comportement de fuite). Notre étude met ainsi en évidence l’effet négatif des bruits anthropogéniques sur les activités de nourrissage des raies-aigles. Ces bruits produits par les bateaux pourraient néanmoins avoir un effet positif pour l’aquaculture marine s’ils pouvaient être utilisés comme répulsifs des raies, principaux prédateurs de l’huître perlière.
ISSN: 1631-0691

Droits : http://creativecommons.org/licenses/by-nc-nd/
hal-01297683
https://hal-univ-perp.archives-ouvertes.fr/hal-01297683
https://hal-univ-perp.archives-ouvertes.fr/hal-01297683/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01297683/file/1-s2.0-S1631069116000020-main.pdf
DOI : 10.1016/j.crvi.2016.01.001

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Understanding how communities respond to natural disturbances is fundamental to assess the mechanisms of ecosystem resistance and resilience. However, ecosystem responses to natural disturbances are rarely monitored both through space and time, while the factors promoting ecosystem stability act at various temporal and spatial scales. Hence, assessing both the spatial and temporal variations in species composition is important to comprehensively explore the effects of natural disturbances. Here, we suggest a framework to better scrutinize the mechanisms underlying community responses to disturbances through both time and space. Our analytical approach is based on beta diversity decomposition into two components, replacement and biomass difference. We illustrate this approach using a 9-year monitoring of coral reef fish communities off Moorea Island (French Polynesia), which encompassed two severe natural disturbances: a crown-of-thorns starfish outbreak and a hurricane. These disturbances triggered a fast logistic decline in coral cover, which suffered a 90% decrease on all reefs. However, we found that the coral reef fish composition remained largely stable through time and space whereas compensatory changes in bio-mass among species were responsible for most of the temporal fluctuations, as outlined by the overall high contribution of the replacement component to total beta diversity. This suggests that, despite the severity of the two disturbances, fish communities exhibited high resistance and the ability to reorganize their compositions to maintain the same level of total community biomass as before the disturbances. We further investigated the spatial congruence of this pattern and showed that temporal dynamics involved different species across sites; yet, herbivores controlling the proliferation of algae that compete with coral communities were consistently favored. These results suggest that compensatory changes in bio-mass among species and spatial heterogeneity in species responses can provide further
ISSN: 1932-6203

hal-01212344
https://hal-univ-perp.archives-ouvertes.fr/hal-01212344
https://hal-univ-perp.archives-ouvertes.fr/hal-01212344/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01212344/file/journal.pone.0138696.pdf
DOI : 10.1371/journal.pone.0138696

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Fish mucus has important biological and ecologicalroles such as defense against fish pathogens andchemical mediation among several species. A non-targetedliquid chromatography–mass spectrometry metabolomicapproach was developed to study gill mucus of eight butterflyfishspecies in Moorea (French Polynesia), and theinfluence of several fish traits (geographic site and reefhabitat, species taxonomy, phylogeny, diet and parasitismlevels) on the metabolic variability was investigated. Abiphasic extraction yielding two fractions (polar and apolar)was used. Fish diet (obligate corallivorous, facultativecorallivorous or omnivorous) arose as the main driver ofthe metabolic differences in the gill mucus in both fractions,accounting for 23% of the observed metabolic variabilityin the apolar fraction and 13% in the polar fraction.A partial least squares discriminant analysis allowed us toidentify the metabolites (variable important in projection,VIP) driving the differences between fish with differentdiets (obligate corallivores, facultative corallivores andomnivorous). Using accurate mass data and fragmentationdata, we identified some of these VIP as glycerophosphocholines,ceramides and fatty acids. Level of monogeneangill parasites was the second most important factor shapingthe gill mucus metabolome, and it explained 10% of themetabolic variability in the polar fraction and 5% in theapolar fraction. A multiple regression tree revealed that themetabolic variability due to parasitism in the polar fractionwas mainly due to differences between non-parasitized andparasitized fish. Phylogeny and butterflyfish species werefactors contributing significantly to the metabolic variabilityof the apolar fraction (10 and 3%, respectively) buthad a less pronounced effect in the polar fraction. Finally,geographic site and reef habitat of butterflyfish species didnot influence the gill mucus metabolome of butterflyfishes.
ISSN: 0722-4028

hal-01563312
https://hal-univ-perp.archives-ouvertes.fr/hal-01563312
DOI : 10.1007/s00338-017-1554-0

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
Different marine habitats are characterised by different soundscapes. How or which differences may be representative of the habitat characteristics and/or community structure remains however to be explored. A growing project in passive acoustics is to find a way to use soundscapes to have information on the habitat and on its changes. In this study we have successfully tested the potential of two acoustic indices, i.e. the average sound pressure level and the acoustic complexity index based on the frequency spectrum. Inside and outside marine protected areas of Moorea Island (French Polynesia), sound pressure level was positively correlated with the characteristics of the substratum and acoustic complexity was positively correlated with fish diversity. It clearly shows soundscape can be used to evaluate the acoustic features of marine protected areas, which presented a significantly higher ambient sound pressure level and were more acoustically complex than non-protected areas. This study further emphasizes the importance of acoustics as a tool in the monitoring of marine environments and in the elaboration and management of future conservation plans. Coral reef ecosystems are among the most biologically diverse and complex marine ecosystems worldwide. In addition to their biological and ecological importance, coral reefs support major economic and physical functions (e.g. food production, tourism, biotechnology development and coastal protection) that are essential for many countries 1. Unfortunately, coral reefs are severely threatened: 20% of coral reefs can no longer be defined as such, another 25% are currently endangered and another 25% will be endangered by 2050 2. The frequency and severity of natural perturbations (e.g. cyclone, outbreaks of predators, particularly the crown-of-thorns starfish [COTS] Acanthaster planci) and anthropogenic perturbations (e.g. ocean acidification, pesticides, rising seawater temperatures) on coral reefs have greatly increased worldwide in the last three decades, and, as a consequence, reef communities (fish, coral and benthic invertebrates) have suffered unprecedented levels of decline 3,4
ISSN: 2045-2322

hal-01370610
https://hal-uvsq.archives-ouvertes.fr/hal-01370610
https://hal-uvsq.archives-ouvertes.fr/hal-01370610/document
https://hal-uvsq.archives-ouvertes.fr/hal-01370610/file/2016%20Sci.Rep.pdf
DOI : 10.1038/srep33326

Éditeur(s) : HAL CCSD
Résumé : International audience
https://hal.archives-ouvertes.fr/hal-01436542

hal-01436542
https://hal.archives-ouvertes.fr/hal-01436542
DOI : 10.1109/IGARSS.2011.6049595

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
As environmental sounds are used by larval fish and crustaceans to locate and orientate towards habitat during settlement, variations in the acoustic signature produced by habitats could provide valuable information about habitat quality, helping larvae to differentiate between potential settlement sites. However, very little is known about how acoustic signatures differ between proximate habitats. This study described within-and between-site differences in the sound spectra of five contiguous habitats at Moorea Island, French Polynesia: the inner reef crest, the barrier reef, the fringing reef, a pass and a coastal mangrove forest. Habitats with coral (inner, barrier and fringing reefs) were characterized by a similar sound spectrum with average intensities ranging from 70 to 78 dB re 1μPa.Hz-1. The
ISSN: 1932-6203

hal-01211705
https://hal-univ-perp.archives-ouvertes.fr/hal-01211705
https://hal-univ-perp.archives-ouvertes.fr/hal-01211705/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01211705/file/journal.pone.0135733.pdf
DOI : 10.1371/journal.pone.0135733

Éditeur(s) : HAL CCSD PeerJ
Résumé : International audience
Understanding the role of predators in food webs can be challenging in highly diverse predator/prey systems composed of small cryptic species. DNA based dietary analysis can supplement predator removal experiments and provide high resolution for prey identification. Here we use a metabarcoding approach to provide initial insights into the diet and functional role of coral-dwelling predatory fish feeding on small invertebrates. Fish were collected in Moorea (French Polynesia) where the BIOCODE project has generated DNA barcodes for numerous coral associated invertebrate species. Pyrosequencing data revealed a total of 292 Operational Taxonomic Units (OTU) in the gut contents of the arc-eye hawkfish (Paracirrhites arcatus), the flame hawkfish (Neocirrhites armatus) and the coral croucher (Caracanthus maculatus). One hundred forty-nine (51%) of them had species-level matches in reference libraries (>98% similarity) while 76 additional OTUs (26%) could be identified to higher taxonomic levels. Decapods that have a mutualistic relationship with Pocillopora and are typically dominant among coral branches, represent a minor contribution of the predators' diets. Instead, predators mainly consumed transient species including pelagic taxa such as copepods, chaetognaths and siphonophores suggesting non random feeding behavior. We also identified prey species known to have direct negative interactions with stony corals, such as Hapalocarcinus sp, a gall crab considered a coral parasite, as well as species of vermetid snails known for their deleterious effects on coral growth. Pocillopora DNA accounted for 20.8% and 20.1% of total number of sequences in the guts of the flame hawkfish and coral croucher but it was not detected in the guts of the arc-eye hawkfish. Comparison of diets among the three fishes demonstrates remarkable partitioning with nearly 80% of prey items consumed by only one predator. Overall, the taxonomic resolution provided by the metabarcoding approach highlights a highly complex interaction web and demonstrates that levels of trophic partitioning among coral reef fishes have likely been underestimated. Therefore, we strongly encourage further empirical approaches to dietary studies prior to making assumptions of trophic equivalency in food web reconstruction. How to cite this article Leray et al. (2015), Metabarcoding dietary analysis of coral dwelling predatory fish demonstrates the minor contribution of coral mutualists to their highly partitioned, generalist diet. PeerJ 3:e1047
ISSN: 2167-8359

Droits : http://creativecommons.org/licenses/by/
hal-01174184
https://hal-univ-perp.archives-ouvertes.fr/hal-01174184
https://hal-univ-perp.archives-ouvertes.fr/hal-01174184/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01174184/file/peerj-1047.pdf
DOI : 10.7717/peerj.1047