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Sere M.G.,Agence Pour la Recherche et la Valorisation Marines ARVAM | Sere M.G.,Oceanographic Research Institute ORI | Sere M.G.,Institute Of La Recherche Pour Le Developpement Ird | Tortosa P.,University of Reunion Island | And 4 more authors.
PLoS ONE | Year: 2013

The scleractinian coral Porites lutea, an important reef-building coral on western Indian Ocean reefs (WIO), is affected by a newly-reported white syndrome (WS) the Porites white patch syndrome (PWPS). Histopathology and culture-independent molecular techniques were used to characterise the microbial communities associated with this emerging disease. Microscopy showed extensive tissue fragmentation generally associated with ovoid basophilic bodies resembling bacterial aggregates. Results of 16S rRNA sequence analysis revealed a high variability between bacterial communities associated with PWPS-infected and healthy tissues in P. lutea, a pattern previously reported in other coral diseases such as black band disease (BBD), white band disease (WBD) and white plague diseases (WPD). Furthermore, substantial variations in bacterial communities were observed at the different sampling locations, suggesting that there is no strong bacterial association in Porites lutea on WIO reefs. Several sequences affiliated with potential pathogens belonging to the Vibrionaceae and Rhodobacteraceae were identified, mainly in PWPS-infected coral tissues. Among them, only two ribotypes affiliated to Shimia marina (NR043300.1) and Vibrio hepatarius (NR025575.1) were consistently found in diseased tissues from the three geographically distant sampling localities. The role of these bacterial species in PWPS needs to be tested experimentally. © 2013 Séré et al.


Puech B.,Service de Reanimation | Batsalle B.,Center Hospitalier Gabriel Martin | Roget P.,Center Hospitalier Gabriel Martin | Turquet J.,Agence Pour la Recherche et la Valorisation Marines ARVAM | And 9 more authors.
Bulletin de la Societe de Pathologie Exotique | Year: 2014

Pufferfish poisoning has rarely been reported in the southwestern Indian Ocean and in the French overseas territories. In Reunion Island, the last notified documented case occurred in 1989 and people are no longer aware of the potential toxicity of pufferfish. We report a family hospitalized for a tetrodotoxin poisoning following the consumption of Lagocephalus sceleratus caught on the coast of Reunion Island in September 2013. Two patients presenting acute vital functions failures were admitted in an ICU. Ten people were admitted simultaneously to the emergency department after consuming L. sceleratus with signs of toxicity appearing within 2 hours. Treatment was supportive, but included the need for mechanical ventilation for two patients. All those affected had complete and uneventful recoveries within a few days. The fish consumed was identified as L. sceleratus, a species known to contain tetrodotoxin. The diagnosis of tetrodotoxin poisoning was suggested by typical clinical manifestations together with the history of very recent consumption of tetrodotoxin-containing fish. Tetrodotoxin was later detected at high levels in food remnants. To the best of our knowledge, there has been no documented case series of tetrodotoxin poisoning reported from Reunion Island for the last 25 years and from the entire Indian Ocean area since 1998. Pufferfish intoxication is one of the most common causes of poisoning among people in coastal regions of Asia but it has also recently been reported in areas where it was previously unknown, particularly along the Mediterranean shores and in Spain. Public health education in French overseas territories and along the Mediterranean shores should be adapted to include increased awareness of the danger of consuming pufferfish. Health teams must be aware of such clinical presentations. © 2014 Springer-Verlag France.


Sere M.G.,Agence Pour la Recherche et la Valorisation Marines ARVAM | Sere M.G.,Oceanographic Research Institute ORI | Sere M.G.,IRD Montpellier | Tortosa P.,University of Reunion Island | And 4 more authors.
Molecular Ecology | Year: 2015

Porites white patch syndrome (PWPS) is a coral disease recently described in the Western Indian Ocean. This study aimed to isolate and identify potential pathogens associated with PWPS utilizing both culture and nonculture screening techniques and inoculation trials. A total of 14 bacterial strains (those dominant in disease lesions, absent or rare in healthy tissues and considered potential pathogens in a previous study) were cultured and used to experimentally inoculate otherwise healthy individuals in an attempt to fulfil Henle-Koch's postulates. However, only one (P180R), identified as closely related (99-100% sequence identity based on 1.4 kb 16S RNA sequence) to Vibrio tubiashii, elicited signs of disease in tank experiments. Following experimental infection (which resulted in a 90% infection rate), the pathogen was also successfully re-isolated from the diseased tissues and re-inoculated in healthy corals colonies, therefore fulfilling the final stages of Henle-Koch's postulates. Finally, we report that PWPS appears to be a temperature-dependent disease, with significantly higher tissue loss (anova: d.f. = 2, F = 39.77, P < 0.01) occurring at 30 C [1.45 ± 0.85 cm2 per day (mean ± SE)] compared to ambient temperatures of 28 and 26 C (0.73 ± 0.80 cm2 per day (mean ± SE) and 0.51 ± 0.50 cm2 per day (mean ± SE), respectively). © 2015 John Wiley and Sons Ltd.


Sere M.,Agence pour la Recherche et la VAlorisation Marines ARVAM | Sere M.,Oceanographic Research Institute ORI | Sere M.,IRD Montpellier | Wilkinson D.A.,University of Reunion Island | And 4 more authors.
PeerJ | Year: 2016

Recent surveys conducted on Reunion Island coral reefs revealed an atypical manifestation of black band disease on the main framework building coral, Porites lutea. This BBD manifestation (PorBBD) presented a thick lighter-colored band, which preceded the typical BBD lesion. Whilst BBD aetiology has been intensively described worldwide, it remains unclear if corals with apparently similar lesions across coral reefs are affected by the same pathogens. Therefore, a multidisciplinary approach involving field surveys, gross lesion monitoring, histopathology and 454-pyrosequencing was employed to provide the first comprehensive characterization of this particular manifestation. Surveys conducted within two geomorphological zones over two consecutive summers and winters showed spatial and seasonal patterns consistent with those found for typical BBD. Genetic analyses suggested an uncharacteristically high level of Vibrio spp. bacterial infection within PorBBD. However, microscopic analysis revealed high densities of cyanobacteria, penetrating the compromised tissue as well as the presence of basophilic bodies resembling bacterial aggregates in the living tissue, adjacent to the bacterial mat. Additionally, classical BBD-associated cyanobacterial strains, genetically related to Pseudoscillatoria coralii and Roseofilum reptotaenium were identified and isolated and the presence of sulfate-reducers or sulfide-oxidizers such as Desulfovibrio and Arcobacter, previously shown to be associated with anoxic microenvironment within typical BBD was also observed, confirming that PorBBD is a manifestation of classical BBD. © 2016 Séré et al.


Pinault M.,CNRS Insular Research Center and Environment Observatory | Pinault M.,University of Reunion Island | Wickel J.,PARETO Ecoconsult Agence de la Reunion | Guyomard D.,Comite Regional des Peches Maritimes et des Elevages Marins CRPMEM | And 2 more authors.
Cybium | Year: 2014

Despite the large number of studies on fish populations of coral reef areas of Reunion Island during the past forty years, the bicolor anthias Pseudanthias bicolor (Randall, 1979), previously recorded from Mauritius and the Maldives in the Indian Ocean, was never observed on the coral reefs of the island. Recently, two specimens of this species were photographed on different artificial habitats during scientific monitoring programs in scuba diving. This study, based on morphologic and morphometric evidences, validates the identification of these specimens as P. bicolor, and therefore represents the westernmost record of the species in the Indian Ocean. In a general context of degradation of coral reef habitats and considering the difficult access to certain non-reef habitats (e.g. depth, large surface area, distance from a port), the example of P. bicolor presented in this study illustrates the importance of artificial habitats for the observation of marine fish diversity. These small habitats of substitution, often monitored according to European regulations, allow occasional identification of new fish species, monitoring of exotic invasive populations or observation of rare species. © SFI.


Guigue C.,Aix - Marseille University | Bigot L.,University of Reunion Island | Turquet J.,Agence Pour la Recherche et la Valorisation Marines ARVAM | Tedetti M.,Aix - Marseille University | And 3 more authors.
Environmental Chemistry | Year: 2015

Environmental context Hydrocarbons are among the most widespread and harmful pollutants found in the aquatic media. Although they have been investigated in various temperate coastal environments, their dynamics in coral reef tropical ecosystems, which are under increasing human pressure, remain poorly understood. It was found that hydrocarbons had moderate to high concentrations, multiple origins (biogenic and anthropogenic) and could be used to track inland intrusions in fore reef waters of the eutrophicated La Saline reef ecosystem (La Reúnion Island, Indian Ocean). Abstract The La Saline fringing reef, which is the most important coral reef complex of La Reúnion Island, (south-western Indian Ocean), is subjected to anthropogenic pressures through river and groundwater inputs. Salinity and biogeochemical parameters (silicates, nitrates, dissolved organic carbon, chlorophyll-a), as well as aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs) were analysed in particulate and dissolved material from groundwaters, rivers, harbour, back reef, fore reef and oceanic waters in the La Saline reef area during the rainy season (February-March 2012). Particulate and dissolved AH concentration ranges were 0.07-144 and 0.06-0.58gL-1 respectively. Particulate and dissolved PAH concentrations ranges were 4.3-326 and 28-350ng L-1 respectively. AHs, dominated by nC15, nC17, nC18 compounds or nC26, nC27, nC29, nC31 compounds, were mainly of biogenic origin (phytoplankton, bacteria, higher-plant debris) although some anthropogenic (petroleum inputs) signatures were recorded in the dissolved phase from the harbour and fore reef areas. PAHs, dominated by two-to three-ring compounds and their alkylated homologues, reflected unburned petroleum inputs, but probably also biogenic sources. From the distribution of salinity, biogeochemical parameters and hydrocarbons, we found that inland waters flowed mainly in the surface and in the southern part of reef waters and that particulate PAHs allowed tracking these inland water intrusions in fore reef waters. Finally, this pilot study highlights the uncoupling between the dynamics of AHs and PAHs in tropical environments. © 2015 CSIRO.


PubMed | University of Reunion Island, Oceanographic Research Institute ORI, Agence pour la Recherche et la Valorisation Marines ARVAM and Institute Of La Recherche Pour Le Developpement Ird
Type: Journal Article | Journal: PloS one | Year: 2014

The scleractinian coral Porites lutea, an important reef-building coral on western Indian Ocean reefs (WIO), is affected by a newly-reported white syndrome (WS) the Porites white patch syndrome (PWPS). Histopathology and culture-independent molecular techniques were used to characterise the microbial communities associated with this emerging disease. Microscopy showed extensive tissue fragmentation generally associated with ovoid basophilic bodies resembling bacterial aggregates. Results of 16S rRNA sequence analysis revealed a high variability between bacterial communities associated with PWPS-infected and healthy tissues in P. lutea, a pattern previously reported in other coral diseases such as black band disease (BBD), white band disease (WBD) and white plague diseases (WPD). Furthermore, substantial variations in bacterial communities were observed at the different sampling locations, suggesting that there is no strong bacterial association in Porites lutea on WIO reefs. Several sequences affiliated with potential pathogens belonging to the Vibrionaceae and Rhodobacteraceae were identified, mainly in PWPS-infected coral tissues. Among them, only two ribotypes affiliated to Shimia marina (NR043300.1) and Vibrio hepatarius (NR025575.1) were consistently found in diseased tissues from the three geographically distant sampling localities. The role of these bacterial species in PWPS needs to be tested experimentally.


Zubia M.,University of French Polynesia | Turquet J.,Agence pour la Recherche et la Valorisation Marines ARVAM | Golubic S.,Boston University
Acta Oecologica | Year: 2016

The marine benthic cyanobacteria of the Iles Eparses, Mozambique Channel, were surveyed for the first time. A total of 39 species are reported: 29 from Europa, 17 from Glorioso and 23 from Juan de Nova Islands. The higher biodiversity in Europa is explained by greater habitat diversity on this Island with unique ecosystems (mangroves, fossil reefs, pools). Average species richness varied between the geomorphological habitat types with higher diversity in shallow environments (fossil reef pools, mangroves, reef flats), which are characterized by high temperatures and high irradiances. The most common species observed on the three islands were Hydrocoleum coccineum, Hydrocoleum glutinosum, Hydrocoleum lyngbyaceum, Phormidium laysanense, Lyngbya sordida, and Symploca hydnoides; which are also the dominant species observed in the Southwest Indian Ocean region. The most frequent species was Phormidium laysanense with extensive cover observed in the northwest of Juan de Nova Island. Our study provided a comparison between the cyanobacterial flora of Iles Eparses and the recorded surveys in the Southwest Indian Ocean region. The low similarity observed between these species lists could be explained by differences in sampling strategies and efforts, as well as by different taxonomic approaches employed in past regional studies. © 2015 Elsevier Masson SAS.

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