Sea anemone (Anthozoa, Actiniaria) diversity in Mo'orea (French Polynesia).

Sea anemones (Order Actiniaria) are a diverse group of marine invertebrates ubiquitous across marine ecosystems. Despite their wide distribution and success, a knowledge gap persists in our understanding of their diversity within tropical systems, owed to sampling bias of larger and more charismatic species overshadowing cryptic lineages. This study aims to delineate the sea anemone diversity in Mo'orea (French Polynesia) with the use of a dataset from the Mo'orea Biocode's "BioBlitz" initiative, which prioritized the sampling of more cryptic and understudied taxa. Implementing a target enrichment approach, we integrate 71 newly sequenced samples into an expansive phylogenetic framework and contextualize Mo'orea's diversity within global distribution patterns of sea anemones. Our analysis corroborates the presence of several previously documented sea anemones in French Polynesia and identifies for the first time the occurrence of members of genera Andvakia and Aiptasiomorpha. This research unveils the diverse sea anemone ecosystem in Mo'orea, spotlighting the area's ecological significance and emphasizing the need for continued exploration. Our methodology, encompassing a broad BLAST search coupled with phylogenetic analysis, proved to be a practical and effective approach for overcoming the limitations posed by the lack of comprehensive sequence data for sea anemones. We discuss the merits and limitations of current molecular methodologies and stress the importance of further research into lesser-studied marine organisms like sea anemones. Our work sets a precedent for future phylogenetic studies stemming from BioBlitz endeavors.

Invertebrate sounds from photic to mesophotic coral reefs reveal vertical stratification and diel diversity.

Although mesophotic coral ecosystems account for approximately 80% of coral reefs, they remain largely unexplored due to their challenging accessibility. The acoustic richness within reefs has led scientists to consider passive acoustic monitoring as a reliable method for studying both altiphotic and mesophotic coral reefs. We investigated the relationship between benthic invertebrate sounds (1.5-22.5 kHz), depth, and benthic cover composition, key ecological factors that determine differences between altiphotic and mesophotic reefs. Diel patterns of snaps and peak frequencies were also explored at different depths to assess variations in biorhythms. Acoustic recorders were deployed at 20 m, 60 m, and 120 m depths across six islands in French Polynesia. The results indicated that depth is the primary driver of differences in broadband transient sound (BTS) soundscapes, with sound intensity decreasing as depth increases. At 20-60 m, sounds were louder at night. At 120 m depth, benthic activity rhythms exhibited low or highly variable levels of diel variation, likely a consequence of reduced solar irradiation. On three islands, a peculiar peak in the number of BTS was observed every day between 7 and 9 PM at 120 m, suggesting the presence of cyclic activities of a specific species. Our results support the existence of different invertebrate communities or distinct behaviors, particularly in deep mesophotic reefs. Overall, this study adds to the growing evidence supporting the use of passive acoustic monitoring to describe and understand ecological patterns in mesophotic reefs.

Prokaryotic communities of the French Polynesian sponge Dactylospongia metachromia display a site-specific and stable diversity during an aquaculture trial.

Dynamics 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.

SARS-CoV-2 seroprevalence and associated factors of infection before and after the Delta wave in French Polynesia: a cross-sectional study.

BACKGROUND: French Polynesia (FP) comprises 75 inhabited islands scattered across five archipelagos. Between July and October 2021, the SARS-CoV-2 Delta variant triggered a much stronger second epidemic wave in FP than the original Wuhan strain, which was dominant from August 2020 to March 2021. Although previous seroprevalence surveys made it possible to determine the proportion of the population infected by SARS-CoV-2 on the two most populated islands (Tahiti and Moorea) after the first (20.6% in Tahiti and 9.4% in Moorea) and second (57.7% in Tahiti) epidemic waves, no data are available for more remote islands. We used blood samples and personal data collected before, during, and after the second wave from inhabitants of several islands within the five archipelagos to assess the prevalence of SARS-CoV-2 infections and identify associated factors. METHODS: Blood samples and personal data were collected between April and December 2021 as part of the MATAEA study, a cross-sectional survey conducted on a random sample of the adult population representative of the five FP archipelagos and stratified by age and gender. IgG antibodies targeting the SARS-CoV-2 nucleocapsid (N) protein were detected using a recombinant antigen-based microsphere immunoassay. Factors associated with anti-SARS-CoV-2-N seropositivity were identified using logistic regression models. RESULTS: Of 1,120 participants, 503 (44.9%) tested positive for anti-SARS-CoV-2-N antibodies, corresponding to a weighted prevalence of 56.8% for the FP population aged 18-69 years. The seroprevalence increased from 21.9% to 62.1% before and during/after the Delta wave. Of these infections, only 28.4% had been diagnosed by health professionals. The odds of being seropositive were lower in males, participants recruited before the Delta wave, those who had never been married, those with a diagnosed respiratory allergy, smokers, and those vaccinated against COVID-19. CONCLUSIONS: Our results confirm the high impact of the Delta wave in FP. By the end of 2021, 56.8% of the FP population aged 18-69 years had been infected by SARS-CoV-2; the majority of these infections went undetected. Individuals with respiratory allergies were found to be less susceptible to SARS-CoV-2 infection.

[In Makemo, a nurse in a remote island setting]. / À Makemo, une infirmière en milieu insulaire isolé.

A nurse graduating in 2018, Noémie's guiding principle has always been her desire to discover IDE practice outside our borders. To this end, once she had her diploma in hand, and in parallel with her nursing practice in her native Isère region, she enriched her knowledge by taking a university diploma (DU) in "international solidarity action in humanitarian health". When she obtained her diploma, she decided to settle in French Polynesia, a French territory at the end of the world. Here, she shares her experiences as a nurse in an isolated island environment, highlighting the added value of this experience.

Detection of Mycobacterium angelicum in Human Urinary Tract, French Polynesia.

We definitively characterized Mycobacterium angelicum, an aquatic zoonotic opportunistic pathogen of the M. szulgai complex, using a polyphasic approach that included whole-genome sequencing. The sequence was obtained on the island of Tahiti, French Polynesia, from a urine specimen collected from a patient experiencing a urinary tract infection.

Characterization of 25 new microsatellite markers for the green turtle (Chelonia mydas) and cross-species amplification in other marine turtle species.

BACKGROUND: The green sea turtle, Chelonia mydas, is a migratory species with a strong natal homing behavior leading to a complex population structure worldwide. The species has suffered severe declines in local populations; it is therefore crucial to understand its population dynamics and genetic structure to adopt appropriate management policies. Here, we describe the development of 25 new microsatellite markers specific to C. mydas and suitable for these analyses. METHODS AND RESULTS: They were tested on 107 specimens from French Polynesia. An average allelic diversity of 8 alleles per locus was reported and observed heterozygosity ranged from 0.187 to 0.860. Ten loci were significantly deviant from the Hardy-Weinberg equilibrium, and 16 loci showed a moderate to high level of linkage disequilibrium (4-22%). The overall Fis was positive (0.034, p-value < 0.001), and sibship analysis revealed 12 half- or full-sibling dyads, suggesting possible inbreeding in this population. Cross-amplification tests were performed on two other marine turtle species, Caretta caretta and Eretmochelys imbricata. All loci successfully amplified on these two species, though 1 to 5 loci were monomorphic. CONCLUSION: These new markers will not only be relevant for further analyses on the population structure of the green turtle and the two other species, but they will also be invaluable for parentage studies, for which a high number of polymorphic loci are necessary. This can provide important insight into male reproductive behavior and migration, an aspect of sea turtle biology that is of critical importance for the conservation of the species.

Targeted census of lionfishes (Scorpaenidae) reveals high densities in their native range.

Indo-Pacific lionfishes generally exhibit cryptic behaviours and so can be missed when conducting non-targeted surveys. Here, the authors report the results from targeted surveys of lionfish at Moorea, French Polynesia. Lionfish from three species (Pterois antennata, Pterois radiata, Dendrochirus biocellatus) were observed at a mean density of 267 individuals ha-1 . This is substantially higher than previous estimates from the same area (Moorea) and represents the highest reported density of lionfishes from their Pacific range. Overall, this study highlights the importance of targeted survey techniques for detecting cryptic species on coral reefs.

Reef environments shape microbial partners in a highly connected coral population.

Evidence is mounting that composition of microorganisms within a host can play an essential role in total holobiont health. In corals, for instance, studies have identified algal and bacterial taxa that can significantly influence coral host function and these communities depend on environmental context. However, few studies have linked host genetics to algal and microbial partners across environments within a single coral population. Here, using 2b-RAD sequencing of corals and metabarcoding of their associated algal (ITS2) and bacterial (16S) communities, we show evidence that reef zones (locales that differ in proximity to shore and other environmental characteristics) structure algal and bacterial communities at different scales in a highly connected coral population (Acropora hyacinthus) in French Polynesia. Fore reef (FR) algal communities in Mo'orea were more diverse than back reef (BR) communities, suggesting that these BR conditions constrain diversity. Interestingly, in FR corals, host genetic diversity correlated with bacterial diversity, which could imply genotype by genotype interactions between these holobiont members. Our results illuminate that local reef conditions play an important role in shaping unique host-microbial partner combinations, which may have fitness consequences for dispersive coral populations arriving in novel environments.

Ecophysiological differentiation between life stages in filmy ferns (Hymenophyllaceae).

Desiccation tolerance was a key trait that allowed plants to colonize land. However, little is known about the transition from desiccation tolerant non-vascular plants to desiccation sensitive vascular ones. Filmy ferns (Hymenophyllaceae) represent a useful system to investigate how water-stress strategies differ between non-vascular and vascular stages within a single organism because they have vascularized sporophytes and nonvascular gametophytes that are each capable of varying degrees of desiccation tolerance. To explore this, we surveyed sporophytes and gametophytes of 19 species (22 taxa including varieties) of filmy ferns on Moorea (French Polynesia) and used chlorophyll fluorescence to measure desiccation tolerance and light responses. We conducted phylogenetically informed analyses to identify differences in physiology between life stages and growth habits. Gametophytes had similar or less desiccation tolerance (ability to recover from 2 days desiccation at - 86 MPa) and lower photosynthetic optima (maximum electron transport rate of photosystem II and light level at 95% of that rate) than sporophytes. Epiphytes were more tolerant of desiccation than terrestrial species in both life stages. Despite their lack of greater physiological tolerances, gametophytes of several species occurred over a wider elevational range than conspecific sporophytes. Our results demonstrate that filmy fern gametophytes and sporophytes differ in their physiology and niche requirements, and point to the importance of microhabitat in shaping the evolution of water-use strategies in vascular plants.

SARS-CoV-2 Wave Two Surveillance in East Asia and the Pacific: Longitudinal Trend Analysis.

BACKGROUND: The COVID-19 pandemic has had a profound global impact on governments, health care systems, economies, and populations around the world. Within the East Asia and Pacific region, some countries have mitigated the spread of the novel coronavirus effectively and largely avoided severe negative consequences, while others still struggle with containment. As the second wave reaches East Asia and the Pacific, it becomes more evident that additional SARS-CoV-2 surveillance is needed to track recent shifts, rates of increase, and persistence associated with the pandemic. OBJECTIVE: The goal of this study is to provide advanced surveillance metrics for COVID-19 transmission that account for speed, acceleration, jerk, persistence, and weekly shifts, to better understand country risk for explosive growth and those countries who are managing the pandemic successfully. Existing surveillance coupled with our dynamic metrics of transmission will inform health policy to control the COVID-19 pandemic until an effective vaccine is developed. We provide novel indicators to measure disease transmission. METHODS: Using a longitudinal trend analysis study design, we extracted 330 days of COVID-19 data from public health registries. We used an empirical difference equation to measure the daily number of cases in East Asia and the Pacific as a function of the prior number of cases, the level of testing, and weekly shift variables based on a dynamic panel model that was estimated using the generalized method of moments approach by implementing the Arellano-Bond estimator in R. RESULTS: The standard surveillance metrics for Indonesia, the Philippines, and Myanmar were concerning as they had the largest new caseloads at 4301, 2588, and 1387, respectively. When looking at the acceleration of new COVID-19 infections, we found that French Polynesia, Malaysia, and the Philippines had rates at 3.17, 0.22, and 0.06 per 100,000. These three countries also ranked highest in terms of jerk at 15.45, 0.10, and 0.04, respectively. CONCLUSIONS: Two of the most populous countries in East Asia and the Pacific, Indonesia and the Philippines, have alarming surveillance metrics. These two countries rank highest in new infections in the region. The highest rates of speed, acceleration, and positive upwards jerk belong to French Polynesia, Malaysia, and the Philippines, and may result in explosive growth. While all countries in East Asia and the Pacific need to be cautious about reopening their countries since outbreaks are likely to occur in the second wave of COVID-19, the country of greatest concern is the Philippines. Based on standard and enhanced surveillance, the Philippines has not gained control of the COVID-19 epidemic, which is particularly troubling because the country ranks 4th in population in the region. Without extreme and rigid social distancing, quarantines, hygiene, and masking to reverse trends, the Philippines will remain on the global top 5 list of worst COVID-19 outbreaks resulting in high morbidity and mortality. The second wave will only exacerbate existing conditions and increase COVID-19 transmissions.

Transfusion risk associated with recent arbovirus outbreaks in French Polynesia.

BACKGROUND AND OBJECTIVES: French Polynesia, where dengue virus (DENV) has been present for a long time, experienced two successive outbreaks of Zika (ZIKV) and chikungunya viruses (CHIKV) between 2013 and 2015. To avoid the transmission of these viruses by transfusion, nucleic acid testing (NAT) has been in place for DENV since 2013 and for ZIKV and CHIKV during epidemics. The objective was to compare the estimated risk of viraemic blood donation with NAT results and to discuss the impact on the prevention of transfusion-related infectious risk. MATERIALS AND METHODS: The average risks of viraemic blood donation were estimated per year for DENV, and during the epidemic periods for ZIKV and CHIKV, using the Biggerstaff and Petersen model based on the incidence rate, the mean length of viraemia and the frequency of asymptomatic infection. The estimated risks were compared with the number of viraemic blood donations detected by NAT. RESULTS: According to the different assumptions, risks estimates ranged from 11·2 to 53·1/100 000 donations for DENV, 746 to 1924/100 000 for ZIKV and 1083 /100 000 for CHIKV. When compared to the number of donations collected during the study periods, these estimates match NAT results (5 blood donors reactive for DENV, 42 for ZIKV and 34 for CHIKV). CONCLUSION: The risks of viraemic blood donation were related to the viral incidence in the general population and concordant with NAT results. These findings suggest that the screening may be optimized by a targeted NAT implementation based on incidence data.

Response to underwater laser pointer in the Orange-finned Anemonefish Amphiprion chrysopterus and three-spot damselfish Dascyllus trimaculatus.

Response of orange-finned anemonefish Amphiprion chrysopterus and three-spot damselfish Dascyllus trimaculatus to red laser-pointer light was studied in Mo'orea, French Polynesia. Four magnificent anemones Heteractis magnifica and their resident fish were observed for typical behaviours (biting, chasing, hiding, posing, lunging and retreating) with and without exposure to laser-pointer light. Lunging behaviour increased significantly for both fish species upon exposure to laser-pointer light; none of the other behaviours changed significantly. We advance the hypothesis that orange-finned anemonefish and three-spot damselfish interpret laser pointer stimulation as a territorial threat.

[Stingray injury: A case in French Polynesia]. / Piqûre de raie pastenague : un cas en Polynésie française.

INTRODUCTION: Stingray injuries occur when people inadvertently step on these fish. Penetration of the barb results in puncture and/or laceration wounds and lesions related to the venom. PATIENTS AND METHODS: We report the case of a 76-year-old woman in French Polynesia who was stung on her right ankle by a stingray. She initially had a hypertensive episode with encephalopathy and a haemorrhagic wound due to an indwelling fragment of the barb. Necrosis due to the poison required medical-surgical management with debridement, which yielded a favourable outcome. DISCUSSION: Stingray injuries are rare and not well-known by doctors. They can be serious due to injury by the barb and to venom poisoning, leading to enzymatic tissue destruction, ischaemia and intense pain. The initial treatment consists in immersion in hot water, as the venom is thermolabile; antibiotics and surgery may be necessary, depending on the condition of the wound.

Dengue virus serotype 2 (DENV-2) outbreak, French Polynesia, 2019.

In 1996-97, the last dengue virus serotype 2 (DENV-2) outbreak occurred in French Polynesia. In February 2019, DENV-2 infection was detected in a traveller from New Caledonia. In March, autochthonous DENV-2 infection was diagnosed in two residents. A DENV-2 outbreak was declared on 10 April with 106 cases as at 24 June. Most of the population is not immune to DENV-2; a large epidemic could occur with risk of imported cases in mainland France.

Seroprevalence of Dengue and Chikungunya Virus Antibodies, French Polynesia, 2014-2015.

We investigated dengue and chikungunya virus antibody seroprevalence in French Polynesia during 2014-2015. Dengue virus seroprevalence was ≈60% among schoolchildren and >83% among the general population; chikungunya virus seroprevalence was <3% before and 76% after Zika virus emergence (2013). Dengue virus herd immunity may affect Zika virus infection and pathogenesis.

Intensive Care Admissions for Severe Chikungunya Virus Infection, French Polynesia.

During the 2014-2015 chikungunya outbreak in French Polynesia, 64 patients with confirmed chikungunya virus infection were admitted into intensive care. Sixty-three were nonpregnant adults; 11 had an atypical form, 21 had severe sepsis or septic shock, and 18 died. These findings indicate that critical illness frequently complicates the course of chikungunya virus infection.

Zika Virus Infection during Pregnancy and Effects on Early Childhood Development, French Polynesia, 2013-2016.

Congenital Zika virus syndrome consists of a large spectrum of neurologic abnormalities seen in infants infected with Zika virus in utero. However, little is known about the effects of Zika virus intrauterine infection on the neurocognitive development of children born without birth defects. Using a case-control study design, we investigated the temporal association of a cluster of congenital defects with Zika virus infection. In a nested study, we also assessed the early childhood development of children recruited in the initial study as controls who were born without known birth defects,. We found evidence for an association of congenital defects with both maternal Zika virus seropositivity (time of infection unknown) and symptomatic Zika virus infection during pregnancy. Although the early childhood development assessment found no excess burden of developmental delay associated with maternal Zika virus infection, larger, longer-term studies are needed.

Investigating the Role of Easter Island in Migration of Zika Virus from South Pacific to Americas.

The role of Easter Island in the dissemination of Zika virus from the Pacific islands into the Americas remains unclear. We analyzed new Zika virus sequences from Eastern Island and found that Zika virus was independently disseminated from French Polynesia into the Americas and Easter Island at around the same time.

Ross River Virus Seroprevalence, French Polynesia, 2014-2015.

Ross River virus (RRV), spread by Aedes and Culex mosquitoes, is the most commonly transmitted arbovirus in Australia. A serosurvey of blood donors in French Polynesia during 2011-2013 suggested that RRV circulated without being detected. We report RRV circulation in French Polynesia based on further screening of blood samples collected during 2014-2015.