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Fare, French Polynesia

Andrefouet S.,Institute Of Recherche Pour Le Developpement | Van Wynsberge S.,Institute Of Recherche Pour Le Developpement | Gaertner-Mazouni N.,University of French Polynesia | Menkes C.,Institute Of Recherche Pour Le Developpement | And 2 more authors.
Biological Conservation | Year: 2013

In 2004, the first no-take area (NTA) dedicated to the conservation of giant clams Tridacna maxima was implemented in Tatakoto Atoll, French Polynesia. This NTA protected a unique area worldwide, with extraordinarily high giant clam densities (up to 337 individuals per m2 on 20-m transect). In 2012, a stock assessment survey revealed a dramatic decrease of the clam population. The reduced densities peaked at 38indm-2 and the stock in the NTA decreased from 20.1±6.0million to 1.9±0.55million clams (mean±95% confidence interval). Losses of similar proportions were observed throughout the atoll. Remarkably, the 83% overall loss of this natural resource used daily for consumption and for exports of clam meat to Tahiti Island went unnoticed by the local population. Field clues, including the size of live juveniles attached to the inside of dead shells, pointed to a massive mortality occurring about 3years before the 2012 survey. Examinations of sea surface temperature satellite data identified a high range of temperature variations before March 2009. In agreement with past and recent events in other atolls, this anomaly is the most likely explanation of the massive loss of giant clams in Tatakoto Atoll, although the exact hydrological and biological secondary mechanisms that occurred in the lagoon remain unclear. The consequences of the massive die-off inside and outside the NTA require new long-term management strategies, by reinforcing the top-down national giant clam management arrangements and by setting flexible management objectives across a network of islands. © 2013 Elsevier Ltd. Source

Direction Des Ressources Marines | Date: 2011-12-14

The present invention relates to a nucleus covered or coated with a film including one or more PHA. The invention also relates to a PHA, characterized in that it is of the type PHB-V, a film and a composition including the PHA. The invention further relates to a film or a composition including a PHA and zosteric acid or a bioactive molecule. The invention moreover relates to a surface, preferably a nucleus, covered with the film of PHA, a method for production thereof, and methods for grafting a pearl oyster and producing a pearl using this nucleus. Finally, the present invention relates to a method for reducing graft failure and/or for improving the quality of the pearl using the nucleus according to the invention.

Tan T.L.S.,University of Queensland | Paul-Pont I.,University of Sydney | Evans O.M.,University of Sydney | Watterson D.,University of Queensland | And 7 more authors.
Fish and Shellfish Immunology | Year: 2015

Ostreid herpesvirus 1 (OsHV-1) has induced mass mortalities of the larvae and spat of Pacific oysters, Crassostrea gigas, in Europe and, more recently, in Oceania. The production of pearls from the Black-lip pearl oyster, Pinctada margaritifera, represents the second largest source of income to the economies of French Polynesia and many Pacific Island nations that could be severely compromised in the event of a disease outbreak. Coincidentally with the occurrence of OsHV-1 in the southern hemisphere, C.gigas imported from New Zealand and France into French Polynesia tested positive for OsHV-1. Although interspecies viral transmission has been demonstrated, the transmissibility of OsHV-1 to P.margaritifera is unknown. We investigated the susceptibility of juvenile P.margaritifera to OsHV-1μvar that were injected with tissue homogenates sourced from either naturally infected or healthy C.gigas. The infection challenge lasted 14 days post-injection (dpi) with sampling at 0, 1, 2, 3, 5, 7 and 14 days. Mortality rate, viral prevalence, and cellular immune responses in experimental animals were determined. Tissues were screened by light microscopy and TEM. Pacific oysters were also challenged and used as a positive control to validate the efficiency of OsHV-1μvar infection. Viral particles and features such as marginated chromatin and highly electron dense nuclei were observed in C.gigas but not in P.margaritifera. Mortality rates and hemocyte immune parameters, including phagocytosis and respiratory burst, were similar between challenged and control P.margaritifera. Herpesvirus-inhibiting activity was demonstrated in the acellular fraction of the hemolymph from P.margaritifera, suggesting that the humoral immunity is critical in the defence against herpesvirus in pearl oysters. Overall, these results suggest that under the conditions of the experimental challenge, P.margaritifera was not sensitive to OsHV-1μvar and was not an effective host/carrier. The nature and spectrum of activity of the humoral antiviral activity is worthy of further © 2015 . Source

Van Wynsberge S.,Institute Of Recherche Pour Le Developpement | Andrefouet S.,Institute Of Recherche Pour Le Developpement | Gilbert A.,GINGER SOPRONER | Stein A.,Direction des Ressources Marines | Remoissenet G.,Direction des Ressources Marines
PLoS ONE | Year: 2013

The giant clam Tridacna maxima has been largely overexploited in many tropical regions over the past decades, and was therefore listed in appendix II of the Convention of International Trade in Endangered Species (CITES) in 1985. In French Polynesia, several atolls and islands harbor the world's highest stocks of giant clams in very shallow and accessible areas, which are therefore highly vulnerable to fishing pressure. The local fishery authority (i.e., Direction des Resources Marines or "DRM") implemented several management schemes in 2002 to control and regulate fishing pressure. However, for further decisions DRM was missing a sensitivity analysis on the effectiveness of the possible management actions. Here, we report on the use of a deterministic Viable Population Analysis (VPA) and spatially-explicit age-based population model that simulated the 30-year trajectory of a Tridacna maxima stock under different management approaches. Specifically, given various scenarios of intra-island larval dispersal, we tested which of No-take-Areas (NTAs), rotational closures, size limits, quotas, and restocking schemes would lead to the highest future stocks in Tubuai and Raivavae, two exploited islands of the Austral archipelago. For both islands, stock abundances were estimated in 2004/2010 and 2005/2010 respectively, and natural mortalities were assessed previously only in Tubuai. When compared to field data, the model successfully predicted the 2010 stocks for Tubuai, but proved to be less reliable for Raivavae, where natural mortality rates may well be different from those on Tubuai. For Tubuai, the spatial model suggested that reducing fishing effort (through fixed quotas) and banning fishing below the 12 cm size limit (as currently implemented) were the most effective management actions to sustain T. maxima populations into the future. Implementing NTAs was of poor effectiveness. NTAs increased giant clam stock inside the protected area, but also increased overfishing in the neighboring areas, and were ineffective overall. © 2013 Van Wynsberge et al. Source

A nucleus coated with a film includes one or more exopolysaccharides (EPS) and optionally one or more bioactive molecules such as bactericidal or bacteriostatic agents, cicatrizing agents and/or anti-inflammatory agents. A method for obtaining the nucleus, in order to inhibit graft rejection in pearl oysters is also described.

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