Résumé : The present report synthesizes the results of the works led in collaboration between the IFREMER, the Hydrographic and Oceanographic service of the French Navy (Oceanographic Mission of the Pacific) and the Departments of the Sea and Fish farming and of the Management and Town planning of the Territory of the French Polynesia. After a reminder of the problems regarding morphological and hydrographic mapping of low islands (atolls) of the Pacific in particular in French Polynesia, a paragraph draws up the assets of the aerial and spatial images as well as the computer-assisted digital mapping. A chapter of the report is then dedicated to the data, to the digital processing methodologies and to the display of the results. The following one develops the applications in particular relative to 4 types of by-products of the images and the (processing : i) the spacemap said "Pacific standard ", ii) said spacemap "maritime leases", iii) the geographical database of the information system SIGMA POE RAVA dedicated to the management of the pearl oyster culture and iiii) the production of bathymetric meshed models. A conclusion approaches the perspectives and the potential developments.
Le présent rapport synthétise les résultats des travaux menés en collaboration entre l'IFREMER, le Service Hydrographique et Océanographique de la Marine (Mission Océanographique du Pacifique) et les Services de la Mer et de l'Aquaculture et de l'Aménagement et de l'Urbanisme du Territoire de la Polynésie française. Après un rappel de la problématique posée en matière de cartographie morphologique et hydrographique des iles basses (atolls) du Pacifique et notamment de Polynésie française, un paragraphe dresse les atouts de l’image aérienne et spatiale ainsi que de la cartographie numérique assistée par ordinateur. Un chapitre du rapport est consacré aux données, aux méthodologies de traitement et à la présentation des résultats. Le suivant développe les applications notamment relatives à 4 types de produits dérivés des images et des traitements : i) la spatiocarte dite «à norme Pacifique», ii) les spatiocartes dites «concessions maritimes», iii) la base géographique du système d’information SIGMA Poe Rava dédié à la gestion de la perliculture et iiii) la production de modèles bathymétriques maillés».Une conclusion aborde les perspectives et développements potentiels

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00195/30644/29099.pdf
http://archimer.ifremer.fr/doc/00195/30644/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Trace metals (Cd, U, Co, Ni, Cu, Ba, Fe, Mn), total organic carbon (TOC) and C and N stable isotope signatures (delta C-313 and delta N-15) were determined in short sediments cores from the inner and outer shelf off Concepcion, Chile (similar to 36 degrees S). The objectives were to establish the effect of environmental conditions on trace metal distributions at two shelf sites, one affected by seasonal oxygenation and the other by permanent low oxygen conditions due to the presence of the oxygen minimum zone (OMZ). We evaluate trace metals as proxies of past changes in primary productivity and the bottom water oxygen regime. Concentrations of pore water sulfides and NH4+ were also measured as indicators of the main diagenetic pathways at each site. Our results for the inner shelf (seasonal suboxia) suggest that the oxidative state of the sediments responds to seasonal pulses of organic matter and that seasonal oxygenation develops during high and low primary productivity in the water column. Here, positive fluxes (to the water column) estimated from pore water concentrations of several elements were observed (Ba, Co, Ni, Fe and Mn). The less reduced environment at this site produces authigenic enrichment of Cu associated with the formation of oxides in the oxic surface sediment layer, and the reduction of U within deeper sediment sections occur consistently with negative estimated pore water fluxes. In the outer shelf sediments (permanent suboxia, OMZ site), negative fluxes (to the sediment) were estimated for all elements, but these sediments showed authigenic enrichments only for Cd, Cu and U. The short oxygenation period during the winter season did not affect the accumulation of these metals on the shelf. The distribution of Cu, Cd and U have been preserved within the sediments and the authigenic accumulation rates estimated showed a decrease from the deep sections of the core to the surface sediments. This could be explained by a gradual decrease in the strength of the OMZ in the last 100 years, in combination with periods of strong oxygenations during El Nino events. (C) 2011 Elsevier Ltd. All rights reserved.
ISSN: 0278-4343

hal-00745672
https://hal.archives-ouvertes.fr/hal-00745672
DOI : 10.1016/j.csr.2011.11.006

Éditeur(s) : Gauthier-Villars
Résumé : Data collected in an area enclosing New Caledonia are analysed both for the open ocean (17 degrees S-27 degrees S, 169 degrees E-170 degrees E; 1972-1992) and for one point in its lagoon (1967-1993), in order to improve our knowledge of the regional environment, with emphasis on seasonal and interannual (i.e. ENSO) variability. Long-term means and seasonal changes in surface wind, sea-surface temperature and salinity, and 0-400 m temperature, salinity and zonal geostrophic current are first described to Set the context. Through comparisons with the Southern Oscillation Index (SOI), it is demonstrated that there are signals in these parameters that are connected with ENSO. During the warm phase of ENSO (SOI < 0, El Nino), we observed saltier-than-average anomalies in sea-surface salinity (similar to 0.2), 0-50 m cold temperature anomalies (similar to 0.5 degrees C) contrasting with the well-known warm eastern equatorial Pacific anomalies, together with westerly (similar to 10 m(2) s(-2)) and southerly (similar to 4 m(2) s-2) wind anomalies over a large part of the studied area. Conversely, anomalies of similar magnitude but of opposite sign were detected during the cold phase of ENSO (SOI > 0; La Nina). The mechanisms which connect these regional anomalies to ENSO evolution at low-latitudes are qualitatively discussed.
Oceanolica Acta (0399-1784) (Gauthier-Villars), 1997 , Vol. 20 , N. 3 , P. 481-491

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00093/20410/18077.pdf
http://archimer.ifremer.fr/doc/00093/20410/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : Since the early 1980's, the Secretariat of the Pacific Community (SPC, formerly the South Pacific Commission) has contributed to the development of FAD programmes for the artisanal fisheries sector in the Pacific region. In particular, it has put considerable efforts into developing technology that would assure a two-year average FAD lifespan, while maintaining costs under US$ 4,000 per FAD unit. From 1996 to 1998, this work led to the publication of three volumes of the SPC FAD Manual. Volume 2 of this manual, "Rigging Deep-Water FAD Moorings", describes in great detail two FAD models that were developed from the original 1983 SPC-recommended model, and gives precise instructions on the way to construct them. Despite SPC's work, the objectives set, in particular the two-year average lifespan for FADs, have not been consistently met, resulting in many FAD programmes in the region being suspended. An analysis of the reasons why this has occurred is presented, along with a short description of the practical research that could be pursued, using different objectives, to introduce new FAD programmes in the region.Original Abstract: Depuis le debut des annees quatre-vingt, le secretariat general de la communaute du Pacifique (SPC, anciennement commission du Pacifique Sud) a soutenu et accompagne le developpement de programmes DCP destines au secteur de la peche artisanale, dans la region Pacifique. Il s'est en particulier efforce de mettre au point des modeles de DCP repondant principalement aux deux criteres suivants: duree de vie superieure a deux ans et cout unitaire moyen inferieur a 4 000 dollars US. Entre 1996 et 1998, ces travaux ont abouti a la publication en trois volumes du manuel de la SPC sur les DCP. Le volume 2 de ce manuel, " La fabrication de DCP pour grandes profondeurs ", presente deux evolutions d'un modele concu en 1983 et en detaille tres precisement les methodes de fabrication. Le present document analyse les raisons pour lesquelles, malgre les efforts deployes, les objectifs fixes, et en particulier la duree de vie minimum de deux ans pour les DCP, n'ont pas ete pleinement atteints et la plupart des programmes DCP de la region ont ete interrompus. Il donne egalement une breve description des axes de recherche appliquee qui pourraient etre suivis, en se fixant d'autres objectifs, pour relancer des programmes DCP dans la region.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15291/12648.pdf
http://archimer.ifremer.fr/doc/00042/15291/

Éditeur(s) : Amer Geophysical Union
Résumé : Since Last Glacial Maximum (23-19 ka), Earth climate warming and deglaciation occurred in two major steps (Bolling-Allerod and Preboreal), interrupted by a short cooling interval referred to as the Younger Dryas (12.5-11.5 ka B. P.). In this study, three cores (MV-33, MV-66, and MD-40) collected in the central part of Pandora Trough (Gulf of Papua) have been analyzed, and they reveal a detailed sedimentary pattern at millennial timescale. Siliciclastic turbidites disappeared during the Bolling-Allerod and Preboreal intervals to systematically reoccur during the Younger Dryas interval. Subsequent to the final disappearance of the siliciclastic turbidites a calciturbidite occurred during meltwater pulse 1B. The Holocene interval was characterized by a lack of siliciclastic turbidites, relatively high carbonate content, and fine bank-derived aragonitic sediment. The observed millennial timescale sedimentary variability can be explained by sea level fluctuations. During the Last Glacial Maximum, siliciclastic turbidites were numerous when the lowstand coastal system was located along the modern shelf edge. Although they did not occur during the intervals of maximum flooding of the shelf (during meltwater pulses 1A and 1B), siliciclastic turbidites reappear briefly during the Younger Dryas, an interval when sea level rise slowed, stopped, or perhaps even fell. The timing of the calciturbidite coincides with the first reflooding of Eastern Fields Reef, an atoll that remained exposed for most of the glacial stages.
Journal Of Geophysical Research-earth Surface (0148-0227) (Amer Geophysical Union), 2008-03-29 , Vol. 113 , N. F01S19 , P. 1-15

Droits : Copyright 2008 by the American Geophysical Union.
http://archimer.ifremer.fr/doc/00079/19014/16592.pdf
DOI:10.1029/2006JF000649
http://archimer.ifremer.fr/doc/00079/19014/

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Outbreaks of the corallivorous crown-of-thorns seastar Acanthaster planci (COTS) represent one of the greatest disturbances to coral reef ecosystems in the Indo-Pacific, affecting not only coral reefs but also the coastal communities which rely on their resources. While injection approaches are increasingly used in an attempt to control COTS densities, most of them display severe drawbacks including logistical challenges, high residual environmental impacts or low cost-effectiveness. We tested a new alternative control method based upon acidic injections of cheap, 100% natural products. We investigated the lethal doses, intra-and inter-specific disease transmission and immune responses of COTS when injected with fresh lime juice (extracted from local Citrus arantifolia) and white spirit vinegar. High COTS mortality was achieved with small volumes: 10–20 ml per seastar induced death in 89%/ 97% of injected specimens after an average 34.3 h/29.8 h for lime juice and vinegar respectively. Highest efficiency was reached for both solutions with double shots of (2 × 10 ml) in two different areas on the body: 100% mortality occurred within 12–24 h, which is similar or faster compared with other current injection methods. Multiple immune measures suggested that death was very likely caused by pH stress from the acidic solutions rather than a bacterial infection. Contagion to either conspecifics or a variety of other reef species was not observed, even at COTS densities 15 times higher than the highest naturally reported. 10 to 20 l lime juice/vinegar could kill up to a thousand COTS at a cost of less than 0.05 USD per specimen; no permits or special handling procedures are required. We conclude that injections of lime juice and vinegar offer great advantages when compared to current best practises and constitute a cheap and natural option for all reefs affected by COTS.
ISSN: 1932-6203

Droits : http://creativecommons.org/licenses/by/
hal-01208272
https://hal-univ-perp.archives-ouvertes.fr/hal-01208272
https://hal-univ-perp.archives-ouvertes.fr/hal-01208272/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01208272/file/journal.pone.0137605.pdf
DOI : 10.1371/journal.pone.0137605

Éditeur(s) : Gauthier-Villars
Résumé : The biology and ecology of the green tropical algae Caulerpa taxifolia (Vahl) C. Agardh have been studied in the lagoons of New Caledonia (South Pacific) with a view to understanding the invasion which began in 1984 in the northwest Mediterranean Sea. A total of 1772 stations were used to establish the spatial and depth distribution of this species, which can be considered as common in New Caledonia, since it has been found in 9 % of the stations. C. taxifolia occurred mainly at depths between 10 and 30 m. Monthly sampling has shown that its growth is maximum during the southern hemisphere spring. From 180 stations randomly sampled in the southwest lagoon we obtained a mean biomass of 0.046 g afdw/m(2), which accounts for only 0.18 % of the macrophytobenthic biomass in this lagoon. Nevertheless the species constitutes a food source which is specific to the small herbivorous mollusc sacoglosses.
Oceanologica Acta (0399-1784) (Gauthier-Villars), 1994 , Vol. 17 , N. 5 , P. 563-569

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00099/21013/18639.pdf
http://archimer.ifremer.fr/doc/00099/21013/

Éditeur(s) : HAL CCSD Station Biologique
Résumé : International audience
Four "morphotypes" of Mytilidae were collected from wood falls in the west Pacific (Vanuatu islands) and in the Bohol sea (Philippines) between 300 and 1800 metre depth. Results from our study demonstrated the existence of extracellular bacteria located between microvilli at the apical surface of the cells all along the lateral zone of the gill filaments in the four mytilid morphotypes analyzed. Based on TEM observations, these Gram-negative bacteria were not methanotrophic due to the lack of concentric stacking of intracellular membranes in their cytoplasm. Based on FISH experiments, these bacteria belong to g-Proteobacteria. These preliminary observations described gill symbiosis-like interactions in metazoan species associated with sunken wood, strengthening the hypothesis that decomposing wood may serve as steps for the introduction of symbiotic Mytilidae to vents and seeps. Phylogenetic analysis of these extracellular bacteria are in progress in our lab in order to compare their 16SrDNA sequences to that of other marine invertebrate symbionts described to date.
ISSN: 0007-9723

hal-00753023
https://hal.univ-antilles.fr/hal-00753023

Éditeur(s) : La recherche face aux pêches artisanales
Résumé : Each of nine people agreed to write a summary regarding changes in research on small-scale fishing in a large region of the world. These summaries that will be presented to you focus respectively on changes in research in Southeast Asia, in the South Pacific along the western coast of Latin America, in West Africa, in the Mediterranean, in Northwest Europe, and in North America. In order to help you reconstruct their actions in the halieutic context of the regions about which they are talking, Serge Garcia will first present us with a panorama of small-scale fishing. By asking them to do this study, we wished to be able to place the symposium's study within an overall framework and in an historical perspective. The objective was to relativise the conclusions that could be drawn from analyses of local situations, or, on the contrary, to allow them to be generalised by using bases of comparison. The summaries are far from being able to offer a planetary geographical coverage, just as they do not really include the evolution of all disciplines. The means available to the organisers did not allow for going up to that point. We must at this point thank the authors who agreed to do this complex work of summarisation, because they succeeded in showing the richness of such a step, which the participants will be able to appreciate in their reports. In this analysis of geographical syntheses, we would like to draw a few comparisons able to fuel the symposium's debates. We will examine how small-scale fishing became a subject of research, and the difficulty of defining it. Then we will see how the various disciplines became mutually involved, then specialised, depending upon the stages through which the research passed on this subject. The role of institutions and the weight of the contextual environment will be examined. Finally, we will propose a few possible directions for the debates on various themes of the symposium. Some outside contributions to the summaries also focus on the evolution of the research and we have taken that into account in this presentation. Limited to one country (Yahaya Jahara) or to one province (Maneschy and Furtado), they are useful complements to the summaries.
(OCR non controlé) Neuf personnes ont accepté de rédiger chacune une synthèse concernant l'évolution des recherches sur les pêches artisanales dans une grande région du monde. Les synthèses qui vont vous être présentées portent respectivement sur l'évolution des recherches en Asie du Sud-Est, dans le Pacifique-sud sur la façade occidentale de l'Amérique Latine, en ,Afrique de l'Ouest, en Méditerranée, en Europe du Nord- Ouest, en Amérique du Nord. Pour vous permettre de resituer leurs interventions dans le contexte halieutique des régions dont ils nous parlent, Serge Garcia nous présentera en premier lieu un panorama des pêches artisanales. En leur demandant ce travail, nous avons souhaité pouvoir replacer les travaux du symposium dans un cadre global et dans une perspective historique. L'objectif était de relativiser les conclusions qui pourraient être tirées d'analyses de situations locales, ou, au contraire, de permettre leur généralisation en disposant de bases de comparaison. Les synthèses sont loin d'offrir une couverture géographique planétaire, tout comme elles n'intègrent pas vraiment l'évolution de toutes les disciplines. Les moyens à la disposition des organisateurs ne permettaient pas d'aller jusque là. Il nous faut remercier ici les auteurs qui ont consenti à faire ce travail complexe de synthèse, car ils ont réussi à démontrer la richesse d'une telle démarche, ainsi que les participants pourront l'apprécier à travers leurs exposés. Dans cette analyse des synthèses géographiques, nous voudrions tenter quelques comparaisons de nature à alimenter les débats du symposium. Nous examinerons comment est née la pêche artisanale en tant qu'objet de recherche, et la difficulté de la définir. Puis nous verrons, en fonction des étapes par lesquelles sont passées les recherches sur ce sujet, comment les différentes disciplines se sont mutuellement impliquées, puis se sont spécialisées. Le rôle des institutions et le poids des contextes seront examinés. Enfin nous proposerons quelques orientations possibles pour les débats sur les différents thèmes du symposium. Certaines contributions extérieures aux synthèses portent aussi sur l'évolution des recherches et nous en avons tenu compte dans cette présentation. Limitées à un pays (Yahaya Jahara) ou à une province (Maneschy et Furtado), elles complètent utilement les synthèses.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1990/acte-2464.pdf
http://archimer.ifremer.fr/doc/00000/2464/

Éditeur(s) : Gauthier-Villars
Résumé : Analysis of Geosat sea level data over the period November 1986-November 1987 has evidenced long, low-frequency equatorial wave propagations over most of the equatorial Pacific basin (Delcroix et al.,1991). The succession of downwelling Kelvin, upwelling Kelvin, and upwelling Rossby waves has raised a series of questions. Is the observed upwelling Rossby wave due to a reflection process on the eastern boundary, or due to wind forcing near the equator? Why is there no evidence of a reflection of the downwelling Kelvin wave? Is this wave sequence a feature of the 1986-1987 El Nino phenomenon or is it to be found in the mean seasonal cycle? We used a linear model forced by the FSU wind stress to study these questions. The results, during the period November 1986-November 1987, show the successive downwelling/ upwelling Kelvin waves and upwelling Rossby wave as in the Geosat observations. Another test was made, using only the part of the forcing responsible for creating Kelvin waves, in order to evaluate the portion of the signals that was due to the reflection process and the part due to local forcing. It appears that wind forcing favourable to upwelling in the eastern part of the equatorial basin is the main mechanism which both generates the upwelling Rossby wave and inhibits the reflection of the downwelling Kelvin wave. However, the reflection of the upwelling Kelvin wave contributes to the upwelling Rossby wave signal, and makes it visible all the way from the eastern to the western sides of the equatorial Pacific. Results of a climatological run show that the successive downwelling/upwelling Kelvin and Rossby wave propagations are present in the mean seasonal cycle. However, the corresponding model signals, as well as the wind forcing anomalies, show a larger amplitude in 1986-1987.
Oceanologica Acta (0399-1784) (Gauthier-Villars), 1992 , Vol. 15 , N. 5 , P. 545-554

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00101/21180/18797.pdf
http://archimer.ifremer.fr/doc/00101/21180/

Éditeur(s) : Copernicus Gesellschaft Mbh
Résumé : The sea surface salinity (SSS) measured from space by the Soil Moisture and Ocean Salinity (SMOS) mission has recently been revisited by the European Space Agency first campaign reprocessing. We show that, with respect to the previous version, biases close to land and ice greatly decrease. The accuracy of SMOS SSS averaged over 10 days, 100 x 100 km(2) in the open ocean and estimated by comparison to ARGO (Array for Real-Time Geostrophic Oceanography) SSS is on the order of 0.3-0.4 in tropical and subtropical regions and 0.5 in a cold region. The averaged negative SSS bias (-0.1) observed in the tropical Pacific Ocean between 5 degrees N and 15 degrees N, relatively to other regions, is suppressed when SMOS observations concomitant with rain events, as detected from SSM/Is (Special Sensor Microwave Imager) rain rates, are removed from the SMOS-ARGO comparisons. The SMOS freshening is linearly correlated to SSM/Is rain rate with a slope estimated to -0.14 mm(-1) h, after correction for rain atmospheric contribution. This tendency is the signature of the temporal SSS variability between the time of SMOS and ARGO measurements linked to rain variability and of the vertical salinity stratification between the first centimeter of the sea surface layer sampled by SMOS and the 5 m depth sampled by ARGO. However, given that the whole set of collocations includes situations with ARGO measurements concomitant with rain events collocated with SMOS measurements under no rain, the mean -0.1 bias and the negative skewness of the statistical distribution of SMOS minus ARGO SSS difference are very likely the mean signature of the vertical salinity stratification. In the future, the analysis of ongoing in situ salinity measurements in the top 50 cm of the sea surface and of Aquarius satellite SSS are expected to provide complementary information about the sea surface salinity stratification.
Ocean Science (1812-0784) (Copernicus Gesellschaft Mbh), 2013 , Vol. 9 , N. 1 , P. 183-192

Droits : Author(s) 2013. CC Attribution 3.0 License.
http://archimer.ifremer.fr/doc/00139/25073/23161.pdf
DOI:10.5194/os-9-183-2013
http://archimer.ifremer.fr/doc/00139/25073/

Éditeur(s) : PSIC 11 - 11th Pacific Science Inter-Congress : Pacific Countries and their Ocean: Facing Local and Global Changes / 2nd Symposium on French Research in the Pacific. March 2 - 6, 2009 Tahiti, French Polynesia
Résumé : Shrimp farming in New Caledonia relies on the culture of a domesticated strain of Litopenaeus stylirostris introduced from Mexico at a time when genetic principles were of little or no consideration. Since then, advances in agriculture and for some aquatic species of importance led caledonian shrimp farmers to reconsider the appropriateness of a genetic improvement strategy adapted to local biotechnical and economical constraints. This questioning involves many different and interrelated aspects: scientific and technologic (genetics, biosecurity, quarantine, ), economic and organizational (financing, diffusion of genetic improvement) and pedagogic (awareness of farmers). Local institutions, producers associations, research centre and sanitary services associated to carry on the test of a first improvement strategy based on the crossing of different strains of L. stylirostris. This conceptually simple approach aimed at eliminating inbreeding, the first genetic limitating factor of improvement in captive populations. A second domesticated strain was obtained from Hawaii by the caledonian farmers, imported through a quarantine under the control of the zoosanitary local authorities, and reproduced and tested as pure or crossbred stocks by Ifremer within the framework of an interdisciplinary research project financed by caledonian institutions. Present results for hybrids (better growth and survival in the absence of virus) demonstrate the validity of this approach. They also bring out the importance to simultaneously integrate in a development scheme, a breeding centre to maintain and reproduce disease free breeders. This strategy and organization, tested in New Caledonia, could possibly be of benefit to other small scale aquaculture activities in the pacific islands.
La filière crevetticole de Nouvelle-Calédonie s’est développée jusqu’à aujourd’hui à partir d’un stock domestiqué de Litopenaeus stylirostris introduit d’Amérique à une époque où les principes de base en génétique n’étaient pas ou peu appliqués en aquaculture. Les avancées récentes en agriculture et chez quelques espèces aquacoles d’importance mondiale ont conduit les acteurs de cette filière à se poser la question de la mise en place d’une stratégie d’amélioration génétique adaptée aux contraintes biotechniques et économiques locales. Cette réflexion comportait à la fois des aspects scientifiques et technologiques (génétique, biosécurité, quarantaine, conservatoire), économiques et organisationnels (coût de l’opération, modalité de diffusion du progrès attendu), pédagogiques (sensibilisation des fermiers). Des acteurs d’horizons différents (institutions locales, association de producteurs, centre de recherche, police zoosanitaire) se sont associés pour monter une opération de testage d’une première stratégie d’amélioration par croisement de souches de la même espèce. Cette stratégie conceptuellement simple visait l’élimination du premier facteur génétique de limitation des performances d’élevage d’une population captive, à savoir une consanguinité d’autant plus élevée que le nombre de géniteurs fondateurs était faible. Une seconde souche domestiquée a ainsi été acquise à Hawaii par les producteurs calédoniens, contrôlée en quarantaine par les services vétérinaires calédoniens en charge de la réglementation sanitaire, reproduite et testée pure et en croisement par l’Ifremer dans le cadre d’un projet de recherche pluridisciplinaire plus large financé par les institutions du Pays. Les résultats obtenus démontrent l’intérêt de la démarche (meilleure croissance, meilleure survie en l’absence de virus). Mais ils montrent aussi l’utilité d’intégrer simultanément dans le plan de développement de la filière une stratégie de conservation des souches parentales afin de disposer de géniteurs exempts de pathogènes. Cette stratégie et cette organisation testées en Nouvelle-Calédonie pourraient vraisemblablement être profitables à d’autres filières aquacoles modestes, en particulier dans les pays insulaires du Pacifique.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00198/30879/29247.pdf
http://archimer.ifremer.fr/doc/00198/30879/

Éditeur(s) : Société Française d'Ichtyologie
Résumé : In the present paper a new genus, Diretmoides, and a new species, Diretmoides parini, of the berycomorph family Diretmidae is described. The hitherto single genus of the family, Diretmus Johnson, 1863, therefore becomes monotypic while the new genus includes two species pauciradiatus (Woods, 1973) and parini sp. nov. The genus Diretmus is mainly charactcrized by three features (1) by its anus placed immediately anterior to the anal fin, (2) by a prepelvic ridge of ventral scutes and (3) by the high number of bony lamellae on the upper third of the operculum. The species of Diretmoides on the other hand have (1) their anus midway between the pelvics and the anal fin, (2) the ventral midline anterior to their pelvics is flat and is covered by normal body-scales and (3) there are only a few lamellae on the upper third of the operculum. Juveniles of the two Diretmoides-species differ from each other in their colour pattern,the adolescents and adults in meristic characters. All described species live meso-to bathypelagically. D. argenteus is widely distributed in tropical and temperate waters of all oceans. The two Diretmoides -species also live in the Atlantic as well as in the Pacific. However there is only one record of Diretmoides parini and none of D. pauciradiatus from the Indian Ocean. In addition to the described species, indication is given of the presumable existence of a third Diretmoides-species from off Japan. Artificial keys to adults and juveniJes are given at the end of this paper. NOT CONTROLLED OCR
Les auteurs décrivent un nouveau genre, Diretmoides, et une nouvelle espèce, Diretmoides parini. Le genre Diretmus ne comprend plus qu'une seule espèce D. argenteus Johnson, 1863; Diretmoides en comporte deux;D. pauciradiatus (Woods, 1973) d D. parini n.sp. Le genre Diretmus est caractérisé principalement par la position de l'anus juste en avant de l'anale par la présence en avant des pelviennes d'une carène épineuse ventrale et par la densité des lamelles osseuses sur le tiers supérieur de l'opercule. Chez Diretmoides l'anus est à mi-distance entre l'anale et les pelviennes; il n'y a pas de carène épineuse ventrale en avant des pelviennes et, sur le tiers supérieur de l'opercule, les lamelles osseuses sont peu nombreuses et éparses. Les jeunes Diretmoides se distinguent les uns des autres par leur coloration, les adolescents et les adultes par leurs caractères méristiques. Tous les Diretmidés actuellement connus sont des espèces méso à bathypélagiques. D. argenteus est largement distribué dans les eaux tropicales et tempérées de tous les océans. Les deux espèces de Diretmoides ont été signalées dans l'Atlantique et te Pacifique mais on ne connaît qu'une seule capture de D. parini dans l'océan indien et aucune de D. pauciradiatus. En outre. l'étude d'exemplaires provenant du Japon a amené les auteurs à souligner l'existence probable d'une troisième espèce de Diretmoides. Deux clés de détermination, l'une pour les adultes, l'autre pour les jeunes des trois espèces décrites, sont données à la fin de cette note. OCR NON CONTRÔLE
Cybium (Société Française d'Ichtyologie), 1981 , Vol. 5 , N. 1 , P. 33-60

Droits : 1981 Société Française d'Ichtyologie
http://archimer.ifremer.fr/doc/1981/publication-3746.pdf
http://archimer.ifremer.fr/doc/00000/3746/

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
We report measurements of long-period P wave polarization (P-pol) in Australia and Tahiti made by combining modeling of the polarization deviation and harmonic analysis. The analysis of the deviation of the horizontal polarization of the P wave as a function of event back azimuth may be used to obtain information about (1) sensor misorientation, (2) dipping discontinuities, (3) seismic anisotropy, and (4) velocity heterogeneities beneath a seismic station. The results from harmonic analysis and a grid search using Snell's law suggest the presence of a dipping seismic discontinuity beneath stations CTAO and CAN in Australia. These results are consistent with published receiver function studies for these stations. The P-pol fast axis orientation is close to the N-S absolute plate motion direction at station TAU (Tasmania), which may be due to plate-motion-driven alignment of olivine crystals in the asthenosphere. Interestingly, measurements of SKS splitting at Tahiti (French Polynesia) show an apparent isotropy, whereas an inversion of P-pol observations at PPTL seismic station located in Tahiti suggests the presence of two anisotropic layers. The fast axis azimuth is oriented E-Win the upper layer, and it is close to the NW-SE orientation in the lower layer. Since P-pol orientations are used for real-time earthquake locations, especially in poorly instrumented areas such as the South Pacific, we show that the bias from anisotropy and sensor misorientation determined here can be corrected to improve the location accuracy, which yields fundamental data for rapid location necessary for effective tsunami warning.
ISSN: 2169-9313

hal-00413141
https://hal.archives-ouvertes.fr/hal-00413141
https://hal.archives-ouvertes.fr/hal-00413141/document
https://hal.archives-ouvertes.fr/hal-00413141/file/FontaineetalJGR2008.pdf
DOI : 10.1029/2008JB005709

Éditeur(s) : Gauthier-Villars
Résumé : The continental shelf is very narrow and steep to the north, and broader to the South. This shelf is structuraly influenced by the Andes. This area is mainly covered with terrigenous deposits, i.e. muds and sands which are recent on the internal shelf and relict on the external shelf. The sediments, supplied by rivers, reflect the intense erosion of the Andean backland. This erosion can only be reduced in situ by the vegetation cover. Clays are the main component of the fine fraction reaching the sea. Three different clay assemblages are observed: 1) an Andean (illite-chlorite) assemblage, reflecting the proximity of the cordillera; 2) a mid-American assemblage (smectite), which supplies the North Pacific Margin through the Choco counter-current; 3) an Equatorial assemblage (smectites) which is brought to the South by the Colombian current.
Oceanologica Acta (0399-1784) (Gauthier-Villars), 1995 , Vol. 18 , N. 1 , P. 1-18

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00097/20862/18480.pdf
http://archimer.ifremer.fr/doc/00097/20862/

Éditeur(s) : Revue Internationale d'Ichtyologie
Résumé : The ichthyofauna of Reunion Island, Southwestern Indian Ocean, was sampled during several ecological and artisanal fisheries studies. Information from these investigations and from other sources were included to compile the present checklist of the marine fishes of the island. A total of 885 species belonging to 150 families was recorded. Nine species are known only from Reunion, indicating endemism of about 1.0%. The most speciose families (Labridae, Gobiidae, Serranidae, and Pomacentridae) were also among the most speciose at the neighbouring Mauritius Island (except gobiids), and, generally, on other islands in the Indian Ocean area (Maldives, Chagos, Madagascar and Christmas Island). The Gobiidae only represented 5.4% of the ichthyofauna, which was similar to the ratio for Aqaba (Red Sea), contrasting with 8.0% recorded for the Maldives, 13.0% at Chagos or other higher percentages recorded in the Pacific Ocean. The Apogonidae and Scaridae are relatively poorly diversified at Reunion, also in contrast with the Maldives, Madagascar, Chagos, Aqaba (Red Sea) and certain Pacific areas. The recent geological origins of Reunion Island and the low diversity of its marine biotopes are probably the most significant factors explaining both the total species richness and species richness of some major families.
L'ichtyofaune de l'île de La Réunion a été étudiée au cours de plusieurs travaux portant sur l'écologie des poissons et sur les pêcheries artisanales. Les informations issues de ces études, ainsi que d'autres sources, ont été compilées dans la présente liste des poissons marins de l'île. Un total de 885 espèces appartenant à 150 familles est recensé. Neuf espèces ne sont connues que de La Réunion, indiquant un endémisme proche de 1,0%. Les familles les plus diversifiées (Labridae, Gobiidae, Serranidae et Pomacentridae) sont aussi parmi les plus diversifiées à l'île Maurice voisine (à l'exception des Gobiidae), ainsi que dans d'autres îles de l'océan Indien (Maldives, Chagos, Madagascar et Christmas). Les Gobiidae ne représentent que 5,4% de l'ichtyofaune totale, ce qui est semblable à ce qui est connu à Aqaba (mer Rouge), mais contraste avec les 8,0% trouvés aux Maldives, les 13,0% trouvés aux Chagos ou d'autres pourcentages élevés dans l'océan Pacifique. Les Apogonidae et les Scaridae sont relativement peu diversifiés à La Réunion, ce qui contraste également avec ce qui est connu des Maldives, Madagascar, Chagos, la mer Rouge et certaines régions de l'océan Pacifique. Le jeune âge géologique de l'île et la faible diversité de ses biotopes marins pourraient être parmi les facteurs les plus importants pouvant expliquer la faible richesse spécifique totale et la richesse spécifique de certaines familles.
CYBIUM (0399-0974) (Revue Internationale d'Ichtyologie), 2004-03 , Vol. 28 , N. 3 , P. 199-216

Droits : 2004 Société Française d'Ichtyologie
http://archimer.ifremer.fr/doc/2004/publication-713.pdf
http://archimer.ifremer.fr/doc/00000/713/

Éditeur(s) : Elsevier
Résumé : The Latin American shrimp Litopenaeus stylirostris was introduced in three different Pacific islands (Tahiti, New Caledonia via Tahiti, and Hawaii) and hatchery-propagated for 7-25 generations to develop shrimp farming based on these domesticated stocks. Three microsatellite markers have been used in an attempt to assess the genetic bases of the populations available to start a selective breeding program. The comparison of eight hatchery stocks (five New Caledonian, two Hawaiian and one Tahitian stocks) and one wild Ecuadorian population showed a much lower variability in the domesticated stocks than in the wild population, especially in New Caledonia and Tahiti (2-3.7 vs. 14-27 alleles per locus; 20-60% vs. 90% expected heterozygosity). The Tahitian and the New Caledonian stocks share the same alleles, suggesting that the loss of alleles occurred during the common past of these populations. On the contrary, New Caledonian and Hawaiian populations share only one common allele at the three loci studied. Although the low genetic variability and the resulting inbreeding of the New Caledonian stocks do not seem to affect their present performance, the results of this study demonstrate the usefulness of the introduction of new stocks in order to increase the potential responses to new controlled or uncontrolled selective pressures. The introduction in New Caledonia of the Hawaiian domesticated stocks, which would provide the local shrimp industry with 40% of the allelic diversity of the species, is advised and preferred to the one of wild animals in order to take advantage (i) of the spontaneous selection which occurred during domestication and (ii) of their favourable sanitary "specific pathogen free" status (no presence of four viruses: WSV, YHV, IHHNV, TSV) which limits the risk of introduction of pathogens.
La crevette d'Amérique latine Litopaenus stylirostris a été introduite dans trois îles du Pacifique (à Tahiti, en Nouvelle-Calédonie via Tahiti, et à Hawaii), et a été ensuite reproduite en écloserie pendant 7 à 25 générations à des fins d'aquaculture. Trois marqueurs microsatellites ont été utilisés pour évaluer les bases génétiques des populations disponibles pour le démarrage d'un programme d'amélioration génétique. L'étude comparative de 8 populations domestiquées (cinq néo-calédoniennes, deux hawaiiennes et une tahitienne) et d'une population sauvage d'Equateur révèle une variabilité très réduite dans les populations d'élevage, en particulier en Nouvelle-Calédonie et à Tahiti (2 à 3.7 allèles par locus au lieu de 14 à 27 en population sauvage ; 20% à 60% d'hétérozygotie au lieu de 90%). Les souches tahitiennes et calédoniennes disposent des mêmes allèles, ce qui suggère que la perte d'allèles a eu lieu lors de l'histoire commune des ces populations. A l'inverse, les populations néo-calédoniennes et hawaiiennes n'ont en commun qu'un seul allèle sur les 3 locus étudiés. Bien que la très faible variabilité génétique du cheptel calédonien ne semble pas affecter ses performances actuelles, les résultats de cette étude démontrent l'utilité de l'introduction de variabilité afin d'augmenter la capacité de réponse à de nouvelles pressions de sélection (contrôlées ou non). L'introduction des souches hawaiiennes en Nouvelle-Calédonie qui permettrait à la filière locale de disposer de 40% de la diversité allélique de l'espèce) est préconisée de préférence à celle d'animaux sauvages afin de bénéficier (i) de la sélection spontanée qu'elles ont subi lors de leur domestication et (ii) de leur statut sanitaire « specific pathogen free, SPF » (absence de 4 virus : WSV, YHV, IHHNV, TSV) qui limite les risques de transferts de pathogènes.
Aquatic Living Resources (0990-7440) (Elsevier), 2003-12 , Vol. 16 , N. 6 , P. 501-508

Droits : 2003 Published by Elsevier, Paris.
http://archimer.ifremer.fr/doc/2003/publication-596.pdf
DOI:10.1016/j.aquliv.2003.07.001
http://archimer.ifremer.fr/doc/00000/596/

Éditeur(s) : Elsevier
Résumé : The ZoNeCo programme is devoted to the evaluation of the marine resources of the Economic Zone of New Caledonia. The results are essentially dependent on the quality of the seafloor mapping. From 1993 to 1996, four geological and geophysical surveys using the EM12 DUAL multibeam echosounder provided swath-mapping and acoustic imagery data of the seafloor of selected sites on the northern and southern parts of the Norfolk ridge, the Loyalty basin, around the Loyalty islands and in the westernmost part of the Economic Zone of New Caledonia. The accuracy of these documents shows the morphology of the seafloor in detail and allows rocky substratum to be differentiated from muddy bottom. It allows favorable emplacements of future exploratory fishing surveys to be determined. The benefits of swath mapping are illustrated by the Halipro 2 deep sea trawling cruise (1996) which used the swath mapping data of ZoNeCo 1 cruise (1993) on the southern prolongation of the New Caledonia mainland and Loyalty Islands.
Le programme ZoNéCo a pour objectif l'évaluation des ressources marines de la zone économique de Nouvelle-Calédonie. Les résultats du programme dépendent essentiellement de la qualité de la cartographie des fonds marins. De 1993 à 1996, au cours de quatre campagnes bathymétriques et géophysiques, une couverture bathymétrique et d'imagerie a été effectuée en utilisant le sondeur multifaisceaux EM 12 DUAL sur des sites choisis sur les segments Nord et Sud de la ride de Norfolk, dans le bassin des Loyauté, autour des îles Loyauté ainsi qu'à l'ouest de la zone économique de Nouvelle-Calédonie. La qualité des cartes obtenues permet de préciser la morphologie du fond mais aussi de différencier un substratum rocheux d'un substratum couvert par des sédiments et d'identifier les sites favorables à la réalisation de campagne de pêche exploratoire. Les bénéfices de la bathymétrie multifaisceaux sont illustrés, à partir des données de ZoNéCo 1 (1993), par la campagne de chalutage profond Halipro 2 (1996) sur la prolongation méridionale de la Grande Terre de Nouvelle-Calédonie et des îles Loyauté.
Oceanologica Acta (0399-1784) (Elsevier), 1999-11 , Vol. 22 , N. 6 , P. 641-650

Droits : 1999 Ifremer / CNRS / IRD / Editions scientifique et mtdicales Elsevier SAS
http://archimer.ifremer.fr/doc/1999/publication-833.pdf
DOI:10.1016/S0399-1784(00)88955-0
http://archimer.ifremer.fr/doc/00000/833/

Éditeur(s) : Springer
Résumé : Series of sensitivity tests were performed with a z-coordinate, global eddy-permitting (1/4 degrees) ocean/sea-ice model (the ORCA-R025 model configuration developed for the DRAKKAR project) to carefully evaluate the impact of recent state-of-the-art numerical schemes on model solutions. The combination of an energy-enstrophy conserving (EEN) scheme for momentum advection with a partial step (PS) representation of the bottom topography yields significant improvements in the mean circulation. Well known biases in the representation of western boundary currents, such as in the Atlantic the detachment of the Gulf Stream, the path of the North Atlantic Current, the location of the Confluence, and the strength of the Zapiola Eddy in the south Atlantic, are partly corrected. Similar improvements are found in the Pacific, Indian, and Southern Oceans, and characteristics of the mean flow are generally much closer to observations. Comparisons with other state-of-the-art models show that the ORCA-R025 configuration generally performs better at similar resolution. In addition, the model solution is often comparable to solutions obtained at 1/6 or 1/10 degrees resolution in some aspects concerning mean flow patterns and distribution of eddy kinetic energy. Although the reasons for these improvements are not analyzed in detail in this paper, evidence is shown that the combination of EEN with PS reduces numerical noise near the bottom, which is likely to affect current-topography interactions in a systematic way. We conclude that significant corrections of the mean biases presently seen in general circulation model solutions at eddy-permitting resolution can still be expected from the development of numerical methods, which represent an alternative to increasing resolution.
Ocean Dynamics (1616-7341) (Springer), 2006-12 , Vol. 56 , N. 5-6 , P. 543-567

Droits : © Springer 2006. Part of Springer Science+Business Media
http://archimer.ifremer.fr/doc/2006/publication-3514.pdf
DOI:10.1007/s10236-006-0082-1
http://archimer.ifremer.fr/doc/00000/3514/

Éditeur(s) : Elsevier
Résumé : The discovery of deep-sea hydrothermal vent fauna, kilometres deep in the oceans, is a great achievement of 20th-century marine biology. The deep-sea hydrothermal food web does not directly depend on the sun's energy. Vent communities rely primarily on trophic associations between chemoautotrophic bacteria and consumers A small. number of endemic taxa are adapted to the inhospitable vent environments that are distributed along ridge crests. Where these vent communities originated and how they dispersed are among the important questions ecologists must answer. Here, by statistical analysis of the most comprehensive database ever assembled about deep-sea hydrothermal fauna, we delineate six major hydrothermal provinces in the world ocean and identify seven possible dispersal pathways between adjacent provinces. Our model suggests that the East-Pacific Rise may have played a pivotal role as a centre of dispersal for the hydrothermal fauna. Our data-driven conclusion will have to be tested by phylogenetic studies and completed by surveys of less-explored fields.
Deep Sea Research Part I: Oceanographic Research Papers (0967-0637) (Elsevier), 2009-08 , Vol. 56 , N. 8 , P. 1371-1378

Droits : 2009 Elsevier Ltd All rights reserved.
http://archimer.ifremer.fr/doc/2009/publication-6936.pdf
http://archimer.ifremer.fr/doc/2009/sup-6936.xls
DOI:10.1016/j.dsr.2009.01.009
http://archimer.ifremer.fr/doc/00000/6936/