Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Ecological resilience assessments are an important part of resilience-based management (RBM) and can help prioritize and target management actions. Use of such assessments has been limited due to a lack of clear guidance on the assessment process. This study builds on the latest scientific advances in RBM to provide that guidance from a resilience assessment undertaken in the Commonwealth of the Northern Mariana Islands (CNMI). We assessed spatial variation in ecological resilience potential at 78 forereef sites near the populated islands of the CNMI: Saipan, Tinian/Aguijan, and Rota. The assessments are based on measuring indicators of resilience processes and are combined with information on anthropogenic stress and larval connectivity. We find great spatial variation in relative resilience potential with many high resilience sites near Saipan (5 of 7) and low resilience sites near Rota (7 of 9). Criteria were developed to identify priority sites for six types of management actions (e.g., conservation, land-based sources of pollution reduction, and fishery management and enforcement) and 51 of the 78 sites met at least one of the sets of criteria. The connectivity simulations developed indicate that Tinian and Aguijan are each roughly 10 × the larvae source that Rota is and twice as frequent a destination. These results may explain the lower relative resilience potential of Rota reefs and indicates that actions in Saipan and Tinian/Aguijan will be important to maintaining supply of larvae. The process we describe for undertaking resilience assessments can be tailored for use in coral reef areas globally and applied to other ecosystems.
ISSN: 0006-3207

Droits : http://creativecommons.org/licenses/by-nc-nd/
hal-01224905
https://hal-univ-perp.archives-ouvertes.fr/hal-01224905
https://hal-univ-perp.archives-ouvertes.fr/hal-01224905/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01224905/file/1-s2.0-S0006320715300926-main.pdf
DOI : 10.1016/j.biocon.2015.09.001

Éditeur(s) : Gauthier-Villars
Résumé : In order to estimate the losses of CaCO3 from bioerosion (grazing and boring), experimental coral substrates were laid in the lagoons of high islands and atolls in French Polynesia. After six months of exposure, the sites could be divided into those exhibiting net bioerosion and those exhibiting net accretion. Of the five sites exhibiting net bioerosion (grazing and macroboring greater than accretion), three were located off high islands and two in atoll lagoons. The average net rate of bioerosion was greatest at Faaa in Papeete Bay, Tahiti (10.45 kg.m(-2).yr(-1)). Of, the two sites exhibiting net accretion, the greatest rate of gain (0.81 kg.m(-2).yr(-1)) was recorded at the eastern site in Takapoto lagoon. Recorded differences in the composition and distribution of macroborers, microborers and the algal turf appeared to be related to the presence or absence of grazing sea urchins (Echino-metra mathaei). It is suggested that the high densities of algal turf recorded at Faaa are a result of elevated nutrients at this site, originating in the sewage discharge from nearby residential and industrial sites.
Oceanologica Acta (0399-1784) (Gauthier-Villars), 1995 , Vol. 18 , N. 5 , P. 531-541

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00097/20795/18419.pdf
http://archimer.ifremer.fr/doc/00097/20795/

Résumé : Dans le cadre de l'extension du RNO aux Antilles, un exercice d"intercomparaison des laboratoires pressentis pour effectuer les analyses du volet « hydrologie » a été organisé par l'IFREMER fin 2000-début 2001. L'exercice comportait l'analyse de cinq paramètres : salinité, nitrate, nitrite, ammonium et phosphate. Chacun des paramètres devait être analysé à deux niveaux de concentration. Les participants étaient au nombre de 3. Chaque laboratoire a reçu deux flacons de 250 ml pour la salinité et huit flacons de 150 ml pour les nutriments (un flacon par paramètre et par niveau). Les laboratoires étaient informés qu'ils devaient analyser les échantillons dans un délai de six semaines environ après réception, ce qui limitait les risques de dérive potentielle des concentrations pouvant provenir d'une instabilité accidentelle des échantillons. L'expédition a été effectuée au début décembre 2000, ce qui a permis une mise à disposition des échantillons dans les laboratoires pour la fin décembre. Ce rapport analyse les résultats de l'exercice et présente une interprétation de ceux-ci.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00018/12911/9866.pdf
http://archimer.ifremer.fr/doc/00018/12911/

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/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The pearl oyster Pinctada margaritifera has the specific ability to produce pearls with the widest range of coloursamong all pearl oyster species. This pearl colour diversity originates from the mantle biomineralising tissue(graft) of the donor oyster, which is originally responsible for the variety of colours of the inner shell surface.This study aimed to: 1) assess the geographic distribution and establish a first stocklist of the colourful oysterphenotypes used as donors in French Polynesia, and 2) investigate the phenotypic relation between inner shellcolouration and the corresponding colour of harvested pearls. With the support of a pearl farmers' network,we investigated the different donor phenotype frequencies among five collection sites (Ahe, Apataki, Takaroa,TakumeandMangareva).Thisdonorevaluationwasmadeduringgraftingofpearloysters(N=49,938)obtainedfrom collector stations. Results showed that pearl production is mainly based on six common colourful donorphenotypes classified as monochromatic and polychromatic profiles, which shown different frequenciesamongthecollectionsites.Experimentalgrafts(N=4640)werethenrealisedandsubsequentcultureconductedat a single site in order to avoidpearl colour variation due to environmental influences. Traceability between do-nors (N = 232) and pearls (N = 2776), revealed that: 1) yellow (gold) and aubergine (reddish) pearls could bemostlyobtainedbyusingthemonochromaticyellowandreddonor phenotypes,respectively,and2)onethirdtoonequarterofgreypearlswasinevitablyharvested,whateverthepolychromaticphenotypechosenasthedonor,which leaves at least half the harvest composed of the attractive green and peacock colours. This preliminarystocklist of colour range together with analysis of the colour phenotype transmission between inner shell andpearl provide the basis for producing multiple pearl oyster “colour lines” through hatchery propagation andwould be helpful for future selective breeding programs.Statement of relevance: Donor shell colour selection predict colours of pearls
ISSN: 0044-8486

hal-01489247
https://hal-univ-perp.archives-ouvertes.fr/hal-01489247
DOI : 10.1016/j.aquaculture.2016.10.017