Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
The brown algal genus Padina (Dictyotales, Phaeophyceae) is distributed worldwide in tropical and temperate seas. Global species diversity and distribution ranges, however, remain largely unknown. Species-level diversity was reassessed using DNA-based, algorithmic species delineation techniques based on cox3 and rbcL sequence data from 221 specimens collected worldwide. This resulted in estimates ranging from 39 to 61 putative species (ESUs), depending on the technique as well as the locus. We discuss the merits, potential pitfalls, and evolutionary and biogeographic significance of algorithmic species delineation. We unveil patterns whereby ESUs are in all but one case restricted to either the Atlantic or Indo-Pacific Ocean. Within ocean basins we find evidence for the vast majority of ESUs to be confined to a single marine realm. Exceptions, whereby ESUs span up to three realms, are located in the Indo-Pacific Ocean. Patterns of range-restricted species likely arise by repeated founder events and subsequent peripatric speciation, hypothesized to dominate speciation mechanisms for coastal marine organisms in the Indo-Pacific. Using a three-gene (cox3, psaA and rbcL), relaxed molecular clock phylogenetic analysis we estimated divergence times, providing a historical framework to interpret biogeographic patterns.
ISSN: 0022-3646

hal-01545323
https://hal.archives-ouvertes.fr/hal-01545323
DOI : 10.1111/jpy.12027

Résumé : This report which is one of final parts of the European project Pace-Net, makes a reminder of the starting points of this project, the setting up of the network further to four meetings: that of the kick off meeting in Nouméa in 2010, then a first workshop in Brisbane in 2011, one second in Brussels in 2012 and the closing seminar in Suva in March, 2013. We propose in conclusion a set of recommendations appropriate to the themes of the project which join the Pacific – Europe collaboration perspectives at the horizon 2020.
Ce rapport qui est une des pièces finales du projet européen Pace-Net fait un rappel des bases de départ de ce projet, du montage du réseau suite à quatre réunions : celle de lancement à Nouméa en 2010, un premier atelier à Brisbane en 2011, une second à Bruxelles en 2012 et le séminaire de clôture à Suva en mars 2013. On propose en conclusion un ensemble de recommandations propres aux thématiques du projet qui s’inscrivent dans la collaboration Pacifique Europe à l’horizon 2020.

Droits : Pace-Net Network - All rights reserved
http://archimer.ifremer.fr/doc/00204/31487/29897.pdf
http://archimer.ifremer.fr/doc/00204/31487/

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
Seabirds concentrate nutrients from large marine areas on their nesting islands playing an important ecological role in nutrient transfer between marine and terrestrial ecosystems. Here we investigate the role of guano on corals reefs across scales by analyzing the stable nitrogen isotopic (delta N-15) values of the scleractinian coral Pocillopora damicornis on fringing reefs around two Pacific remote islets with large seabird colonies. Marine stations closest to the seabird colonies had higher nitrate + nitrite concentrations compared to more distant stations. Coral and zooxanthellae delta N-15 values were also higher at these sites, suggesting that guano-derived nitrogen is assimilated into corals and contributes to their nitrogen requirements. The spatial extent of guano influence was however restricted to a local scale. Our results demonstrate that seabird-derived nutrients not only spread across the terrestrial ecosystem, but also affect components of the adjacent marine ecosystem. Further studies are now needed to assess if this nutrient input has a positive or negative effect for corals. Such studies on remote islets also open fresh perspectives to understand how nutrients affect coral reefs isolated from other anthropogenic stressors.
ISSN: 2045-2322

hal-01681575
https://hal.archives-ouvertes.fr/hal-01681575
DOI : 10.1038/s41598-017-03781-y

Résumé : This report makes the synthesis of the works and the results acquired thanks to the development of the project Pace-Net (2010-2013) registered in the 7th framework program of the European Commission aiming to create a scientific and technological network between Europe and the Pacific in front of main common stakes. These concern the biodiversity and the environmental management, the climate change, the energy, the water, the agriculture and the forest, the natural risks, the fisheries and aquaculture and the trans-cutting approaches
Ce rapport effectue la synthèse des travaux et des résultats acquis à la faveur du développement du projet Pace-Net (2010-2013) inscrit dans le 7 ème programme cadre de la Commission Européenne et visant à faire naître un réseau scientifique et technologique entre l'Europe et le Pacifique face aux grands enjeux posés. Ceux-ci concernent la biodiversité et la gestion environnementale, le changement climatique, l’énergie, l’eau, l’agriculture et la forêt, les risques naturels, la pêche et de l’aquaculture et les approches intégratrices.

Droits : Pace-Net Network - All rights reserved
http://archimer.ifremer.fr/doc/00204/31488/29898.pdf
http://archimer.ifremer.fr/doc/00204/31488/