Consulta: creatorFacets:"Ternon, Jean-francois"
Registros recuperados: 4
Data/hora: 26/07/2024 22:31:47

Comparison of mesozooplankton communities at three shallow seamounts in the South West Indian Ocean
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Noyon, Margaux; Rasoloarijao, Zo; Huggett, Jenny; Ternon, Jean-francois; Roberts, Michael.
Seamounts are recognised as hotspots of biodiversity, attracting large numbers of top predators, but the underlying mechanisms are still unclear. We studied mesozooplankton abundance and size distribution at three shallow seamounts (60m, 240m and 18m deep) in the South West Indian Ocean, along a latitudinal gradient (19°S, 27°S and 33°S). Samples were analysed using a ZooScan, allowing the use of a size-based approach. Differences were observed between seamount areas, but overall zooplankton communities did not seem to be affected by the changes in topography. Only in the lee of La Pérouse seamount was the zooplankton community slightly more concentrated than upstream, suggesting that zooplankton were flushed downstream of the seamount. The southernmost...
Tipo: Text
Palavras-chave: Normalised biovolume size spectrum (NBSS); Mesoscale eddies; Topography; Oligotrophic environment; Pelagic ecology.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00609/72157/70920.pdf

Micronekton distributions and assemblages at two shallow seamounts of the south-western Indian Ocean: Insights from acoustics and mesopelagic trawl data
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Annasawmy, Pavanee; Ternon, Jean-francois; Cotel, Pascal; Cherel, Yves; Romanov, Evgeny V.; Roudaut, Gildas; Lebourges-dhaussy, Anne; Ménard, Fréderic; Marsac, Francis.
Micronekton distributions and assemblages were investigated at two shallow seamounts of the south-western Indian Ocean using a combination of trawl data and multi-frequency acoustic visualisation techniques. La Pérouse (∼60 m) seamount is located on the outskirts of the oligotrophic Indian South Subtropical Gyre province with weak mesoscale activities and low primary productivity all year round. The “MAD-Ridge” seamount (thus termed in this study; ∼240 m) is located in the productive East African Coastal (EAFR) province with high mesoscale activities to the south of Madagascar. This resulted in higher micronekton species richness at MAD-Ridge compared to La Pérouse. Resulting productivity at MAD-Ridge seamount was likely due to the action of mesoscale...
Tipo: Text
Palavras-chave: Micronekton; Seamount; South-western Indian Ocean; Acoustics; Seamount-associated fauna.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00510/62135/66368.pdf

Ocean currents and gradients of surface layer properties in the vicinity of the Madagascar Ridge (including seamounts) in the South West Indian Ocean
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Vianello, Patrick; Ternon, Jean-francois; Demarcq, Herve; Herbette, Steven; Roberts, Michael J.
This work is part of the MADRidge Project special issue which aims to describe pelagic ecosystems in the vicinity of three prominent shallow seamounts in the South West Indian Ocean: one here named MAD-Ridge (240 m below the surface) plus Walters Shoal (18 m) on the Madagascar Ridge, and La Pérouse (60 m) on the abyssal plain east of Madagascar. The three span latitudes 20°S and 33°S, some 1500 km. The study provides the background oceanography for the once-off, multidisciplinary snapshot cruise studies around the seamounts. As life on seamounts is determined by factors such as summit depth, proximity to the light layers of the ocean, and the ambient circulation, a first description of regional spatial-field climatologies (16–22 years) and monthly...
Tipo: Text
Palavras-chave: South West Indian Ocean; Madagascar Ridge; Seamounts; Walters shoal; Sea surface temperature; Eddy kinetic energy; Mixed layer depth; Chlorophyll-a; Geostrophic currents.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00634/74581/74476.pdf

Seamounts, plateaus and governance issues in the southwest Indian Ocean, with emphasis on fisheries management and marine conservation, using the Walters Shoal as a case study for implementing a protection framework
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Marsac, Francis; Galletti, Florence; Ternon, Jean-francois; Romanov, Evgeny V.; Demarcq, Herve; Corbari, Laure; Bouchet, Philippe; Roest, Walter; Jorry, Stephan; Olu, Karine; Loncke, Lies; Roberts, Michael J.; Ménard, Frédéric.
There is a growing interest in the management of seamounts of the South Western Indian Ocean (SWIO) both in waters under national jurisdictions and in the Areas Beyond National Jurisdiction (ABNJ). On the one hand, new scientific knowledge has been gathered through various oceanographic cruises during the past decade and, on the other hand, new agreements are under consideration globally to promote conservation and sustainable use of the biodiversity in the ABNJ, where the deep sea ecosystems associated to seamounts are a growing matter of concern. SWIO seamounts have attracted interests from fishing operators since the 1960s, while mining exploration contracts have been recently granted. Seamounts are known to shelter rich, fragile and poorly resilient...
Tipo: Text
Palavras-chave: International Law of the Sea; Vulnerable Marine Ecosystems; Deep-sea fisheries; Deep-sea mining; Benthic biodiversity; Saya de Malha Bank; South Indian Ocean Fisheries Agreement; Areas Beyond National Jurisdiction; Amended Nairobi Convention; Marine protected areas.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00598/71049/69362.pdf