Consulta: subjectFacets:"Mozambique Channel"
Registros recuperados: 14
Data/hora: 16/06/2024 16:58:02

Living (stained) benthic foraminifera from the Mozambique Channel (eastern Africa): Exploring ecology of deep-sea unicellular meiofauna
Provedor de dados: 5
Autores: Fontanier, Christophe; Garnier, Eline; Brandily, Christophe; Dennielou, Bernard; Bichon, S.; Gayet, Nicolas; Eugene, Thibaut; Rovere, Mickael; Gremare, A.; Deflandre, B.
Live (Rose-Bengal stained) deep-sea foraminiferal faunas have been studied at four stations between 530–3200-m depth in the Mozambique Channel (eastern Africa) to understand how complex environmental conditions (e.g., organic matter, oxygenation) control their ecological structure (i.e., diversity, density, and microhabitats). Two upper-slope stations, located at 530- and 780-m depth off Madagascar, are bathed by well-oxygenated bottom waters. They are characterized by fine sediments enriched in highly degraded organic matter (low amino-acid bio-availability and reduced chlorophyllic freshness). Mineralization of organic compounds results in relatively moderate oxygen penetration depth (i.e., 15 and 30 mm) in sediment. Interestingly, foraminiferal species...
Tipo: Text
Palavras-chave: Mozambique Channel; Foraminifera; Diversity; Microhabitat; Organic matter.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00344/45505/45057.pdf

A Late Quaternary record of highstand shedding from an isolated carbonate platform (Juan de Nova, southern Indian Ocean)
Provedor de dados: 5
Autores: Counts, John; Jorry, Stephan; Vazquez Riveiros, Natalia; Jouet, Gwenael; Giraudeau, Jacques; Cheron, Sandrine; Boissier, Audrey; Miramontes, Elda.
A 27 m core collected on the seafloor near Juan de Nova island at 1909 m depth in the SW Indian Ocean preserves a high‐resolution record of carbonate sediment export to the deep sea over the past 1 Myr. Core chronology was established using calcareous nannofossil biostratigraphy and benthic foraminiferal δ18O. Throughout the core, preserved highstand intervals (MIS 1, 5, 7, 9, 11, 13, 15, 23 and 25) are marked by an increase in the aragonite content within the sediment. Aragonite is likely sourced from the nearby Juan de Nova carbonate platform ~10 km to the south, and is interpreted to result from flooding of the platform top. Platform inundation allows carbonate muds to be winnowed from their original shallow‐water environment of deposition, suspended in...
Tipo: Text
Palavras-chave: Aragonite; Atoll; MIS 11; Mozambique Channel; Sea-level change.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00474/58553/61108.pdf

The key role of the Northern Mozambique Channel for Indian Ocean tropical tuna fisheries
Provedor de dados: 5
Autores: Chassot, Emmanuel; Bodin, Nathalie; Sardenne, Fany; Obura, David.
The Northern Mozambique Channel (NMC) is a tropical area of similar to 1 million km(2) where pelagic fisheries supply proteins to more than 9 million people living in Comoros, Mayotte, and along the coasts of Mozambique, Tanzania and Madagascar. Although uncertain, statistics suggest that about 20,000 mt of tropical tuna and other pelagic fish are annually caught by artisanal fisheries in the area. The NMC is also a major seasonal fishing ground for high-seas fleets that export an annual average catch of more than 20,000 mt to tuna can and sashimi markets of high-income countries for a value estimated to be more than 100 million USD. The fisheries productivity of the NMC appears to be highly variable in relation to strong annual and seasonal variability in...
Tipo: Text
Palavras-chave: Bigeye; Fisheries management; Mozambique Channel; Skipjack; Yellowfin.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00512/62366/66661.pdf

Foraging strategy of a tropical seabird, the red-footed booby, in a dynamic marine environment
Provedor de dados: 5
Autores: Weimerskirch, Henri; Le Corre, Matthieu; Jaquemet, Sébastien; Marsac, Francis.
The foraging behaviour of animals depends on the distribution, abundance and predictability of their food resources. In the marine environment, top predators such as seabirds are known to concentrate their foraging effort in specific oceanic features where productivity is elevated or prey concentrated. When marine productivity is low and prey distribution unpredictable, such as in tropical waters, selection should favour the evolution of flexible foraging strategies. By using GPS, Argos transmitters and activity recorders, we studied the foraging strategy of red-footed boobies (RFBs) Sula sula breeding on Europa Island in the Mozambique Channel, to examine the way a central place forager searches for prey in tropical waters. RFBs only foraged during the...
Tipo: Text
Palavras-chave: Sula sula; GPS; Satellite tracking; Mozambique Channel; Chlorophyll concentration; Sea-level height anomalies.
Ano: 2005
URL: https://archimer.ifremer.fr/doc/00209/32068/30526.pdf

Impact of tectonic and volcanism on the Neogene evolution of isolated carbonate platforms (SW Indian Ocean)
Provedor de dados: 5
Autores: Courgeon, Simon; Jorry, Stephan; Jouet, Gwenael; Camoin, G.; Boudagher-fadel, M. K.; Bachelery, P.; Caline, B.; Boichard, R.; Revillon, Sidonie; Thomas, Yannick; Thereau, Estelle; Guerin, Charline.
Understanding the impact of tectonic activity and volcanism on long-term (i.e. millions years) evolution of shallow-water carbonate platforms represents a major issue for both industrial and academic perspectives. The southern central Mozambique Channel is characterized by a 100 km-long volcanic ridge hosting two guyots (the Hall and Jaguar banks) and a modern atoll (Bassas da India) fringed by a large terrace. Dredge sampling, geophysical acquisitions and submarines videos carried out during recent oceanographic cruises revealed that submarine flat-top seamounts correspond to karstified and drowned shallow-water carbonate platforms largely covered by volcanic material and structured by a dense network of normal faults. Microfacies and well-constrained...
Tipo: Text
Palavras-chave: Carbonate platform; Drowning; Volcanism; Tectonic; Mozambique Channel.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00384/49554/50048.pdf

Modelling cyclonic eddies in the Delagoa Bight region
Provedor de dados: 5
Autores: Cossa, O.; Pous, Stephane; Penven, P.; Capet, X; Reason, C. J. C.
The objective of this study is to document and shed light on the circulation around the Delagoa Bight region in the southern Mozambique Channel using a realistic modelling approach. A simulation including mesoscale forcings at the boundaries of our regional configuration succeeds in reproducing the general circulation in the region as well as the existence of a semi-permanent cyclonic eddy, whose existence is attested by in situ measurements in the Bight. Characterised by a persistent local minimum in SSH located around 26 °S—34 °E, this cyclonic eddy termed herein the Delagoa Bight lee eddy occurs about 25% of the time with no clear seasonal preference. Poleward moving cyclones, mostly generated further north, occur another 25% of the time in the Bight...
Tipo: Text
Palavras-chave: Delagoa Bight; Cyclonic lee eddy; Coastal countercurrent; Numerical model; Mozambique Channel; Shelf processes.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00318/42941/42449.pdf

Growth and demise of Cenozoic isolated carbonate platforms: New insights from the Mozambique Channel seamounts (SW Indian Ocean)
Provedor de dados: 5
Autores: Courgeon, Simon; Jorry, Stephan; Camoin, G. F.; Boudagher-fadel, M. K.; Jouet, Gwenael; Revillon, Sidonie; Bachelery, P.; Pelleter, Ewan; Borgomano, J.; Poli, E.; Droxler, A. W.
Although long-term evolutions of isolated shallow-water carbonate platforms and demise episodes leading to guyot formation have been the subject of numerous studies during the last decades, their driving processes are still the subject of active debates. The Mozambique Channel (SW Indian Ocean) is characterized by several flat-topped seamounts ranging from 11°S to 21°S in latitudes. Based on a comprehensive geomorphologic study and on dredged samples analysis, we show that these features correspond to tropical isolated shallow-water carbonate platforms. Coupling strontium isotopy and foraminifera biostratigraphy, well-constrained chronostratigraphy results indicate that shallow-water carbonate production started in the Mozambique Channel during distinct...
Tipo: Text
Palavras-chave: Carbonate platform; Drowning; Cenozoic; Mozambique Channel; East African rift system.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00347/45827/46634.pdf

First record of the coloured righteye flounder, Poecilopsetta colorata (Teleostei: Poecilopsettidae) from the Sakalaves seamounts in the Mozambique Channel
Provedor de dados: 5
Autores: Chen, Wei-jen; Chen, Jhen-nien; Pernet, Marie Eve Julie; Olu, Karine.
Background: The coloured righteye flounder, Poecilopsetta colorata Günther, 1880 was previously known from the eastern Indian Ocean to the South China Sea and Indonesia. Here, a new record from the western Indian Ocean is reported. Results: The new record is based on a specimen collected on the Sakalaves seamounts at 375 m in depth in the Mozambique Channel during a recent oceanographic survey. Four other teleost fish species including an uncommon ophidiid species, Neobythites somaliaensis Nielsen, 1995 were also collected on the same seamounts.  Conclusions: The presence of P. colorata in the Mozambique Channel suggests a broad and Indo-West Pacific wide distribution for this relatively rare deep-sea species. The sequence of the cytochrome oxidase...
Tipo: Text
Palavras-chave: Fishes; New record; Distribution; Western Indian Ocean; Mozambique Channel; Sakalaves seamounts; COI; PAMELA-MOZ01 cruise.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00353/46385/46009.pdf

Intermediate and deep ocean current circulation in the Mozambique Channel: New insights from ferromanganese crust Nd isotopes
Provedor de dados: 5
Autores: Charles, Claire; Pelleter, Ewan; Révillon, Sidonie; Nonnotte, Philippe; Jorry, Stephan; Kluska, Jean-michel.
The Mozambique Channel plays a key role in the exchange of water masses between the Indian and Atlantic Oceans, which include the North Atlantic Deep Water (NADW) inflow from the south and the North Indian Deep Water (NIDW), an aged form of the NADW spreading poleward from the northern and equatorial Indian Ocean basin. Several authors assume that the Davie Ridge acts as a topographic barrier to the northward advection of NADW, which would therefore be absent in the Comoros Basin. Other studies suggest that the NADW flows from the south of the Mozambique Channel to the Comoros Basin, indicating that the Davie Ridge may not currently constitute a blocking topographic barrier to deep water mass circulation. To address this question, we studied ferromanganese...
Tipo: Text
Palavras-chave: Ferromanganese crusts; Nd isotopes; Paleoceanography; Mozambique Channel; North Atlantic Deep Water.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00653/76488/77569.pdf

Influence of mesoscale eddies on biological production in the Mozambique Channel: Several contrasted examples from a coupled ocean-biogeochemistry model
Provedor de dados: 5
Autores: Jose, Yonss; Aumont, Olivier; Machu, Eric; Penven, Pierrick; Moloney, C. L.; Maury, Olivier.
The impact of mesoscale activity on phytoplankton and nutrient distribution in the Mozambique Channel was simulated by coupling a biogeochemical model (PISCES) with a regional oceanic model (ROMS). Examples of the effects of eddies on the biogeochemistry of the Mozambique Channel are presented to illustrate the complexity of the system. In the model, several cyclonic eddies were found with low concentrations of chlorophyll at their cores, which contrasts with previous studies in the open ocean. In addition, several anticyclonic eddies were simulated with high concentrations of chlorophyll at their cores. Phytoplankton growth within these mesoscale features (both cyclonic and anticyclonic eddies) occurred in response to nutrient injection into the euphotic...
Tipo: Text
Palavras-chave: Ocean physical-biogeochemical coupling; Cyclonic and anticyclonic eddies; Chlorophyll; Nutrients; Mozambique Channel.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00162/27320/25549.pdf

Technologie et utilisation des DCP ancres dans les eaux de la collectivite territoriale de Mayotte (archipel des Comores, canal du Mozambique, ocean Indien)
Provedor de dados: 5
Autores: Wendling, Bertrand; Le Calve, S.
The volcanic island of Mayotte (374 km super(2)) is part of the Comoros Archipelago, which is situated on the North of Mozambic's Canal (Indian Ocean). Mayotte is composed of two islands and some thirty small islands distributed in a lagoon of more than 1,000 km super(2). Being one of the French Republic's Territorial Collectivity, this island is characterized by a very fast demographic evolution (growth rate : 5.8 %), which constitutes the foundation of the development problematic. Most of local halieutic production comes from the reef (nearly 2,000 t in 1999), the technic of "palangrotte" (deep line) is still dominating. The fishing fleet is composed of monoxyl pirogues and polyester fishing boats for the 1,200 fishermen. The first FADs (Fish Aggregating...
Tipo: Text
Palavras-chave: Artisanal fishing Attracting techniques Lagoon fisheries Tuna fisheries Article Geographic Terms: Comoro Is.; Mayotte ISW; Indian Ocean ISW; West Indian Ocean; Mozambique Channel.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/00042/15290/12647.pdf

Phylogeography of the green turtle, Chelonia mydas, in the Southwest Indian Ocean
Provedor de dados: 5
Autores: Bourjea, Jerome; Lapegue, Sylvie; Gagnevin, L; Broderick, D; Mortimer, J.a.; Ciccione, S; Roos, David; Taquet, Coralie; Grizel, Henri.
Patterns of mitochondrial DNA (mtDNA) variation were used to analyse the population genetic structure of southwestern Indian Ocean green turtle (Chelonia mydas) populations. Analysis of sequence variation over 396 bp of the mtDNA control region revealed seven haplotypes among 288 individuals from 10 nesting sites in the Southwest Indian Ocean. This is the first time that Atlantic Ocean haplotypes have been recorded among any Indo-Pacific nesting populations. Previous studies indicated that the Cape of Good Hope was a major biogeographical barrier between the Atlantic and Indian Oceans because evidence for gene flow in the last 1.5 million years has yet to emerge. This study, by sampling localities adjacent to this barrier, demonstrates that recent gene...
Tipo: Text
Palavras-chave: Phylogeography; Mozambique Channel; Mitochondrial DNA; Indian Ocean; Control region; Chelonia mydas.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2185.pdf

Suppressing and enhancing effects of mesoscale dynamics on biological production in the Mozambique Channel
Provedor de dados: 5
Autores: Jose, Y. S.; Penven, P.; Aumont, O.; Machu, E.; Moloney, C. L.; Shillington, F.; Maury, O.
We used a coupled physical-biogeochemical model to investigate how the strong eddy activity typical of the Mozambique Channel affects biological production. A numerical experiment was carried out, in which mesoscale dynamics were suppressed by cancelling the nonlinear terms for horizontal momentum in the Naviers-Stokes equation.  Mesoscale dynamics were found to be responsible for (1) increased offshore production in the Mozambique Channel as a result of net eddy-induced offshore transport of nutrient-rich coastal waters; (2) decreased shelf production along the central Mozambican and south-west Madagascar coast caused by a reduction in nutrient availability related to the net eddy-induced lateral transport of nutrients; (3) increased coastal production...
Tipo: Text
Palavras-chave: Mesoscale dynamics; Chlorophyll; Primary production; Mozambique Channel.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00317/42860/42286.pdf

Recent thecideide brachiopods from a submarine cave in the Department of Mayotte (France), northern Mozambique Channel
Provedor de dados: 5
Autores: Simon, Eric; Hiller, Norton; Logan, Alan; Theuerkauff, Dimitri; Mottequin, Bernard.
For the first time large numbers of thecideide brachiopods have been collected from the Mozambique Channel, more particularly from the western part of the Comorian Island of Mayotte (France). The moderately diverse brachiopod fauna is from a submarine cave situated on the second barrier reef encircling this island, with three different genera being found: Thecidellina, Ospreyella and Minutella. The last genus is represented by M. cf. minuta (Cooper, 1981), which was first discovered around Madagascar. Ospreyella is represented by a new species (O. mayottensis sp. nov.) as is Thecidellina, which is represented by T. leipnitzae sp. nov. This species is markedly distinct from T. europa Logan et al., 2015 from Europa Island in the southern Mozambique Channel...
Tipo: Text
Palavras-chave: Brachiopoda; Thecidellina; Ospreyella; Minutella; New species; Allopatric speciation; Mozambique Channel.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00501/61313/64873.pdf