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Aschenbroich, Adelaide; Michaud, Emma; Stieglitz, Thomas; Fromard, Francois; Gardel, Antoine; Tavares, Marcos; Thouzeau, Gerard. |
This study in French Guiana evaluates the changes of crab assemblages and their bioturbation activities between mangrove early stages (pioneer and young mangrove) and within stages by taking their spatial heterogeneity (tidal channels, flat areas, pools) into account. The results show differences in crab assemblage structure between and within the early stages of mangrove in relation to microhabitat and sediment characteristics. The sediment reworking rates are a function of the biomass or density of particular species (Ucides cordatus, Uca cumulanta) and burrower functional groups. Crab species or functional interaction mediate changes in sediment reworking rates suggesting the need to consider entire benthic communities rather than single species. This... |
Tipo: Text |
Palavras-chave: Mangroves; Crabs; Community composition; Bioturbation; French Guiana; Amazon. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00350/46154/45852.pdf |
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Anthony, Edward J.; Brunier, Guillaume; Gardel, Antoine; Hiwat, Michael. |
The 350-km long coast of Suriname, South America, is part of a unique system in the world characterized by large-scale mud supply from the Amazon and exposed to Atlantic waves. Large banks migrate alongshore from the Amazon to the Orinoco delta, separated by ‘inter-bank’ zones. Banks dissipate waves, partially weld onshore, and are colonized by mangroves, whereas waves in inter-bank areas cause shoreline erosion, mitigated where rare cheniers develop. Cheniers assure coastal protection and recreational and ecosystem services, notably providing nesting sites for marine turtles. Cheniers are also under pressure from sand mining. In order to gain a better understanding of how these cheniers form and evolve, a study was conducted on Braamspunt beach, a major... |
Tipo: Text |
Palavras-chave: Chenier; Amazon-Orinoco coast; Mud bank; Muddy Guianas coast; Beach morphodynamics. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00489/60088/63426.pdf |
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Abascal-zorrilla, Noelia; Vantrepotte, Vincent; Huybrechts, Nicolas; Ngoc, Dat Dinh; Anthony, Edward J.; Gardel, Antoine. |
The estuarine turbidity maximum (ETM) zone occurs in river estuaries due to the effects of tidal dynamics, density-driven residual circulation and deposition/erosion of fine sediments. Even though tropical river estuaries contribute proportionally more to the sediment supply of coastal areas, the ETM in them has been hardly studied. In this study, surface suspended particulate matter (SPM) determined from OLI (Operational Land Imager)-Landsat 8images was used to gain a better understanding of the spatio-temporal dynamics of the ETM of the tropical Maroni estuary (located on the Guianas coast, South America). A method to estimate the remotely-sensed ETM location and its spatiotemporal evolution between 2013 and 2019 was developed. Each ETM was defined from... |
Tipo: Text |
Palavras-chave: Estuarine turbidity maximum; Landsat-8; Tropical estuary; Mud banks; French Guiana. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00641/75263/75468.pdf |
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Ross, Lauren; Sottolichio, Aldo; Maury, Tanguy; Lesourd, Sandric; Gardel, Antoine. |
Observations of water level, current velocity, river discharge, wind and salinity were collected in the Maroni estuary, on the border of French Guiana and Suriname during the wet season of 2018 to explore subtidal circulation patterns. Measurements are complimented by the application of analytical models with an aim to diagnose forcing mechanisms responsible for producing subtidal flows during the day of data collection and to extrapolate these findings to other time periods with variable wind and river forcing. Subtidal along-channel flows were found to be dominated by river discharge, with seaward directed velocities found throughout the channel section reaching 40 cm s −1 . This pattern was altered with strong southwesterly winds, which produced and... |
Tipo: Text |
Palavras-chave: Tropical estuary; Subtidal flow; Wet season; Wind-driven flow; Channel curvature. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00594/70588/68772.pdf |
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Jolivet, Morgane; Anthony, Edward J.; Gardel, Antoine; Brunier, Guillaume. |
On the 1500 km-long mud-dominated Guianas coast of South America, between the mouths of the two mega-rivers, the Amazon and the Orinoco, debouch numerous small rivers draining the humid tropical/equatorial Guiana Shield. The geomorphic development of the mouths of these rivers reflects interactions among water discharge, fluvial sediment load, and the alongshore migration of Amazon-derived mud banks alternating with inter-bank areas. The mouth of the Maroni River, astride the French Guiana-Suriname border, shows advanced estuarine infill and geomorphic development characterized by a western (downdrift) side comprising numerous recent cheniers and an eastern (updrift) side bound by an old (>2000 years B.P.) chenier. A multi-decadal analysis of the beach... |
Tipo: Text |
Palavras-chave: River mouth; Estuarine beach; Amazon-Orinoco coast; Mud bank; Beach morphodynamics. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00509/62041/66187.pdf |
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Rousseau, Yann; Blanchard, Fabian; Gardel, Antoine. |
The present study focuses on the structure and dynamics of the ichthyoplankton community of the Mahury Estuary (French Guiana) and the factors that influence them. Data were collected on three mangrove sites located in the inner, middle, and outer areas of the estuary. More than 45 000 larvae were collected, representing 31 families and 67 taxa. The community was numerically dominated by few species: Engraulidae was the most abundant family, followed by Gobiidae, Eleotridae, and Sciaenidae. As expected, the most abundant larval taxa were estuarine and mangrove species, with the addition of freshwater species in the inner area of the estuary and taxa with marine affinities in the outer area. The densities of most species were influenced by site more than by... |
Tipo: Text |
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Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00384/49559/50342.pdf |
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Diop, Bassirou; Sanz, Nicolas; Blanchard, Fabian; Walcker, Romain; Gardel, Antoine. |
This paper investigates the role of mangrove as an habitat in the evolution of the French Guiana shrimp stock to explain the recent collapse of shrimp production. To achieve our aim, we use the open access fishery model developed by Barbier and Strand [1998. “Valuing Mangrove-Fishery Linkages-A Case Study of Campeche, Mexico.” Environmental and Resource Economics 12: 151–166] and integrate mangrove surface into the shrimp natural growth function. This enables to account directly for the effects of mangrove surface changes on the stock dynamics and thus production. Our results indicate that financial losses in the French Guiana shrimp fishery increase when mangrove surface decreases and are mitigated when mangrove surface increases. We show that changes in... |
Tipo: Text |
Palavras-chave: Shrimp fishery; Mangrove; Habitat; Production function; Open access. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00458/56936/59376.pdf |
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