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| Registros recuperados: 61 | |
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| Pastoral nomads such as West Africa’s Woɗaaɓe are renowned for the impressive environmental knowledge they apply to successfully raise animal herds in arid and variable environments. We looked at such herders’ knowledge not as based on individual learning and expertise but as ultimately social in the sense that it is formed, made available, and linked to pastoral decision making in the public and interactive space of permanent talking, discussing, and negotiating among peers. Drawing on theoretical ideas from science and technology studies, a number of concrete social situations of information management and pastoral decision making were explored in detail to reveal the distinctly social character of... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Fulani; Local environmental knowledge; Niger; Pastoral nomads; Science and technology studies; West Africa; Woɗ Aaɓ E. |
| Ano: 2014 |
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| Le Lay, Matthieu; Galle, Sylvie. |
| West African rainfall is characterized by a strong variability, both at decadal and interannual scales. In order to quantify the hydrological impacts of such a variability, analysis of rainfall patterns at fine scales is highly essential. This diagnostic study aims to characterize the Sudanese rainfall regime at hydrological scales, using a raingauge data set collected on the upper Oueme River catchment (Benin) between 1950 and 2002. A long-term drought is observed during the 1970s and 1980s, as in the Sahel. However, the interannual variability remains significant in the Sudanese region. The study of the seasonal cycle, based on the distinction between the oceanic and continental monsoon regimes, shows that the majority of rainfall changes occur in the... |
| Tipo: Text |
Palavras-chave: Catchment; Sudanese climate; Rainfall deficit; Monsoon; Precipitation; West Africa. |
| Ano: 2005 |
URL: https://archimer.ifremer.fr/doc/00203/31460/30115.pdf |
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| Ba, Kamarel; Thiaw, Modou; Fall, Massal; Thiam, Ndiaga; Meissa, Beyah; Jouffre, Didier; Thiaw, Omar Thiom; Gascuel, Didier. |
| For the first time in Senegal, assessments based on both stochastic and deterministic production models were used to draw a global diagnosis of the fishing impact on coastal demersal stocks. Based one national fisheries databases and scientific trawl surveys data: (i) trends in landings since 1971 were examined, (ii) abundance indices of 10 stocks were estimated using linear models fitted to surveys data and commercial catch per unit efforts, and (iii) stock assessments were carried out using pseudo-equilibrium Fox and Pella-Tomlinson models and a Biomass dynamic production model fitted in a Bayesian framework to abundance indices. Most stocks have seen their abundance sharply declining over time. All stocks combined, results of stock assessments suggest a... |
| Tipo: Text |
Palavras-chave: Coastal demersal species; Delta-GLM models; Surplus production models; Bayesian approach; Overexploitation; West Africa. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00626/73792/74929.pdf |
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| Leboulanger, C; Bouvy, M; Pagano, M; Dufour, Robert; Got, P; Cecchi, P. |
| This study focused on the effects of two pesticides, paraquat (herbicide) and deltamethrin (insecticide), which are two common molecules used intensively in Burkina Faso. Natural bacterial populations, phytoplankton cultures (one cyanobacterium, Cylindrospermopsis raciborskii, and one chlorophycea, Monoraphidium sp.), and two species of zooplankton (Diaphanosoma excisum and Moina micrura) were isolated from aquatic communities and were used as biological targets in the experimental protocols. Paraquat was moderately toxic to bacteria and phytoplankton, whereas deltamethrin was significantly toxic only to the zooplankton species. Paradoxically, the chlorophycea Monoraphidium sp. exhibited a significant increase of in vitro fluorescence after 48 h at the... |
| Tipo: Text |
Palavras-chave: West Africa; Reservoirs; Planktonic organisms; Deltamethrin; Paraquat. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-5287.pdf |
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| Lebel, Thierry; Parker, Douglas J.; Flamant, Cyrille; Hoeller, Hartmut; Polcher, Jan; Redelsperger, Jean-luc; Thorncroft, Chris; Bock, Olivier; Bourles, Bernard; Galle, Sylvie; Marticorena, Beatrice; Mougin, Eric; Peugeot, Christophe; Cappelaere, Bernard; Descroix, Luc; Diedhiou, Arona; Gaye, Amadou; Lafore, Jean-philippe. |
| The AMMA (African Monsoon Multidiscplinary Analysis) field programme aimed at documenting the West African Monsoon (WAM) climate system, in all its geophysical components. It also includes an important socio-economic component. Encompassing a wide range of spatial and time scales, AMMA is one of the most ambitious such programmes ever set up. While the key accomplishments of AMMA are summarised in this paper, a few lessons of broad interest are also drawn both as a tribute to the extraordinary efforts made by a community of several hundreds of people and as possible guidelines for ensuring a long lasting future to integrated climate and environmental studies in West Africa. |
| Tipo: Text |
Palavras-chave: Field campaigns; Instrument deployment; Long-term monitoring; Capacity building; West Africa. |
| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00214/32510/30990.pdf |
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| Stöhr, Sabine; Weber, Alexandra; Boissin, Emilie; Chenuil, Anne. |
| The conspicuous Mediterranean brittle star Ophioderma longicauda (Bruzelius, 1805) has been discovered to represent a cryptic species complex, consisting of six nuclear clusters with contrasting reproductive modes (broadcast spawners and brooders). Here, O. longicauda is re-described. It is distinguished by a dark reddish-brown colouration both dorsally and on the ventral disc, and multiple tumid dorsal arm plates. One eastern Mediterranean brooding cluster is described as O. zibrowii sp. nov., characterized by a dark olive-green colour both dorsally and on the ventral disc, and single dorsal arm plates. Another brooder is described from Tunisia as O. hybrida sp. nov., with a highly variable morphology that reflects its origin by hybridization of... |
| Tipo: Text |
Palavras-chave: Brittle stars; New species; Morphology; Mediterranean Sea; West Africa. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00610/72236/71039.pdf |
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| Le tixerant, Matthieu; Bonnin, Marie; Gourmelon, Françoise; Ragueneau, Olivier; Rouan, Mathias; Ly, Ibrahima; Ould zein, Ahmed; Ndiaye, Fatou; Diedhiou, Mohamed; Ndao, Souleye; Ndiaye, Mamadou Bassirou. |
| In the marine environment, positive law generates multiple zones and regulatory limits that overlap in space, justifying a cartographic representation as a relevant approach to promote understanding (synthetic vision), analysis (highlighting legal anomalies, inconsistencies and redundancies), dissemination and communication to different audiences (awareness-raising). The article presents a methodology leading to the mapping of marine and coastal environmental law in West Africa, using a geographic information base to produce static or interactive cartographic representations via a Geographic Data Infrastructure (GDI). It shows the contribution of this type of mapping to a transversal approach in a multi-activity, multi-sectoral and multi-scale context. A... |
| Tipo: Text |
Palavras-chave: Afrique de l’ouest; Mer; Littoral; Droit de la mer; Environnement; SIG; Cartographie; West Africa; Sea; Coastal zone; Law of the sea; Environment; GIS; Cartography. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00656/76813/81628.pdf |
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| Koranteng, Ka; Mcglade, Jm. |
| Using time series analyses, some physical parameters of the continental shelf waters of the Gulf of Guinea were examined. Analysis of coastal sea surface temperatures from Ghana and Ivory Coast, and offshore sea surface temperatures from the Gulf of Guinea clearly shows spatial and inter-annual patterns of cooling in coastal waters of West Africa. The behaviour of the decomposed trend of coastal and offshore sea surface temperatures, sub-surface: temperature measured at 100 m depth off Ghana and salinity showed that the observational period (1963-1992) could be divided into three climatic periods: the period before 1972, from 1972 to 1982, and the period after 1982. In the first period, sea surface temperature at both coastal and offshore areas and bottom... |
| Tipo: Text |
Palavras-chave: Environnement marin; Afrique de l'Ouest; Séries temporelles; Marine environment; West Africa; Time series. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00322/43363/42852.pdf |
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| Descroix, Luc; Sané, Yancouba; Thior, Mamadou; Manga, Sylvie-paméla; Ba, Boubacar Demba; Mingou, Joseph; Mendy, Victor; Coly, Saloum; Dièye, Arame; Badiane, Alexandre; Senghor, Marie-jeanne; Diedhiou, Ange-bouramanding; Sow, Djiby; Bouaita, Yasmin; Soumaré, Safietou; Diop, Awa; Faty, Bakary; Sow, Bamol Ali; Machu, Eric; Montoroi, Jean-pierre; Andrieu, Julien; Vandervaere, Jean-pierre. |
| In West Africa, as in many other estuaries, enormous volumes of marine water are entering the continent. Fresh water discharge is very low, and it is commonly strongly linked to rainfall level. Some of these estuaries are inverse estuaries. During the Great Sahelian Drought (1968–1993), their hyperhaline feature was exacerbated. This paper aims to describe the evolution of the two main West African inverse estuaries, those of the Saloum River and the Casamance River, since the end of the drought. Water salinity measurements were carried out over three to five years according to the sites in order to document this evolution and to compare data with the historical ones collected during the long dry period at the end of 20th century. The results show that in... |
| Tipo: Text |
Palavras-chave: Water salinity; Inverse estuaries; West Africa; Drought; Mangrove. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00612/72434/71381.pdf |
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| Diankha, Ousmane; Ba, Aliou; Brehmer, Patrice; Brochier, Timothee; Sow, Bamol Ali; Thiaw, Modou; Gaye, Amadou Thierno; Ngom, Fambaye; Demarcq, Herve. |
| We investigate Sardinella aurita and Sardinella maderensis recruitment success relative to the variability of oceanographic conditions in Senegalese waters using generalized additive models (GAM). Results show that recruitment of both species is marked by a strong intra-annual (seasonal) variation with minimum and maximum in winter and summer, respectively. Their interannual variations are synchronous until 2006 (recruitment decreasing), while from 2007 there is no synchrony. The model developed shows that sardinella recruitment variability is closely related to the tested environmental variables in the study area. However, the key environmental variables influencing the recruitment success are different for both species: the Coastal Upwelling Index and... |
| Tipo: Text |
Palavras-chave: Recruitment success; Sardinella aurita; Sardinella maderensis; Upwelling; West Africa. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00611/72299/71189.pdf |
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| Kane, Ea; Ball, Ac; Brehmer, Patrice. |
| Over the last thirty years, the poor state of certain fish stocks in the Large Marine Ecosystem of the Canary Current gradually revealed the limits of the West African fisheries management. The Ecosystem Approach advocated in Mauritania, calls to change the perception of fisheries management to incorporate participatory management considerations total admissible catches (TACs) and fishing quotas. An experiment around, a total allowable capture of 800 tons of pink lobster (Palinurus mauritanicus) is at the heart of this approach using methodological tools of analysis / assessment of the economic performance of crawfish exploratory fishery. Survey results show that during the period from February 2015 to January 2016, the fishery was based on a total of 23... |
| Tipo: Text |
Palavras-chave: Palinurus mauritanicus; Economic performance; European fleet; Turnover; Added value; Mauritania; West Africa. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00514/62524/69274.pdf |
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| Chima, Kelvin I.; Do Couto, Damien; Leroux, Estelle; Gardin, Silvia; Hoggmascall, Nick; Rabineau, Marina; Granjeon, Didier; Gorini, Christian. |
| Located on a divergent margin dominated by gravity tectonics above overpressured marine shales, the Niger Delta slope has been described as having a stepped profile characterized by ‘filled ponded basins’ that are prone to erosion and sediment bypass. Previous studies based on 3D seismic data have described the depositional architecture of the western Niger Delta's upper slope, but calibration of the seismic facies is lacking and the timing of major changes in sedimentary record remains elusive. In this study, seismic sequence-stratigraphy, 3D geomorphological analyses of high-resolution 3D seismic data, and bio/chronostratigraphic analyses from four boreholes, enabled the identification and characterization of the depositional architecture in Neogene... |
| Tipo: Text |
Palavras-chave: West Africa; Niger Delta; Seismic sequence stratigraphy; Filled ponded basins; Mass-transport deposits; Turbidite systems; Chronostratigraphy. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00503/61492/65302.pdf |
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| Ba, Aliou; Chaboud, Christian; Schmidt, Joern; Diouf, Malick; Fall, Massal; Deme, Moustapha; Brehmer, Patrice. |
| In the early 2000s, Senegal set up several Marine Protected Areas (MPAs) along its coastal zone with the purpose of biodiversity conservation and to support sustainable management of fisheries. However, the impact of MPAs may vary according to the type of fisheries. In Senegal, the sardinella fishery accounts for 70% of total catches. This fishery is of crucial importance for national food security and employment. Given this importance, it is necessary to evaluate the impact of MPAs, often being considered as a tool for fisheries management. An analytical, dynamic and spatial bio-economic model of sardinella fishery, considering fish and fisher migration, has been developed and scenarios over forty years have been analyzed. The results show that the... |
| Tipo: Text |
Palavras-chave: Small scale fisheries; MPA; Bioeconomic modeling; Fishing capacity; Fishery management; Sardinella aurita; Sardinella maderensis; Aichi targets; West Africa. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00605/71672/73087.pdf |
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| Registros recuperados: 61 | |
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