Consulta: subjectFacets:"West Africa"
Registros recuperados: 61
Data/hora: 11/06/2024 08:03:05

Climate Factors Play a Limited Role for Past Adaptation Strategies in West Africa
Provedor de dados: 7
Autores: Mertz, Ole; Department of Geography and Geology, University of Copenhagen; om@geo.ku.dk; Reenberg, Anette; Department of Geography and Geology, University of Copenhagen ; Ar@geo.ku.dk; Barbier, Bruno; International Cooperation Center for Agronomic Research and Development (CIRAD); bbarbier@cirad.fr; Dabi, Daniel; Department of Geography and Planning, Faculty of Environmental Sciences, University of Jos; davoo65@yahoo.com.
Tipo: Peer-Reviewed Reports
Palavras-chave: Adaptation; Climate variability; Livestock; Rainfed crops; West Africa.
Ano: 2010

The social nature of environmental knowledge among the nomadic Wo&amp;#0599;aa&amp;#0595;e of Niger
Provedor de dados: 7
Pastoral nomads such as West Africa&amp;#8217;s Wo&amp;#0599;aa&amp;#0595;e are renowned for the impressive environmental knowledge they apply to successfully raise animal herds in arid and variable environments. We looked at such herders&amp;#8217; 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; Wo&amp;#0599; Aa&amp;#0595; E.
Ano: 2014

Rebuilding Resilience in the Sahel: Regreening in the Maradi and Zinder Regions of Niger
Provedor de dados: 7
Autores: Sendzimir, Jan; International Institute of Applied Systems Analysis (IIASA); sendzim@iiasa.ac.at; Reij, Chris P; Centre for International Cooperation, Vrij Universitaet; CP.Reij@dienst.vu.nl; Magnuszewski, Piotr; Center for Systems Solutions; piotr.magnuszewski@crs.org.pl.
The societies and ecosystems of the Nigerien Sahel appeared increasingly vulnerable to climatic and economic uncertainty in the late twentieth century. Severe episodes of drought and famine drove massive livestock losses and human migration and mortality. Soil erosion and tree loss reduced a woodland to a scrub steppe and fed a myth of the Sahara desert relentlessly advancing southward. Over the past two decades this myth has been shattered by the dramatic reforestation of more than 5 million hectares in the Maradi and Zinder Regions of Niger. No single actor, policy, or practice appears behind this successful regreening of the Sahel. Multiple actors, institutions and processes operated at different levels, times, and scales to initiate and sustain this...
Tipo: Peer-Reviewed Reports
Palavras-chave: Agro-forestry; Farmer managed natural regeneration; Maradi Region; Niger; Pastoralism; Reforestation; Regreening; Resilience; Vulnerability; West Africa; Zinder Region.
Ano: 2011

Seasonal cycle and interannual variability of rainfall at hydrological scales. The West African monsoon in a Sudanese climate
Provedor de dados: 5
Autores: 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

Long-term fishing impact on the Senegalese coastal demersal resources: diagnosing from stock assessment models
Provedor de dados: 5
Autores: 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

Responses of Planktonic Microorganisms from Tropical Reservoirs to Paraquat and Deltamethrin Exposure
Provedor de dados: 5
Autores: 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

The AMMA field campaigns: accomplishments and lessons learned
Provedor de dados: 5
Autores: 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

Resolving the Ophioderma longicauda (Echinodermata: Ophiuroidea) cryptic species complex: five sisters, three of them new
Provedor de dados: 5
Autores: 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

Panafrican events within the Adrar Souttouf Massif (Moroccan Mauritanides).
Provedor de dados: 5
Autores: Villeneuve, Michel; Bellon, Hervé; El Archi, A; Sahabi, M; Rehault, Jean Pierre; Olivet, Jean-louis; Aghzer, A.
The Adrar Souttouf belt (Western Sahara) lies in the northern part of the Mauritanide belt and was considered as a part of the Hercynian Mauritanian-Appalachian belt. Recently the presence of a Panafrican protolith (595 Ma) was evidenced by the age of inherited zircons from an eclogitic unit and led to consider complex Panafrican events included in the Hercynian belt, as in the central and southern Mauritanide belt. Our new field survey completed by ten K-Ar dating (whole rocks and separate minerals) confirmed that multiphased Panafrican formations outcrop within the center of the Adrar Souttouf massif. Diverse events ranged from ca. 1000 to 500 Ma, some of them being indicative of an oceanic type environment and metamorphism. The 1000 Ma metamorphic event...
Tipo: Text
Palavras-chave: Radiometric datations; Hercynian; Panafrican; Mauritanian belt; Sahara; West Africa; Datations radiochronologiques; Hercynien; Panafricain; Mauritanides; Sahara; Afrique de l'Ouest.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1809.pdf

Cartographic Atlas of Marine Environmental Law in West Africa. Methodology and use for spatial planning
Provedor de dados: 5
Autores: 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

Spatial distribution of main clupeid species in relation to acoustic assessment surveys in the continental shelves of Senegal and The Gambia
Provedor de dados: 5
Autores: Sarre, Abdoulaye; Krakstad, Jens-otto; Brehmer, Patrice; Mbye, Ebou Mass.
This work compiles hydroacoustic recordings and catch data over Senegambia (Senegal and The Gambia) from assessment surveys on the major clupeid species to identify sources of bias in abundance estimates caused by their horizontal distribution. The latitudinal distribution of small pelagic fish is often well known, while their "across shelf" distribution on the continental shelf is less understood. The southern part of the Senegambian shelf has a wide shallow water (&lt; 10 m) area that makes up 20% (1500NM(2)) of the total shelf surface, while the northern part accounts for 3% (200NM(2)). These areas are not assessed by conventional fisheries acoustics surveys and therefore increase the uncertainty of the assessment of these species. Our findings show...
Tipo: Text
Palavras-chave: Fish distribution; Ethmalosa fimbriata; Ilisha africana; Sardinella spp.; West Africa.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00426/53765/72090.pdf

Complexity in trophic structure and stability in a modelled West African estuary
Provedor de dados: 5
Autores: Villanueva, Ching-maria; Diouf, P.s.; Albaret, J.-j.; Moreau, J.
Un modèle Ecopath de l'estuaire du Sine-Saloum (Sénégal) comportant au total 37 groupes fonctionnels a été appliqué dans la présente étude en vue de déterminer les faits essentiels de ce système aquatique. La grande biodiversité spécifique des poissons de l'écosystème peut y jouer un rôle en assurant son intégrité, spécialement en présence de facteurs de stress, bien qu'il ait été observé que ce n'est pas entièrement le cas. Les résultats montrent qu'un autre facteur de mitigation est le niveau des forces d'interaction entre les groupes fonctionnels. La stabilité est accrue par des relations plus faibles et des pyramides plus courtes et plus larges. Bien que différentes questions se posent concernant les facteurs conduisant à la stabilité d'un système, les...
Tipo: Text
Palavras-chave: Stabilité des systèmes; Sénégal; Omnivorie; Estuaire; Ecosystème côtier; Ecopath; Biodiversité; Afrique de l'Ouest; West Africa; System Stability; Senegal; Omnivory; Estuary; Ecopath; Coastal Ecosystem; Biodiversity.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-2554.pdf

Climatic trends in continental shelf waters off Ghana and in the Gulf of Guinea, 1963-1992
Provedor de dados: 5
Autores: 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

Inverse Estuaries in West Africa: Evidence of the Rainfall Recovery?
Provedor de dados: 5
Autores: 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

Comparative analysis of trophic structure and interactions of two tropical lagoons
Provedor de dados: 5
Autores: Villanueva, Ching-maria; Laleye, P; Albaret, J; Lae, Raymond; Tito De Morais, Luis; Moreau, J.
A comparative study of the Ebrie lagoon (Ivory Coast) and Lake Nokoue (Benin) was made based on ecotrophic model outputs that describe each system's structure and functioning. Two models were constructed using the Ecopath software to differentiate main biomass flows in the systems.   Results indicate that biomasses and productions in both ecosystems are concentrated in trophic levels (TL) 2 and 3. Higher TL biomasses and productions in Lake Nokoue compared to Ebrie lagoon may be explained by the presence of acadjas. High production per biomass (P/B) and food consumption per biomass (Q/B) values indicate the high productivity of these systems and the abundance of juveniles in most groups which utilize these systems as refuge zones and nurseries. The...
Tipo: Text
Palavras-chave: Ecopath; System maturity; Transfer efficiency; West Africa; Tropical lagoons.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-2009.pdf

Contrasted optimal environmental windows for both sardinella species in Senegalese waters
Provedor de dados: 5
Autores: 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

Total admissible catches and experimental fishing quotas in the pink lobster (Palinurus mauritanicus, Gruvel 1911): A new opportunity for economic development in West Africa?
Provedor de dados: 5
Autores: 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

Variability of key biological parameters of round sardinella Sardinella aurita and the effects of environmental changes
Provedor de dados: 5
Autores: Balde, Bocar Sabaly; Sow, Fambaye N.; Ba, Kamarel; Ekau, Werner; Brehmer, Patrice; Kantoussan, Justin; Fall, Massal; Diouf, Malick.
We examined growth rates and reproductive characteristics of Sardinella aurita off Senegal and other coastal areas over a 20 year period (1995-2014) to determine how they relate to variations in environmental characteristics of coastal waters. Based on fish length-frequency data and a coastal upwelling index, we found that S. aurita recruitment tends to occur during the periods of most intensive upwelling (March-April off Senegal). Peak reproduction corresponds to periods of low sea-surface temperature (in February or March). The sex ratio was remarkably consistent during the 30 year study period and so was not affected by environmental changes. We hypothesise that S. aurita takes advantage of the higher zooplankton productivity that occurs in coastal...
Tipo: Text
Palavras-chave: Data poor fisheries; Environmental variability; Size structure; Small pelagic; Spawning period; West Africa.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00491/60229/67183.pdf

Seismic stratigraphy and depositional architecture of Neogene intraslope basins, offshore western Niger Delta
Provedor de dados: 5
Autores: 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

The potential impact of marine protected areas on the Senegalese sardinella fishery
Provedor de dados: 5
Autores: 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

Trophic connectivity between offshore upwelling and the inshore food web of Banc d’Arguin (Mauritania): New insights from isotopic analysis
Provedor de dados: 5
Autores: Carlier, Antoine; Chauvaud, Laurent; Van Der Geest, Matthijs; Le Loc'H, Francois; Le Duff, Michel; Vernet, Marc; Raffray, Jean; Diakhate, Djibril; Labrosse, Pierre; Wague, Abdoulaye; Le Goff, Clement; Gohin, Francis; Chapron, Bertrand; Clavier, Jacques.
Banc d’Arguin (BA), Mauritania, is a nationally protected shallow gulf &gt; 10,000 km2 between the Sahara desert and the upwelling system off the Mauritanian coast. In the southeast, BA consists of a 500 km2 tidal flat, the most important wintering site for shorebirds using the East Atlantic Flyway. The Mauritanian upwelling-driven phytoplankton production supports the most productive fisheries worldwide, but little is known about its trophic role in the functioning of the inshore BA food web. Using stable isotopes as trophic tracers to distinguish between upwelling-driven phytoplankton, open ocean phytoplankton, and benthic primary producers, we assessed the spatial extent to which the inshore BA food web is fuelled by upwelling-driven phytoplankton...
Tipo: Text
Palavras-chave: Banc d'Arguin; West Africa; Food web structure; Remote sensing; Stable isotope; Upwelling.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00269/37999/36078.pdf

Fish-length based indicators for improved management of the sardinella fisheries in Senegal
Provedor de dados: 5
Autores: Baldé, Bocar Sabaly; Fall, Massal; Kantoussan, Justin; Sow, Fambaye Ngom; Diouf, Malick; Brehmer, Patrice.
Fisheries management is difficult especially in developing countries where there are little or no data available for stock assessment. Here, a simple model based on the length-based Bayesian biomass (LBB) is applied to length frequencies collected on the two sardinella species (Sardinella maderensis and S. aurita) collected in Senegalese waters (2004 to 2014) to diagnose these stocks and to support the development of fishery management options that may improve the livelihoods of artisanal fishermen. Annual mean length of both species of sardinella showed a large variation during the decadal study period. It is assumed that such variations are due to environmental changes. According to our results, based on the current exploitation rate, both sardinella...
Tipo: Text
Palavras-chave: Data poor fisheries; Fisheries management; Shared stocks; Small scale fisheries; Small pelagic fish; West Africa.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00512/62318/67184.pdf

Competition or cooperation in transboundary fish stocks management: Insight from a dynamical model
Provedor de dados: 5
Autores: Nguyen-trong, Hieu; Brochier, Timothee; Auger, Pierre; Trinh, Viet Duoc; Brehmer, Patrice.
An idealized system of a shared fish stock associated with different exclusive economic zones (EEZ) is modelled. Parameters were estimated for the case of the small pelagic fisheries shared between Southern Morocco, Mauritania and the Senegambia. Two models of fishing effort distribution were explored. The first one considers independent national fisheries in each EEZ, with a cost per unit of fishing effort that depends on local fishery policy. The second one considers the case of a fully cooperative fishery performed by an international fleet freely moving across the borders. Both models are based on a set of six ordinary differential equations describing the time evolution of the fish biomass and the fishing effort. We take advantage of the two time...
Tipo: Text
Palavras-chave: Shared fish stock; Aggregation of variables; ODE; Pelagic; Fisheries management; West Africa.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00442/55310/72108.pdf

Climate and pelagic fisheries in the Canary and Guinea currents 1964-1993: The role of trade winds and the southern oscillation
Provedor de dados: 5
Autores: Binet, D.
Upwellings off the coasts of western Africa provide abundant but fluctuating marine resources. Sea surface temperature and wind stress, monitored by the ship-of-opportunity observation network, are compared to fishery statistics from 1964 onwards. In the Canary Current, off Sahara and Mauritania, upwellings are mostly wind driven. In the Guinea Current, off Cote d'Ivoire and Ghana, the link with local wind is very weak. In the southern Canary Current, two wind-intensification periods occurred in the early 1970s and from 1986 onwards. On each occasion, Sardina pilchardus landings were multiplied approximately threefold. During the first event, catches of species living at the periphery of the upwelling, Sardinella, Trachurus, Decapterus and Scomber,...
Tipo: Text
Palavras-chave: Pelagic fisheries; West Africa; Trade winds; Oceanic currents; Southern Oscillation.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00093/20390/18057.pdf

The PPEAO experimental fishing dataset: Fish from West African estuaries, lagoons and reservoirs
Provedor de dados: 5
Autores: Simier, Monique; Ecoutin, Jean-marc; Tito De Morais, Luis.
Background This paper describes a dataset of fish, crustacean and mollusc occurrences extracted from the “Experimental Fishing” section of the IRD's PPEAO information system. PPEAO stands for “Fish communities and artisanal fisheries of West African estuarine, lagoon and freshwater ecosystems”. This database contains information collected using two different methods: experimental fishing and surveys of the artisanal fisheries that exploit these ecosystems. The database is accessible at http://ppeao.ird.fr. New information The current dataset is available on GBIF.org at 10.15468/ra4voa. It comprises the occurrences of 314 fish, crustacean and mollusc taxa collected in experimental sampling surveys of different aquatic ecosystems in West Africa between 1979...
Tipo: Text
Palavras-chave: Coastal area; Crustacean; Estuary; Experimental fishing; Fish; Lagoon; Mollusc; Reservoir lake; Tropical area; West Africa.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00482/59324/62086.pdf

Leptochiton denhartogi, a new species of Polyplacophora (Mollusca) from Angola
Provedor de dados: 16
Autores: Strack, H.L.
Leptochiton denhartogi is described and compared with several closely related species.
Tipo: Article / Letter to the editor
Palavras-chave: Polyplacophora; Leptochitonidae; New species; Angola; West Africa; 42.73.
Ano: 2003
URL: http://www.repository.naturalis.nl/record/220572

Is sexual size dimorphism in relative head size correlated with intersexual dietary divergence in West African forest cobras, Naja melanoleuca?
Provedor de dados: 16
Autores: Luiselli, Luca; Akani, Godfrey C.; Corti, Claudia; Angelici, Francesco M.
Sex-biased differences in dietary habits of snakes are often linked to pronounced sexual size dimorphism in absolute body size or in relative head size. We studied the food habits of free-ranging forest cobras (Naja melanoleuca) in southern Nigeria to find whether any intersexual dietary divergence is present in this species, and measured both museum vouchers and freeranging specimens to find whether any intersexual divergence in relative head size is present. We demonstrated that: (1) head sizes increases more rapidly with SVL in females than in males, with a result that, at the same body length, the females tended to have significantly larger heads; (2) males and females were nearly identical in dietary habits, both if we consider prey size or prey type;...
Tipo: Article / Letter to the editor
Palavras-chave: Serpentes; Cobras; Naja melanoleuca; Dietary habits; Sexual size dimorphism; Ecology; West Africa.
Ano: 2002
URL: http://www.repository.naturalis.nl/record/534295

The type-locality of Pteronetta hartlaubii (Cassin, 1859) (Aves, Anatidae)
Provedor de dados: 16
Autores: Mees, G.F.
Currently, the type locality of Pteronetta hartlaubii is considered to be the Camma River, Gabon, but this is an error, and must be Rio Boutry, Gold Coast (now Ghana), where the holotype was obtained by H.S. Pel. In a note, reference is made to a few other specimens obtained by the collectors Pel and Nagtglas which in recent literature have been overlooked.
Tipo: Article / Letter to the editor
Palavras-chave: Anatidae; Pteronetta hartlaubii; Type locality; Gabon; Ghana; West Africa; 42.83.
Ano: 2003
URL: http://www.repository.naturalis.nl/record/220307

Palaemon vicinus spec. nov. (Crustacea: Decapoda: Palaemonidae), a new species of caridean shrimp from the tropical eastern Atlantic
Provedor de dados: 16
Autores: Ashelby, C.W.
A new species of Palaemon, P. vicinus spec. nov., is described from the tropical eastern Atlantic. The new species is very close to P. elegans Rathke, 1837, under which name it was previously recorded from West Africa. Palaemon vicinus spec. nov. is easily separated from P. elegans by possessing a small tooth on the fifth abdominal pleuron (quadrate in P. elegans) and by having 2-3 rows of setae in the grooming brush of the fifth pereiopod (4-5 in P. elegans). The discovery of the new species amongst material identified as P. elegans further highlights the need to reassess species level characters in the genus Palaemon.
Tipo: Article / Letter to the editor
Palavras-chave: Crustacea; Decapoda; Caridea; Palaemonidae; Palaemoninae; New species; West Africa; 42.74.
Ano: 2009
URL: http://www.repository.naturalis.nl/record/315880

A new species of the operculate land snail genus Maizaniella from Liberia (Gastropoda, Caenogastropoda)
Provedor de dados: 16
Autores: Winter, A.J. de.
Maizaniella sapoensis spec. nov. from Liberia is described. The species is provisionally att ributed to the subgenus Spirulozania. It is by far the smallest known member of the genus, with an adult shell diameter of just over 2 mm.
Tipo: Article / Letter to the editor
Palavras-chave: Mollusca; Gastropoda; Maizaniidae; Maizaniella; Spirulozania; West Africa; Liberia; Sapo National Park; 42.73.
Ano: 2009
URL: http://www.repository.naturalis.nl/record/311945

Eriosema arenicola stat. nov. and some notes on Eriosema glomeratum (Leguminosae-Papilionoideae) in West Africa
Provedor de dados: 16
Autores: Maesen, L.J.G. van der; Wieringa, J.J.
Eriosema arenicola deserves species status. Its nearest relatives are discussed and a key to distinguish the taxa is provided. Three maps depict the occurrence of the taxa.
Tipo: Article / Letter to the editor
Palavras-chave: Eriosema; Leguminosae-Papilionoideae; West Africa.
Ano: 2012
URL: http://www.repository.naturalis.nl/record/525905

Gulella adami, a new species of land snail from the Ivory Coast, West Africa (Gastropoda Pulmonata: Streptaxidae)
Provedor de dados: 16
Autores: Bruggen, A.C. van.
Gulella adami spec. nov. is described from a classical West African locality, Assini in the Ivory Coast (Côte d'Ivoire). It is most unusual in showing two superficial parietal processes, which may also be interpreted as a double angular lamella, in the aperture of the shell. The shell closely resembles that of various Enidae in SE Europe and adjoining areas around the Mediterranean, thereby providing a striking example of convergent evolution.
Tipo: Article / Letter to the editor
Palavras-chave: Gastropoda; Pulmonata; Streptaxidae; Gulella; New species; Enidae; Convergent evolution; Ivory Coast; West Africa; 42.73.
Ano: 1994
URL: http://www.repository.naturalis.nl/record/318885

Quelques genres de mollusques prosobranches marins inconnus ou peu connus de l'Afrique occidentale
Provedor de dados: 27
Autores: Adam, W.; Knudsen, J.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Taxonomy Prosobranchia Africa; West Africa.
Ano: 1969
URL: http://www.vliz.be/imisdocs/publications/294747.pdf

Sécurité alimentaire en Afrique de l’Ouest : Enjeux et Eléments Stratégique pour sa Réalisation.
Provedor de dados: 31
Autores: Dembele,   Niama Nango; Staatz,   John M.
The situation analysis and perspectives on food security West Africa shows a widening gap between the needs of consumption and nutrition and food availability at Global countries, households and individuals. Low gains productivity in food production and import capacity are the major constraints to the achievement of security Food in the region. The agricultural growth becomes the prerequisite for improving the food situation.
Tipo: Working or Discussion Paper
Palavras-chave: Food Security; West Africa; Agricultural and Food Policy; Community/Rural/Urban Development; Food Security and Poverty; International Development; International Relations/Trade; Marketing; Q18; Q17; Q13.
Ano: 2010
URL: http://purl.umn.edu/58546

EFFECTIVENESS OF BYLAWS IN THE MANAGEMENT OF NATURAL RESOURCES: The West African Experience
Provedor de dados: 31
Autores: Alinon,   Koffi; Kalinganire,   Antoine.
The role of various stakeholders in the management of natural resources is not clear in the West African countries. This paper discusses the historical changes in power delegation from central origins to peripheral institutions. The analysis covers the rise of bylaws across the Western African countries and links the multiplicity of bylaws to the amplification of the decentralization movement.   On the basis of a literature review and their own practitioners’ experiences, the authors demonstrate the pertinence of bylaws as a tool for better management of natural resources. In the West African Francophone context, bylaws could stand both for regulations enacted by decentralized authorities or “local conventions” binding village community groups. Where...
Tipo: Working or Discussion Paper
Palavras-chave: Bylaws; West Africa; Natural resource management; Decentralization; Resource /Energy Economics and Policy.
Ano: 2008
URL: http://purl.umn.edu/50892

Trading out of Poverty: WTO Agreements and the West African Agriculture. A Report of the Food Security II Cooperative Agreement
Provedor de dados: 31
Autores: Nouve,   Kofi; Staatz,   John M.; Schweikhardt,   David B.; Yade,   Mbaye.
This report is a brief survey of WTO agreements and their implications for the West African economies (including Chad). The study reviews the positions of West African countries on various WTO issues and compares these positions with positions expressed by major trade partners, particularly the Cairns Group, the European Union, Japan, Sub-Sahara Africa, and the United States.
Tipo: Report
Palavras-chave: Food security; Food policy; World trade organization; Poverty; West Africa; International trade; Market access; Food Security and Poverty; International Relations/Trade; Downloads July 2008-July 2009: 29; F0.
Ano: 2002
URL: http://purl.umn.edu/54573

Economic impacts of soil fertility management research in West Africa
Provedor de dados: 31
Autores: Akinola,   Adebayo A.; Alene,   Arega D.; Adeyemo,   Remi; Sanogo,   Diakalia; Olanrewaju,   Adetunji S.
This paper assesses the potential economic impacts of balanced nutrient management systems technology options: BNMS-manure, which combines inorganic fertilizer and organic manure, and BNMS-rotation, which is maize–soybean rotation, in maize-based systems in the northern Guinea savanna areas of Nigeria, Ghana, Togo and Benin. The economic surplus analysis suggested that BNMS-manure research and extension could achieve returns ranging from 17 to 25% and a maximum adoption of 24 to 48%, for the conservative and base scenario respectively; and that BNMS-rotation research and extension could achieve returns ranging from 35 to 43% and a maximum adoption of 20 to 40%, for the conservative and base scenario respectively. Our results were consistent with earlier...
Tipo: Journal Article
Palavras-chave: Balanced nutrient management systems; BNMS-manure; BNMS-rotation; Economic surplus; Northern Guinea savanna; West Africa; Crop Production/Industries; Research and Development/Tech Change/Emerging Technologies.
Ano: 2009
URL: http://purl.umn.edu/56932

Food sovereignty and agricultural trade policy commitments: How much leeway do West African nations have?
Provedor de dados: 31
Autores: Laroche Dupraz,   Catherine; Postolle,   Angele.
The 2008 food crisis has challenged the political legitimacy and economic efficiency of the liberalization of international agricultural trade. An alternative vision defended by the food sovereignty movement is that longterm food security cannot rely on dependency on food imports, but must be built on the development of domestic production with enough barrier protection to shelter it from world price fluctuations and unfair trading. The purpose of this paper is to look into whether the West African nations can achieve food sovereignty given their various trade commitments and other external constraints. The particularity of our approach is to combine a historical economic analysis with a political approach to food sovereignty and trade commitments. Our...
Tipo: Working or Discussion Paper
Palavras-chave: Food sovereignty; West Africa; Protection; Agricultural policy; WTO negotiations; Agricultural and Food Policy.
Ano: 2011
URL: http://purl.umn.edu/115439

Do U.S. Cotton Subsidies Affect Competing Exporters? An Analysis of Import Demand in China
Provedor de dados: 31
Autores: Muhammad,   Andrew; McPhail,   Lihong Lu; Kiawu,   James.
We estimate the demand for imported cotton in China and assess the competitiveness of cotton-exporting countries. Given the assertion that developing countries are negatively affected by U.S. cotton subsidies, our focus is the price competition between the United States and competing exporters (Benin, Burkina Faso, Chad, Mali, India, and Uzbekistan). We further project how U.S. programs affect China’s imports by country. Results indicate that if U.S. subsidies make other exporting countries worse off, this effect is lessened when global prices respond accordingly. If subsidies are eliminated, China’s cotton imports may not fully recover from the temporary spike in global prices.
Tipo: Article
Palavras-chave: China; Cotton; Import demand; Rotterdam model; Subsidies; United States; West Africa; International Relations/Trade; F17; Q11; Q17.
Ano: 2012
URL: http://purl.umn.edu/123786

THE IMPACT OF HOUSEHOLD-LEVEL DETERMINANTS OF CHILD HEALTH AND NUTRITION: CROSS-COUNTRY EVIDENCE FROM WEST AFRICA
Provedor de dados: 31
Autores: Penders,   Christopher L.; Staatz,   John M.
Poor child health and nutrition persist throughout West Africa.  This research analyzes the impact of key economic variables, including income, education and background characteristics, on child health and nutrition across nine different countries.  The results are interpreted in the context of differing levels of economic development among these nations.  The findings do not show wealth and parental education to be robust across the sample, but maternal background characteristics have a positive, statistically significant and highly consistent effect across all the countries.  The importance of mothers' height does not simply represent a genetic influence, but can be interpreted to signify that women with a healthier upbringing, and hence taller, have...
Tipo: Conference Paper or Presentation
Palavras-chave: West Africa; Economic Development; Health; Nutrition; Food Consumption/Nutrition/Food Safety; Health Economics and Policy.
Ano: 2001
URL: http://purl.umn.edu/20586

A Hedonic Analysis of Cattle Prices in the Central Corridor of West Africa: Implications for Production and Marketing Decisions
Provedor de dados: 31
Autores: Williams,   Timothy O.; Okike,   Iheanacho; Spycher,   Ben.
Detailed weekly sales transactions data for the period January 2000-June 2001 from three frontier markets in the central corridor of West Africa were analyzed to identify the factors influencing short-run, intra-year cattle prices. The empirical results indicate that in addition to market location and seasonality of supply and sales, market participants show systemic preferences for specific cattle attributes (sex, weight, condition and finish) and are willing to pay premium prices consistent with their preferences. Communicating this information to producers can assist them to tailor their production and marketing decisions to meet market expectations and thereby improve their competitiveness, profitability and intra-regional livestock trade. Innovative...
Tipo: Conference Paper or Presentation
Palavras-chave: Livestock markets; Hedonic price model; Market information; West Africa; Livestock Production/Industries; C21; D4; Q13; Q17.
Ano: 2006
URL: http://purl.umn.edu/25423

Faciliter l’adoption d’interventions de securite alimentaire dans le secteur des aliments de rue et dans les champs
Provedor de dados: 31
Autores: Karg,   Hanna; Drechsel,   Pay; Amoah,   Philip; Jeitler,   Regina.
This chapter discusses the implementation challenges of the WHO Guidelines on safe wastewater use pertaining to the adoption of the so-called ‘post-treatment’ or ‘non-treatment’ options, like safer irrigation practices or appropriate vegetablewashing in kitchens. Due to limited risk awareness and immediate benefits of wastewater irrigation, it is unlikely that a broad adoption of recommended practices will automatically follow revised policies or any educational campaign and training. Most of the recommended practices do not only require behaviourchange but might also increase operational costs. In such a situation, significant efforts are required to explore how conventional and/or social marketing can support the desired behaviour-change towards the...
Tipo: Book
Palavras-chave: Food safety; Restaurants; Public health; Social behaviour; Wastewater irrigation; Vegetables; Guidelines; West Africa; Ghana; Agricultural and Food Policy; Crop Production/Industries; Food Consumption/Nutrition/Food Safety; Food Security and Poverty; Health Economics and Policy.
Ano: 2011
URL: http://purl.umn.edu/124376

ARE WEALTH TRANSFERS BIASED AGAINST GIRLS? GENDER DIFFERENCES IN LAND INHERITANCE AND SCHOOLING INVESTMENT IN GHANA'S WESTERN REGION
Provedor de dados: 31
Autores: Quisumbing,   Agnes R.; Payongayong,   Ellen M.; Otsuka,   Keijiro.
This study attempts to analyze changing patterns of land transfers and schooling investments by gender over three generations in customary land areas of Ghana's Western Region. Although traditional matrilineal inheritance rules deny landownership rights to women, women have increasingly acquired land through gifts and other means, thereby reducing the gender gap in landownership. The gender gap in schooling has also declined significantly, though it persists. We attribute such changes to the increase in women's bargaining power due to an agricultural technology that increased the demand for women's labor, contributing to the reduction of "social" discrimination as well as weak "parental" discrimination.
Tipo: Working or Discussion Paper
Palavras-chave: Property rights; Land inheritance; Agricultural growth; West Africa; Africa south of Sahara; Wealth transfers; Gender; Ghana; Education; Labor and Human Capital.
Ano: 2004
URL: http://purl.umn.edu/60311

Drivers and Modifiers of Lowland Use in West Africa
Provedor de dados: 31
Autores: Erenstein,   Olaf.
Lowland development efforts in West Africa have a mixed record. The paper posits that this is due to the neglect of: (1) market opportunity as driving force for lowland use; and (2) the wider context within which lowlands are used as important modifier. The paper applies a regression-based decomposition framework to analyze the factors driving and modifying lowland use in West Africa. It uses community-level data from 1014 geo-referenced lowland units around four urban centers along an agro-ecological gradient in Cote d'Ivoire and Mali. Tobit models are used to explain the extent of lowland non-use (seasonal fallow), its diversity (in terms of rice and other crop cultivation) and its land use intensity (double cropping). Results highlight that proximity to...
Tipo: Conference Paper or Presentation
Palavras-chave: Urban - rural linkages; Market access; Agro-ecological gradient; West Africa; Lowland use; Peri-urban agriculture; O18; O3; Q15; Land Economics/Use.
Ano: 2006
URL: http://purl.umn.edu/25288

Agricultural Value Chain Development in West Africa – Methodological framework and case study of mango in Benin
Provedor de dados: 31
Autores: van Melle,   Cathelijne; Coulibaly,   Ousmane; Hell,   Kerstin.
Globalization and competitiveness of agricultural commodities could have significant potential benefits for food security and poverty reduction in West Africa. Participation in global trade and economy is potentially important but not enough to ensure benefits at all levels of the chains and equitable distribution of income for each participant. Efficiency is key in the commodity value chain, but effective support functions and services, infrastructure, legal and policy environment are important. This paper presents the framework of value chain concept and analysis, as a guide to enhance competitiveness of commodities at national, regional or global level. The paper applies the value chain framework to a case study on mango in Benin, West Africa. The...
Tipo: Conference Paper or Presentation
Palavras-chave: Benin; Mango; Value chain; West Africa; Agribusiness; Agricultural and Food Policy; Community/Rural/Urban Development; Crop Production/Industries; Demand and Price Analysis; Environmental Economics and Policy; Food Consumption/Nutrition/Food Safety; Food Security and Poverty; Institutional and Behavioral Economics; International Development; International Relations/Trade; Marketing; Productivity Analysis; Research and Development/Tech Change/Emerging Technologies.
Ano: 2008
URL: http://purl.umn.edu/51994

Fiscal Reform and Monetary Union in West Africa
Provedor de dados: 31
Autores: Hefeker,   Carsten.
The paper explores the interaction between the proposed monetary union for ECOWAS and structural reforms of fiscal policy. The effects depend to a large extent on the degree of similarity of member countries. In a monetary union of similar countries, member states run a more distortive fiscal policy, while their structural reform efforts will fall. This is also the case for countries that unilaterally peg to an anchor currency or introduce a foreign currency. In an monetary union with dissimilar countries the reverse can happen for those member states that are confronted with high distortion countries. This result implies that current WAEMU members will run a less distortive fiscal policy after the inclusion of other members of ECOWAS.
Tipo: Working or Discussion Paper
Palavras-chave: West Africa; Monetary union; Fiscal policy; Structural reforms; Financial Economics; F33; E61; E63.
Ano: 2003
URL: http://purl.umn.edu/26257

Eude sur : identification des besoins d’information des operateurs économiques pour le développement des échanges en Afrique de l’ouest. rapport de synthèse
Provedor de dados: 31
Reports (in French) on Stakeholders' Market Information Needs to Engage in Regional Trade. West Africa synthesis report.
Tipo: Working or Discussion Paper
Palavras-chave: Market information; West Africa; Agriculture; Food security; Trade; Agricultural and Food Policy; Food Security and Poverty; International Relations/Trade; Marketing; Q17.
Ano: 2008
URL: http://purl.umn.edu/57267

A HEDONIC MODEL OF RICE TRAITS: ECONOMIC VALUES FROM FARMERS IN WEST AFRICA
Provedor de dados: 31
Autores: Dalton,   Timothy J.
New crop varieties often have been promoted in developing countries based upon superior yield vis-a-vis locally available varieties.  This research presents a hedonic model for upland rice by drawing upon the input characteristics and consumer good characteristics model literature.  Model specification tests determine that a combination of production and consumption characteristics best explains the willingness to pay for new upland rice varieties.  This non-separable household model specification determined that four traits explain the willingness to pay for new rice varieties: plant cycle length, plant height, grain elongation/swelling and tenderness.  Yield was not significant explanatory variable for the willingness to pay for seed.  The implications...
Tipo: Conference Paper or Presentation
Palavras-chave: Hedonic; Upland rice; West Africa; Household modelling; Crop Production/Industries.
Ano: 2003
URL: http://purl.umn.edu/25804

The Economic Impact and the Distribution of Benefits and Risk from the Adoption of Insect Resistant (Bt)  Cotton in West Africa
Provedor de dados: 31
Autores: Falck-Zepeda,   Jose Benjamin; Horna,   J. Daniela; Smale,   Melinda.
Cotton is the largest source of export receipts of several West African countries. Statistics however show a decreasing tendency in cotton yields and an increasing tendency in pesticide use. Under this circumstances there appear to be potential payoffs from the use of biotechnology products in the farming systems of the region. In this study we estimate different scenarios for the potential deployment of insect resistant cotton in selected countries in West Africa (WA). We use an economic surplus model augmented with a more rigorous sensitivity analysis of model parameters. Hypothetical scenarios of Bt cotton adoption in WA are simulated and single point values of model parameters are substituted with probability distributions. The scenarios include: no...
Tipo: Working or Discussion Paper
Palavras-chave: Bt cotton; West Africa; Economic surplus; Risk; Probability distributions; Impact assessment; Net benefits; Crop Production/Industries.
Ano: 2007
URL: http://purl.umn.edu/42395

Staple Food Market Sheds in West Africa
Provedor de dados: 31
Autores: Haggblade,   Steven; Longabaugh,   Steven; Boughton,   Duncan; Dembele,   Niama Nango; Diallo,   Boubacar Cisse; Staatz,   John M.; Tschirley,   David L.
This paper aims to identify the geographic extent of major staple food market sheds in West Africa as well as the major trade corridors that link surplus producing areas with the deficit markets they serve. The method employed combines data on the spatial distribution of rural and urban population, maps of differing food staple zones, crop production data and consumption patterns as described in an array of recent household surveys to map major urban food markets as well as principal surplus production zones. Expert knowledge from traders and other market monitors in the region enable the authors to identify the major commodity flows linking the markets with their major supply zones. These efforts aim to summarize a large volume of information simply and...
Tipo: Working Paper
Palavras-chave: West Africa; Food markets; Marketing.
Ano: 2012
URL: http://purl.umn.edu/121866

Approche méthodologique. Analyse de la compétitivité et l'évolution des avantages comparatifs dans la sous-région.
Provedor de dados: 31
Autores: Diallo,   Boubacar Cisse; Crawford,   Eric W.; Dembele,   Niama Nango.
Tipo: Working or Discussion Paper
Palavras-chave: Mali; Food security; Rice; Maize; West Africa; Competivity; Agricultural and Food Policy; Community/Rural/Urban Development; Demand and Price Analysis; Food Security and Poverty; International Development; International Relations/Trade; Q12; Q18; Q17; Q13.
Ano: 2009
URL: http://purl.umn.edu/58550

A plot of one's own: gender relations and irrigated land allocation policies in Burkina Faso
Provedor de dados: 31
Autores: Zwarteveen,   Margreet Z.
Discusses the potential opportunities and pitfalls of introducing market forces into the process of water allocation. Proposes several preconditions for beneficial privatization of water allocation and argues for a more sophisticated form of analysis than that generally allowed by proponents of basic needs or of free market approaches.
Tipo: Report
Palavras-chave: Women in development; Gender; Land use; Land management; Policy; Female labor; Households; Irrigated farming; Social impact; West Africa; Burkina Faso; Dakiri; Agribusiness; Agricultural and Food Policy; Community/Rural/Urban Development; Consumer/Household Economics; Crop Production/Industries; Farm Management; Food Consumption/Nutrition/Food Safety; Food Security and Poverty; Land Economics/Use; Political Economy; Productivity Analysis; Resource /Energy Economics and Policy; Risk and Uncertainty.
Ano: 1996
URL: http://purl.umn.edu/61114

Betting on cotton: Potential payoffs and economic risks of adopting transgenic cotton in West Africa
Provedor de dados: 31
Autores: Falck-Zepeda,   Jose Benjamin; Horna,   J. Daniela; Smale,   Melinda.
Cotton is the largest source of export receipts in several West African nations where yields are declining and pesticide use is rising. Although there may be payoffs to introducing genetically modified Bt (Bacillus thurigiensis) cotton, limited information is available to predict its potential economic impact and there is uncertainty about its performance. Recognizing these constraints, we use an economic surplus model augmented with stochastic simulation to estimate ex ante the impact and distribution of benefits from Bt cotton. We consider the effects of adoption on both yields and abating crop damage, and offer scenarios depicting the policy options faced by West African stakeholders. The findings indicate that although the total net benefits of...
Tipo: Journal Article
Palavras-chave: Crop biotechnology; Bt cotton; Economic surplus model; West Africa; Agricultural development; Risk; Crop Production/Industries.
Ano: 2008
URL: http://purl.umn.edu/56962

Taking a New Look at Empirical Models of Adoption: Average Treatment Effect Estimation of Adoption Rates and their Determinants
Provedor de dados: 31
Autores: Diagne,   Aliou.
This paper shows that the observed sample adoption rate does not consistently estimate the population adoption rate even if the sample is random. It is proved that instead the sample adoption rate is a consistent estimate of the population joint exposure and adoption rate, which does not inform about adoption per se. Likewise, it is shown that a model of adoption with observed adoption outcome as dependent variable and where exposure to the technology is not observed and controlled for cannot yield consistent estimates of the determinants of adoption. Such model can at best provide consistent estimates of the effects of the included explanatory variables on joint exposure and adoption. Even for that to be possible, the model must be explicitly specified as...
Tipo: Conference Paper or Presentation
Palavras-chave: Technology Adoption; Rice; NERICA; West Africa; Average Treatment Effect; Research and Development/Tech Change/Emerging Technologies; C8; O3; Q12; Q16; Q55.
Ano: 2006
URL: http://purl.umn.edu/25623

Conflicts, Rural Development and Food Security in West Africa
Provedor de dados: 31
Autores: Flores,   Margarita.
This paper examines food security in the context of conflict in West Africa. The analysis developed in the paper recognises the importance of defining conflict type and the trends in conflict so that conflict and post-conflict policies may be implemented. The relationship between food security and conflict is analysed. Whilst conflict exacerbates food security, food insecurity can itself fuel conflict. Strategies designed to assist in post-war rehabilitation need to address key dimensions of food security: availability, access and stability. It is argued in this paper, that consideration of these three dimensions are necessary joint conditions in moving towards a reduction in the numbers of hungry. The cases of Sierra Leone and Liberia are examined to...
Tipo: Working or Discussion Paper
Palavras-chave: West Africa; Conflict; Food Security; Crisis; Hunger; Food Security and Poverty; N47; N57; O13; O18.
Ano: 2004
URL: http://purl.umn.edu/23811

Assessing potential impact of avian influenza on poultry in West Africa: a spatial equilibrium model analysis
Provedor de dados: 31
Autores: You,   Liangzhi; Diao,   Xinshen.
In this paper, the authors analyze the potential economic impacts of avian influenza (AI) in West Africa, taking Nigeria as an example. They find that, depending on the size of the affected areas, the direct impact of the spread of AI along the two major migratory bird flyways would be the loss of about 4 percent of national chicken production. However, the indirect effect-consumers’ reluctance to consume poultry if AI is detected, causing a decline in chicken prices-is generally larger than the direct effect. The study estimates that Nigerian chicken production would fall by 21 percent and chicken farmers would lose US$250 million of revenue if the worst-case scenario occurred. The negative impact of AI would be unevenly distributed in the country, and...
Tipo: Report
Palavras-chave: Avian influenza; Spatial equilibrium model simulation; West Africa; Nigeria; Livestock Production/Industries.
Ano: 2006
URL: http://purl.umn.edu/55399

Regional Biotechnology Regulations: Design Options and Implications for Good Governance
Provedor de dados: 31
Autores: Birner,   Regina; Linacre,   Nicholas A.
Many developing countries are currently in the process of designing regulatory systems that should allow them to use genetically modified organisms (GMOs) for agricultural development, while also managing the food safety and environmental risks potentially associated with these technologies. Various regions of the developing world are seeking to establish regional systems of biotechnology regulation. However, considerable costs are associated with biotechnology regulation, and biosafety specialists are scarce. In addition, there is no consistent understanding of how regional systems of biotechnology regulation can be designed to be effective and efficient, while also fulfilling the principles of good governance, such as transparency, voice and...
Tipo: Working or Discussion Paper
Palavras-chave: Regional biotechnology regulation; Regulatory federalism; Transaction cost economics; West Africa; European Union; Research and Development/Tech Change/Emerging Technologies.
Ano: 2008
URL: http://purl.umn.edu/42346

Perspectives d’évolution des marches céréaliers pour la campagne de commercialisation 2005/06
Provedor de dados: 31
Autores: Diarra,   Salifou Bakary; Dembele,   Niama Nango.
The 2005 – 2006 marketing campaign was difficult because of the drought that occurred in all countries in the region. As a result, the price of sorghum, millet, maize and rice soared. State actions to improve cereals supply through tax-exempt rice imports did not achieve the expected outcomes. Rice has been the main contributing factor to the rise of cereals price. The low levels of stocks of rice in the world and the supply in fertilizers below expectations along with a decrease in productivity have contributed to the rise of rice prices at the national level.
Tipo: Working or Discussion Paper
Palavras-chave: Cereal markets; Food security; Mali; West Africa; Prices; Agricultural and Food Policy; Consumer/Household Economics; Food Security and Poverty; Q11; Q12; Q13.
Ano: 2006
URL: http://purl.umn.edu/57142

The Role of Credit Access in Improving Cocoa Production in West African Countries
Provedor de dados: 31
Autores: Nyemeck,   J.B.; Gockowski,   James; Nkamleu,   Guy Blaise.
This study uses survey data to examine the role of access to credit on cocoa production, in West African cocoa production countries under conditions of agricultural policy liberalization. The study specifies and estimates econometric models to simulate the counterfactual of what cocoa production would be in the absence of credit facilities. The survey results show that about 54% of cocoa farmers have access to credit in Nigeria, and respectively 37% in Cameroon, while in Ghana and Côte d’Ivoire only a few cocoa farmers have access to credit. We find that the cocoa farmer’s capacity such as, the cocoa farm size, and the mutuality status of the farmer are more important as a determinants of cocoa farmers access to credit as well as another set of variables...
Tipo: Conference Paper or Presentation
Palavras-chave: Credit; Cocoa; Farmer; West Africa; Agricultural and Food Policy; Agricultural Finance; Environmental Economics and Policy; Farm Management; Food Consumption/Nutrition/Food Safety; Food Security and Poverty; International Relations/Trade; Labor and Human Capital; Marketing; Productivity Analysis; Research and Development/Tech Change/Emerging Technologies.
Ano: 2008
URL: http://purl.umn.edu/52095

Cashew cultivation in Guinea-Bissau – risks and challenges of the success of a cash crop
Provedor de dados: 63
Autores: Catarino,Luís; Menezes,Yusufo; Sardinha,Raul.
In recent decades a boom in cashew (Anacardium occidentale)cultivation has taken place in Guinea-Bissau, leading to the replacement of traditional slash-and-burn agriculture by a cash crop. As a result, the country is currently one of the world’s largest producers of raw cashew nuts and the cashew sector has acquired enormous importance in Guinea-Bissau’s economy. Changes induced by the cashew boom at social and environmental levels are yet to be analyzed and understood. The present study provides an account of the process of cashew expansion in Guinea-Bissau, reviews the current situation and discusses its future prospects. The cashew tree was introduced into the country by the Portuguese in the XIXth century, but only effectively expanded in the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: West Africa; Agroforestry systems; Cashew nut; Tree crops.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162015000500459

First record of Macrostemum alienum Ulmer 1907 (Trichoptera: Hydropsychidae: Macronematinae) from Ile-Ife, Southwestern Nigeria, West Africa
Provedor de dados: 49
Autores: Ogbogu,Sylvester Sunday; Adu,Williams Babasola.
Macrostemum alienum Ulmer, 1907, was collected in Ile-Ife, Southwestern Nigeria and is reported for the first time. The implication of this as regards the geographical distribution of this species is discussed.
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Macrostemum alienum; Larva; Trichoptera Hydropsychidae; Macronematinae; Nigeria; West Africa.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032006000300016