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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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| Diankha, Ousmane; Demarcq, Herve; Fall, Massal; Thiao, Djiga; Thiaw, Modou; Sow, Bamol Ali; Gaye, Amadou Thierno; Brehmer, Patrice. |
| This study investigated variations of landings of two key species, Sardinella aurita and Sardinella maderensis, in Senegalese waters over a ten-year period (2004-2013). Using generalized additive models, it was found that fishing gear played a major role in explaining differences in monthly landings for both species (51-71% deviance explained). Its effect was more significant in the southern part of Senegal. Fishing effort (number of trips) accounted only for 4-18% of variability in landings. Purse seine (PS) fishing was the most important contributor to the landings of both species. In addition, in the southern area, surrounding gillnet fishing was also important for S. maderensis. Modeling results showed that the relationship between monthly effort and... |
| Tipo: Text |
Palavras-chave: Effects of fishing; Generalized additive model; Sardinella aurita; Sardinella maderensis; Purse seine; Surrounding gillnet; Senegal. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00616/72808/72585.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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| Le Croizier, Gael; Schaal, Gauthier; Gallon, Regis; Fall, Massal; Le Grand, Fabienne; Munaron, Jean-marie; Rouget, Marie-laure; Machu, Eric; Le Loc'H, Francois; Lae, Raymond; De Morais, Luis Tito. |
| The link between trophic ecology and metal accumulation in marine fish species was investigated through a multi-tracers approach combining fatty acid (FA) and stable isotope (SI) analyses on fish from two contrasted sites on the coast of Senegal, one subjected to anthropogenic metal effluents and another one less impacted. The concentrations of thirteen trace metal elements (As, Cd, Co, Cr, Cu, Fe, Li, Mn, Ni, Pb, Sn, U, and Zn) were measured in fish liver. Individuals from each site were classified into three distinct groups according to their liver FA and muscle SI compositions. Trace element concentrations were tested between groups revealing that bioaccumulation of several metals was clearly dependent on the trophic guild of fish. Furthermore,... |
| Tipo: Text |
Palavras-chave: Trace elements; Biochemical tracers; Diet; Contamination; Senegal; Tropical fish. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00348/45908/45707.pdf |
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| Le Croizier, Gael; Schaal, Gauthier; Point, David; Le Loc'H, Francois; Machu, Eric; Fall, Massal; Munaron, Jean-marie; Boye, Aurelien; Walter, Pierre; Lae, Raymond; De Morais, Luis Tito. |
| Bioaccumulation of toxic metal elements including mercury (Hg) can be highly variable in marine fish species. Metal concentration is influenced by various species-specific physiological and ecological traits, including individual diet composition and foraging habitat. The impact of trophic ecology and habitat preference on Hg accumulation was analyzed through total Hg concentration and stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) analyses in the muscle of 132 fish belonging to 23 different species from the Senegalese coast (West Africa), where the marine ecosystem is submitted to nutrients inputs from various sources such as upwelling or rivers. Species-specific ecological traits were first investigated and results showed that vertical (i.e.... |
| Tipo: Text |
Palavras-chave: Methylmercury sources; Trophic ecology; Feeding habitat; Metal bioaccumulation; Chemical tracers; Isotopic niche. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00458/57013/58912.pdf |
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| Institut de Recherche pour le Développement, Paris (France); Fall, Massal. |
| Français - Les traits essentiels de la côte sénégalaise, repères historiques de la pêche, communautés de pêcheurs, caractéristiques des flottes et modes d’accès à la ressource et d’interaction sont analysés. Les caractéristiques, tendances décroissantes de l’abondance,niveaux d’exploitation, mesures d’aménagement, relations interspécifiques, changements potentiels et sources de variation des stocks démersaux côtiers sont précisés. Les notions de tactiques et stratégies de pêche sont passées en revue, conceptualisées puis étudiées.Le modèle «Dynamique Conjointe Exploitation Ressource» utilisé repose sur la définition de 4 typologies. L’utilisation de méthodes de classification et de connaissances d’experts conduit à considérer 32 stocks, 31 strates, 82... |
| Tipo: Theses and Dissertations |
Palavras-chave: Fisheries; Demersal fisheries; Modelling; Stocks; Ecosystems; Community fishing; Inland waters; Marine water; Hydrologic cycle; Fishermen; Fishing fleet; Shrimp fisheries; Capture fisheries; Fisheries management; Trawling; Artisanal fishing; Fishing licenses. |
| Ano: 2009 |
URL: http://hdl.handle.net/1834/5004 |
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