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| Registros recuperados: 31 | |
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| Brochier, Timothee; Auger, Pierre-amael; Pecquerie, Laure; Machu, Eric; Capet, Xavier; Thiaw, Modou; Mbaye, Baye Cheikh; Braham, Cheikh-baye; Ettahiri, Omar; Charouki, Najib; Sene, Ousseynou Ndaw; Werner, Francisco; Brehmer, Patrice. |
| Small pelagic fish (SPF) species are heavily exploited in eastern boundary upwelling systems (EBUS) as their transformation products are increasingly used in the world food chain. Management relies on regular monitoring, but there is a lack of robust theories for the emergence of the populations’ traits and their evolution in highly variable environments. This work aims to address existing knowledge gaps by combining physical and biogeochemical modelling with an individual life-cycle based model applied to round sardinella (Sardinella aurita) off northwest Africa, a key species for regional food security. Our approach focused on the processes responsible for seasonal migrations, spatio-temporal size-structure, and interannual biomass fluctuations.... |
| Tipo: Text |
Palavras-chave: Small pelagic fish; Sardinella aurita; Fish migration; Eastern boundary upwelling system; Individual based biophysical models; Dynamic energy budget. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00433/54433/56088.pdf |
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| Ndiaye, Ndeye Aida; Maiguizo-diagne, Halima; Diadhiou, Hamet Diaw; Ndiaye, Waly Ndianco; Diedhiou, Fulgence; Cournac, Laurent; Gaye, Mohamed Lamine; Fall, Saliou; Brehmer, Patrice. |
| he fisheries sector, particularly aquaculture, is a fundamental source of nutrition for humans, particularly in developing countries. The modern development of fish farming requires energy for production systems. This study investigates the potential of using organic wastes derived from fish fattening to produce on‐farm energy through the process of methanization. Oreochromis niloticus faeces methanogen potential was determined with (IFF) and without (UIFF) methanizer microbial inoculum. At the end of the manure methanation trials, the resulting digestates were tested as organic fertilizers for agriculture. The tests showed that inoculated fish faeces had faster biogas kinetics production compared with uninoculated fish faeces. In both cases, the produced... |
| Tipo: Text |
Palavras-chave: Biogas; Digests; Energy recovery; Fish faeces; Methanation; Sustainable science. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00588/70033/70230.pdf |
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| Kouame Kanga, Désiré; Kouassi Aka, Marcel; Trokourey, Albert; Toualy, Elisée; N’guessan, Benjamin K.; Brehmer, Patrice; Ostrowski, Marek. |
| The spatial and seasonal variability of the mixed layer depth (MLD) was studied using hydrological data from several databases collected over the period October 1973 to March 2017 at 10 °W between latitudes 2 °N and 10 °S in the Gulf of Guinea. The density threshold method with 0.03 kg m-3 criterion was used to calculate the MLD. In the equatorial band, the seasonal average MLD is 20 m whatever the season. At 6 °S and 10 °S, the MLD is relatively higher during the cold season. The MLD varies between 21 and 37 m at 6 °S, and the seasonal averages MLD are 21 and 40 m respectively during the hot and cold seasons. At 10 °S, during the hot season, the MLD varies between 28 and 52 m and the seasonal average is 39.5 m. During the cold season, the MLD varies... |
| Tipo: Text |
Palavras-chave: Atlantic Ocean; Gulf of Guinea; Mixed Layer; Spatial Variability; Seasonal Variability.. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00684/79619/82344.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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| Brehmer, Patrice; Sancho, Gorka; Trygonis, Vasilis; Itano, David; Dalen, John; Fuchs, Ariel; Faraj, Abdelmalek; Taquet, Marc. |
| This work presents a methodological synthesis for the in situ monitoring of fish aggregating devices (FADs) using a combination of optical, echosounder and SCUBA observations conducted in the vicinity of drifting FADs. The acoustic methods allowed, according to the devices used, the description of the spatial organisation and dynamics of biotic scattering layers, individual fishes, schools, shoals and mammals, while visual, photographic and video observations permitted species identification within a range of 0 to ~ 25 m. Based on these results, we elaborate on the interest to combine acoustic and visual methods, and present an autonomous instrumented drifting buoy for remotely monitoring fish diversity and abundance in the pelagic ecosystems. The... |
| Tipo: Text |
Palavras-chave: Optical; Census; Acoustics; Buoy; Seaorbiter; Biomonitoring; Conservation; Environmental monitoring; Fish; Pelagic. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00461/57252/59265.pdf |
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| Ba, Kamarel; Thiaw, Modou; Lazar, Najih; Sarr, Alassane; Brochier, Timothee; Ndiaye, Ismaila; Faye, Alioune; Sadio, Oumar; Panfili, Jacques; Thiaw, Omar Thiom; Brehmer, Patrice. |
| The stock of the Senegalese flat sardinella, Sardinella maderensis, is highly exploited in Senegal, West Africa. Its growth and reproduction parameters are key biological indicators for improving fisheries management. This study reviewed these parameters using landing data from small-scale fisheries in Senegal and literature information dated back more than 25 years. Age was estimated using length-frequency data to calculate growth parameters and assess the growth performance index. With global climate change there has been an increase in the average sea surface temperature along the Senegalese coast but the length-weight parameters, sex ratio, size at first sexual maturity, period of reproduction and condition factor of S. maderensis have not changed... |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00616/72851/72887.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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| Diogoul, Ndague; Brehmer, Patrice; Demarcq, Herve; El Ayoubi, Salaheddine; Thiam, Abou; Sarre, Abdoulaye; Mouget, Anne; Perrot, Yannick. |
| The resistance of an east border upwelling system was investigated using relative index of marine pelagic biomass estimates under a changing environment spanning 20-years in the strongly exploited southern Canary Current Large marine Ecosystem (sCCLME). We divided the sCCLME in two parts (north and south of Cap Blanc), based on oceanographic regimes. We delineated two size-based groups (“plankton” and “pelagic fish”) corresponding to lower and higher trophic levels, respectively. Over the 20-year period, all spatial remote sensing environmental variables increased significantly, except in the area south of Cap Blanc where sea surface Chlorophyll-a concentrations declined and the upwelling favorable wind was stable. Relative index of marine pelagic... |
| Tipo: Text |
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| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00676/78789/81019.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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| Diogoul, Ndague; Brehmer, Patrice; Perrot, Yannick; Tiedemann, Maik; Abou Thiam,; El Ayoubi, Salaheddine; Mouget, Anne; Migayrou, Chloe; Sadio, Oumar; Sarre, Abdoulaye. |
| Understanding the relationship between sound-scattering layers (SSLs) and pelagic habitat characteristics is a substantial step to apprehend ecosystem dynamics SSLs are detected on echo sounders representing aggregated marine pelagic organisms. In this study, SSL characteristics of zooplankton and micronekton were identified during an upwelling event in two contrasting areas of the Senegalese continental shelf. Here a cold upwelling-influenced inshore area was sharply separated by a strong thermal boundary from a deeper, warmer, stratified offshore area. Mean SSL thickness and SSL vertical depth increased with the shelf depth. The thickest and deepest SSLs were observed in the offshore part of the shelf. Hence, zooplankton and micronekton seem to occur... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00606/71777/70261.pdf |
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| Brehmer, Patrice; Thang Do Chi,; Laugier, Thierry; Galgani, Francois; Laloe, Francis; Darnaude, Audrey M.; Fiandrino, Annie; Mouillot, David. |
| 1. Abiotic and biotic variables of coastal lagoons are highly heterogeneous in both space and time, and this heterogeneity complicates the assessment of their ecological status. These variables are essential to the monitoring and preservation of these fragile ecotones and the resources and services they sustain. 2. An integrative approach for evaluating the ecological status of coastal lagoons, based on field investigations of the key parameters driving their functioning and a set of selected ecological indicators matching lagoon management information needs for societal benefits, is investigated. Consistency in lagoon status evaluation from multiple and different variables was estimated, through a case study comparing three adjacent yet contrasting French... |
| Tipo: Text |
Palavras-chave: Coastal lagoon; Ecological assessment; Ecotoxicology; Eutrophication; Indicator; Management; Mediterranean Sea; Observatory. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00056/16702/14202.pdf |
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| Guillard, Jean; Brehmer, Patrice; Colon, Michel; Guennegan, Yvon. |
| Fish schools are aggregative structures encountered in all types of aquatic environments but have as yet been little studied in freshwaters except at small spatial scales. This study represents the three dimensional description of juvenile fish schools (Perca fluviatilis and Rutilus rutilus) in a lake environment using high resolution multibeam sonar system operating at a frequency of 455 kHz, composed of 60 beams of 1.5 degrees allowing a 90 degrees observation plane. The in situ diurnal schooling behaviour of young-of-the-year fish of both species is confirmed. The morphological, energetic and spatial variables of these schools are described and related to one another. The structures described are of the same order of magnitude as those described in the... |
| Tipo: Text |
Palavras-chave: Annecy Lake; Rutilus rutilus; Perca fluviatilis; Sonar; 3 D structure; Shoaling behaviour. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1661.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: 31 | |
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