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| Registros recuperados: 31 | |
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| Wang, Zhaohui Aleck; Moustahfid, Hassan; Mueller, Amy V.; Michel, Anna Pm; Mowlem, Matthew; Glazer, Brian T.; Mooney, T. Aran; Michaels, William; Mcquillan, Jonathan S.; Robidart, Julie C.; Churchill, James; Sourisseau, Marc; Daniel, Anne; Schaap, Allison; Monk, Sam; Friedman, Kim; Brehmer, Patrice. |
| Advancing our understanding of ocean biogeochemistry, biology, and ecosystems relies on the ability to make observations both in the ocean and at the critical boundaries between the ocean and other earth systems at relevant spatial and temporal scales. After decades of advancement in ocean observing technologies, one of the key remaining challenges is how to cost-effectively make measurements at the increased resolution necessary for illuminating complex system processes and rapidly evolving changes. In recent years, biogeochemical in situ sensors have been emerging that are threefold or more lower in cost than established technologies; the cost reduction for many biological in situ sensors has also been significant, although the absolute costs are still... |
| Tipo: Text |
Palavras-chave: In situ; Sensor; OceanObs; Ocean technology; EOVs; Biogeochemistry; Biology; Cost effective. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00514/62567/66921.pdf |
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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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| 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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| Brehmer, Patrice; Laugier, Thierry; Kantoussan, J.; Galgani, Francois; Mouillot, D.. |
| Ensuring the sustainability of fish resources necessitates understanding their interaction with coastal habitats, which is becoming ever more challenging in the context of ever increasing anthropogenic pressures. The ability of coastal lagoons, exposed to major sources of disturbance, to provide resources and suitable habitats for growth and survival of juvenile fish is especially important. We analysed three lagoons with different ecological statuses and habitat quality on the basis of their eutrophication and ecotoxicity (Trix test) levels. Fish abundances were sampled using fishing and horizontal beaming acoustic surveys with the same protocols in the same year. The relative abundance of Anguilla anguilla, Dicentrarchus labrax or the Mugilidae group was... |
| Tipo: Text |
Palavras-chave: Fish; Shallow water; Ecotoxicity; Lagoon; Habitat quality; Amphidromous. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00148/25963/24083.pdf |
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| Thiaw, Modou; Auger, Pierre-amael; Ngom, Fambaye; Brochier, Timothee; Faye, Saliou; Diankha, Ousmane; Brehmer, Patrice. |
| The objective of this study was to assess the effect of environmental variations on the abundance of Sardinella aurita and Sardinella maderensis in Senegalese waters in the upwelling system. Monthly data indicating the abundance of sardinella were first estimated from commercial statistics, using Generalized Linear Model from 1966 to 2011. Abundance indices (AIs) were then compared with environmental indices, at the local scale, a Coastal Upwelling Index (CUI) and a coastal Sea Surface Temperature (SST) index, and on a large scale, the North Atlantic Oscillation (NAO), the Atlantic Multidecadal Oscillation (AMO) and the Multivariate El Nino Southern Oscillation Index (MEI), using correlations and times series analyses. The results showed that the abundance... |
| Tipo: Text |
Palavras-chave: Climatic change; Oceanography; Sardinella aurita; Sardinella maderensis; Small pelagic; Small-scale fisheries. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00611/72307/71213.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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| 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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| Machu, Eric; Capet, Xavier; Estrade, Philippe; Ndoye, S.; Brajard, J.; Baurand, Francois; Auger, P.-a.; Lazar, A.; Brehmer, Patrice. |
| The northeastern Atlantic hosts the most ventilated subsurface waters of any eastern boundary upwelling system, while coastal upwelling source waters are slightly above hypoxic levels. Anoxic conditions have previously been found offshore inside mesoscale eddies whose core waters undergo oxygen consumption for many months. Based on circumstantial in situ observations this study demonstrates that the Senegalese coastal ocean is subjected to episodic occurrence of zero dissolved oxygen concentration at depth along with elevated nitrite concentration (11 mmol/m3) and nitrate/nitrite deficit to phosphate, thereby indicating severe anoxia and intense nitrogen loss. The anoxic event was associated with a prolonged upwelling relaxation episode in March 2012 and a... |
| Tipo: Text |
Palavras-chave: Oxygen; Canary upwelling system; Anoxia; Denitrification; Shallow continental shelf. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00479/59020/61640.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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| Brehmer, Patrice; Vercelli, Catherine; Gerlotto, Francois; Sanguinede, Fabien; Pichot, Yves; Guennegan, Yvon; Buestel, Dominique. |
| The exploitation of offshore mussel farms is becoming important throughout the world, but monitoring this activity remains a difficult task. Here, we propose a specific method for this purpose. A total of 140 long-lines were monitored on a mussel culture ground in the French Mediterranean Sea during four experimental surveys deploying multibeam sonar devices mounted on poles (Reson Seabat 6012, 455 kHz) on small boats. This allowed geo-referenced observations to be made of the submerged mussel long-lines, as well as three-dimensional (3D) drawings of the long-line structures and the sea bed shapes, using long-line longitudinal sonar sampling. Three sonar data-analysis methods were applied: (i) direct two-dimensional (2D) visual interpretation of raw sonar... |
| Tipo: Text |
Palavras-chave: Management; Sonar; Open sea; Long line; Mussel. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1672.pdf |
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| Capet, Xavier; Estrade, Philippe; Machu, Eric; Ndoye, Siny; Grelet, Jacques; Lazar, Alban; Marie, Louis; Dausse, Denis; Brehmer, Patrice. |
| Upwelling off southern Senegal and Gambia takes place over a wide shelf with a large area where depths are shallower than 20 m. This results in typical upwelling patterns that are distinct (e.g., more persistent in time and aligned alongshore) from those of other better known systems, including Oregon and Peru where inner shelves are comparatively narrow. Synoptic to superinertial variability of this upwelling center is captured through a 4-week intensive field campaign, representing the most comprehensive measurements of this region to date. The influence of mesoscale activity extends across the shelf break and far over the shelf where it impacts the midshelf upwelling (e.g., strength of the upwelling front and circulation), possibly in concert with wind... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00374/48541/48842.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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| 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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| 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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| Registros recuperados: 31 | |
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