Patrice Brehmer

Patrice Brehmer
Institute of Research for Development | IRD · 195 - Marine Environmental Sciences Laboratory (LEMAR)

Tropical Fisheries / Socio-ecosystem / Fisheries acoustics
Based at the Sub Regional Fisheries Commission (SRFC), Dakar, Senegal (West Africa)

About

277
Publications
59,770
Reads
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1,847
Citations
Citations since 2016
150 Research Items
1339 Citations
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Introduction
AWA project "Build the Foundation of a West African observatory" "Create a sub-regional task force on the ecosystem approach to the management of fisheries and the marine environment in the West African Waters under the effect of climate change" https://orcid.org/0000-0001-8949-9095 https://horizon.documentation.ird.fr
Additional affiliations
July 2020 - July 2020
Ressources Aquatiques Québec
Position
  • Associated Researcher
Description
  • Ressources Aquatiques Québec: Regroupement interinstitutionnel pour le développement durable de l’industrie aquacole et des pêches au Québec regroupant une quarantaine de chercheurs québécois possédant un important réseau de collaborateurs à l’échelle provinciale, nationale et internationale.
March 2013 - December 2018
Institut Sénégalais de Recherches Agricoles
Position
  • Associated Researcher
Description
  • Based at CRODT (Fisheries and Oceanography)
January 1998 - July 2020
French National Research Institute for Sustainable Development
Position
  • Senior Researcher
Description
  • A French public research institution, IRD supports an original model of equitable scientific partnership and interdisciplinary, citizen, sustainability science committed to the achievement of the Sustainable Development Goals. Institut de Recherche pour le Développement (the French National Research Institute for Sustainable Development) is an internationally recognised multidisciplinary organisation, working mainly in partnership with countries in the Mediterranean and intertropical zone.
Education
January 1999 - January 2004
Agrocampus Ouest
Field of study
  • Behavioural ecology and fisheries acoustics
January 1998 - January 1999
Agrocampus Ouest
Field of study
  • Fisheries
January 1997 - December 1997
Paul Valéry University, Montpellier 3
Field of study
  • Animal Behaviour

Publications

Publications (277)
Article
Studies of small pelagic fish biomass are limited by the fact that research vessels and fishing boats are usually restricted to working areas with a bottom depth >20 m. Consequently, “unsampled” areas can represent a large proportion of the continental shelf, and the biomass in those areas can be important and must be taken into account in assessme...
Article
Full-text available
The development of acoustics tools and methods for monitoring anthropized ecosystems represents a new field for the application of acoustics. Monitoring such an environment was not possible with single vertical echo sounders, due to the fact that the artificial structures and the natural targets were not distinguishable. Monitoring data were collec...
Article
Full-text available
Data exploitation, acquired by medium-frequency omnidirectional multibeam sonar, enables original studies in fisheries research but is seldom used despite the fact that such equipment is found on most fishing vessels and a number of research vessels. This is the only system for real-time monitoring of fish schools within a horizontal omnidirectiona...
Article
Full-text available
We compared echo sounder measurements of fish schools on Venezuelan and Senegalese coastal shelves. In both areas @@iSardinella aurita@ was the predominant aggregative species; the stocks are known to be genetically independent. Persistent school typology is described by analysing 7 acoustic surveys in Venezuela and comparing with pioneer observati...
Article
Full-text available
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 regime...
Article
Marine pollution around West African big cities is of major concerns. Nevertheless, few attempts have been performed so far particularly on microplastic assessment. We had led first survey targeting microplastic in West African coastal waters (2016); and evaluated on the same sites microbiological contamination as well as marine sediment toxicity a...
Article
Small pelagic fishes are the main fish resource in North West Africa. In Senegal this resource is mainly represented by Sardinella aurita and S. maderensis and the fishery is mostly composed by artisanal fishing units using purse seines and encircling gill nets. It is of great importance for the Senegalese economy and food security. Since the 1970′...
Article
Full-text available
Information on the biological parameters of exploited fish stocks facilitates the objective assessment and management of these living resources. The sardine (Sardina pilchardus) is considered as overexploited in northwest Africa. It is a key species of the Canaries current large marine ecosystem (CCLME) of the Atlantic Ocean due to its socioeconomi...
Conference Paper
Full-text available
In West Africa, numerous economies are dependent on fisheries resources; this sector can reach almost 10% of the national gross domestic product and represents a central sector for food security as the most important animal protein for human consumption and aquafeeds. Due to overexploitation, West African fish stocks are under serious threats and m...
Technical Report
Full-text available
Note Politique, projet AWA (Pollution marine, dégradation des habitats marins et effets du changement climatique en Afrique de l'ouest). AWAtox un projet de démonstration AWA Dossier Noctiluca-mai 2022 "Etat des connaissances sur le premier bloom algal massif de Noctiluca scintillans observé sur la Petite Côte du Sénégal". 1. Observation de la pre...
Article
Full-text available
High-resolution multibeam sonar allows estimating movements of pelagic fish schools at short range. Taking advantage of this methodology, we calculated a Straightness Index (SI) to quantify the proportion of schools migrating actively from those residents in lagoon channels. This information enhances our knowledge of both fish school displacements...
Article
Full-text available
The recent fisheries management approach by Mauritania recommends that Total Allowable Catch (TAC) quotas, identified as essential for maintaining fish stocks, be shared (allocated) among fishing fleets operating in Mauritanian waters. However, the efficiency of such management regulations is debated. This issue can be identified as the typical dil...
Presentation
Full-text available
Marine communities are strongly structured by bathymetry and distance from the coast. Shallow coastal areas host diverse and abundant fish communities and are subjected to strong anthropo-genic pressures. However, assessments of good ecological status of pelagic fish populations do not generally take into account the ultra-coastal fringe of the coa...
Poster
Full-text available
Understanding the relationship between sound scattering layers (SSLs) and pelagic habitat char-acteristics 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 e...
Article
Full-text available
To identify key nonspecific organisational characteristics of the mid-trophic pelagic communities, which remain a challenge, we work with sound scattering layers (SSLs). Application was tested in the three African Atlantic Large Marine Ecosystems (AALMEs) to assess the utility of adapting and developing new acoustic variables. Our methodology allow...
Article
The European Marine Strategy Framework Directive (MSFD) requires the achievement of good ecological status of the marine environment (Ministère de l’Écologie, du Développement durable et de l’Énergie, 2013) for all members of European Union. This directive concerns all the component of the marine environment, including fish. Up to now, fish are are...
Poster
Full-text available
In this work, we are interested in the application of functional and classical statistical methods on acoustic (Sv) and environmental (temperature, fluo-rescence, salinity and turbidity) data from the AWA campaign conducted on the West African coast. The results of the multivariate functional principal component analysis show the variation of the p...
Conference Paper
Full-text available
Fisheries science has been trying to identify the best way to analyze and predict the quantity of fish biomass and its spatial distribution since several decades without enough positive results using, among others, kirigng model, co-kiriging model, Species Distribution Modeling and Joined Species Distribution Modeling, based on conventional statist...
Article
Surveying pelagic fish population dynamics in ultra-shallow waters (<20m) is often limited by research vessel size, which not usually navigate in shallow waters. Here, we use a multibeam echosounder to detect fish shoals and assess their characteristics (acoustic density and 3-D morphology) in ultra-shallow waters to follow European Marine Strategy...
Research Proposal
Full-text available
L’objectif de Art Sunu Geej est : la protection des écosystèmes marins au Sénégal et au-delà dans toute la sous région afin d’en assurer leur durabilité. Pour ce faire on propose de (i) promouvoir l’intérêt de la recherche scientifique auprès de la société civile en particulier des jeunes, des actons de médiations scientifiques et le développement...
Technical Report
Full-text available
1. Présence d’une micro-algue toxique sur la presqu’île de Dakar. 2. Cette micro-algue, relâche des toxines - analogues de la toxine palytoxine - qui ont des effets sur la santé humaine avec des symptômes variables qui peuvent s’apparenter à la grippe saisonnière. 3. Faible connaissance de cette toxine par les services de santé et de la médecine gé...
Article
Full-text available
Artificial reefs (ARs) are one of the most popular means of supporting marine ecosystem conservation and coastal fisheries, particularly in developing countries. However, ARs generate complex socio-bio-economic interactions that require careful evaluation. This is particularly the case for ARs outside no-take zones, where fish might be subject to e...
Article
Full-text available
Plain Language Summary The tropical Atlantic Ocean is characterized by strong year‐to‐year surface temperature fluctuations which can be classified into basin‐scale climate modes. In this study, we examine to which extent these modes of variability have a signature on the surface chlorophyll‐a concentration, a proxy of the biological activity at se...
Article
Using trophodynamic models, the present study evaluated how a decade fishing closure inside and outside two marine protected areas (MPAs) in Senegal has influenced on the ecosystem trophic network. Scientific surveys in the Bamboung MPA (68 km², mangrove) were conducted since 2003, one year before fishery closure. The resulting dataset was used to...
Chapter
Full-text available
Most fisheries are happening in the coastal and shelf areas and are thus often in the Exclusive Economic Zones (EEZs) of countries and as such are under the jurisdiction of only one country. Exceptions are transboundary stocks, which migrate between the EEZs of several countries (e.g. Sardinella spp. in North West Africa, a shared stock between Mor...
Chapter
Full-text available
The tropical Atlantic climate has undergone long-term changes that are projected to accelerate under future global warming. The impact of these changes extends from the marine ecosystem to continental climate. The Tropical Atlantic Observing System (TAOS) is key to monitoring and understanding these changes and reducing uncertainties in climate pro...
Article
L’objectif de l’article est de caractériser les initiatives individuelles et collectives mises en oeuvre par les pêcheurs artisans sénégalais pour faire face à la crise (écologique et économique). De telles initiatives s’organisent autour de dynamiques nouvelles « politiques » et « techniques », « légales » ou « illégales » à l’exemple de la pêche...
Preprint
Full-text available
Artificial reefs (ARs) are one of the most popular means of supporting marine ecosystem conservation and coastal fisheries, particularly in developing countries. However, ARs generate complex socio-bio-economic interactions that require careful evaluation. This is particularly the case for ARs outside no-take zones, where fish might be subject to e...
Article
Full-text available
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
L’objectif de l’article est de caractériser les initiatives individuelles et collectives mises en oeuvre par les pêcheurs artisans sénégalais pour faire face à la crise (écologique et économique). De telles initiatives s’organisent autour de dynamiques nouvelles « politiques » et « techniques », « légales » ou « illégales » à l’exemple de la pêche...
Article
Full-text available
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...
Article
Full-text available
In the context of climate change, which accentuates the growing scarcity of fishery resources, young fishermen are exploring increasingly remote fishing grounds with the immediate consequence of numerous cases of accidents and disappearances at sea and many human and material losses. Faced with this situation of looking for solutions to prevent acc...
Technical Report
Le projet d’Appui à la Gestion Durable des petits pélagiques en Afrique de l’Ouest (AGD-pélagique) (CSRP-MAVA), a pour objectif d’aider à améliorer la gestion des petits pélagiques en Afrique de l’Ouest. Les outils mis en place dans cette optique sont l’harmonisation et la dématérialisation des formulaires d’enquête de pêche artisanale dans quatre...
Article
Full-text available
Au Sénégal, peu d'études sur le plan planctonique ont été réalisées pour l'évaluation de l'efficacité des Aires Marines Protégées. Dans cette perspective, la caractérisation de la flore phytoplanctonique et sa distribution spatio-temporelle à l'intérieur et à l'extérieur de l'AMP de Bamboung a été réalisée en avril et en septembre 2016. Des prélève...
Technical Report
Rapport de Synthèse, Conseil Scientifique de l’Institut Sénégalais de Recherches Agricoles. Editeur Aboubakry Sarr (15 auteurs). Comité Scientifique & Technique 2020
Preprint
Full-text available
Quantitative and qualitative analysis of acoustic backscattered signals from the seabed bottom to the sea surface is used worldwide for fish stocks assessment and marine ecosystem monitoring. Huge amounts of raw data are collected yet require tedious expert labeling. This paper focuses on a case study where the ground truth labels are non-obvious:...
Article
Quantitative and qualitative analysis of acoustic backscattered signals from the seabed bottom to the sea surface is used worldwide for fish stocks assessment and marine ecosystem monitoring. Huge amounts of raw data are collected yet require tedious expert labeling. This paper focuses on a case study where the ground truth labels are non-obvious:...
Article
Full-text available
To assess the eastern Atlantic tropical mixed layer depth (MLD) at 4°W in the Gulf of Guinea, water temperature and density profiles from over five hundred historical observational Conductivity – Temperature - Depth (CTD) data were used. These data, obtained from key oceanographic survey databases covering 60 years (1956 to 2016) were used for a nu...
Article
Full-text available
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 ev...
Chapter
Description This book highlights mathematical research interests that appear in real life, such as the study and modeling of random and deterministic phenomena. As such, it provides current research in mathematics, with applications in biological and environmental sciences, ecology, epidemiology and social perspectives. The chapters can be read ind...
Technical Report
Le projet d’Appui à la Gestion Durable des petits pélagiques en Afrique de l’Ouest (AGD-pélagique) logé à la CSRP-et financé par la MAVA, a pour objectif d’aider à améliorer la gestion des petits pélagiques en Afrique de l’Ouest. Pour se faire l’IRD coordonne l’harmonisation et la dématérialisation des formulaires d’enquête de pêche artisanale dans...
Article
Full-text available
Résumé : Sur la base de nombreuses études de cas conduites sur le littoral sénégalais, cet article révèle que l’analyse des pêcheries artisanales sénégalaises sous l’angle des stratégies postcoloniales et des crises successives ne suffit plus à rendre compte d’un secteur en pleine mutation, marqué par l’émergence de dynamiques participatives et dur...
Article
The 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...
Book
Full-text available
Technical support: Ndague DIOGOUL (IRD, Sénégal), Cordula Zenk (Geomar, Germany) and Mahaut de Vareilles (UiB, Norway) With the collaboration of: Noel Keenlyside (Norway), Jorge M. NASCIMENTO (CABO VERDE), Vito Melo RAMOS (CABO VERDE), Bamol Ali SOW (SENEGAL), Heino FOCK (GERMANY), Joern SCHMIDT (GERMANY), Werner EKAU (GERMANY), Adama MBAYE (SENEGA...
Article
Full-text available
Successful recruitment in small pelagic fish populations inhabiting upwelling zones is subject to variation in fecundity and is driven by spatial and temporal fluctuations in environmental conditions, that is, mainly sea surface temperature, salinity and food availability. These fluctuations in abiotic factors have stimulated small pelagic fish pop...
Poster
Full-text available
TriAtlas Project Presentation at OceanObs19 Overall objective and plan Cross-Atlantic Network of Excellence in Marine Science (CANEMS). The TRIATLAS key challenge. To develop the understanding and the capacity (observational, modelling, and human) to best predict changes in the tropical Atlantic marine ecosystem and its societal impacts. To as...
Article
Full-text available
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...
Article
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 (20...
Article
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 to...
Article
Full-text available
Sound scattering layers SSLs distribution and their relationship to pelagic habitat characteristics is a first step to understand their role in ecosystem dynamics and their interactions with other pelagic components such as small pelagic fish. In this study two areas of the Senegalese shelf have been characterized during upwelling season correspond...
Article
The avoidance reaction by fish in front of an approaching vessel is a major source of bias in direct biomass assessment and ecological studies based on fisheries acoustics data. An experiment was carried out to compare echosounder data obtained using a small speedboat and a research fisheries vessel generating significant higher noise above convent...
Article
Full-text available
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 sca...
Article
Full-text available
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 sca...
Article
Full-text available
Plain language summary Oxygen is a key requirement for respiration by marine living organisms. Warming of the atmosphere and the ocean surface reduces the oxygenation of offshore waters. Similarly, the extra load of nutrients from agriculture or waste waters modifies algal production, particularly in coastal regions, often resulting in oxygen‐deple...