Jean Guillard

Jean Guillard
French National Institute for Agricultural Research | INRA · Department of Forest, Grassland and Freshwater Ecology

32.99
 · 
PhD, HDR
About
115
Research items
17,539
Reads
974
Citations
Introduction
Hydroacoustics: a method to study fish population (and more) . From spatio-temporal dynamics of pelagic fish population, species identification from school structures to shallow waters studies. Fish population in lakes: evolution and impacts on food web.
Research Experience
Oct 1999 - Sep 2001
Institute of Research for Development
Position
  • CR1
Oct 1994 - Sep 1995
ORSTOM
Position
  • CR2
Education
Oct 2011
University of Grenoble
Field of study
  • ecology - fresh water
Sep 1988 - Jun 1991
Claude Bernard University Lyon 1
Field of study
  • ecology - fresh water
Network
Cited By
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Following
Projects
Projects (5)
Project
EAGLES (East African Great Lake Ecosystem Sensitivity to changes) was a project funded by BELSPO (Belgian Science Policy) that run from 2010 to 2015. The project is now officially over, although, various papers are in elaboration, submitted, or in press. The general objective of the EAGLES project was to understand, monitor and forecast how the ecosystem of a large African lake, Lake Kivu, responds to human-induced changes, in order to predict the effects of environmental changes on the goods and services provided by the ecosystem. Lake Kivu, is part of the East African Great Lakes (border between Rwanda and Democratic Republic of Congo), and is of particular interest for several reasons, one of them being methane extraction from bottom layers of the lake. Although this allows producing electricity for the surrounding countries, this should be made in a sustainable way, in particular with regards to the lake’s ecosystem and resources, including fisheries. The project's final report is available here: https://www.researchgate.net/publication/288829278_East_African_Great_Lake_Ecosystem_Sensitivity_to_changes
Archived project
Réponses Adaptatives des Populations et des Peuplements de Poissons aux Pressions de l'Environnement
Research
Research items (115)
Article
Full-text available
Nam Theun 2 is the largest neo-reservoir in Lao PDR that was impounded to produce electricity. The objective of this study was to assess the input of the offshore zone to the total fish production. Hydroacoustics in areas > 5 m deep were sampled during the cold-dry season for 2 consecutive years. Results showed low fish densities (200–300 ind. ha⁻¹...
Article
Full-text available
Total lengths (LT) of 50 free‐swimming fish in a tank, silver carp Hypophthalmichthys molitrix and rainbow trout Oncorhynchus mykiss, were measured using a DIDSON (Dual‐frequency IDentification SONar) camera. Using sound metrics software, multiple measurements of each fish (LT, side aspect angle and distance from the camera) at different times were...
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
Biological traits of Oreochromis niloticus were studied in order to identify potential differences between the population of the Nam Theun 2 Reservoir and other populations in Asia and in Africa. The study also aimed to characterize the demographic structure of the exploited population by fisheries in the reservoir. Toluidine-stained transverse sec...
Presentation
Table ronde animée par M. Vidard : « Quelles avancées scientifiques pour répondre aux enjeux sociétaux autour des lacs ? » organisée à la suite du congrès « Big Lakes – Small world » (Evian, septembre 2018). version courte 15 minutes environ : https://www.youtube.com/watch?v=edJ51QFE00U&feature=youtu.be
Article
Full-text available
Hydroacoustics has become a requisite method to assess fish populations and allows to describe the relationships of fish with other elements of the aquatic ecosystem. This nonintrusive method is currently an integral part of the sampling procedures recommended for fish stock assessment by the Water Framework Directive and has been standardized by t...
Article
Biological traits of Oreochromis niloticus were studied in order to identify potential differences between the population of the Nam Theun 2 Reservoir and other populations in Asia and in Africa. The study also aimed to characterize the demographic structure of the exploited population by fisheries in the reservoir. Toluidine-stained transverse sec...
Poster
Full-text available
The Nam Theun 2 Reservoir, impounded in 2008 on a tributary of the Mekong (Lao PDR), is one of the largest hydroelectric project in Southeast Asia of the last ten years (lake surface between 86 km² at low level and 489 km² at the highest). Many environmental and social programs were developed in collaboration of local institutions and population si...
Article
Full-text available
• Although parasites are expected to affect their host's fitness, quantitative proof for impacts of parasitism on wild populations is hampered by confounding environmental factors, including dietary resource. • Herein, we evaluate whether the physiological conditions of European perch (Perca fluviatilis) in three large peri‐alpine lakes (Geneva, An...
Article
Full-text available
The complementarity of two high-resolution spatiotemporal acoustic methods, telemetry and hydroacoustics, was evaluated during the same time window to obtain fish distribution in a canyon-shaped reservoir, the Bariousses Reservoir (France). These methods act at an individual scale for telemetry and a community scale for hydroacoustics. The temporal...
Article
Full-text available
Hydroacoustic methods are routinely used for fish population assessment and monitoring in lakes and reservoirs around the world and are particularly embedded in European and North American lake management. However, the comparability of hydroacoustic results can be difficult to assess due to the large number of variables (sound frequency, sound puls...
Article
Full-text available
p>Through cascading effects within lake food webs, commercial and recreational fisheries may indirectly affect the abundances of organisms at lower trophic levels, such as phytoplankton, even if they are not directly consumed. So far, interactive effects of fisheries, changing trophic state and climate upon lake ecosystems have been largely overloo...
Technical Report
In the previous report (D4.1, September 2016) we have developed predictive linkages between indicators of environmental quality and ecosystem services, and different types of pressures, single or multiple, across river basins from all over Europe, in a latitudinal and a west-east gradient, and having very different conditions of climate and land us...
Article
Full-text available
Climate forcing, in combination with local anthropogenic pressures, has drastically modified the physical and chemical properties of lakes worldwide, affecting the abundance and diversity of fish populations. In the context of these combined changes, understanding the interactions between global and local forcing has become a major challenge for de...
Article
Full-text available
Length–weight relationships (LWRs) were determined for eight Asian freshwater fish species that were not yet recorded in any peer-reviewed journal indexed in the Web of Science or the FishBase database. Fish specimens from Nam Theun 2 reservoir in Lao PDR, were collected from April 2012 to August 2016 using several methods to cover a large size-spe...
Article
Full-text available
To preserve ecosystem services of tropical reservoirs that provide food and income for local populations, it is necessary to monitor fish population temporal dynamics, stock, and yield fishing. The aim of this review is to provide information to who monitor fish populations in tropical reservoirs. The topics, investigative methods, observation scal...
Article
Full-text available
The aim of the present study was to understand how seasonal fish distributions affect acoustically derived fish biomass estimates in a shallow reservoir in a semi-arid country (Tunisia). To that end, sampling events were performed during four seasons (spring (June), summer (September), autumn (December) and winter (March)) that included day and nig...
Article
Full-text available
During 1970-1990's, deep Lago Mayor and most of shallow Lago Menor were oligotrophic with high water transparency and strong nitrogen limitation. Greens and cyanobacteria (Anabaena) dominated the phytoplankton, except diatoms during the dry season, with low biomass and primary production. Windy and rainy periods drove nutrient enrichment seasonalit...
Article
Full-text available
RESUME. Depuis les années 1970, la nécessité d'obtenir des informations robustes sur les densités, les abondances des peuplements de poissons, en s'affranchissant des statistiques de pêches, a été le point de départ de l'utilisation des méthodes hydroacoustiques (échosondage). Cette approche est devenue au cours de ces 40 dernières années un outil...
Article
Full-text available
Fish species diversity can be lost through interacting stressors including habitat loss, stocking and overfishing. Although a multitude of stressors have played a role in the global decline of coregonid (Coregonus spp.) diversity, a number of contemporary studies have identified habitat loss stemming from eutrophication as the primary cause. Unfort...
Conference Paper
Full-text available
The aim of this study is to characterize the fish population evolution of Nam Theun 2, a large neo-reservoir of Lao PDR. Since its impoundment in 2008, annual experimental fishing using gillnets are performed at rainy and dry seasons in reservoir, transition and river areas. Since 2012, three sampling stations within the reservoir were added, and t...
Conference Paper
Full-text available
In a context of potential overexploitation of fisheries resources in the Sabana-Camagüey Archipelago (Cuba), the Cuban national authorities have expressed the need to collect more in situ information on fish of commercial interest in spawning areas. A newly developed low cost single-beam scientific echosounder has been recently acquired by the Cuba...
Conference Paper
Full-text available
Acoustic technology in use for over 40 years has proven to be an effective tool to collect high-quality data describing animal size, abundance, behavior (1) across a wide range of spatio-temporal scales in aquatic ecosystems (2). It is considered as compatible with best practices defined by European Directives and applied as an alternative and/or c...
Research
L’hydroacoustique, méthode non intrusive, permet l’observation et la description des populations de poissons en utilisant les propriétés physiques du son dans l’eau et est adaptée à une visualisation de nuit et en eaux turbides. Le DIDSON (dual-frequency identification sonar), un sonar haute fréquence, initialement mis au point en 1999 pour l’indus...
Book
Full-text available
Comité de rédaction Carole BIRCK - ASTERS Cyril BOURG - DREAL Rhône-Alpes Sébastien CACHERA - CISALB Anne CLEMENS - ZABR Magali CONDAMINES - CIPEL Jean-Marcel DORIOZ - INRA CARRTEL Jean GUILLARD - INRA CARRTEL Stéphan JACQUET - INRA CARRTEL Renaud JALINOUX - CISALB Audrey KLEIN - CIPEL Alain MARTINET - Région Rhône-Alpes Bernard MONTUELLE - INRA C...
Answer
The best solution is to use hydroacoustic from a boat:
Winfield, I. J., C. Onoufriou, M. J. O’Connell, M. Godlewska, R. M. Ward, A.
F. Brown and M. L. Yallop. 2007. Assessment in two shallow lakes of a hydroacoustic system for surveying aquatic macrophytes. Hydrobiologia 584:111-119
Article
Full-text available
Several decades of research have led to the acceptance of hydroacoustics as a reliable measurement method to monitor fish population in lakes, but full standardisation and intercalibration are still lacking. The aim of this study was to investigate the effect of sound frequency on acoustic parameters, such as volume backscattering strength, target...
Conference Paper
Full-text available
A fish population monitoring on 6 years by experimental fishing (gillnets) was carried out in the area of the hydro-power project Nam Theun 2 (NT2) in Lao PDR since impoundment in 2008. Three aquatic areas were studied (river upstream, transition area and reservoir), as well as different drowned habitats (dense/light forests, agricultural soils) sh...
Article
Nodularin (NOD) and cylindrospermopsin (CYN) are hepatotoxic cyanotoxins that are present in numerous ecosystems where bloom episodes occur. In this review, the different effects of both of these cyanotoxins on the different ontogenic stages of various fish species were summarised to clarify the state-of-the-art scientific knowledge on this topic....
Article
Full-text available
Nodularin (NOD) and cylindrospermopsin (CYN) are hepatotoxic cyanotoxins that are present in numerous ecosystems where bloom episodes occur. In this review, the different effects of both of these cyanotoxins on the different ontogenic stages of various fish species were summarised to clarify the state-of-the-art scientific knowledge on this topic....
Answer
Thanks all for your answer.
The target is certainely a school of juvenile fish (likely catfish)
Question
A Didson video with an amazing target:  look at the 7 m range and follow the target: https://vimeo.com/99981009
Data were recorded in a river, in Britanny (France), in September 2013.
Any idea about  this target?
Article
Full-text available
http://www.pourlascience.fr/ewb_pages/a/article-l-ecoute-des-bancs-de-poissons-32536.php
Article
Full-text available
European Union legislation, through the Water Framework Directive (2000/60/EC), as well as national legislation, such as the ‘Grenelle Environnement’ (2007) in France, requires restoration of ecological connectivity in streams to improve free circulation of migratory fish. Different methods (e.g. capture by trap or net, telemetry, hydroacoustics) a...
Technical Report
Après l’important changement observé entre 2009 et 2010, marqué par l’importante baisse de la biomasse phytoplanctonique et la disparition de l’efflorescence à Planktothrix rubescens, une nouvelle bascule semble avoir opéré au cours de l’année 2013, avec la plus faible biomasse phytoplanctonique jamais enregistrée sur l’ensemble de la chronique, un...
Article
Full-text available
A dam has been recently modified on the Couesnon River in the vicinity of Mont Saint Michel to control and remove the volume of sediment brought into the bay by tidal waters. This paper shows that this dam has an impact on Atlantic salmon (Salmo salar) migration and that adult fish experience adaptive responses. Upstream migration activities were r...
Article
1. We sampled Lake Bourget (surface area = 44 km2) using CEN standard gillnet and provisional standard acoustic survey methods over 3 years (2005, 2010 and 2011) as the fish community responded to re-oligotrophication. A total of 16 species were caught in benthic gillnets and three species in pelagic gillnets. 2. Lake Bourget results were consisten...
Conference Paper
Full-text available
One of the main species in the Caribbean cost of Yucatan-Mexico is the Mero (Epinephelus striatus), but the fisheries are beginning to go down and the principal reason could be the over-catch. The objective of this work is to study the aggregations of the Nassau Grouper, as well as the rest of the fish populations associated with the slope of the M...
Article
Full-text available
Abstract: The European Union Water Framework Directive requires monitoring of biological quality elements to assess the ecological status of aquatic ecosystems and assure their good quality. Hydroacoustics could provide an effective tool for monitoring certain aspects of fish populations in fresh waters, but to ensure the comparability of datasets...
Article
Full-text available
Due to the importance of young-of-the-year (YOY) perch in the peri-alpine regions where they are consumed, the microcystin (MC) contamination of YOY perch was analysed both in field (Lake Bourget, France) and experimentally using force-feeding protocols with pure MCs. In-situ, schools of YOY perch present in the epilimnion of the lake were never fo...
Article
Full-text available
Cyanobacterial blooms induce significant costs that are expected to increase in the near future. Cyanobacterial resistance to zooplankton grazing is one factor thought to promote bloom events. Yet, numerous studies on zooplankton ability to graze upon cyanobacteria have been producing contradictory results and such a puzzle might arise from the lac...
Article
1. Sampling of lake fish assemblages is a challenging task in fish science, and the information obtained strongly depends on the choice of sampling gear. The use of more than one sampling technique is generally preferred in order to achieve a comprehensive view on fish assemblage structure. Therefore, the knowledge of whether catches between fishin...
Article
Full-text available
Limnothrissa miodon, a small pelagic clupeid fish introduced at the end of the 1950s into Lake Kivu, became an important resource for the human populations of this area. The total stock of pelagic fish populations of this lake was estimated in 2008 by two hydroacoustic surveys, using an EK60 split-beam sounder (frequency 70 kHz). The total fish sto...
Article
Two techniques, the conventional purse seine method and a novel method using vertical hydroacoustic surveys at fixed positions, were applied simultaneously in the Gambia River estuary to sample a fish population. Environmental parameters were measured simultaneously. Four surveys were performed during different hydrological seasons to reflect the m...
Article
Full-text available
In the present study, juvenile whitefish weighing 2 g were exposed by force-feeding to two ecologically relevant doses (0.05 and 0.5 μg per fish) of microcystin-LR (MC-LR). Then over 96 h the MC uptake in fish liver and muscle was measured, as the activity of the detoxification enzyme glutathione S-transferase (GST) in the liver, and the genotoxici...
Article
Full-text available
This contribution reviews the knowledge on fish diversity and fisheries in Lake Kivu, with an emphasis on the biology and stock assessment of the introduced Tanganyika sardine, Limnothrissa miodon. Lake Kivu is famous, compared to the other African great lakes, for its poor fish fauna, with 29 species comprising a.o. 15 endemic haplochromines and a...
Thesis
Full-text available
Ce bilan scientifique retrace et synthétise un parcours de recherche réalisé dans de multiples écosystèmes aquatiques, des lacs Alpins aux estuaires tropicaux, du lac Baïkal (Sibérie) au lac Kivu (Afrique de l’Est). Les questions de recherche abordées sont centrées sur les communautés ichtyaires, étudiées in situ, à différentes échelles spatiales d...
Article
Lake Bourget (France) provides drinking water and is a place for professional and recreational fishing. Since the mid 1990s, the lake has been exhibiting blooms of the filamentous cyanobacterium Planktothrix rubescens. This species is able to produce microcystin-LR and RR, toxins that contaminate different fish tissues and, if concentrated in the l...
Article
Full-text available
Fish school swimming speeds is essential for ecological and management studies. The multibeam sonar in horizontal beaming provided dynamic echo traces of mobile fish schools. We used two school swimming speed indicators: the average of a series of instantaneous speed values, and the exploratory speed. These swimming speeds were estimated for each f...