References of "Ovidio, Michaël"
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See detailHydroélectricité et poissons
Ovidio, Michaël ULg; Florence, Hauregard

Learning material (2009)

Chercheur au Laboratoire de Démographie des Poissons et d’Hydroécologie de l’Université de Liège, Michaël OVIDIO présentait le 30 avril dernier, dans le cadre des Jeudis de l’Aquapôle, un exposé sur l’ « ... [more ▼]

Chercheur au Laboratoire de Démographie des Poissons et d’Hydroécologie de l’Université de Liège, Michaël OVIDIO présentait le 30 avril dernier, dans le cadre des Jeudis de l’Aquapôle, un exposé sur l’ « Impact des barrages et des turbinages hydroélectriques sur la dynamique des populations de poissons et la qualité de leurs habitats » . Sans vouloir être source de conflits avec les producteurs d’hydroélectricité, cet exposé avait pour objectif d’informer le grand public sur cette problématique, car la notion d’énergie verte, largement utilisée pour caractériser l’hydroélectricité, ne doit pas s’arrêter au seul aspect des pollutions. [less ▲]

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See detailL’impact des prises d’eau industrielles et des turbinages hydroélectriques sur la dynamique des populations de poissons et la qualité de leur habitat dans les cours d’eau navigables. Le cas de la Meuse et de l’Ourthe en Wallonie.
Philippart, Jean-Claude ULg; Ovidio, Michaël ULg

Scientific conference (2009, March)

La dynamique des populations de poissons, c’est-à-dire la variation dans le temps et l’espace de leur abondance, est la résultante de trois processus écologiques fondamentaux : i) l’apport de nouveaux ... [more ▼]

La dynamique des populations de poissons, c’est-à-dire la variation dans le temps et l’espace de leur abondance, est la résultante de trois processus écologiques fondamentaux : i) l’apport de nouveaux jeunes (recrutement) grâce à la reproduction naturelle (parfois renforcée ou compensée par des repeuplements en poissons d’élevage), ii) la perte d’individus à tous les stades de développement à cause des différents facteurs de mortalité (mauvaise qualité de l’eau, actions mécaniques, maladies et parasites, prédation, pêche) et iii) les phénomènes d’émigration-immigration qui mettent en jeu des migrations, particulièrement importantes chez les poissons amphihalins anadromes comme les salmonidés (saumon et truite de mer, lamproies de rivière et de mer) et catadromes commel’anguille européenne dans nos régions. Au cours de leurs migrations vers l’aval, les poissons sont confrontés à une forme de pression anthropique, les prises d’eau de tous types, qui peut provoquer des pertes démographiques importantes lorsque les ouvrages dérivent de grands volumes d’eau comme c’est le cas avec les prises d’eau de refroidissement des centrales électriques thermiques classiques et nucléaires et les grandes centrales hydroélectriques au fil de l’eau qui existent sur la Meuse et le cours inférieur de ses affluents navigables (Ourthe, Sambre). Ces mortalités résultent du placage des poissons entraînés sur les dispositifs de filtration de l’eau à l’entrée des installations (tambours filtrants et/ou grilles à barreaux) ou de leur passage forcé dans des turbines hydroélectriques de divers types, grandeurs et vitesses de rotation. L’exposé présente un aperçu des connaissances actuelles sur l’importance quantitative et le degré de gravité écologique des mortalités causées par les prises d’eau industrielles et les turbines hydroélectriques sur les populations de poissons de Wallonie, en accordant une attention particulière aux smolts du saumon atlantique et de la truite de mer et aux anguilles argentées sub-adultes. L’ analyse est complétée par un bref inventaire des moyens disponibles et à développer pour tenter de réduire les mortalités mécaniques des poissons migrateurs au niveau des ouvrages anciens en place et surtout des nouveaux ouvrages, spécialement les centrales hydroélectriques, en construction ou programmés. [less ▲]

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See detailHabitat Choice by Atlantic Salmon Parr in Relation to Turbulence at a Reach Scale
Enders, Eva C; Roy, Mathieu L; Ovidio, Michaël ULg et al

in North American Journal of Fisheries Management (2009), 29(6), 1819-1830

The variables commonly used to describe the physical habitat of Atlantic salmon Salmo salar parr are average velocity, water depth, and substrate. A variety of micro- and mesohabitat models have been ... [more ▼]

The variables commonly used to describe the physical habitat of Atlantic salmon Salmo salar parr are average velocity, water depth, and substrate. A variety of micro- and mesohabitat models have been developed using these variables to assess habitat quality. However, Atlantic salmon parr live in highly turbulent streams and rivers in which intense fluctuations of water velocity occur. Laboratory experiments have shown that turbulence affects the behavior and energetics of fish. Nevertheless, habitat use in relation to the strong temporal variability of velocity in natural environments has rarely been studied. In this study, Atlantic salmon parr habitat was examined in relation to turbulence in the Patapedia River, Quebec. Rather than taking the usual approach of surveying a large population at one point in time, we used an intensive radiotelemetry tracking survey that focused on the habitat use of a few individual fish over an extended period. We analyzed habitat use in relation to several dynamic hydraulic variables. Our results revealed that under naturally turbulent conditions, the parr displayed high individual variability in their habitat use. Such heterogeneous use of habitat suggests that individuals are not constrained to a single habitat type. Furthermore, no differences were observed in habitat use among the four daily periods (dawn, day, dusk, and night) for individual parr. [less ▲]

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See detailhybridization behaviour between two common European cyprinid fish species - silver bream Blicca bjoerkna and common bream Abramis brama - in a controlled environment
Nzau Matondo, Billy; Ovidio, Michaël ULg; Philippart, Jean-Claude ULg et al

in Animal Biology (2009), 59

The egg release–mating comparison, heterospecific matings and mating success under two hybridization conditions – (i) mixing one sex per species and (ii) mixing both sexes from each species – were ... [more ▼]

The egg release–mating comparison, heterospecific matings and mating success under two hybridization conditions – (i) mixing one sex per species and (ii) mixing both sexes from each species – were investigated to determine whether silver bream Blicca bjoerkna and common bream Abramis brama can hybridize in nature. The results revealed that non-matings in hybridization experiments of silver bream females × common bream males can be explained by territorial and aggressiveness activities observed in common bream. In common bream females × silver bream males, heterospecific matings were observed but their numbers were signifi cantly lower than the spawning numbers, and in this experiment, a female mated with one to four heterospecifi c males. In mixing both sexes from both species, similar spawning – mating numbers were observed but heterospecific matings accounted for only 27% of the total matings, with 24% accounting for heterospecifi c matings between common bream females and silver bream males, directly or by opportunism. Mating success was characterized by the occurrence of fertilized eggs after matings. Natural hybridization occurred preferentially between common bream females and silver bream males. [less ▲]

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See detailMovement behaviour of the small benthic Rhine sculpin Cottus rhenanus (Freyhof, Kottelat & Nolte, 2005) as revealed by radio-telemetry and pit-tagging
Ovidio, Michaël ULg; Detaille, Aurelie; Bontinck, Charlotte et al

in Hydrobiologia (2009), 636(1), 119-128

From February 2006 to June 2007, we followed the movement patterns of the Rhine sculpin (Cottus rhenanus) by combining short-term radio-telemetry (n = 10 radio-tagged sculpin with a miniature 0.5-g ... [more ▼]

From February 2006 to June 2007, we followed the movement patterns of the Rhine sculpin (Cottus rhenanus) by combining short-term radio-telemetry (n = 10 radio-tagged sculpin with a miniature 0.5-g transmitter) and long-term individual (PIT-tag) mark-recapture (n = 452 PIT-tagged sculpin during six removal electric fishing operations) studies in a small tributary of the River Meuse, Belgium. During a 25- to 27-day period, the radio-tracked sculpin displayed various mobility patterns, showing frequent movement from one day to another and longitudinal home ranges from 7 to 46 m, with cumulative distances up to 149 m. During the mark-recapture study, most (99%) recaptured PIT-tagged individuals moved from their original 5-m long site, subsequently using longitudinal home ranges between 5 and 435 m (mean, 50 m; median, 20 m). The most common movement behaviour was alternation between upstream and downstream movements (62%), followed by directional upstream (26%) and directional downstream (11%) movement. Using the latest available techniques, this study builds on the current knowledge on the Cottus genus and closes gaps in the comprehension of sculpin movement and home range at a scale that had not been investigated to date. [less ▲]

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See detailCan turbulence statistics reflect the meso-habitat choice of juvenile salmonids
Enders, Eva; Ovidio, Michaël ULg; Hallot, Eric ULg et al

in Proceedings of the combined conference on Hydro-Informatics and Ecohydraulics, Concepcion, Chile, January 2009. (2009)

Variables commonly used to describe the physical habitat of Atlantic salmon Salmo salar L. parr are average velocity, water depth, and substrate. A variety of micro- and meso-habitat models have been ... [more ▼]

Variables commonly used to describe the physical habitat of Atlantic salmon Salmo salar L. parr are average velocity, water depth, and substrate. A variety of micro- and meso-habitat models have been developed using these variables to assess habitat quality. However, Atlantic salmon parr live in highly turbulent streams and rivers, in which intense fluctuations of water velocity occur. Laboratory experiments have shown that turbulence affects the behavior and energetics of fish. Nevertheless, habitat use in relation to the strong temporal variability of velocity in natural environments has rarely been studied. In this study, Atlantic salmon parr habitat was examined in relation to turbulence in the Patapédia River, Québec, Canada. We analyzed meso-habitat use in relation to several dynamic hydraulic variables. Our results revealed that in a natural turbulent condition, parr displayed high individual variability in habitat use in relation to turbulence. Such heterogeneous use of habitat suggests that individuals are not constrained to a single habitat type but that they have a tendency to use areas with lower turbulence. [less ▲]

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See detailBases biologiques et éco-hydrauliques pour la restauration de la continuité piscicole en rivière : premier bilan et perspectives en Région Wallonne (Belgique).
Ovidio, Michaël ULg; Philippart, Jean-Claude ULg; Denoel, Philippe et al

Conference (2008, October)

Dans le prolongement de la Directive Benelux d’avril 1996 (libre circulation des poissons migrateurs) et de la Directive Cadre sur l’Eau de l’Union Européenne (2000/60/CE), le rétablissement de la ... [more ▼]

Dans le prolongement de la Directive Benelux d’avril 1996 (libre circulation des poissons migrateurs) et de la Directive Cadre sur l’Eau de l’Union Européenne (2000/60/CE), le rétablissement de la continuité piscicole dans nos cours d’eau fait partie des objectifs prioritaires de la Direction des Cours d’eau Non Navigables du Ministère de la Région Wallonne. Depuis 1997, différents acteurs, gestionnaires, sociétés de pêches et scientifiques abordent en profondeur cette problématique par l’exécution de différentes actions intégrées. Depuis environ 10 ans, un travail de terrain considérable est accompli pour le compte de la Région wallonne par la Fédération de Pêche Vesdre-Amblève (asbl) qui répertorie et géoréférence la totalité des obstacles physiques susceptibles de perturber la continuité piscicole dans les cours d’eau de Wallonie. En parallèle, le Laboratoire de Démographie des Poissons et d’Hydroécologie (LDPH) de l’Université de Liège étudie l’impact biologique de certains de ces obstacles sur les populations de poissons, principalement en utilisant la technique du radio-pistage. Ces recherches permettent de mieux connaître les phénomènes de mobilité et de migrations des poissons de nos cours d’eau ainsi que leurs capacités à franchir en remontée des obstacles typologiquement très différents. Ces travaux permettent d’identifier les sites critiques qui doivent prioritairement êtres équipés de dispositifs de franchissement efficaces. Le contrôle scientifique du fonctionnement des passes migratoires nouvellement construites démontre clairement leurs effets positifs sur la qualité écologique et piscicole de la rivière. De tels résultats justifient fortement de multiplier ce type d’action de restauration écologique (hydromorphologique) dans d’autres cours d’eau. Au cours de notre exposé, nous présenterons, avec des résultats concrets, un premier bilan des travaux déjà effectués et nous dégagerons les perspectives à moyen et long terme en matière de libre circulation des poissons dans les cours d’eau wallons, non seulement en remontée mais aussi en descente (ou dévalaison). [less ▲]

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See detailUpstream migration of fish at natural obstructions and fish passes efficiency in Southern Belgium.
Ovidio, Michaël ULg; Orban, Patrice; Lambot, Francis et al

Conference (2008, July)

Fragmentation of rivers by physical obstacles has resulted in the drastic range reduction or extinction of numerous diadromous and potadromous species of fish worldwide. In order to implement to partially ... [more ▼]

Fragmentation of rivers by physical obstacles has resulted in the drastic range reduction or extinction of numerous diadromous and potadromous species of fish worldwide. In order to implement to partially or completely re-establish the free movements of fish in the entire watercourse, the Walloon regional government (Southern Belgium) initiated an integrated restoration project whose objectives are 1) To perform a complete inventory of all obstacles that may potentially interfere with the longitudinal connectivity and the free movements of fish, 2) To test, using radio telemetry, the ability of representative fish species (Salmonidae, Thymallidae, Cyprinidae, Esocidae and Cottidae) to clear different typologies of physical obstacles, 3) To determine the problematic sites that should be improved with priority. 4) To construct fish passage facilities and to examine their biological efficiencies. During our talk we will synthesize the results of ten years of research and define the different options for the future. [less ▲]

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See detailThe restoration of the longitudinal connectivity in Southern Belgian rivers. Synthesis of a 10-years study and perspectives
Ovidio, Michaël ULg; Orban, Patrice; Lambot, Francis et al

Conference (2008, June)

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See detailConvention d’études pour le suivi scientifique de la réhabilitation du saumon atlantique dans le bassin de la Meuse
Micha, Jean-Claude; Malbrouck, Christelle; Fossion, Pierre et al

Report (2008)

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See detailFertility in first-generation hybrids of roach, Rutilus rutilus (L.), and silver bream, Blicca bjoerkna (L.)
Nzau Matondo, Billy; Nlemvo, A. B.; Ovidio, Michaël ULg et al

in Journal of Applied Ichthyology (2008), 24(1), 63-67

Fertility in first-generation hybrids of roach, Rutilus rutilus, and silver bream, Blicca bjoerkna, was investigated. Sperm and egg production of hybrids at first sexual maturity were examined. Eggs from ... [more ▼]

Fertility in first-generation hybrids of roach, Rutilus rutilus, and silver bream, Blicca bjoerkna, was investigated. Sperm and egg production of hybrids at first sexual maturity were examined. Eggs from female hybrids were artificially fertilized with the sperm of a corresponding hybrid male; a hybrid male from the reciprocal crossbreeding; a parental species male R. rutilus; and a parental species male B. bjoerkna. The results revealed that gametogenesis was normal in female hybrids. However, in male hybrids, a low efficiency of gametogenesis was observed. The semen of male hybrids was extremely dilute, with spermatozoa concentration lower than that in parental species. Nevertheless, these F1 hybrids (males and females) from reciprocal crossbreeding were fertile. F2 and backcross generations were produced, but F2 crosses from the female hybrid and corresponding hybrid male displayed a drastically slower hatching rate. Also higher proportions of deformed embryos were hatched than in other post-F1-generation crosses. [less ▲]

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See detailSexual maturity, reproductive behaviour and fertility in the first-generation hybrids of Blicca bjoerkna L. x Abramis brama L.
Matondo, Billy Nzau; Ovidio, Michaël ULg; Philippart, Jean-Claude ULg et al

in Cybium (2008), 32(2), 286-289

Sexual maturity, reproductive behaviour and fertility in the artificial first-generation hybrids of silver bream, Blicca bjoerkna, and common bream, Abramis brama, were investigated in this study. The ... [more ▼]

Sexual maturity, reproductive behaviour and fertility in the artificial first-generation hybrids of silver bream, Blicca bjoerkna, and common bream, Abramis brama, were investigated in this study. The results revealed that the females and males of hybrids attained their first sexual maturity at the same age. Maturity in F, hybrids was observed at the same moment as maturity in the common bream, the latter being the parental species. Sizes of male hybrids at maturity were intermediate to their parents but female hybrids were closer to the highest parental species, the common bream. As for reproductive behaviour, the numbers of spawning and mating behaviours observed were highly similar. Female hybrids mated simultaneously and successively with all types of males, except the common bream male. resulting in fertilised eggs. Male hybrids exhibited aggressiveness and territorial activities as in parental species common bream. Successful survival was observed in all post-F-1 (F-2 and backcross) generations at each developmental stage, proving that these hybrids are fertile. [less ▲]

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See detailMorphological recognition of artificial F1 hybrids between three common European cyprinid species: Rutilus rutilus, Blicca bjoerkna and Abramis brama.
Matondo, B. N.; Ovidio, Michaël ULg; Poncin, Pascal ULg et al

in Dong Wu Xue Bao = Acta Zoologica Sinica (2008), 54(1),

The F1 hybrids of roach Rutilus rutilus, silver bream Blicca bjoerkna, and common bream Abramis brama from experimental reciprocal cross-breedings were identified at 18 months of age in relation to the ... [more ▼]

The F1 hybrids of roach Rutilus rutilus, silver bream Blicca bjoerkna, and common bream Abramis brama from experimental reciprocal cross-breedings were identified at 18 months of age in relation to the parental species. The morphological analysis, including quantitative (plastic and meristic) and nonmetric features differing in the roach, the silver bream and the common bream, revealed that roach * common bream and roach * silver bream hybrids were easier to distinguish from their parents than silver bream * common bream hybrids. These roach hybrids had many morphological similarities such as the upper iris coloured in red as in the roach, and they were morphologically intermediate to the two parents. This contrasted with the silver bream * common bream hybrids, in which intermediate characteristics were also observed, but with some parental variants. Roach * silver bream hybrids were distinguishable from roach * common bream hybrids by its large eye, its lower scale numbers along the lateral line and its two rows of pharyngeal teeth. Silver bream * common bream hybrids, compared to the two other types of hybrids studied, had higher anal fin soft ray numbers and a clear eye iris with a median black line. In all interspecific crosses of these three cyprinid species fish, the reciprocal hybrids were generally indistinguishable. [less ▲]

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See detailRegulated discharge produces substantial demographic changes on four typical fish species of a small salmonid stream
Ovidio, Michaël ULg; Capra, Hervé; Philippart, Jean-Claude ULg

in Hydrobiologia (2008), 609

A hydroelectric power plant (HPP) started operation in December 2002 on the River Lhomme, (mean annual flow: 1.78 m(3) s(-1)supercript stop; mean annual water temperature: 9.9 degrees C). The new HPP ... [more ▼]

A hydroelectric power plant (HPP) started operation in December 2002 on the River Lhomme, (mean annual flow: 1.78 m(3) s(-1)supercript stop; mean annual water temperature: 9.9 degrees C). The new HPP bypasses the river over a length of 1.2 km. The minimum flow allowed in the bypassed section is currently fixed at 0.220 m(3) s(-1)supercript stop. Before the construction of the HPP, two contrasted 150-m-long reaches of the Lhomme were selected to estimate their total fish population abundance and to analyse their fish population dynamics. Electrofishing was carried out in each of these two reaches on 23 April 2002 in a natural flow situation to remove the fish. Other inventories were carried out in late April or early May in 2003, 2004, 2005 and 2006 in minimum flow conditions. The results revealed a prompt and severe decrease in the total fish biomass (up to 81% for grayling from 2002 to 2006) combined with severe changes in the fish community structure that were not observed in a reference site. The effects of the flow reduction varied considerably depending on the size of the individuals, the species concerned and their habitat availability, which was modelled using a classical physical habitat simulation (EVHA method). [less ▲]

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See detailMovement patterns and spawning activity of individual nase Chondrostoma nasus (L.) in flow-regulated and weir-fragmented rivers
Ovidio, Michaël ULg; Philippart, Jean-Claude ULg

in Journal of Applied Ichthyology (2008), 24(3), 256-262

Eighteen adult nase Chondrostoma nasus (L.) (37.6-48.2 cm FL) from three highly fragmented Belgian rivers were tagged with surgically implanted radio transmitters and manually tracked from the banks of ... [more ▼]

Eighteen adult nase Chondrostoma nasus (L.) (37.6-48.2 cm FL) from three highly fragmented Belgian rivers were tagged with surgically implanted radio transmitters and manually tracked from the banks of the rivers for 3-34 weeks. Their movements were mainly recorded during the circum reproduction period in 2001, 2002 and 2006 in river stretches delimited by physical barriers and/or minimum flow conditions. To reach the spawning grounds, nase displayed different patterns of movements that were mainly influenced by the configuration of the study site, the date of observation and the associated environmental conditions. Nase never cleared any physical obstacle but were able to spawn in minimum flow conditions or just downstream from physical obstacles. Nase were present on spawning grounds in late March in the warmest spring (2001) and from mid-April to early May in the coldest spring (2006). After spawning, a major proportion of C. nasus migrated a substantial distance downstream, whereas others remained near their capture site and showed frequent movements, sometimes corresponding to group displacements from one river to another. [less ▲]

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See detailMating patterns of first-generation hybrids of the roach, Rutilus rutilus (L.), and the silver bream, Blicca bjoerkna (L.)
Nzau Matondo, Billy; Ovidio, Michaël ULg; Philippart, Jean-Claude ULg et al

in Journal of Ethology (2008), 26(1), 179-183

Mating patterns among first-generation hybrids of the roach, Rutilus rutilus, and the silver bream, Blicca bjoerkna, between hybrids or with parent-species males, have been investigated under experimental ... [more ▼]

Mating patterns among first-generation hybrids of the roach, Rutilus rutilus, and the silver bream, Blicca bjoerkna, between hybrids or with parent-species males, have been investigated under experimental reproduction conditions. The results reveal that the level of sexual activity of these hybrids is high. Hybrid females mated simultaneously and successively with all types of male, resulting in fertilised eggs. Individual participation of roach males in mating was never observed, however. [less ▲]

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