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 References of "Descy, Jean-Pierre"      in Complete repository Arts & humanities   Archaeology   Art & art history   Classical & oriental studies   History   Languages & linguistics   Literature   Performing arts   Philosophy & ethics   Religion & theology   Multidisciplinary, general & others Business & economic sciences   Accounting & auditing   Production, distribution & supply chain management   Finance   General management & organizational theory   Human resources management   Management information systems   Marketing   Strategy & innovation   Quantitative methods in economics & management   General economics & history of economic thought   International economics   Macroeconomics & monetary economics   Microeconomics   Economic systems & public economics   Social economics   Special economic topics (health, labor, transportation…)   Multidisciplinary, general & others Engineering, computing & technology   Aerospace & aeronautics engineering   Architecture   Chemical engineering   Civil engineering   Computer science   Electrical & electronics engineering   Energy   Geological, petroleum & mining engineering   Materials science & engineering   Mechanical engineering   Multidisciplinary, general & others Human health sciences   Alternative medicine   Anesthesia & intensive care   Cardiovascular & respiratory systems   Dentistry & oral medicine   Dermatology   Endocrinology, metabolism & nutrition   Forensic medicine   Gastroenterology & hepatology   General & internal medicine   Geriatrics   Hematology   Immunology & infectious disease   Laboratory medicine & medical technology   Neurology   Oncology   Ophthalmology   Orthopedics, rehabilitation & sports medicine   Otolaryngology   Pediatrics   Pharmacy, pharmacology & toxicology   Psychiatry   Public health, health care sciences & services   Radiology, nuclear medicine & imaging   Reproductive medicine (gynecology, andrology, obstetrics)   Rheumatology   Surgery   Urology & nephrology   Multidisciplinary, general & others Law, criminology & political science   Civil law   Criminal law & procedure   Criminology   Economic & commercial law   European & international law   Judicial law   Metalaw, Roman law, history of law & comparative law   Political science, public administration & international relations   Public law   Social law   Tax law   Multidisciplinary, general & others Life sciences   Agriculture & agronomy   Anatomy (cytology, histology, embryology...) & physiology   Animal production & animal husbandry   Aquatic sciences & oceanology   Biochemistry, biophysics & molecular biology   Biotechnology   Entomology & pest control   Environmental sciences & ecology   Food science   Genetics & genetic processes   Microbiology   Phytobiology (plant sciences, forestry, mycology...)   Veterinary medicine & animal health   Zoology   Multidisciplinary, general & others Physical, chemical, mathematical & earth Sciences   Chemistry   Earth sciences & physical geography   Mathematics   Physics   Space science, astronomy & astrophysics   Multidisciplinary, general & others Social & behavioral sciences, psychology   Animal psychology, ethology & psychobiology   Anthropology   Communication & mass media   Education & instruction   Human geography & demography   Library & information sciences   Neurosciences & behavior   Regional & inter-regional studies   Social work & social policy   Sociology & social sciences   Social, industrial & organizational psychology   Theoretical & cognitive psychology   Treatment & clinical psychology   Multidisciplinary, general & others     Showing results 1 to 20 of 93 1 2 3 4 5     Convention Région wallonne et HGE-ULg Caractérisation complémentaire des masses d’eau dont le bon état dépend d’interactions entre les eaux de surface et les eaux souterraines - Délivrable D1.8 Rapport finalBrouyère, Serge ; Briers, Pierre ; Descy, Jean-Pierre et alReport (2017)Mechanisms of interactions between groundwater bodies and rivers whose status and anthropogenic use can be detrimental from a quantitative and qualitative point of view to one or the other of these two ... [more ▼]Mechanisms of interactions between groundwater bodies and rivers whose status and anthropogenic use can be detrimental from a quantitative and qualitative point of view to one or the other of these two compartments of the water cycle. In addition, contamination of groundwater by nitrate remains relevant. Based on these observations, a study financed by the Public Service of Wallonia was carried out over a period of 39 months to investigate (1) the direction, importance and dynamics of water exchange between groundwater and rivers at the scale of a river section; (2) the impact of these interactions on river baseflows and the river ecological status as a function of groundwater withdrawal and recharge at the catchment scale; (3) mechanisms and timing of transfer and abatement of pollutants (nitrate) between groundwater and surface waters at the watershed scale. The consequences of these mechanisms on the medium- and long-term evolution of groundwater and surface water quality were to be determined. To achieve this, the project relied on the implementation of a series of field investigations essentially focused on the interfaces between surface water and groundwater compartments (soil and unsaturated zone and water-table interface), while acquiring additional information on groundwater. The investigations carried out in the watersheds of the upstream Hoyoux and Triffoy watershed in the Condroz region aimed to provide 6 specific responses to water quantity and quality issued associated with groundwater – surface water interactions in the selected basins and generic responses in the form of new knowledge concerning the mechanisms of recharge and groundwater - river exchanges, concerning the evolution of nitrate concentrations in watersheds, data and measurements for the parameterization of models, and water resources management tools in the form of quantitative and qualitative indicators for groundwater - surface water interactions. [less ▲]Detailed reference viewed: 127 (26 ULiège) Effects of human land use on the terrestrial and aquatic sources of fluvial organic matter in a temperate river basin (The Meuse River, Belgium)Lambert, Thibault; Bouillon, Steven; Darchambeau, François et alin Biogeochemistry (2017)The impact of human activities on the concentrations and composition of dissolved organic matter (DOM) and particulate organic matter (POM) was investigated in the Walloon Region of the Meuse River basin ... [more ▼]The impact of human activities on the concentrations and composition of dissolved organic matter (DOM) and particulate organic matter (POM) was investigated in the Walloon Region of the Meuse River basin (Belgium). Water samples were collected at different hydrological periods along a gradient of human disturbance (50 sampling sites ranging from 8.0 to 20,407 km2) and during a 1.5 year monitoring of the Meuse River at the city of Liège. This dataset was completed by the characterization of the DOM pool in groundwaters. The composition of DOM and POM was investigated through elemental (C:N ratios), isotopic ($\delta$13C) and optical measurements including excitation emission matrix fluorescence with parallel factor analysis (EEM--PARAFAC). Land use was a major driver on fluvial OM composition at the regional scale of the Meuse Basin, the composition of both fluvial DOM and POM pools showing a shift toward a more microbial/algal and less plant/soil-derived character as human disturbance increased. The comparison of DOM composition between surface and groundwaters demonstrated that this pattern can be attributed in part to the transformation of terrestrial sources by agricultural practices that promote the decomposition of soil organic matter in agricultural lands and subsequent microbial inputs in terrestrial sources. In parallel, human land had contrasting effects on the autochthonous production of DOM and POM. While the in-stream generation of fresh DOM through biological activity was promoted in urban areas, summer autochthonous POM production was not influenced by land use. Finally, soil erosion by agricultural management practices favored the transfer of terrestrial organic matter via the particulate phase. Stable isotope data suggest that the hydrological transfer of terrestrial DOM and POM in human-impacted catchment are not subject to the same controls, and that physical exchange between these two pools of organic matter is limited. [less ▲]Detailed reference viewed: 28 (2 ULiège) Iron-dependent nitrogen cycling in a ferruginous lake and the nutrient status of Proterozoic oceansMichiels, Celine C.; Darchambeau, François ; Roland, Fleur et alin Nature Geoscience (2017), advance online publicationNitrogen limitation during the Proterozoic has been inferred from the great expanse of ocean anoxia under low-O2 atmospheres, which could have promoted NO3- reduction to N2 and fixed N loss from the ocean ... [more ▼]Nitrogen limitation during the Proterozoic has been inferred from the great expanse of ocean anoxia under low-O2 atmospheres, which could have promoted NO3- reduction to N2 and fixed N loss from the ocean. The deep oceans were Fe rich (ferruginous) during much of this time, yet the dynamics of N cycling under such conditions remain entirely conceptual, as analogue environments are rare today. Here we use incubation experiments to show that a modern ferruginous basin, Kabuno Bay in East Africa, supports high rates of NO3- reduction. Although 60 of this NO3- is reduced to N2 through canonical denitrification, a large fraction (40\%) is reduced to NH4+, leading to N retention rather than loss. We also find that NO3- reduction is Fe dependent, demonstrating that such reactions occur in natural ferruginous water columns. Numerical modelling of ferruginous upwelling systems, informed by our results from Kabuno Bay, demonstrates that NO3- reduction to NH4+ could have enhanced biological production, fuelling sulfate reduction and the development of mid-water euxinia overlying ferruginous deep oceans. This NO3- reduction to NH4+ could also have partly offset a negative feedback on biological production that accompanies oxygenation of the surface ocean. Our results indicate that N loss in ferruginous upwelling systems may not have kept pace with global N fixation at marine phosphorous concentrations (0.04-0.13[thinsp][mu]M) indicated by the rock record. We therefore suggest that global marine biological production under ferruginous ocean conditions in the Proterozoic eon may thus have been P not N limited. [less ▲]Detailed reference viewed: 39 (5 ULiège) Stream-aquifer interactions: a combined field - methodological approach in fractured carbonate catchmentsBrouyère, Serge ; Briers, Pierre ; Orban, Philippe et alConference (2016, December 16)Stream-aquifer studies remain a challenge due to numerous factors impacting these interactions. They play a fundamental role in terms of quantity and quality of water, in particular on the ecological ... [more ▼]Stream-aquifer studies remain a challenge due to numerous factors impacting these interactions. They play a fundamental role in terms of quantity and quality of water, in particular on the ecological status of rivers. Field quantification of such interactions is a first step but it has to be in relation with the whole budgets of water and transported substances across the catchment in order to represent their importance on overall fluxes. Numerous complementary investigations have to be undertaken to achieve such understanding of catchment behavior, in particular to estimate specific indicators and to achieve representative data for modeling stream-aquifer interactions. From that situation, our study aims to characterize and quantify stream-aquifer interactions to assess reliability of diverse field experiments methodologies. A catchment has been studied for 3 years in quantitative and qualitative ways via a dense instrumentation and monitoring. Numerous complementary investigations (discharge measurements, hydrogeochemistry, distributed temperature sensing, base flow separation…) have been applied to reach the objectives. We achieved a large and diversified measurement dataset of groundwater-surface water interactions and whole water budget. This allowed reaching an improved understanding of the catchment behavior to quantify importance of the groundwater component on the dynamics and chemistry of the stream and on the consequences on river ecological status. The investigations on several subcatchments allows also to propose a general typology of stream catchment in terms of groundwater dependence based on the combination of various groundwater contexts and groundwater-stream interaction indicators. Methodologies applied in this study allow to emphasize strength and weakness of numerous investigations in a stream aquifer project and conclusions can be reproduced and generalized to other contexts. [less ▲]Detailed reference viewed: 36 (5 ULiège) Nitrate dynamic and pathways in fractured limestone aquifers : From soil leaching to groundwater discharge in surface waterBriers, Pierre ; Schmit, Flore; Orban, Philippe et alConference (2016, July 27)Fractured – karstified limestone aquifers constitute important, but vulnerable groundwater reservoirs in many areas across the World. Such carbonate systems are highly heterogeneous leading to a high ... [more ▼]Fractured – karstified limestone aquifers constitute important, but vulnerable groundwater reservoirs in many areas across the World. Such carbonate systems are highly heterogeneous leading to a high spatial and temporal variability of fluxes across the soil – vadose zone – groundwater – surface water continuum. One of the main challenges worldwide is to protect such groundwater bodies from diffuse pollutions, in particular agricultural chemicals such as nitrate. To face such problems and to propose adequate pollution mitigation scenarios, the objective here was to better understand and quantify nitrate dynamics and pathways in the subsurface and at the groundwater – surface water interface. The transfer of nitrate was investigated in different ways such as monitoring of concentrations in both groundwater and surface water, tracer experiments in the unsaturated – saturated continuum and regional investigations on groundwater chemistry including stable isotopes of nitrate and other compounds. Results show that nitrate concentrations are relatively stable both in groundwater and surface water during the low flow period (i.e. from spring to autumn). A temporary but significant increase in nitrate concentration is observed in groundwater and rivers during the winter, related to release of residual nitrate from agricultural soils driven by infiltration water. In period of high precipitations and runoff, dilution is measured in the river. Monitoring and tracer test results also highlight the fact that the migration of dissolved contaminants across the unsaturated zone of limestone rocks is very fast and governed by gravitational flows. In the rivers, macroinvertebrates and benthic diatoms were sampled at several sites to assess ecological status and structural and functional response to alteration of water quality (nutrient enrichment) and quantity (current velocity and stream habitats). Diatom indices and community structure indicated good to very good status in both studied streams, indicating that elevated nitrate concentration have no detectable effect on biological quality of the surface waters. The combination of all these results allows developing a detailed conceptual model of the dynamics of nitrate (and other agricultural contaminants) in fractured / karstified limestone aquifers, with improved estimates of nitrate trends and dynamics in both groundwater and rivers. [less ▲]Detailed reference viewed: 143 (18 ULiège) Le bassin du Triffoy et les eaux souterraines : Exemple de caractérisation des échanges entre nappe et rivièreBriers, Pierre ; Descy, Jean-Pierre; Schmit, Flore et alin Atlas du Karst Wallon - Bassins versants du Hoyoux et de la Solières (2016)Detailed reference viewed: 38 (2 ULiège) Rapport final de la convention relative à la caractérisation complémentaire des masses d'eau dont le bon état dépend d'interactions entre les eaux de surface et les eaux souterrainesBrouyère, Serge ; Briers, Pierre ; Schmit, Flore et alReport (2016)Detailed reference viewed: 58 (29 ULiège) Phytoplankton dynamics in the Congo RiverDescy, Jean-Pierre; Darchambeau, François ; Lambert, Thibault et alin Freshwater Biology (2016)* We report a dataset of phytoplankton in the Congo River, acquired along a 1700-km stretch in the mainstem during high water (HW, December 2013) and falling water (FW, June 2014). Samples for ... [more ▼]* We report a dataset of phytoplankton in the Congo River, acquired along a 1700-km stretch in the mainstem during high water (HW, December 2013) and falling water (FW, June 2014). Samples for phytoplankton analysis were collected in the main river, in tributaries and one lake, and various relevant environmental variables were measured. Phytoplankton biomass and composition were determined by high-performance liquid chromatography analysis of chlorophyll a (Chl a) and marker pigments and by microscopy. Primary production measurements were made using the 13C incubation technique. In addition, data are also reported from a 19-month regular sampling (bi-monthly) at a fixed station in the mainstem of the upper Congo (at the city of Kisangani). * Chl a concentrations differed between the two periods studied: in the mainstem, they varied between 0.07 and 1.77 μg L−1 in HW conditions and between 1.13 and 7.68 μg L−1 in FW conditions. The relative contribution to phytoplankton biomass from tributaries (mostly black waters) and from a few permanent lakes was low, and the main confluences resulted in phytoplankton dilution. Based on marker pigment concentration, green algae (both chlorophytes and streptophytes) dominated in the mainstem in HW, whereas diatoms dominated in FW; cryptophytes and cyanobacteria were more abundant but still relatively low in the FW period, both in the tributaries and in the main channel.  15) varied between 64.3 and 434.1 mg C m−2 day−1 in FW conditions and between 51.5 and 247.6 mg C m−2 day−1 in HW. Phytoplankton biomass in the Congo River mainstem was likely constrained by hydrological factors (accumulation due to increased retention time during FW, dilution by increased discharge during HW), even though increased nutrient availability in the FW period might have also stimulated phytoplankton production. * In contrast to other tropical river systems where connectivity with the floodplain and the presence of natural lakes and man-made reservoirs play a prominent role in the recruitment of phytoplankton to the main river, our results show that phytoplankton growth in the Congo River can take place in the main channel, with hydrological processes allowing maintenance of phytoplankton biomass even during HW. [less ▲]Detailed reference viewed: 11 (2 ULiège) Identifying the factors determining blooms of cyanobacteria in a set of shallow lakesDescy, Jean-Pierre; Leprieur, Fabien; Pirlot, Samuel et alin Ecological Informatics (2016), 34There is a strong interest in developing a capacity to predict the occurrence of cyanobacteria blooms in lakes and to identify the measures to be taken to reduce water quality problems associated with the ... [more ▼]There is a strong interest in developing a capacity to predict the occurrence of cyanobacteria blooms in lakes and to identify the measures to be taken to reduce water quality problems associated with the occurrence of potentially harmful taxa. Here we conducted a weekly to bi-weekly monitoring program on five shallow eutrophic lakes during two years, with the aim of gathering data on total cyanobacterial abundance, as estimated from marker pigments determined by HPLC analysis of phytoplankton extracts. We also determined bloom composition and measured weather and limnological variables. The most frequently identified taxa were Aphanizomenon flos-aquae, Microcystis aeruginosa, Planktothrix agardhii and Anabaena spp. We used the data base composed of a total of 306 observations and an adaptive regression trees method, the boosted regression tree (BRT), to develop predictive models of bloom occurrence and composition, based on environmental conditions. Data processing with BRT enabled the design of satisfactory prediction models of cyanobacterial abundance and of the occurrence of the main taxa. Phosphorus (total and soluble reactive phosphate), dissolved inorganic nitrogen, epilimnion temperature, photoperiod and euphotic depth were among the best predictive variables, contributing for at least 10 % in the models, and their relative contribution varied in accordance with the ecological traits of the taxa considered. Meteorological factors (wind, rainfall, surface irradiance) had a significant role in species selection. Such results may contribute to designing measures for bloom management in shallow lakes. [less ▲]Detailed reference viewed: 29 (9 ULiège) Case study 2: Groundwater – surface water interaction in limestone areas of the GWB BE_Meuse_RWM021 (Belgium)Brouyère, Serge ; Briers, Pierre ; Schmit, Flore et alin Hinsby, Klaus; Schutten, Johan; Craig, Matt (Eds.) et al Technical Report on Groundwater Associated Aquatic Ecosystems (2015)The achievement of good status in groundwater bodies involves meeting a series of conditions, which are defined in the Water Framework Directive (WFD) and, in the case of good chemical status, are given ... [more ▼]The achievement of good status in groundwater bodies involves meeting a series of conditions, which are defined in the Water Framework Directive (WFD) and, in the case of good chemical status, are given further detail in the Groundwater Directive (GWD). One of these conditions is to ensure that groundwater inputs to associated surface waters do not result in failure to meet the environmental objectives of those waters or result in significant diminution in status/ecological or chemical quality of those waters. GWAAE (Groundwater Associated Aquatic Ecosystems) are those surface water bodies (SWBs), including rivers, standing waters and transitional waters where the surface water ecology and hydrology is dependent on contributions from groundwater in order to meet their environmental objectives under the WFD. These environmental objectives may vary, and therefore the associated environmental quality standards (EQS) or flow/level requirements of GWAAEs may differ between high status and good status SWBs. As noted in the Blueprint for Water, analysis of the first River Basin Management Plans has shown that Member States (MS) have experienced difficulties in understanding the interactions between groundwater and surface water and undertaking the necessary status assessments. This was highlighted in a survey carried out by Working Group Groundwater (WGGW) in 2014/15, which indicated that only half of the MS had assessed quantitative interactions and very few had addressed chemical pressures, including the derivation of threshold values (TVs) that were appropriate to the WFD objectives for GWAAEs. This report aims to further knowledge on what GWAAE are, how they are aligned to WFD processes, and support Member States to properly include the needs of these ecosystems in river basin management planning. The report clarifies the categories of GWAAE and their relative dependence on groundwater and collates current available knowledge and experience via a number of examples and case studies. Terminology and status assessment procedures are explained and pragmatic approaches are proposed which leave some flexibility for MS to adapt to their own specific needs. This technical report, which is not a "guidance document", makes use of and complements existing CIS documents, including existing technical reports on groundwater dependent terrestrial ecosystems (GWDTEs) and Guidance Document 18 (Guidance on Groundwater Status and Trend Assessment). A number of recommendations for technical users of the report are highlighted in boxes in each Chapter. The common themes from these recommendations are collated in Chapter 8, as issues and questions to WGGW and MS in general. The key message from this is the need for closer interaction between scientific disciplines, practitioners and Working Groups in developing conceptual understanding for GWAAEs and implementation of WFD requirements, including identification of GWAAEs, their characterisation and monitoring, and adopting appropriate status assessment methodologies. [less ▲]Detailed reference viewed: 40 (7 ULiège) Bacterial community composition in three freshwater reservoirs of di erent alkalinity and trophic statusLlirós, Marc; Inceoglu, Ozgul; Garcia-Armisen, Tamara et alPoster (2015, August 23)Detailed reference viewed: 21 (2 ULiège) Vertical Distribution of Functional Potential and Active Microbial Communities in Meromictic Lake Kivuİnceoğlu, Özgul; Llirós, Marc; Crowe, Sean A. et alin Microbial Ecology (2015)Detailed reference viewed: 19 (1 ULiège) Bacterial Community Composition in Three Freshwater Reservoirs of Different Alkalinity and Trophic StatusLlirós, Marc; Inceoğlu, Özgul; García-Armisen, Tamara et alin PLoS ONE (2014)Detailed reference viewed: 34 (1 ULiège) Characterization of stream - aquifer interaction in carbonate rocksBriers, Pierre ; Sohier, Catherine ; Schmit, Flore et alPoster (2014, September 30)Groundwater - surface water interactions play a fundamental role in terms of quantity and quality of water and in terms of ecological quality of rivers. Despite many research efforts and the necessity to ... [more ▼]Groundwater - surface water interactions play a fundamental role in terms of quantity and quality of water and in terms of ecological quality of rivers. Despite many research efforts and the necessity to better understand such interactions in order to reach effective management of water resources, stream-aquifer exchanges remain poorly understood, in particular in fractured carbonate environments. [less ▲]Detailed reference viewed: 55 (9 ULiège) Production of dissolved organic matter by phytoplankton and its uptake by heterotrophic prokaryotes in large tropical lakesMorana, Cédric; Sarmento, Hugo; Descy, Jean-Pierre et alin Limnology and Oceanography (2014), 59(4), 1364-1375In pelagic ecosystems, phytoplankton extracellular release can extensively subsidize the heterotrophic prokaryotic carbon demand. Time-course experiments were carried out to quantify primary production ... [more ▼]In pelagic ecosystems, phytoplankton extracellular release can extensively subsidize the heterotrophic prokaryotic carbon demand. Time-course experiments were carried out to quantify primary production, phytoplankton excretion, and the microbial uptake of freshly released dissolved organic carbon (DOC) derived from phytoplankton extracellular release (DOCp) in four large tropical lakes distributed along a productivity gradient: Kivu, Edward, Albert, and Victoria. The contributions of the major heterotrophic bacterial groups to the uptake of DOCp was also analyzed in Lake Kivu, using microautoradiography coupled to catalyzed reporter deposition fluorescent in situ hybridization. The percentage of extracellular release (PER) varied across the productivity gradient, with higher values at low productivity. Furthermore, PER was significantly related to high light and low phosphate concentrations in the mixed layer and was comparatively higher in oligotrophic tropical lakes than in their temperate counterparts. Both observations suggest that environmental factors play a key role in the control of phytoplankton excretion. Standing stocks of DOCp were small and generally contributed less than 1% to the total DOC because it was rapidly assimilated by prokaryotes. In other words, there was a tight coupling between the production and the heterotrophic consumption of DOCp. None of the major phylogenetic bacterial groups that were investigated differed in their ability to take up DOCp, in contrast with earlier results reported for standard labeled single-molecule substrates (leucine, glucose, adenosine triphosphate). It supports the idea that the metabolic ability to use DOCp is widespread among heterotrophic prokaryotes. Overall, these results highlight the importance of carbon transfer between phytoplankton and bacterioplankton in large African lakes. [less ▲]Detailed reference viewed: 131 (1 ULiège) Understanding the performance of the FLake model over two African Great LakesThiery, Wim; Martynov, Andrey; Darchambeau, François et alin Geoscientific Model Development [=GMD] (2014), 7Detailed reference viewed: 15 (0 ULiège) Primary production in a tropical large lake: The role of phytoplankton compositionDarchambeau, François ; Sarmento, Hugo; Descy, Jean-Pierrein Science of the Total Environment (2014), 473-474Detailed reference viewed: 29 (0 ULiège) Impact of the invasive Asian clam, Corbicula spp., on a large river ecosytemPigneur, Lise-Marie; Falisse, Elodie; Roland, Kathleen et alin Freshwater Biology (2014), 59(3), 573-583During the past recent decades, Asiatic clams (Corbicula spp.) have spread spectacularly in several large European rivers. In the River Meuse, a transnational lowland river, an important chlorophyll a ... [more ▼]During the past recent decades, Asiatic clams (Corbicula spp.) have spread spectacularly in several large European rivers. In the River Meuse, a transnational lowland river, an important chlorophyll a decline has been recorded since the mid-2000s, which seems to be related to the invasion by these exotic bivalves. This study aimed at verifying that hypothesis, using clam density data from field surveys, water quality monitoring data, and a simulation model. Estimated Corbicula densities were between 50 and 900 individuals m-2, depending on the site. Using a maximum filtration rate per clam body mass of 0.086 m3 g C-1 day-1 at 20°C derived from the literature, we ran simulations with a non-stationary model to estimate the impact of the exotic bivalve on the river plankton and water quality. In the stretches where the invasive clams developed best, comparison with a clam-free scenario allowed estimating a 70 % phytoplankton biomass loss due to their filtration, leading to a 61 % loss of annual primary productivity. Model simulations also showed that zooplankton may have suffered as much as 75 % loss in terms of biomass. The simulations also point to substantial effects of the invasive Corbicula on the river oxygen budget and on nutrient cycling. We expect that, in the heavily regulated sectors of the river, the loss of planktonic production due to the invasive filter-feeders will negatively affect other suspension feeders and alter ecosystem function and productivity. [less ▲]Detailed reference viewed: 88 (15 ULiège) Dissolved primary production and heterotrophic prokaryote reassimilation in a large oligotrophic tropical lake (Lake Kivu, Eastern Africa)Morana, Cédric; Sarmento, Hugo; Bouillon, Steven et alConference (2012, July 11)Detailed reference viewed: 42 (0 ULiège) Lake Kivu, Limnology and Biogeochemistry of a Tropical Great LakeDescy, Jean-Pierre; Darchambeau, François ; Schmid, MartinBook published by Springer (2012)In the heart of Africa, a unique lake has attracted the attention of scientists since the beginning of the 20th century. At the foot of the Virunga volcano chain, Lake Kivu harbors a vast amount of ... [more ▼]In the heart of Africa, a unique lake has attracted the attention of scientists since the beginning of the 20th century. At the foot of the Virunga volcano chain, Lake Kivu harbors a vast amount of dissolved carbon dioxide and methane, making it the most dangerous lake on Earth. But the lake also furnishes many goods and services for surrounding populations and may soon become the most important energy supplier in the area. At the beginning of gas exploitation, the time has come to gather the wealth of scientific information acquired during past and present research on Lake Kivu. The eleven chapters cover many aspects of the physics, geochemistry and biology of the lake, with a particular focus on the unique physical and geochemical features of the water column and on the ecological functioning of the surface waters. The impacts of the introduced fish species and the potential impacts of methane exploitation are also summarized. This multi-disciplinary book may also be used as an introduction to the limnology and biogeochemistry of large tropical lakes, as it covers various aspects of the physics, geochemistry, biology and ecology of the African Great Rift lakes. [less ▲]Detailed reference viewed: 17 (1 ULiège) 1 2 3 4 5