Search publications of the members of the Royal Belgian institute of natural Sciences
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Total suspended matter maps from CHRIS imagery of a small inland water body in Oostende (Belgium)
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Optical detection of a Noctiluca scintillans bloom
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Variability of the spectral reflectance and transparency of river plume waters caused by hydrodynamic processes
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Radar signatures of river outflow fronts
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Towards an operational monitoring system for turbid waters
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POWERS - User requirements document
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Conservation research Matters Initiative
- Report on the 2013 "Conservation Research Matters" Conference - downloadable from http://www.biodiversity.be/1861; 42 pp.
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Larval dispersal and juvenile dynamics of flatfish in the Southern North Sea.
- Marine populations display some of the most extreme patterns of spatial and temporal heterogeneity in demographic factors. Over the past few decades, many marine fisheries have declined or even collapsed. This is in large part, due to climate change and detrimental anthropogenic influences (e.g. habitat degradation and overfishing). Due to a highly complex optimal window between biological needs and favorable environmental factors, marine species are very susceptible to natural perturbations. This leads to unpredictable reproductive success, high mortality and obscure population delineations. Preventing a complete collapse offish stock requires a thorough knowledge of the recruitment dynamics. With the B-FishConnect project we want to disentangle the physical and biological factors influencing dispersal and recruitment in flatfish. Within the project, we will focus on four commercially important flatfish species in the North Sea: sole, plaice, turbot and brill. To quantify the role of physical and biological factors on the population dynamics, a combination of hydrodynamic and demographic-genetic models will be applied. The output of these models will be compared to empirical field data. The focus of this project will be on the post-larval and juvenile stages of flatfish. Information on the spatial-temporal dynamics of larvae and juveniles will be gathered by an intense sampling campaign along the coast as well as on sea. Additional information will be obtained through historical datasets. The larval dispersal history will be inferred by analysing the otolith microstructure of juvenile flatfish. The effect of the larval history and local habitat characteristics on the future survival and condition of juvenile flatfish will be investigated. This will be accomplished by using biomarkers and condition indices. The derived information on life-history traits, population structure and spatio-temporal dynamics will be used to validate the dispersal models (Lacroix et al., 2013). In a later phase this will allow us to test different ecological hypotheses and to assess the impact of various scenarios related to climate change and human impact on flatfish in the North Sea. Consequently these data will be vital for fisheries and conservation management.
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Outputs of the Strategic Foresight workshop “Nature-Based Solutions in a BiodiversA context"
- Report on the Nature-Based Solutions workshop organized in Belspo (Brussels) on 11-12 June 2014. Downloadabe from http://www.biodiversa.org/671; 45 pp.
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Belgian Biodiversity Platform, Annual Report 2013
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Belgian Biodiversity Platform, Annual Report 2014
- Downloadable from http://www.biodiversa.org/497/download; 44 pp.
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Vers une approche semi-automatique pour la définition de motifs d'argumentation utilisés dans les résumés de projets scientifiques du domaine de la biodiversité
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Assessing connectivity in young flatfish and its implementation in fisheries management.
- Recently, it has been shown that commercial fisheries target specific size/age classes, causing a loss of genetic diversity as well as altering life cycles (fisheries-induced evolution). This represents a serious threat for the future of commercial stocks. Such features have also been observed in the North Sea stocks of sole (Solea solea), which have been overfished in the past 20 years. For example, heavy fishing pressure has led to smaller individuals. Given its commercial importance in the North Sea fishery, a larger effort has to be made to preserve this valuable resource. To improve sole stock management, managers would benefit from an upgraded biological assessment of population structure and connectivity patterns. We will address the following questions: 1. Does larval dispersal vary in time and space? 2. What biotic and abiotic factors are driving larval connectivity? And once known, 3. Can we predict the impact of changes in physical and biological drivers? 4. Can we define sub-populations based on connectivity patterns? My research project aims at filling those gaps, by focusing on population connectivity at the larval and postlarval stages. A suite of 200 highly variable SNPs (Single Nucleotide Polymorphisms) and state-of-the-art genotyping (Illumina-Veracode) will be employed to investigate the population structure of sole at a regional scale (<150km) within the North Sea and eastern English Channel. Additional insights will be gained by otolith microchemistry, used to trace the movement of single individuals between spawning and nursery grounds. Temporal variability will be studied through the combination of two years of intensive sampling and historical datasets spanning the last two decades. Finally, results of hydrodynamic modelling of larval dispersal will be compared to collected data in order to investigate the role of selected biotic and abiotic factors in driving connectivity. Overall, this study will help the sustainable management of the fishery by defining significant ecological units, while the molecular markers will allow tracing any fish present on the market to its origin, hence fighting illegal fishing.
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How sensitive is sole larval dispersal in the North Sea to the parametrization of larval duration? A modelling study.
- Connectivity throughout the life cycle of flatfish remains an open question, especially at the early life stages. The case of sole (Solea solea) is of particular interest because it is one of the most valuable commercial species in the North Sea. It is crucial to understand how the spawning grounds and nurseries are connected and what are the processes influencing larval retention and dispersal in order to propose appropriate management measures. Especially, dispersal during the larval stage is still poorly known. The transport of sole larvae from the spawning grounds to the nurseries is driven by hydrodynamic processes but the final dispersal pattern and larval abundance at nurseries might be affected by biological processes and environmental factors. Larval Transport Models (LTMs) coupled to Individual-Based Models (IBMs) are more and more commonly used to assess the relative contribution of these processes on the larval dispersal. IBMs allow to take into account growth to estimate the duration of dispersal based on environmental conditions met by the larvae. These models may be sensitive to process parametrization and may give different results for parametrizations derived from the same data set. The Larvae&Co model (Lacroix et al., 2013) used in the frame of B-FishConnect project couples the 3D hydrodynamic model Coherens with an IBM of sole larvae. It is used here to investigate the impact of parametrization of the stage duration on the dispersal of sole larvae in the North Sea. In this study, we compare two parametrizations (Rochette et ai, 2012 and Lacroix et ai, 2013) of the stage duration (temperature dependent) derived from the same data set (mainly Fonds, 1979). We show that only small differences of the stage duration parametrization may induce significant differences of the dispersal pattern, connectivity and larval recruitment at nursery. This highlights the importance to parametrize biological processes with accuracy and the need to collect sufficient data (samples, genotypes and otoliths) and conduct experimental studies to derive biological processes parametrizations in order to improve model’s reliability.
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Ecosystem Models as Support to Eutrophication Management in the North Atlantic Ocean (EMoSEM).
- A major challenge in EU marine governance is to reach the good environmental status (GES) in the north-eastern Atlantic (NEA). Existing approaches do not integrate the eutrophication process in space (continuum river-ocean) and in time (past, present and future status). A strong need remains for (i) knowledge/identification of all the processes that control eutrophication and its consequences, (ii) consistent and harmonized reference levels assigned to each eutrophication-related indicator, (iii) identification of the main rivers directly or indirectly responsible for eutrophication nuisances in specific areas, (iv) an integrated transboundary approach and (v) realistic and scientific-based nutrient reduction scenarios. The SEAS-ERA project EMoSEM (http://www2.mumm.ac.be/emosem/) aims to develop and combine the state-of-the-art modelling tools describing the river-ocean continuum in the NEA continental seas with the objective to: (i) suggest innovative ecological indicators to account for HABs in the GES definition, (ii) estimate the needs to reach GES in all marine areas (distance-to-target requirement, DTTR), (iii) identify “realistic” scenarios of nutrient reduction in the river watersheds of NEA and (iv) assess the impact of the “realistic” scenarios in the sea, and compare to DTTR. Marine ecological models will be used to track the nutrients in the sea, and trace back their riverine or oceanic sources with the transboundary nutrient transport method (TBNT). TBNT application is a prerequisite for DTTR estimates. A generic watershed model applied to NEA rivers will calculate terrestrial nutrient exports to the sea under different scenarios: (i) A past “pristine-like” scenario, where natural nutrient exports are estimated in the absence of human influence and (ii) a series of future “realistic” scenarios, where different wastewater treatments and agricultural practices are combined. EMoSEM will deliver coupled river-coastal-sea mathematical models and will provide guidance to end-users (policy- and decision makers) for assessing and combating eutrophication problems in the NEA continental waters.
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Connectivity and genetic structure of flatfish for fisheries management and traceability in Belgium.
- Early life stages are critical in determining connectivity. Effective fishery management requires understanding of how spawning grounds and nurseries are connected and what processes influence larval retention and dispersal. These mechanisms maintain a high genetic diversity which is essential to grantee population resilience to environmental changes. Marine populations are often believed to be panmictic because there are few obvious barriers to gene flow in the ocean. However, recent work based on Next Generation Sequencing has shown that even highly mobile species have a population structure at reduced spatial scale. Once determined, population structure is the best level to monitor fish stocks. Each population has its own genetic signature therefore traceability system in the industry would highly benefit from a precise mapping and monitoring of stocks, especially for sole in the North Sea. Given its commercial importance in the North Sea fishery, a larger effort has to be made to preserve the flatfish valuable resource. In this project we will address the following questions: 1- Does larval dispersal vary in time and space? 2- What biotic and abiotic factors are driving larval connectivity? 3- Can we define sub-populations based on connectivity patterns? A suite of 1536 SNPs (Single Nucleotide Polymorphisms) and state-of-the-art genotyping (Illumina Golden Gate genotyping) have been employed to investigate the genetic population structure of sole larvae and post-larvae at the European scale. We have obtained four groups: (1) a mixed group with populations within the North Sea and eastern English Channel; and the three most geographically extreme populations were clearly separated: (2) the German Bight on one side and (3) the Celtic Sea and (4) the Irish Sea on the other side. Finally, results of hydrodynamic individual based model of larval dispersal developed by Lacroix and collaborators will be compared to collected da¬ta in order to investigate the role of selected biotic and abiotic factors in driving connectivity. Temporal variability will be studied combing three years of intensive sampling and historical data spanning the last two decades. Overall, this study will help the sustainable management of fishery by defining significant ecological units, while the molecular markers will allow tracing any fish present on the market to its origin, hence fighting illegal fishing and enabling efficient traceability.
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Minéralisation et genèse du gîte stratiforme de Ravandje (Iran central)
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Contribution à l'étude des Rutelinae du Sénégal II (Coleoptera, Scarabaeoidea, Melolonthidae, Rutelinae)
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La grotte sépulcrale de Humain (Marche-en-Famenne, B). Les restes humains et le gobelet campaniforme du Néolithique récent/final.
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Contribution to the knowledge of the bionomics of some steppe Westpalaearctic species belonging to tribe Prionini Latreille, 1802, with the description for the first time of the females of Polylobarthron margelanicum (Théry, 1896) and Mesoprionus petrovitzi (Holzschuh, 1981 (Coleoptera, Cerambycidae, Prioninae)
