Characterization & Management of Natural Resources

published in: 2022 - 2021 - 2020 - 2019 - 2018 - 2017 - 2016


Guava & immune response of catfish

Nhu TQ, Hang BTB, Huong DTT, Scippo M-L, Phuong NT, Quetin-Leclercq J, Kestemont P. 2023. Psidium guajava L.- dichloromethane and ethyl acetate fractions ameliorate striped catfish (Pangasianodon hypophthalmus) status via immune response, inflammatory, and apoptosis pathways. Fish & Shellfish Immunology 138:108851. DOI: 10.1016/j.fsi.2023.108851.

Psidium guajava is known to possess immune-modulatory properties in humans and other mammals. Although the positive effects of P. guajava-based diets on the immunological status have been shown for some fish species, the underlying molecular mechanisms of its protective effects remain to be investigated. The aims of this study were to evaluate the immune-modulatory effects of two guava fractions from dichloromethane (CC) and ethyl acetate (EA) on striped catfish with in vitro and in vivo experiments...

The Twihinate carbonatite (Moroccan Sahara)

Boukirou W, Bouabdellah M, Hoernle K, Hauff F, Slezak P, Chaib M, El Gadarri M, Yans J, Errami A, Levresse G. 2023. The Twihinate carbonatite (Moroccan Sahara): Evidence for compositional mantle heterogeneity and northwestern African plate geodynamics. Chemical Geology 637:121648. DOI: 10.1016/j.chemgeo.2023.121648.

Carbonatites are rocks rich in rare earths, niobium and tantalum, metals now widely used in high-tech and renewable energy. The Cretaceous Twihinate carbonatite in the Moroccan Sahara is a ∼ 5 km diameter ring-shaped intrusion made of an inner core preserving sparse occurrences of medium- to coarse-grained calcite carbonatite encircled by a ring of vuggy siliceous breccia. The Twihinate carbonatite is enriched in large ion lithophile elements (Cs, Rb, Ba, U and Th) and light rare earth elements (LREE), but shows negative anomalies in high field strength elements (particularly Ta, Zr, Hf and Ti)... 

Green color of speleothems

Vlieghe M, Rochez G, Pire-Stevenne S, Storme J-Y, Dekoninck A, Vanbrabant Y, Namur O, Zhang Y, Van Ham-Meert A, Donnadieu J-P, Berbigé M, Hasbroucq J-L, Yans J. 2023. Ni-rich mineral nepouite explains the exceptional green color of speleothems. Scientific Reports 13:15017. DOI: 10.1038/s41598-023-41977-7.

Speleothems are secondary mineral structures typically found in karstic caves and usually composed of calcite or aragonite. Despite being naturally white, some might exhibit unusual colors, such as blue, black, red, yellow or green. The causes of these exceptional colorations are poorly understood, especially for green speleothems, which are barely reported. Here we describe the occurrence of the green Ni‑bearing serpentine nepouite in green aragonite and calcite speleothems, in the Aven du Marcou (Hérault, France). Nepouite is mainly found as flat lamellar crystals in the outer rim of green speleothems and crystallized alongside radially grown aragonite crystals...

Immunomodulatory effects of docosahexaenoic acid (DHA) in common carp

Nguyen TM, Tran Thi NT, Nguyen TH, Do TNA, Kestemont P. 2023. Immunomodulatory effects of graded levels of docosahexaenoic acid (DHA) in common carp (Cyprinus carpio) – In vitro and in vivo approaches. Fish & Shellfish Immunology 134:108585. DOI: 10.1016/j.fsi.2023.108585.

Resolvins work as anti-inflammatory mediators and are also called the immunomodulators in immune system that have potent multilevel mechanisms of action in disease models and promote resolution in animal models. D-series resolvins (such as DHA) play potent anti-inflammatory roles such as activating factors that reduce inflammation and blocking pro-inflammatory responses. The results of thi study suggest that docosahexaenoic acid is able to modulate an acute inflammation in immune cells by modifying the expression of key genes, with the DHA treatment at a dose of 75 μM/mL inducing the highest anti-inflammatory response. The dietary supplementation of DHA did not influence fish growth and feed utilization in the in vivo model; however, positive effects in immune responses and pathogenic resistance were observed in fish fed a diet supplemented with DHA at 20 g/kg of feed.


Plant extracts for striped catfish

Nhu PN, Hang BTB, Phuong NT, Kestemont P, Huong DTT. 2022. Effects of plant extracts on selected haematological parameters, digestive enzymes, and growth performance of striped catfish, Pangasianodon hypophthalmus (Sauvage, 1878) fingerlings. AACL Bioflux 15:1790–1806.

This study examined the effects of dietary supplementation with selected plant extracts on the haematology, enzymatic activities, and growth of striped catfish fingerlings. The enhancement of haematological parameters in conjunction with increased digestive enzyme activity may contribute to the improved health of catfish following the intake of a diet supplemented with plant extracts at different doses and feeding durations. A diet including Psidium guajava 0.2 and Phyllanthus amarus 0.2 extracts administered for 60 days has the potential to modify hematology, enzymatic activity as well as the growth of P. hypophthalmus. Hence, the preference of fish for various plant extract-based diets should be assessed, as these results could demonstrate high use and intake of aquafeed which may lead to improve growth performance of fish.

Immune responses and acute inflammation in common carp

Nguyen TM, Agbohessou PS, Nguyen TH, Tran Thi NT, Kestemont P. 2022. Immune responses and acute inflammation in common carp Cyprinus carpio injected by E.coli lipopolysaccharide (LPS) as affected by dietary oils. Fish & Shellfish Immunology 122:1–12. DOI: 10.1016/j.fsi.2022.01.006.

Eicosanoids, resolvins, and lipoxins formed from long-chain polyunsaturated fatty acids (LC-PUFAs) are the main lipid mediators in the inflammatory processes explaining the influence of dietary lipid sources on the immune system. This study aimed to determine the effects of dietary plant oils instead of fish oil or LC-PUFA supplementation in these oils on fish immune and inflammatory responses under normal and LPS-stimulated conditions. The use of plant oil did not cause any negative effects on fish growth, feed utilization, and survival. The supplementation of LC-PUFAs in diet did not lead to any change in husbandry variables measured in common carp. LPS was able to stimulate the immune system as well as induce acute inflammation in common carp. The dietary lipid sources have modified the immune responses and some other physiological processes involved in acute inflammatory processes. The fish oil-based diet supported an increase of the pro-inflammatory responses while the plant oil mixture or LC-PUFA supplemented diets led to higher anti-inflammatory responses and cytoprotection.

Antiskarn-hosted strategic metal mineralization in Morocco

Bouabdellah M, Boukirou W, Jébrak M, Bigot F, Yans J, Mouttaqi A, El Gadarri M, Errami A, Levresse G. 2022. Discovery of antiskarn-hosted strategic metal mineralization in the Upper Cretaceous Twihinate carbonatite intrusion (West African Craton Margin, Moroccan Sahara). Ore Geology Reviews 149:105105. DOI: 10.1016/j.oregeorev.2022.105105.

Although volumetrically insignificant among igneous rocks, carbonatites and their metasomatized and weathered derivatives stand out as the ones most targeted rock types as they provide most of the world’s strategic metals production such as niobium, rare earth elements (REE), tantalum, phosphorous, copper, iron and fluorine. The Twihinate prospect is currently considered as one of the most promising carbonatite-hosted strategic metals discoveries that have been made in the Moroccan Sahara over the last two decades. The Nb-P-Fe ± LREE ± U-Th-rich mineralization and associated base metal sulfides, fluorite and baryte are hosted by an Upper Cretaceous calcite carbonatite and its overlying weathered derivates. Our petrographic, mineralogical and geochemical data indicate that part of the newly discovered mineralization is related to a widespread metasomatic event which resulted in development of the Twihinate antiskarn lithotypes. The ore mineralogy consists predominantly of oxides (vanadiferous titanomagnetite), pyrochlore group minerals, phosphates (apatite, monazite), and REE-fluorcarbonates (bastnäsite-(Ce)) with subordinate amounts of sulfides (chalcopyrite, sphalerite, and galena), fluorite and baryte. In addition to the above-referenced strategic metals, the Twihinate ore is characterized by widespread occurrence of vanadiferous titanomagnetite. This V enrichment could constitute a per value for the explored occurrences through the development of mining of magnetite-bearing carbonatitic rocks and related antiskarn rocks targeting V as a by-product. Petrogenetically, we propose that the calc-silicate antiskarn rocks and related Nb-P-Fe ± LREE ± U-Th-rich mineralization were formed as a result of silica contamination of the residual carbonatite-derived melts by the surrounding Silurian-Devonian granitic rocks.

Goethite record in the High Atlas Foreland (Morocco)

Verhaert M, Gautheron C, Dekoninck A, Vennemann T, Pinna-Jamme R, Mouttaqi A, Yans J. 2022. Unravelling the Temporal and Chemical Evolution of a Mineralizing Fluid in Karst-Hosted Deposits: A Record from Goethite in the High Atlas Foreland (Morocco). Minerals 12:1151. DOI: 10.3390/min12091151.

Timing and duration of ore deposit formation are crucial to understanding the mineralization process. To address this, the geochronological (U-Th)/He method, geochemical and H- and O-isotope compositions of pure goethite formed in the Imini karst-hosted Mn district (High Atlas, Morocco) were examined in detail. Two main generations of cavity-filling and fracture-filling goethite are identified, and both precipitated prior to the massive Mn oxide ore. The δD and δ18O values reveal that the mineralizing fluid of cavity and fracture-filling goethite is meteoric-derived but enriched in 18O due to fluid–rock interactions with the host rock dolostone or mixing with O2-rich surface water resident in an open karst system. The cavity-filling goethite precipitated between 95 to 80 Ma, whereas fracture-filling goethite formed between 80 to 50 Ma. Ore deposition occurred discontinuously during the early Atlas doming associated with one or more early compressional events in the Atlas tectonism. The increase in δD values and depletion in U content result from a change in the mineralizing fluid within the karst system. At about 50 Ma, the fluid is notably enriched in U, Cu and trace metals.

The Meuse River basin - book chapter

Tockner K, Zarfl C, Robinson CT (eds.). 2022. Chapter 5.1 - Continental Atlantic Rivers: The Meuse, Loire and Adour-Garonne Basins. In: Rivers of Europe (Second Edition). Elsevier, 225–289. DOI: 10.1016/B978-0-08-102612-0.00020-1. P. Kestemont co-author of subChapter 5.1.1. The Meuse River basin

The Meuse is an international river that has been used by man for centuries and it is still the main source of drinking water for large cities in Belgium and the Netherlands. In fact, water quantity and quality have been a major issue between the various riparian countries and political regions. Many kinds of data have been generated in the past decades on various aspects of the river: (a) hydrology for the need of predicting and controlling floods; (b) water chemistry in the context of water pollution assessment and control; and (c) biology and ecology for water quality assessment and studies on aquatic biodiversity community dynamics and ecosystem function.

Petrogenesis of dolomite carbonatite in Morocco

Boukirou W, Bouabdellah M, Chakhmouradian AR, Mouttaqi A, Reguir EP, Hauff F, Cuney M, Jébrak M, Yans J, Hoernle K. 2022. Petrogenesis of the late Paleoproterozoic Gleibat Lafhouda dolomite carbonatite (West African Craton Margin, Moroccan Sahara) and its relevance to the onset of fragmentation of the Columbia supercontinent. Chemical Geology 594:120764. DOI: 10.1016/j.chemgeo.2022.120764.

Carbonatites are considered among the deepest direct probes into the Earth's upper mantle and an important terrestrial carbon reservoir. Additionally, carbonatites are of economic interest because of their mineral endowment, which includes such low-abundance metals as rare earth elements (REE) and Nb. These metals are critically important for a wide array of advanced green energy, transportation, communication and digital technologies and are difficult to substitute or recycle. Dolomite carbonatites and calcite carbonatites represent, respectively, the Mg-rich and Ca-rich compositional end-members of the petrologically intriguing rock clan. The other, less common end-members are ankerite and siderite carbonatites (Fe-rich), silicocarbonatites sensu lato (Si-rich), and natrocarbonatites (Na- and K-rich). This study provides updated information on the regional and local geological setting of the GL carbonatites and describe in detail their petrography, mineralogy, whole-rock major- and trace-element geochemistry, and report new stable (C and O) and radiogenic (Sr, Nd, Pb) isotopic data for these rocks. This new information is interpreted in a petrogenetic and geodynamic context using published experimental work and data on similar carbonatites elsewhere in the world.


Mining for silver in Morocco

Diallo M, Bouabdellah M, Levresse G, Yans J, Castorina F, Klügel A, Mouhagir M, El Mouden S, Maacha L. 2021. Mineralogy, Fluid Inclusion, and C-O-Sr Isotope Geochemistry to Unravel the Evolution of the Magmatic-Hydrothermal System at the Igoudrane Silver-Rich Deposit (Imiter District, Eastern Anti-Atlas, Morocco). Minerals 11:997. DOI: 10.3390/min11090997.

The Igoudrane mine with a total production of 700,000 t of ore grading 485 g/t Ag is currently one of the most productive mines in the Imiter district of the eastern Anti-Atlas in Morocco. The silver-rich ± base metal deposit occurs dominantly as vein- and hydrothermal breccia-hosted orebodies at the interface between the lower Ediacaran turbidites of the Saghro Group and the unconformably overlying, dominantly felsic volcanic, and volcaniclastic rocks of the late Ediacaran Ouarzazate Group. This study reports the first attempt that combines underground mapping of the Igoudrane silver-rich deposit, drill core examination, petrographic, electron microprobe, and LA-ICP-MS analyses in conjunction with fluid inclusion microthermometry and stable (C, O) and radiogenic (Sr) isotopic data to constrain the origin and evolution of the mineralizing fluids and depositional processes that led to the precipitation of silver mineralization in this deposit.

Supergene Non-Sulfide Biomineralization

Bouabdellah M, Boukirou W, Potra A, Melchiorre E, Bouzahzah H, Yans J, Zaid K, Idbaroud M, Poot J, Dekoninck A, Levresse G. 2021. Origin of the Moroccan Touissit-Bou Beker and Jbel Bou Dahar Supergene Non-Sulfide Biomineralization and Its Relevance to Microbiological Activity, Late Miocene Uplift and Climate Changes. Minerals 11:401. DOI: 10.3390/min11040401.

Supergene non-sulfide Zn-Pb ± Cu deposits have long been ignored by the mining industry but become more and more attractive due to new developments in hydrometallurgy and higher Zn-Pb ± Cu grades than conventional deposits. Their economic value depends on the geologic setting and initial mineralogy. This study filled a gap of knowledge by assessing the role of microbial processes on the formation of such non-sulfide Zn-Pb ± Cu deposits in the Moroccan Atlasic system. Field observations have been combined with thorough mineralogical and geochemical investigations to constrain the origin(s) and evolution of the supergene fluid(s) and depositional processes that led to the precipitation of the non-sulfide mineralization. Macrotextural and carbon and sulfur isotope evidence support the hypothesis that microorganisms played a major role in the formation of the major Moroccan non-sulfide Pb-Zn ± Cu deposits in the Atlasic system.

Mineralization & mammalian biostratigraphy

Yans J, Verhaert M, Gautheron C, Antoine P-O, Moussi B, Dekoninck A, Decrée S, Chaftar H-R, Hatira N, Dupuis C, Pinna-Jamme R, Jamoussi F. 2021. (U-Th)/He Dating of Supergene Iron (Oxyhydr-)Oxides of the Nefza-Sejnane District (Tunisia): New Insights into Mineralization and Mammalian Biostratigraphy. Minerals 11:260. DOI: 10.3390/min11030260.

For nearly 15 years, the Geologists (team around Johan Yans) have been interested in the mineralization (Pb-Zn, Fe-Mn, U-REE-Au, clays) of the Nefza district in Tunisia. This article is a synthesis of their research, which highlights the iron oxide (goethite) dating of meteoric alteration events ~9 and ~1 million years ago. The originality of the article is that – for the very first time! - these dates make it possible to date certain Rhinoceroidae in the region with greater precision. The study was carried out in partnership with various Belgian, French and Tunisian research institutes.

Manganese formation in the Eastern High Atlas, Morocco

Lafforgue L, Dekoninck A, Barbarand J, Brigaud B, Bouabdellah M, Verhaert M, Mouttaqi A, Yans J. 2021. Geological and geochemical constrains on the genesis of the sedimentary-hosted Bou Arfa Mn(-Fe) deposit (Eastern High Atlas, Morocco). Ore Geology Reviews 133:104094. DOI: 10.1016/j.oregeorev.2021.104094.

Carbonate-hosted Mn deposits are widespread in North Africa with most of the Mn ores being hosted by Mesozoic dolomitic formations of the Moroccan Atlasic system. Previous studies suggested that the Bou Arfa Mn(-Fe) deposit has a strictly synsedimentary origin. New petrographical, mineralogical and geochemical data presented here show that three dolomitization phases accompanied the ore formation. The Bou Arfa Mn(-Fe) mineralization (High Atlas, Morocco) is thus formed by post-sedimentary processes and dolomitization is considered as the main driver for Mn and Fe concentration. These results  arise from a multi-year study in collaboration with the University of Paris-Saclay, Mohammed I of Oujda and the Office National des Mines et des Hydrocarbures.

Eels & hydropower plants

Ben Ammar I, Cornet V, Houndji A, Baekelandt S, Antipine S, Sonny D, Mandiki SNM, Kestemont P. 2021. Impact of downstream passage through hydropower plants on the physiological and health status of a critically endangered species: The European eel Anguilla anguilla. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 254:110876. DOI: 10.1016/j.cbpa.2020.110876.

Hydropower plants (HPPs) are a source of “green” energy but also a threat to migrating fish such as the European eel (Anguilla anguilla). They impede the free movement of eels and access to suitable habitats during their growth phase and prevent or delay downstream migration. Though fish survival and damages are well-documented, the condition of surviving and unharmed fish remains unknown. This study assesses the impact of the passage through HPPs on the survival, the physiological and health status of adult eels. After a deliberate passage through turbines, direct mortality, external and internal damages, stress and immune biomarkers such as plasma cortisol and glucose levels, alternative complement (ACH50), lysozyme and peroxidase activities, and total immunoglobulin (Ig) content were measured. Results show that the passage affected energy expenditure and innate immunity. Thus, HPPs can not only have an impact in terms of direct mortality and injuries but also affect the physiological and health condition of the surviving eels. This may explain the delayed mortality observed in telemetric studies and cumulative impact of the passage through several HPPs may compromise the ability of adult eels to successfully migrate to the ocean.

Boni M, Yans J. 2021. Editorial for Special Issue “Supergene Evolution of Polymetallic Deposits, Including Non-Laterite Fe and Mn Ores.” Minerals 11:946. DOI: 10.3390/min11090946.

Yans J. 2021. Maintien et développement de l’exploitation des ressources minérales en Europe : le cas de la Wallonie. In: L’économie des ressources minérales et le défi de la soutenabilité 2. ISTE Editions, 111–127.

Yans J, Boulvain F, Tourneur F, Poot J, Rochez G. 2021. D’où proviennent les pierres noires de l’église Saint-Loup? La science s’en mêle…. Société Archéologique de Namur.

Non-invasive determination of fish maturity

Roosta Z, Falahatkar B, Sajjadi M, Paknejad H, Mandiki SNM, Kestemont P. Comparative study on accuracy of mucosal estradiol-17β, testosterone and 11-ketotestosterone, for maturity, and cutaneous vitellogenin gene expression in goldfish (Carassius auratus). Journal of Fish Biology n/a. DOI: 10.1111/jfb.14963.

Providing a non-invasive procedure to track fish maturity remains a priority in broodstocks' management. In the present study, the main goal was to assess reproduction status by measuring sex steroids and vitellogenin (VTG) in the skin mucosa, as a non-invasive method. For this purpose, the present study compared the levels of estradiol-17β (E2), testosterone (T), 11-ketotestosterone (11-KT), VTG and calcium (Ca) in skin mucosa and blood plasma of goldfish (Carassius auratus). Skin mucosal and blood samples were collected, as well as gonad tissues, from goldfish, as a seasonal spawner. The results show that measuring the mucosal androgens could be considered as an accurate, non-invasive method to monitor fish maturity.

Potential perception mechanisms for eliciting activities

Deboever E, Van Aubel G, Rondelli V, Koutsioubas A, Mathelie-Guinlet M, Dufrene YF, Ongena M, Lins L, Van Cutsem P, Fauconnier M-L, Deleu M. Modulation of plant plasma membrane structure by exogenous fatty acid hydroperoxide is a potential perception mechanism for their eliciting activity. Plant, Cell & Environment n/a. DOI: 10.1111/pce.14239.

Oxylipins are lipid-derived molecules that are ubiquitous in eukaryotes and whose functions in plant physiology have been widely reported. They appear to play a major role in plant immunity by orchestrating reactive oxygen species (ROS) and hormone-dependent signalling pathways. The present work focuses on the specific case of fatty acid hydroperoxides (HPOs). Although some studies report their potential use as exogenous biocontrol agents for plant protection, evaluation of their efficiency in planta is lacking and no information is available about their mechanism of action. In this study, the potential of two plant defence elicitors and the underlying mechanism of action is investigated. Arabidopsis thaliana leaf resistance to Botrytis cinerea was observed after root application with HPOs. They also activate early immunity-related defence responses, like ROS. As previous studies have demonstrated their ability to interact with plant plasma membranes (PPM), we have further investigated the effects of HPOs on biomimetic PPM structure using complementary biophysics tools. Results show that HPO insertion into PPM impacts its global structure without solubilizing it. The relationship between biological assays and biophysical analysis suggests that lipid amphiphilic elicitors that directly act on membrane lipids might trigger early plant defence events.

Dipteran-based meal and Nile tilapia

Agbohessou PS, Mandiki SNM, Gougbédji A, Megido RC, Lima L-MW, Cornet V, Lambert J, Purcaro G, Francis F, Lalèyè PA, Kestemont P. 2021. Efficiency of fatty acid-enriched dipteran-based meal on husbandry, digestive activity and immunological responses of Nile tilapia Oreochromis niloticus juveniles. Aquaculture 545:737193. DOI: 10.1016/j.aquaculture.2021.737193.

This study aimed to compare the enrichment capacity of polyunsaturated fatty acids (PUFA) and the long chain polyunsaturated fatty acids (LC-PUFA) of two dipteran species, black soldier fly (BSF) - and a blowfly, Chrysomya putoria (CP), and to test its influence on growth, digestive activities and immune responses of Nile tilapia. The results showed a higher efficiency of LC-PUFA enrichment for CP larvae compared to BSF ones, and a CP larval-based diet balanced in PUFA and LC-PUFA resulted in a greater stimulation of the processes of nutrient utilization, and thus a greater growth capacity. In addition, an improved DHA content was observed in the muscles of fish fed with the CP/FOD larval meal compared to those fed with all other insect larval meals. Nevertheless, all types of dipteran larval meal were palatable to Nile tilapia and enriched fish muscles with EPA except those fed the BSF/VGD diet. In addition, all types of dipteran larval meal boosted the immune status regardless of species or dietary essential fatty acid quality. Further studies are needed to elucidate the potential beneficial effects of BSF or CP larval meal on pathogen resistance in Nile tilapia.

Diet and skeletal anomalies in pikeperch larvae

El Kertaoui N, Lund I, Betancor MB, Carpentier C, Montero D, Kestemont P. 2021. Dietary DHA and ARA level and ratio affect the occurrence of skeletal anomalies in pikeperch larvae (Sander lucioperca) through a regulation of immunity and stress related gene expression. Aquaculture 544:737060. DOI: 10.1016/j.aquaculture.2021.737060.

Pikeperch (Sander lucioperca) is of great potential for the expansion of the EU aquaculture industry. However, larval survival is low and skeletal anomalies frequent. Pikeperch larvae are very stress sensitive to lack or low levels of n-3 dietary essential long chain polyunsaturated fatty acids (LC-PUFA, n-3). This study investigated the effect of different dietary DHA and ARA levels and ratios on larval development and performance, digestive capacity, fatty acids composition, skeleton anomalies and molecular markers of oxidative stress status, stress response, fatty acid synthesis, eicosanoids synthesis, and bone development. The results suggest an antagonistic effect of ARA and DHA fatty acids on immune/stress response of pikeperch, and its influence on bone development and deformity occurrence.

Optimal rearing conditions for Atlantic salmon fry

Cornet V, Geay F, Erraud A, Mandiki SNM, Flamion E, Larondelle Y, Rollin X, Kestemont P. 2021. Modulations of lipid metabolism and development of the Atlantic salmon (Salmo salar) fry in response to egg-to-fry rearing conditions. Fish Physiology and Biochemistry. DOI: 10.1007/s10695-021-00959-0.

To maintain or restore wild salmon populations, artificial reproduction from wild salmon breeders is common. In nature, the survival rate of salmon embryo is extremely variable (0 to 90%, mostly between 2 and 35%) due to water conditions, pathogens, pollutants, prey, etc. Conversely, controlled conditions used in fish culture allow a high survival rate of fry at the emergent stage, which, however, may not be well adapted for life in nature. Here, three factors affecting the fitness and physiology of salmon fry at their emergence were tested against a semi-natural incubation method in river: the origin of water (river vs drilling), the type of support in the incubator (support matrix vs plastic sheets) and the type of incubators (Californian vs vertical trays). Fry incubated in vertical trays + river water were similar in growth and lipid composition to those in semi-natural incubators. Further, the support matrix improved fish growth, lipid consumption and distribution compared to fry on plastic sheets, leading to large amounts of several PUFAs which may increase adaptation to cold conditions. Drilling water with lower amounts of fine particles (provoking the clogging of eggs) improved the survival rate compared to river water. To conclude, using a substrate combined with drilling water in artificial incubators could increase fry fitness and its adaption to wild life.

Melatonin improves immunity in pike-perch

Baekelandt S, Cornet V, Mandiki SNM, Lambert J, Dubois M, Kestemont P. 2021. Ex vivo approach supports both direct and indirect actions of melatonin on immunity in pike-perch Sander lucioperca. Fish & Shellfish Immunology 112:143–150. DOI: 10.1016/j.fsi.2021.03.005.

High stocking densities in aquaculture lead to overcrowding and affect fish health increasing the risk of infections. The search for alternatives of antibiotics and vaccines are based on the improvement of immunocompetence of cultured fish species through the use of stimulants. The melatonin hormone (Mel), is a multifunctional molecule in vertebrates with potential immunomodulatory capacity. This study shows with ex-vivo experiments in Pike perch, that Mel, with or without combination of cortisol, influences the expression of a set of immunity-related genes in the main fish lymphoid organs, the head kidney and the spleen. These genes include genes encoding for pro-inflammatory proteins, acute-phase proteins, and key factors of the adaptive immune system. Thus, immunoenhancing properties of Mel was confirmed under basal immune conditions in teleosts, and a direct action of Mel on immune organs was demonstrated.

Get rid of fishmeal for a more sustainable aquaculture

Agbohessou PS, Mandiki SNM, Gougbédji A, Megido RC, Hossain MS, Jaeger PD, Larondelle Y, Francis F, Lalèyè PA, Kestemont P. Total replacement of fish meal by enriched-fatty acid Hermetia illucens meal did not substantially affect growth parameters or innate immune status and improved whole body biochemical quality of Nile tilapia juveniles. Aquaculture Nutrition n/a. DOI:

Millions of tons of fish produced and captured every year are not used for human food, but mainly to produce fishmeal (FM) and fish oil (FO). FM is used as a protein source in compound feeds for many fish species in aquaculture, but its quantity and access are limited. The research group of Patrick Kestemont (URBE) is continuously searching for valuable alternatives to help preserve natural resources and render aquaculture more sustainable. One protein source could stem from insect larval meal, mixed with vegetable oil. This study investigates black soldier fly (BSF) larval meal enriched with fatty acids (FAs) on the growth and innate immune status of Nile tilapia juveniles. The results demonstrate that BSF meal can totally replace FM without substantial negative effects.

Rainbow trout and rapeseed oil diet

Gesto M, Madsen L, Andersen NR, El Kertaoui N, Kestemont P, Jokumsen A, Lund I. 2021. Early performance, stress- and disease-sensitivity in rainbow trout fry (Oncorhynchus mykiss) after total dietary replacement of fish oil with rapeseed oil. Effects of EPA and DHA supplementation. Aquaculture 536:736446. DOI: 10.1016/j.aquaculture.2021.736446.

Different vegetable oils (VO) have been investigated as potential substitutes of fish oil (FO) in aquaculture feed and several of them have proven to be successful in terms of fish growth rates, survival rates, biometric indices or feeding efficiency, even when used as the only oils in the feed. The aim of this study was to evaluate the effects of a 100% FO oil substitution by rapeseed oil on rainbow trout fry performance. Specifically, the objective was to test the effects of FO substitution on fish early growth and digestive metabolism, but also on the stress- and disease-resilience of the fish. Total replacement of FO by rapeseed oil in the feed did not compromise rainbow trout growth performance after an initial weaning period of several weeks, in spite of the altered fatty acid composition of the juveniles. Furthermore, fish fed VO-based diets showed no large differences in their responses to mild acute and/or repeated stress when compared to fish fed a control, FO-based commercial diet. Dietary rapeseed oil inclusion had, in contrast, important deleterious effects on the ability of fish to survive infection challenges.


Genesis of As-Pb-Rich Supergene Mineralization in Morocco

Verhaert M, Madi A, Basbas AE, Elharkaty M, Oummouch A, Oumohou L, Malfliet A, Maacha L, Yans J. 2020. Genesis of As-Pb-Rich Supergene Mineralization: The Tazalaght and Agoujgal Cu Deposits (Moroccan Anti-Atlas Copperbelt). Economic Geology 115:1725–1748. DOI: 10.5382/econgeo.4779.

In the Moroccan Anti-Atlas, sulfide deposits hosted by Neoproterozoic to Cambrian formations underwent significant weathering, leading to the formation of supergene profiles. Supergene deposits are of high interest for mining industries due to the near-surface situation and softened host rocks allowing easy and fast accessibility. An additional benefit of secondary ores is their common higher metal contents, compared to primary sulfides. Of special scientific interest is the formation of supergene ores at the interface between tectonic and climate processes, and their mineralogical diversity. The investigated Tazalaght and Agoujgal deposits are characterized by diversified copper secondary ores, including Cu-Pb arsenates. Even if some differences exist in terms of mineralogical and chemical contents between the two ore deposits, the processes responsible for the formation of these supergene ores are very similar. At both sites, the oxidation of base metal sulfides and tennantite resulted in an acidic environment and in the mobilization of several ions.

Multistage genesis of a Cretaceous manganese deposit in Morocco

Dekoninck A, Ruffet G, Missenard Y, Parizot O, Magoua M, Mouttaqi A, Rochez G, Yans J. 2020. Multistage genesis of the late Cretaceous manganese karst-hosted Tasdremt deposit (High Atlas, Morocco). Mineralium Deposita. DOI: 10.1007/s00126-020-01017-0.

In 2016, the Geology Department was prospecting for ancient manganese deposits in the Tasdremt region near the Aoulouz dam, 100 km east of Taroudant (Morocco), in collaboration with the University of Paris-Sud, the University of Rennes and the Moroccan National Office of Hydrocarbons and Mines. These karstic deposits are a crucial witness to the periods of meteoric alteration during the Upper Cretaceous, thanks to the Ar-Ar dating of Mn oxides (cryptomelane).

Environmental changes in the early Eocene

Garel S, Dupuis C, Quesnel F, Jacob J, Yans J, Magioncalda R, Fléhoc C, Schnyder J. 2020. Multiple early Eocene carbon isotope excursions associated with environmental changes in the Dieppe-Hampshire Basin (NW Europe) Multiples excursions isotopiques du carbone de l’Eocène inférieur associées à des changements environnementaux dans le Bassin de Dieppe-Hampshire (Europe du NO). Bulletin de la Société Géologique de France 191. DOI: 10.1051/bsgf/2020030.

The early Eocene experienced a series of short-lived global warming events, known as hyperthermals, associated with negative carbon isotope excursions (CIE). The Paleocene-Eocene Thermal Maximum (PETM or ETM-1) and Eocene Thermal Maximum 2 (ETM-2) are the two main events of this Epoch, both marked by massive sea-floor carbonate dissolution. Their timing, amplitude and impacts are rather well documented, but CIEs with lower amplitudes also associated with carbonate dissolution are still poorly studied (e.g. events E1 to H1), especially in the terrestrial realm where hiatus/disconformities and various sedimentary rates in a single succession may complicate the assignation to global isotopic events. This article presents a new high-resolution multi-proxy study on the terrestrial, lagoonal and shallow marine late Paleocene-early Eocene succession from two sites of the Cap d’Ailly area in the Dieppe-Hampshire Basin (Normandy, France).

The Giant Copper Deposit of Tizert (Morocco)

Poot J, Verhaert M, Dekoninck A, Oummouch A, El Basbas A, Maacha L, Yans J. 2020. Characterization of Weathering Processes of the Giant Copper Deposit of Tizert (Igherm Inlier, Anti-Atlas, Morocco). Minerals 10:620. DOI: 10.3390/min10070620.

The Tizert copper deposit in Morocco is considered to be the largest Copper deposit in the Western Anti-Atlas today. Its resources are estimated at almost 57 million tons with a Cu content of 1.03%. The site is characterized by Cu mineralization carried by malachite, chalcocite, covellite, bornite and chalcopyrite. The host rocks are mainly limestones and sandstones/siltstones. The supergene enrichment is most likely related to episodes of uplift/doming (last event since 30 Ma), which triggered the exhumation of primary/hypogene mineralization. Copper is highly demanded in renewable energies and high technology applications, due to its good electrical and thermal conductivity (up to 15% Cu in smartphones!).

Salmons & hydropower plants

Ben Ammar I, Baeklandt S, Cornet V, Antipine S, Sonny D, Mandiki SNM, Kestemont P. 2020. Passage through a hydropower plant affects the physiological and health status of Atlanstic salmon smolts. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 247:110745. DOI: 10.1016/j.cbpa.2020.110745.

Atlantic salmon migrate from nursery areas in rivers to the oceanic feeding areas at smolt stage and back again at adult stage. Dams associated with hydroelectric power plants (HPP) disrupt their migration routes and affect fish movement and survival. This study evaluates the short and mid-term physiological and immune response of salmon smolts after passing through Andenne HPP (Meuse River, Belgium). Direct mortality and external damages, stress and immune biomarkers such as plasma cortisol and glucose levels, complement and peroxidase activities were measured directly. Further, immune and oxidative stress parameters related to gene expression up to 120 h after passage. Results show that not only mortality and visible damages were higher after passage through the HPP compared to a control group, but also energy and immunity parameters were affected. This partially explains the delayed mortality observed in many studies leading to a poor success of restocking programs.

Underground Flash Flood Events

Watlet A, Camp MV, Francis O, Poulain A, Rochez G, Hallet V, Quinif Y, Kaufmann O. 2020. Gravity Monitoring of Underground Flash Flood Events to Study Their Impact on Groundwater Recharge and the Distribution of Karst Voids. Water Resources Research 56:e2019WR026673. DOI: 10.1029/2019WR026673.

Flash flood events are expected to become increasingly common with the global increases in weather extremes. They are a significant natural hazard that affects karst landscapes, which host large resources of drinking water worldwide. This study analyses 20 incave flash flood events affecting the Rochefort karst system (Belgium). Continuous gravity measurements at one single station were used and water level sensors installed in caves. Underground flood events typically produce a peak in the gravity signal, due to an increase in the associated mass change. After the flood, the gravity values drop but remain slightly increased compared to before the flood event. Via forward gravity modeling, the authors demonstrate that this remaining anomaly can be reasonably explained by the infiltration of local rainfall within the karst system rather than by allogenic recharge of the aquifer.

Hormonal stimulation in pikeperch

Żarski D, Ben Ammar I, Bernáth G, Baekelandt S, Bokor Z, Palińska-Żarska K, Fontaine P, Horváth Á, Kestemont P, Mandiki SNM. 2020. Repeated hormonal induction of spermiation affects the stress but not the immune response in pikeperch (Sander lucioperca). Fish & Shellfish Immunology 101:143–151. DOI: 10.1016/j.fsi.2020.03.057.

Controlled reproduction remains a challenge in aquaculture, especially for newly domesticated fish species, such as pikeperch (Sander lucioperca). Sperm quality and quantity is crucial for the success of a selective-breeding program. It is common practice to stimulate fish with hormones, either with human chorionic gonadotropin (hCG) or salmon gonadoliberine analogue (sGnRHa). This study shows that hormonal stimulation increased quality and quantity of sperm. No effects on immune response were detected, but HCG affected stress response in pikeperch males. Sperm quality was further negatively correlated with immune markers, pronouncing the need to carefully revise broodstock management and selection practices in aquaculture.

Biotic resource use by fisheries

Luong AD, Dewulf J, De Laender F. 2020. Quantifying the primary biotic resource use by fisheries: A global assessment. Science of The Total Environment 719:137352. DOI: 10.1016/j.scitotenv.2020.137352.

Capture fisheries contribute to fish production via fishmeal and fish oil which are important for livestock production as well as aquaculture systems. Estimates of primary production required (PPR) are used to assess the ecological impacts of fishing. Currently, the calculation of Specific PPR (SPPR) relies on simplified and invalid assumptions. In this study, SPPRs of more than 1700 species were directly calculated based on food web flow matrices using an advanced SPPR calculation framework for five countries. The trophic level of a species was the most important ecological factor determining its SPPR. The results indicate that the conventional approach underestimates PPRs by up to a factor of 5. This new approach gives a more conservative assessment of marine biotic resource use.

Fe-rich bentonites from Westerwald

Fontaine F, Christidis GE, Yans J, Hollanders S, Hoffman A, Fagel N. 2020. Characterization and origin of two Fe-rich bentonites from Westerwald (Germany). Applied Clay Science 187:105444. DOI: 10.1016/j.clay.2020.105444.

The Westerwald region is one of the major ceramic clay mining areas of Germany. The mined clays were deposited on the weathered Rhenish massif during Eocene and Oligocene and were protected from erosion by a large alkaline basalt cover. Two Fe-rich bentonite layers exposed in quarries of the Eastern part of the Westerwald were investigated with X-ray diffraction, thermogravimetric analysis, infrared spectroscopy, optical microscopy, scanning electron microscopy, chemical analyses and cation exchange capacity (CEC). In both bentonite layers, the main mineral is a high-charge Fe-rich beidellite containing exchangeable Ca and Mg. Even if they both derive from mafic volcanic rocks, the difference in accessory minerals and trace element content leads to the conclusion that they have a different precursor.

Supergene ore of Cu–Co in the Kongo

Fontaine L, De Putter T, Bernard A, Decrée S, Cailteux J, Wouters J, Yans J. 2020. Complex mineralogical-geochemical sequences and weathering events in the supergene ore of the Cu–Co Luiswishi deposit (Katanga, D.R. Congo). Journal of African Earth Sciences 161:103674. DOI: 10.1016/j.jafrearsci.2019.103674.

The Luiswishi copper and cobalt (Cu–Co) ore deposit (Haut-Katanga, D.R. Congo) belongs to the Katanga Copperbelt (KCB), a world-class Cu–Co district. The primary orebodies in the KCB consist of sulphide ore hosted in Neoproterozoic fine-grained siliciclastic and carbonate sedimentary rocks. The secondary weathered ores are still poorly documented, though most of them are strongly enriched in both copper and cobalt with regard to the primary sulphide ores. Combined mineralogical and geochemical investigations on both host rocks and ore minerals allow identifying and characterizing three distinct zones in the studied profile, from base to top: the protore, which contains sulphides and massive dolomite; the cementation zone where oxides and sulphides coexist, and the saprolite, comprised of oxidized ores only.
The demand for these geological resources (such as copper and cobalt, but also manganese, see above) will be growing in the coming years / decades, in particular to supply high-tech products and renewable energies.

COS-OGA Elicitation in Tomato

Moreau S, van Aubel G, Janky R, Van Cutsem P. 2020. Chloroplast Electron Chain, ROS Production, and Redox Homeostasis Are Modulated by COS-OGA Elicitation in Tomato (Solanum lycopersicum) Leaves. Frontiers in Plant Science 11. DOI: 10.3389/fpls.2020.597589.

Elicitation of plant cells induces a whole array of cytoplasmic and nuclear defense responses, a topic currently subject to particular attention by plant pathologists. Here, the effect of repeated elicitations of tomato by the COS-OGA elicitor was studied. Tomato plants were treated three times with the elicitor and compared their transcriptomes to control plants using RNA-Seq. It was shown that the response to the COS-OGA elicitor involved the modulation of the electron transport chain in thylakoids and impacted the redox homeostasis of different cell compartments including the apoplast. Therefore, beyond its protective effect against biotic stresses, the elicitation appears to be a major modulator of energy partitioning in plant leaves and repeated COS-OGA treatments most probably induce a long-term acclimation of plants, without any metabolic cost in terms of fresh and dry weights.

Plant oils for carp immunity

Nguyen TM, Mandiki SNM, Salomon JMAJ, Baruti JB, Thi NTT, Nguyen TH, Nhu TQ, Kestemont P. 2021. Pro- and anti-inflammatory responses of common carp Cyprinus carpio head kidney leukocytes to E.coli LPS as modified by different dietary plant oils. Developmental & Comparative Immunology 114:103828. DOI: 10.1016/j.dci.2020.103828.

To fight injuries or microbial infections, inflammation processes are launched. The inflammatory pathway involves many components including inducers, sensors and mediators. N-3 long chain polyunsaturated fatty acids (LC-PUFAs) play an important role in fish immune systems in particular and in animals more generally, and their imbalance or inadequate supply could lead to negative effects on fish health. The LC-PUFAs such as ARA, EPA, and DHA in fish diets are mainly provided by fish oil, which is however, very expensive. Plant-derived oils are much more available and cheaper. This study investigated how to maximise the utilisation of dietary plant oil for an efficient inflammatory response in common carp. The results indicate that the immune competence of fish fed plant oil mixture was comparable to the one of fish fed fish oil diet.

Plant oils for catfish immunity

Nhu TQ, Dam NP, Bich Hang BT, Bach LT, Thanh Huong DT, Buu Hue BT, Scippo M-L, Phuong NT, Quetin-Leclercq J, Kestemont P. 2020. Immunomodulatory potential of extracts, fractions and pure compounds from Phyllanthus amarus and Psidium guajava on striped catfish (Pangasianodon hypophthalmus) head kidney leukocytes. Fish & Shellfish Immunology 104:289–303. DOI: 10.1016/j.fsi.2020.05.051.

Due to the increasing demand for sustainable applications in aquaculture, plant-based natural sources are a promising source for medicinal discovery to strengthen fish immunity. Among plants of potential medical interest, guava (Psidium guajava) and bhumi amla (Phyllantus amarus) are known to possess pharmacological activities including anti-bacterial, anti-oxidant as well as immune response activities. Earlier studies only focused on the immunomodulatory effects of crude ethanol extracts of these plants. The present study now tries to identify the type of compound(s) which could contribute to this activity. The crude extracts were fractioned with increasing polarity solvents and separated into fractions containing different concentrations and types of bioactive compounds (from less polar to more polar compounds) and investigated using striped catfish head kidney leukocyte model. Hexane fractions of both plant extracts inhibited the viability of HKLs (head kidney leukocytes), while several other fractions enhanced the cell viability. All P. guajava fractions at all or some concentration considerably enhanced the respiratory burst assay production in HKLs. Similarly, nitric oxide synthase production was also significantly increased by some or all concentrations of P. guajava dichloromethane and ethyl acetate fractions.

Plant diets for rainbow trout

Hossain MS, Chance AB, El Kertaoui N, Wattiez X, Houndji A, Mandiki SNM, Kestemont P. Dietary inorganic monophosphates in high plant ingredient-based diets influence nutrient digestibility, postprandial macro-mineral status and immune functions of juvenile rainbow trout, Oncorhynchus mykiss. Aquaculture Nutrition n/a. DOI: 10.1111/anu.13156.

Inorganic monophosphates supplementation effects in high plant ingredient‐based diets of juvenile Oncorhynchus mykiss were evaluated by feeding four experimental diets supplemented with 11.4, 10.0, 11.5 and 10.0 g/kg of monocalcium phosphate (MCP), monoammonium phosphate (MAP), monopotassium phosphate (MKP) and monosodium phosphate (MSP), respectively. After 60 days, MAP and MKP supplemented groups showed improved growth and feed intake (p > .05). Apparent digestibility coefficient of dry matter (ADCDM) was significantly higher in MSP diet followed by MKP, MCP; MAP diet showed significantly lower ADCDM. MAP and MSP diets showed significantly higher mineral digestibility. The postprandial plasma P levels were significantly influenced by the dietary treatments and the period after a single meal. MAP, MKP and MSP groups showed significantly higher baseline P concentration than MCP. The other macro‐minerals (Ca, Mg, K and Na) were significantly influenced by the postprandial time. MSP and MKP diets showed significantly higher lysozyme activity. Total immunoglobulin was significantly higher in MSP group. MKP diet showed significantly higher expression of cd4‐2β genes compared with MCP. Significantly higher lysozyme gene expression observed in MSP diet followed by MKP; MAP and MCP groups showed significantly lower value. Finally, MAP, MKP and MSP significantly improved nutrient digestibility, mineral bioavailability and immune functions of rainbow trout compared with MCP in high plant ingredient‐based diets.

Traditional medicine in aquaculture

Nhu TQ, Bich Hang BT, Cornet V, Oger M, Bach LT, Anh Dao NL, Thanh Huong DT, Quetin-Leclercq J, Scippo M-L, Phuong NT, Kestemont P. 2020. Single or Combined Dietary Supply of Psidium guajava and Phyllanthus amarus Extracts Differentially Modulate Immune Responses and Liver Proteome in Striped Catfish (Pangasianodon hyphophthalmus). Frontiers in Immunology 11. DOI: 10.3389/fimmu.2020.00797.

In aquaculture, infectious pathogens (e.g., viruses, bacteria, parasites, and fungi) causing high mortality rates are a major problem leading to tremendous economic losses. Guava (Psidium guajava) and bhumi amla (Phyllanthus amarus), two well-known plants in traditional medicine were tested on their effects on immune responses, disease resistance and liver proteome profiles in striped catfish Pangasianodon hypophthalmus. The diets based on the plant extracts improved growth parameters as well as the cellular immune responses in spleen and the humoral immune responses in plasma. Fish mortality following bacterial infection was lower with single Pg and Pa extracts, and to lesser extent with combined extracts compared to a control group.

Plant oil diets for carps

Nguyen TM, Mandiki SNM, Gense C, Tran TNT, Nguyen TH, Kestemont P. 2020. A combined in vivo and in vitro approach to evaluate the influence of linseed oil or sesame oil and their combination on innate immune competence and eicosanoid metabolism processes in common carp (Cyprinus carpio). Developmental & Comparative Immunology 102:103488. DOI: 10.1016/j.dci.2019.103488

Fish oil for aquaculture comes from fish stock that are currently overexploited. Consequently, fish oil is very expensive. Plant oils, much cheaper, could serve as ideal alternative lipid sources for fish diets. This study uses pure or mixed linseed and sesame oil to test innate immune competence and eicosanoid metabolism in common carp (Cyprinus carpio). Results show that plant oils did not induce any negative effects on fish growth, survival, and immune competence status. When the oils were mixed, carps even utilised the food more efficiently and seemed more effective in inducing a better immunomodulatory response when exposed to lipopolysaccharides of Escherichia coli through a more active eicosanoid metabolism process.


Methane: CO2-broadening coefficients

Vispoel B, Fissiaux L, Lepère M. 2019. CO2-broadening coefficients in the ν3 fundamental band of methane. Journal of Molecular Spectroscopy. DOI: 10.1016/j.jms.2018.12.004.

The key goal of the “ExoMars Trace Gas Orbiter” mission is the detection of methane in the atmosphere of Mars, which could give indications for biological life on Mars. The Martian atmosphere consists to 96% of CO2 and thus, requires very special sets of parameters to enable accurate remote sensing. In particular, CO2-broadening coefficients are primordial. This study used tuneable diode-laser spectroscopy to measure the CO2-broadening coefficients for 11 lines in the ν3 band of methane. Such measurements are required for the studies of atmospheres containing a large amount of carbon dioxide.

Belgian Black Marbles

Boulvain F, Poulain G, Tourneur F, Yans J. 2019. Potential Discrimination of Belgian Black Marbles Using Petrography, Magnetic Susceptibility and Geochemistry. Archaeometry. DOI: 10.1111/arcm.12530.

The world famous black marbles of Belgium are used since the Roman Antiquity. These rocks are not marbles in a petrographic meaning; instead they correspond to several varieties of fine‐grained, well‐cemented Paleozoic limestones, without dots, veins or fossils. But these marbles are difficult to distinguish from each other. This paper synthesizes the geological data already bibliographically available and provides new accurate geological data to compare and discriminate them. Five marbles were investigated in this study. The results confirm that discrimination is not straightforward and needs a combination of very different techniques, ranging from petrography to geochemical analysis. However, all these techniques are destructive.

Solé F, Noiret C, Desmares D, Adnet S, Taverne L, De Putter T, Mees F, Yans J, Steeman T, Louwye S, Folie A, Stevens NJ, Gunnell GF, Baudet D, Yaya NK, Smith T. 2019. Reassessment of historical sections from the Paleogene marine margin of the Congo Basin reveals an almost complete absence of Danian deposits. Geoscience Frontiers 10:1039–1063. DOI: 10.1016/j.gsf.2018.06.002.

Elementary analyses of willemite mineralisation

Choulet F, Richard J, Boiron M-C, Dekoninck A, Yans J. 2019. Distribution of trace elements in willemite from the Belgium non-sulphide deposits. European Journal of Mineralogy 31:983–997. DOI: 10.1127/ejm/2019/0031-2871.

Samples of willemite (Zn2SiO4) mineralisation from the historical non-sulphide Zn–Pb deposits of La Calamine (eastern Belgium) have been recovered from collections of the Geological Survey of Belgium. Textural and chemical analyses were used to evaluate the critical element distribution (Ge, In, Ga) and deportment. Willemite is a mineral of secondary origin and occurs as a variety of types that are continuously formed between the protore stage (sulphides) and the late supergene stage (carbonates and hydrated phases). Different types of willemite may be distinguished on the basis of their shape and zoning characteristics, also marked by a significant change of major-element compositions in the late generation of willemite. Among the trace elements, anomalous high contents of P, Cd, As, Pb, Ag and Sb were noted. While Ga and In contents are very low (less than 4 ppm) or even below detection limits, significant Ge contents up to 250 ppm were measured. Such contents are consistent with values reported from willemite mineralization throughout the world.

Dating of Manganese oxides

Dekoninck A, Monié P, Blockmans S, Hatert F, Rochez G, Yans J. 2019. Genesis and 40Ar/39Ar dating of K-Mn oxides from the Stavelot Massif (Ardenne, Belgium): Insights into Oligocene to Pliocene weathering periods in Western Europe. Ore Geology Reviews 115:103191. DOI: 10.1016/j.oregeorev.2019.103191.

The occurrence of Ordovician Fe-Mn-rich sediments in the Stavelot inlier (NE Ardennes, Rhenish Massif, Belgium) has drawn the attention of geoscientists for more than one century, as they contain natural “coticule” whetstones and numerous weathered Manganese (Mn) deposits. The Mn-bearing sediments have undergone greenschist facies metamorphism in relation to the Caledonian and Variscan orogenesis. More recent weathering processes transformed the early mineral assemblages into secondary Mn oxides. This study investigates the weathering processes of these Mn-rich rocks by new mineralogical, petrographical and geochemical data and a new 40Ar/39Ar geochronology of K-Mn oxides.

Climate change in the Palaeocene

Wouters S, Spassov S, Martinez M, Steurbaut E, Storme J-Y, Yans J, Devleeschouwer X. 2019. Depositional changes during the Danian–Selandian transition in Loubieng (France), Zumaia (Spain) and Sidi Nasseur (Tunisia): insights from and limits of rock magnetism. Geological Magazine:1–19. DOI: 10.1017/S0016756819000281.

Depositional changes that occurred during the Danian–Selandian transition are studied in France, Spain and Tunisia. These changes are linked to climatic events such as hyperthermals, i.e. short-term warming events. Here, rock-magnetic techniques are used that are very sensitive and allow the identification, characterization and quantification of magnetic minerals in rocks by measuring magnetic parameters. These help to understand a wide range of geological processes involving these minerals. For example, humidity levels or detrital or biogenic origin of minerals can be determined.

OM-MADE - an open-source program

Tinet A-J, Collon P, Philippe C, Dewaide L, Hallet V. 2019. OM-MADE: An open-source program to simulate one-dimensional solute transport in multiple exchanging conduits and storage zones. Computers & Geosciences 127:23–35. DOI: 10.1016/j.cageo.2019.03.001.

OM-MADE (One-dimensional Model for Multiple Advection, Dispersion, and storage in Exchanging zones) is an open-source python code to simulate one-dimensional solute transport in conduits. It enables the simulation of multiple exchanging flow and storage zones in steady-state flow conditions. It further helps with the interpretation of multi-peaked breakthrough curves that can be observed in karstic system tracer tests.

River channelization increases competition among young fish

Latli A, Michel LN, Lepoint G, Kestemont P. 2019. River habitat homogenisation enhances trophic competition and promotes individual specialisation among young of the year fish. Freshwater Biology 64:520–531. DOI: 10.1111/fwb.13239.

Large rivers are heavily modified for navigation, which may reduce food availability for young fish and their chance to reach the adult age. In the Meuse River, decrease of fish abundance is thought to be linked to a drastic reduction of phytoplankton biomass. The trophic niches of four fish species at various stages of development were studied to compare intra‐ and interspecific competition between reaches that differ in their degree of channelization. In the heavily channelized reach, resource diversity was lower. Trophic competition between larval stages was thus increased, leading also to the consumption of vegetation, which is a suboptimal energy source.

2 x Plant extract-based diets for striped catfish

Nhu TQ, Bich Hang BT, Bach LT, Buu Hue BT, Quetin-Leclercq J, Scippo M-L, Phuong NT, Kestemont P. 2019. Plant extract-based diets differently modulate immune responses and resistance to bacterial infection in striped catfish (Pangasianodon hypophthalmus). Fish & Shellfish Immunology 92:913–924. DOI: 10.1016/j.fsi.2019.07.025.

Nhu TQ, Bich Hang BT, Vinikas A, Bach LT, Buu Hue BT, Thanh Huong DT, Quetin-Leclercq J, Scippo M-L, Phuong NT, Kestemont P. 2019. Screening of immuno-modulatory potential of different herbal plant extracts using striped catfish (Pangasianodon hypophthalmus) leukocyte-based in vitro tests. Fish & Shellfish Immunology 93:296–307. DOI: 10.1016/j.fsi.2019.07.064.

Striped catfish (Pangasius hypophthalmus) is one of the most important commercial fish species cultured in Vietnam. Yet, intensive production with high stocking densities increases mortality rates due to bacterial infections and cause enormous economic losses. The use of herbal immunostimulants in aquaculture would offer an environmentally friendly approach in disease management. Two studies – in vivo & in vitro - confirmed the positive effects of medicinal plant extracts by improving the immune response of striped catfish. Both, hematological parameters (total red blood cells, white blood cells, lymphocytes, monocytes, and neutrophils) and humoral immune responses (lysozyme, complement and total immunoglobulin) of fish fed with extract-based diets were significantly higher than of those fed with the control diet. Ethanol plant extracts stimulated striped catfish immune system by affecting peripheral blood mononuclear cells (PBMCs) and head kidney leukocytes (HKLs). The results offer an effective strategy to improve striped catfish health by enhancing their immune system, and to promote sustainable aquaculture.

Systemic defense activation in rice

Singh RR, Chinnasri B, De Smet L, Haeck A, Demeestere K, Van Cutsem P, Van Aubel G, Gheysen G, Kyndt T. 2019. Systemic defense activation by COS-OGA in rice against root-knot nematodes depends on stimulation of the phenylpropanoid pathway. Plant Physiology and Biochemistry. 142:202–210. DOI: 10.1016/j.plaphy.2019.07.003.

Infections with parasitic nematodes, e.g. the root-knot nematode (RKN), cause important agricultural losses in rice production. The conventional control of RKN with nematicides is challenging and not environmentally friendly. This study tests formulations of chitosan oligomers (COS) and pectin-derived oligogalacturonides (OGA), COS-OGA, for their potential and mode-of-action as preventive measures to control RKN Meloidogyne graminicola infection in rice. FytoSol® and FytoSave® applied to leaves 24h before nematode inoculation reduced root-galling and nematode development significantly, showing for the first time a systemic effect of these defence elicitors. The systemic defence activation is not correlated with defence hormone accumulation in the rice shoots and roots but dependent on the stimulation of the phenylpropanoid pathway.

Plant oil diets for common carp

Nguyen TM, Mandiki SNM, Tran TNT, Larondelle Y, Mellery J, Mignolet E, Cornet V, Flamion E, Kestemont P. 2019. Growth performance and immune status in common carp Cyprinus carpio as affected by plant oil-based diets complemented with β-glucan. Fish & Shellfish Immunology 92:288–299. DOI: 10.1016/j.fsi.2019.06.011.

A major constraint in the future of aquaculture is the limited availability of fish meal and fish oil. Alternative solutions to feed fish with plant products would be much cheaper and much more abundant. Most plant-derived oils contain polyunsaturated fatty acids (PUFA) but no long chain PUFAs (LC-PUFA, > 18C), that play an important role in fish (and human) health. Omnivorous fish species such as the common carp (Cyprinus carpio) are able to biosynthesise LC-PUFAs from plant oil PUFA precursors. This study compares the immunocompetence status of fish fed with fish- and plant oil. After bacterial infection, mortality rate did not differ. Thus, common carp fed plant oil-based diets are able to produce substantial amounts of LC-PUFA for sustaining growth rate, immune status and disease resistance similar to fish fed a fish oil-based diet.

Cloning and modelling of enzymes

Tinti E, Geay F, Lopes Rodrigues M, Kestemont P, Perpète EA, Michaux C. 2019. Molecular cloning and 3D model of a fatty-acid elongase in a carnivorous freshwater teleost, the European perch (Perca fluviatilis). 3 Biotech 9:242. DOI: 10.1007/s13205-019-1773-x.

The European perch (Perca fluviatilis) is a carnivorous freshwater fish able to metabolise polyunsaturated fatty acids (PUFA) into highly unsaturated fatty acids (HUFA), that are essential fatty acids for humans and animals. This makes it a potential candidate for sustainable aquaculture development, since input-intensive fish oil could be replaced by vegetable oil. This study investigates especially the fatty-acid elongase (ELOVL) family, one of the two enzymatic systems implied in the HUFA biosynthesis. To gain knowledge on its molecular structure, molecular cloning and 3D modelling approaches are applied.

The best diet for pikeperch larvae

El Kertaoui N, Lund I, Assogba H, Domínguez D, Izquierdo MS, Baekelandt S, Cornet V, Mandiki SNM, Montero D, Kestemont P. 2019. Key nutritional factors and interactions during larval development of pikeperch (Sander lucioperca). Scientific Reports 9:7074. DOI: 10.1038/s41598-019-43491-1.

Pikeperch as great potential for European aquaculture. However, nutritional requirements for freshwater species are yet not well understood. Following a fractional factorial experimental design, this study is a first attempt to evaluate the simultaneous effects of selected fatty acids, vitamins and minerals, in total, 8 nutritional variables to identify their respective importance and interactions in pikeperch larval development. Survival, growth rate, sekletal anomalies etc. were analysed. Essential elements in larval diet were Ca/P, long chain polyunsaturated fatty acids and vitamins (C & E).

Vegetable oils for catfish

Sourabié A, Mandiki SNM, Geay F, Ahoulé AG, Naert N, Toguyeni A, Kestemont P. Tropical Vegetable Oils Do Not Alter Growth Performance in African Catfish through a High n-6 Polyunsaturated Fatty Acids Biosynthesis Capacity. Lipids 0. DOI: 10.1002/lipd.12145.

Fish oil, usually used for fish nutrition in aquaculture, was completely replaced by vegetable oils to feed African catfish. This did not affect growth performance with the exception of Shea butter diet, where growth was lower. Other indicators (muscle arachidonic acid, gene expression in the liver) support the recommendation that fish oil could be replaced by desert date oil.

Pikeperch & salinity

Lund I, Rodríguez C, Izquierdo MS, El Kertaoui N, Kestemont P, Reis DB, Dominguez D, Pérez JA. 2019. Influence of salinity and linoleic or α-linolenic acid based diets on ontogenetic development and metabolism of unsaturated fatty acids in pike perch larvae (Sander lucioperca). Aquaculture 500:550–561. DOI: 10.1016/j.aquaculture.2018.10.061.

Pike perch farming predominantly takes place in freshwater. However, their osmotic tolerance in a saline environment may offer a growth potential for rearing this teleost fish in low saline waters. The study examines effects of fatty acids and salinity at low saline rearing conditions. A detailed evaluation of the different types of skeleton anomalies as well as the expression of related molecular markers was conducted for the first time in the larval phases of this species. One of several articles published within the project Diversify!

Pikeperch & Light

Baekelandt S, Mandiki SNM, Schmitz M, Kestemont P. 2019. Influence of the light spectrum on the daily rhythms of stress and humoral innate immune markers in pikeperch Sander lucioperca. Aquaculture 499:358–363. DOI: 10.1016/j.aquaculture.2018.09.046.

The culture of Pikeperch (Sander lucioperca) is still limited due to impaired growth and high mortality during the young developmental stages. Inadequate rearing conditions probably increase stress levels since aquaculture management has not been optimized yet. This study investigates the daily variations of stress markers (plasma cortisol and glucose and some humoral innate immune markers) and the effect of light spectrum on these variations.


Spectral lines of phosphine

Salem, J, Blanquet, G, Lepère, M, & Younes, R ben 2018, ‘H2-broadening, shifting and mixing coefficients of the doublets in the ν2 and ν4 bands of PH3 at room temperature’, Molecular Physics, vol. 0, no.0, pp. 1–10, DOI: 0.1080/00268976.2017.1423125

Molecular spectroscopy measures light that is emitted, absorbed, or scattered by materials or molecules to study, identify and quantify those materials. This study determines the doublet spectral lines of phosphine (PH3) when perturbed by hydrogen at room temperature. A collisional relaxation matrix groups the spectroscopic parameters: intensities, line widths, line shifts and line mixing parameters. The collisional process and the physical effects on the spectra of phosphine were measured using a tunable diode-laser spectrometer.

Underground galleries

Quinif Y, Hallet V. 2018. The Karstic System of Han-sur-Lesse. In: Demoulin A ed. Landscapes and Landforms of Belgium and Luxembourg. World Geomorphological Landscapes. Cham: Springer International Publishing, 139–158. DOI: 10.1007/978-3-319-58239-9_9.

The karstic system of Han-sur-Lesse is the archetype of underground meander cutoff. Located in the “Calestienne”, a narrow bench extending along the northern margin of the Lower Devonian Ardenne, it comprises all caves and underground flow paths related to the epigenetic Lesse River across the Givetian limestone anticline of Boine.

Post-Paleozoic evolution of the northern Ardenne Massif

Barbarand J, Bour I, Pagel M, Quesnel F, Delcambre B, Dupuis C, Yans J. 2018. Post-Paleozoic evolution of the northern Ardenne Massif constrained by apatite fission-track thermochronology and geological data. BSGF - Earth Sciences Bulletin 189:16. DOI: 10.1051/bsgf/2018015.

This work characterizes the vertical evolution of the northern Ardenne and the Brabant massifs considering new fission-track data, using robust geological constraints. Fission track dating is a radiometric dating technique based on analyses of the damage trails, or tracks, left by fission fragments in certain uranium-bearing minerals and glasses. The damage appears as linear features referred to as fission tracks. This technique is useful at unravelling the thermal evolution of rocks and minerals.

Unusual H- and O-isotope compositions in the Tamra deposit, Tunisia

Dekoninck, A, Moussi, B, Vennemann, T, Jamoussi, F, Mattielli, N, Decrée, S, Chaftar, H-R, Hatira, N, & Yans, J 2018, ‘Mixed hydrothermal and meteoric fluids evidenced by unusual H- and O-isotope compositions of kaolinite-halloysite in the Fe(-Mn) Tamra deposit (Nefza district, NW Tunisia)’, Applied Clay Science, vol. 163, pp. 33–45,

The iron mine of Tamra (Nefza District, NW Tunisia) is a 50 m thick Upper Mio-Pliocene sedimentary series impregnated by Fe-Mn oxides associated with white clay lenses with high halloysite and kaolinite content. The unusually high δ18O values of the kaolinite-halloysite and goethite-hematite deposit show that these latter minerals did not originate solely from an equilibrium state with pure meteoric waters. The most appropriate explanation for their relatively heavy isotopic values is a hydrothermal fluid-rock interaction of the meteoric fluid with the underlying carbonate rocks (marls and skarns).

Groundwater recharge processes

Poulain, A, Watlet, A, Kaufmann, O, Camp, MV, Jourde, H, Mazzilli, N, Rochez, G, Deleu, R, Quinif, Y, & Hallet, V 2018, ‘Assessment of groundwater recharge processes through karst vadose zone by cave percolation monitoring’, Hydrological Processes, vol. 32, no. 13, pp. 2069–2083, doi: 10.1002/hyp.13138

Recharge processes of karst aquifers are difficult to assess given their strong heterogeneity and the poorly known effect of vadose zone on infiltration. However, recharge assessment is crucial for the evaluation of groundwater resources. This experimental study identifies and quantifies recharge modes in the Rochefort Cave (Belgium). The quantification allowed investigating the question of recharge efficiency and aquifer vulnerability. Both methods used, i.e. discharge monitoring and artificial dye tracing highlighted a two‐flow component behaviour with a continuous diffuse recharge and an ephemeral quickflow recharge.

Where do the “Lorraine limestones” from the Saint-Paul Cathedral of Liège come from?

Lecuit, MX, Fronteau, G, Boulvain, F, Boulvain, F, Dechamps, F, Eyssautier-Chuine, S, Piavaux, M, Yans, J (2018) Geochemical characterization of “Lorraine limestones” from the Saint-Paul Cathedral of Liège (Belgium): assumptions for the true provenance of the building stones, Environmental Earth Sciences 77: 361.

Some architectural specific elements of the Saint-Paul Cathedral in Liège (Belgium) are made from ochre building stones, so-called “Lorraine limestones” (13th-15th century). However, within a radius of 200km, no such rocks can be found. This multi-analytical approach applied petrography, Rare Earth Elements geochemistry and studied archives and archeological material to characterize the stones used in the church and to compare them with ochre limestones outcropping in the north-east of the Paris Basin. The results make it highly probable that a very restricted geographical area near the ancient port of Donchery (Ardennes, France) including Dom-le-Mesnil and Hannogne ancient quarries of Bajocian limestones (Middle Jurassic) are the potential origin location for the stones used in the Saint-Paul Cathedral.

Underground lakes traced

Dewaide, L, Collon, P, Poulain, A, Rochez, G, & Hallet, V 2018, ‘Double-peaked breakthrough curves as a consequence of solute transport through underground lakes: a case study of the Furfooz karst system, Belgium’, Hydrogeology Journal, vol. 26, no.2, pp. 641–650, doi: 10.1007/s10040-017-1671-4

To study underground lakes, dye tracers are injected into the cave system and their transport measured. In karst systems, such measurements can result in double-peaked breakthrough curves (BTCs) – often reported but poorly understood. From physical laboratory experiments only, it has been proposed that these result from solute transport through underground lakes or pools. This report first describes field data (tracer tests in various hydrologic conditions) which point towards the double peak being linked to a nonlinear process that originates within the lakes. Observations took place on the Furfooz karst system in southern Belgium, where the River Lesse sinks partially into a swallow hole. The water follows a solitary conduit leading to an underground lake that is directly connected to a second underground lake.

Groundwater infiltration dynamics revealed with long-term ERT monitoring

Watlet, A, Kaufmann, O, Triantafyllou, A, Poulain, A, Chambers, JE, Meldrum, PI, Wilkinson, PB, Hallet, V, Quinif, Y, Van Ruymbeke, M, & Van Camp, M 2018, ‘Imaging groundwater infiltration dynamics in the karst vadose zone with long-term ERT monitoring’, Hydrology and Earth System Sciences, vol. 22, no.2, pp. 1563–1592, doi: 10.5194/hess-22-1563-2018

Karst regions are important sources of drinking water and their improved management is essential. This necessitates a better understanding of superficial water movements (Water infiltration and recharge processes), which are strongly heterogeneous in karst areas and measure with conventional hydrological methods. This study is the first long-term (3 y) and permanently installed electrical resistivity tomography (ERT) monitoring in a karst landscape (Rochefort Cave Laboratory, Belgium). Three types of hydrological dynamics, corresponding to areas with distinct lithological and structural features, could be identified.

Mineralogy and Genesis of an Ore in the Eastern High Atlas, Morocco

Verhaert, M, Bernard, A, Saddiqi, O, Dekoninck, A, Essalhi, M & Yans, J 2018, ‘Mineralogy and Genesis of the Polymetallic and Polyphased Low Grade Fe-Mn-Cu Ore of Jbel Rhals Deposit (Eastern High Atlas, Morocco)’, Minerals, vol. 8, no. 2, p. 39. DOI: 10.3390/min8020039

The Jbel Rhals deposit, also known as “Guelb en Nahas” (“Copper Hill”) is located in the Oriental High Atlas of Morocco and hosts a polymetallic Fe-Mn-Cu ore. It has been shortly exploited during the 19th–20th centuries but receives again attention. This work presents a petrological, mineralogical, and geochemical synthesis of the deposit with a focus on the supergene processes responsible for the current ore mineralogy. A metallogenic model explains the genesis of the ores. Special attention is given to “strategic” or “critical” raw materials in supergene mineral phases.

Sourabié A, Mandiki SNM, Geay F, Sene T, Toguyeni A, Kestemont P. 2018. Fish proteins not lipids are the major nutrients limiting the use of vegetable ingredients in catfish nutrition. Aquaculture Nutrition 24:1393–1405. DOI: 10.1111/anu.12676.

Demoulin, A, Barbier, F, Dekoninck, A, Verhaert, M, Ruffet, G, Dupuis, C & Yans, J 2018, Erosion Surfaces in the Ardenne–Oesling and Their Associated Kaolinic Weathering Mantle. in A Demoulin (ed.), Landscapes and Landforms of Belgium and Luxembourg. World Geomorphological Landscapes, Springer Verlag, Cham, pp. 63-84. DOI: 10.1007/978-3-319-58239-9_5

Alternative soil amendments

Li, Z, Delvaux, B, Yans, J, Dufour, N, Houben, D, & Cornelis, J-T 2018, ‘Phytolith-rich biochar increases cotton biomass and silicon-mineralomass in a highly weathered soil’, Journal of Plant Nutrition and Soil Science, vol. 181, no. 4, pp. 537–546, doi: 10.1002/jpln.201800031

Non‐essential silicon (Si) is beneficial to plants by improving photosynthetic activity and alleviating stresses. Natural soil weathering and removal of harvested biomass leads to desilication. Si‐rich biomass (e.g. Miscanthus) can be transformed into biochar (= charcoal used as a soil amendment) to supply bioavailable Si. The authors show that Miscanthus biochar is an alternative Si amendment to supply bio-available Si, increase plant biomass, and promote the biological cycle of Si in the soil–plant system. The positive impact of a Si-rich biochar was larger in old, desilicated, highly-weathered Nitisol.

 Diets for pikeperch larvae

Lund, I, Kertaoui, NE, Izquierdo, MS, Dominguez, D, Hansen, BW, & Kestemont, P 2018, ‘The importance of phospholipids combined with long-chain PUFA in formulated diets for pikeperch (Sander lucioperca) larvae’, British Journal of Nutrition, vol. 120, no. 6, pp. 628–644, doi: 10.1017/S0007114518001794

Pikeperch (Sander lucioperca; also: zander) is considered one of the most valuable food fish native to Europe. This study aimed to determine optimal dietary levels of soyabean lecithin (SBL)-derived phospholipids (PL) in starter feeds for pikeperch larvae. Liver proteomic analyses, physiological expression and interactions in larval proteins, bone anomalies, digestive enzymatic activity, candidate gene expression and skeleton morphogenesis were examined. The supplementation of essential fatty acids had beneficial effects on pikeperch larvae development.

Possible alternatives to control blight disease in potatoes

van Aubel, G, Serderidis, S, Ivens, J, Clinkemaillie, A, Legrève, A, Hause, B and Van Cutsem, P 2018, Oligosaccharides successfully thwart hijacking of the salicylic acid pathway by Phytophthora infestans in potato leaves. Plant Pathology doi:10.1111/ppa.12908

Potato late blight (caused by Phytophthora infestans), the most important potato disease worldwide, requires massive amounts of fungicides. Stimulating the plant’s innate immunity opens ways to new biological plant protection tools such as elicitor molecules. This study shows that especially one elicitor oligosaccharide - FytoSol, a new composition still under development by the spin-off FytoFend - was efficient in controlling the diversion of late blight. It could become part of an integrated pest management strategy allowing for reduction of fungicide use and related environmental impact in potato fields.

Optimal aquaculture modalities for pikeperch

Baekelandt, S, Redivo, B, Mandiki, SNM, Bournonville, T, Houndji, A, Bernard, B, El Kertaoui, N, Schmitz, M, Fontaine, P, Gardeur, J-N, Ledoré, Y, & Kestemont, P 2018, ‘Multifactorial analyses revealed optimal aquaculture modalities improving husbandry fitness without clear effect on stress and immune status of pikeperch Sander lucioperca’, General and Comparative Endocrinology, vol. 258, pp. 194–204, doi: 10.1016/j.ygcen.2017.08.010

High mortality and impairment in growth rate during pikeperch (Sander lucioperca) ongrowing are among the major bottlenecks for its development in aquaculture. These failures may be related to high stress responsiveness since the rearing conditions are not yet optimized for this species. The objectives were to characterize the stress and immunological responses of pikeperch to major aquaculture modalities, and to identify the optimal aquaculture conditions for improving its welfare status.

Reproduction performances of pikeperch

Khendek, A, Chakraborty, A, Roche, J, Ledoré, Y, Personne, A, Policar, T, Żarski, D, Mandiki, R, Kestemont, P, Milla, S, & Fontaine, P 2018, ‘Rearing conditions and life history influence the progress of gametogenesis and reproduction performances in pikeperch males and females’, Animal, vol 12(11), pp. 2335-2346, DOI: 10.1017/S1751731118000010

Pikeperch (Sander lucioperca) is a highly valuable fish in Europe and could be a promising candidate for the development of aquaculture. However, its reproduction in the wild highly depends on the season demanding a controlled photothermal program for their domestication. This study investigated gametogenesis and reproduction of two groups of pikeperch with different life histories. Only those fish that had been exposed to natural changes in temperature/photoperiod conditions were able to spawn successfully.


Le Cong, T, Doménech, JL, Lepère, M & Tran, H 2017, 'Molecular dynamic simulations of N2-broadened methane line shapes and comparison with experiments' The journal of chemical physics, vol 146, no. 9, 094305. DOI: 10.1063/1.4976978

Capette, L & Hallet, V 2017, Captage SWDE de Blaton (Bernissart) - Aperçu hydrogéologique. Cellule de diagnostic "pesticide - captage" CRAW - SPGE. UNamur Département de géologie. Commissioned Report.

Capette, L & Hallet, V 2017, Site Lhoist de Marche-les-Dames - Estimation par modélisation des débits d'exhaure pour une cote altimétrique de +3 m du fond de fosse : situation actuelle et extension projetée. Commissioned Report.

Capette, L & Hallet, V 2017, SWDE - Prises d'eau de Gesves (Hoûte E1 et Houyoux G1) - Aperçu hydrogéologique. Cellule de diagnostic "pesticide - captage" CRAW - SPGE. UNamur Département de géologie. Commissioned Report.

Latli, A, Sturaro, N, Desjardin, N, Michel, LN, Otjacques, W, Lepoint, G & Kestemont, P 2017, 'Isotopic half-life and enrichment factor in two species of European freshwater fish larvae: an experimental approach' Rapid Communications in Mass Spectrometry, vol 31, no. 8, pp. 685-692. DOI: 10.1002/rcm.7838

Latli, A, Descy, J-P, Mondy, CP, Floury, M, Viroux, L, Otjacques, W, Marescaux, J, Depiereux, E, Ovidio, M, Usseglio-Polatera, P & Kestemont, P 2017, 'Long-term trends in trait structure of riverine communities facing predation risk increase and trophic resource decline' Ecological Applications, vol 27, no. 8, pp. 2458-2474.  DOI: 10.1002/eap.1621

Mellery J, Brel J, Dort J, Geay F, Kestemont P, Francis DS, Larondelle Y, Rollin X. 2017. A n-3 PUFA depletion applied to rainbow trout fry (Oncorhynchus mykiss) does not modulate its subsequent lipid bioconversion capacity. British Journal of Nutrition 117:187–199. DOI: 10.1017/S0007114516004487.

Poulain, A, Rochez, G, Van Roy, J-P, Dewaide, L, Hallet, V & De Sadelaer, G 2017, 'A compact field fluorometer and its application to dye tracing in karst environments' Hydrogeology Journal, vol 25, no. 5, pp. 1517–1524. DOI: 10.1007/s10040-017-1577-1

Schnyder J, Pons D, Yans J, Tramoy R, Abdulanova S. 2017. Integrated stratigraphy of a continental Pliensbachian–Toarcian Boundary (Lower Jurassic) section at Taskomirsay, Leontiev Graben, southwest Kazakhstan. Geological Society, London, Special Publications 427:337–356. DOI: 10.1144/SP427.15.

Verhaert, M, Bernard, A, Dekoninck, A, Lafforgue, L, Saddiqi, O & Yans, J 2017, 'Mineralogical and geochemical characterization of supergene Cu–Pb–Zn–V ores in the Oriental High Atlas, Morocco' Mineralium Deposita, vol 52, no. 7, pp. 1049-1064. DOI: 10.1007/s00126-017-0753-5, 10.1007/s00126-017-0753-5

Yans J, 2017. Gestion durable des ressources minérales en Wallonie (Belgique) : singularités et pistes de réflexion. In: L’industrie minière et le développement durable : une perspective internationale francophone. ed. Rouleau A, Gasquet D, CERM, Université du Québec à Chicoutimi et Institut de la Francophonie pour le développement durable, Collection Points de repère, 26, 99-114. link

Clinckemaillie A, Decroës A, van Aubel G, Santos SC dos, Renard ME, Van Cutsem P, Legrève A. 2017. The novel elicitor COS-OGA enhances potato resistance to late blight. Plant Pathology 66:818–825. DOI: 10.1111/ppa.12641.

Douxfils, J, Fierro-Castro, C, Mandiki, R, Emile, W, Tort, L & Kestemont, P 2017, 'Dietary β-glucans differentially modulate immune and stress-related gene expression in lymphoid organs from healthy and Aeromonas hydrophila-infected rainbow trout (Oncorhynchus mykiss)' Fish and Shellfish Immunology, vol 63, pp. 285-296. DOI: 10.1016/j.fsi.2017.02.027

Khendek, A, Alix, M, Viot, S, Ledoré, Y, Rousseau, C, Mandiki, R, Kestemont, P, Policar, T, Fontaine, P & Milla, S 2017, 'How does a domestication process modulate oogenesis and reproduction performance in Eurasian perch?' Aquaculture, vol 473, pp. 206-214. DOI: 10.1016/j.aquaculture.2017.02.003

Khuyen, TD, Mandiki, SNM, Cornet, V, Douxfils, J, Betoulle, S, Bossier, P, Reyes-López, FE, Tort, L & Kestemont, P 2017, 'Physiological and immune response of juvenile rainbow trout to dietary bovine lactoferrin' Fish & Shellfish Immunology, vol 71, pp 359-371. DOI: 10.1016/j.fsi.2017.10.027

Mandiki, R, Milla, S, Nkogo Robles, S & Kestemont, P 2017, 'Corticosteroids deeply depress the in vitro steroidogenic capacity of Eurasian perch ovary at the end of the reproductive cycle' General and Comparative Endocrinology, vol 245, pp. 44-54. DOI: 10.1016/j.ygcen.2017.02.002

Mellery, J, Brel, J, Dort, J, Geay, F, Kestemont, P, Francis, DS, Larondelle, Y & Rollin, X 2017, 'A n-3 PUFA depletion applied to rainbow trout fry (Oncorhynchus mykiss) does not modulate its subsequent lipid bioconversion capacity' British Journal of Nutrition, vol 117, no. 2, pp. 187–199. DOI: 10.1017/S0007114516004487

Mellery, J, Scalisi, F, Bonnineau, C, Kestemont, P, Rollin, X & Larondelle, Y 2017, 'Impact of lignans on the polyunsaturated fatty acid metabolic processing in a rainbow trout (Oncorhynchus mykiss) cell line' Aquaculture, vol 476, pp. 106-110. DOI: 10.1016/j.aquaculture.2017.04.022

Schmitz, M, Baekelandt, S, Bequet, S & Kestemont, P 2017, 'Chronic hyperosmotic stress inhibits renal Toll-Like Receptors expression in striped catfish (Pangasianodon hypophthalmus, Sauvage) exposed or not to bacterial infection' Developmental and Comparative Immunology, vol 73, pp. 139-143. DOI: 10.1016/j.dci.2017.03.020


Etienne T, Gattuso H, Michaux C, Monari A, Assfeld X, Perpète EA. 2016. Fluorene-imidazole dyes excited states from first-principles calculations—Topological insights. Theoretical Chemistry Accounts 135:111. DOI: 10.1007/s00214-016-1866-0.

Flot, JF, Debortoli, N, Hallet, B & Van Doninck, K 2016, 'Response to Signorovitch et al.' Current Biology , vol 26, no. 16, pp. R755. DOI: 10.1016/j.cub.2016.06.052

Leclere, L, Fransolet, M, Cambier, P, El Bkassiny, S, Tikad, A, Dieu, M, Vincent, SP, Van Cutsem, P & Michiels, C 2016, 'Identification of a cytotoxic molecule in heat-modified citrus pectin' Carbohydrate Polymers, vol 137, pp. 39-51. DOI: 10.1016/j.carbpol.2015.10.055

Le Cong, T, Fissiaux, L, Lepère, M & Tran, H 2016, 'Isolated line shape of methane with various collision partners' Journal of Quantitative Spectroscopy and Radiative Transfer, vol 185, pp. 27-36. DOI: 10.1016/j.jqsrt.2016.07.017

Salem, J, Blanquet, G, Lepère, M & Aroui, H 2016, 'H2 Line-mixing coefficients in the ν2 and ν4 bands of PH3 at low temperature' Journal of Quantitative Spectroscopy and Radiative Transfer, vol 173, pp. 34-39. DOI: 10.1016/j.jqsrt.2016.01.010

Barthélemy, J, Carletti, T, Collier, L, Hallet, V, Moriamé, M & Sartenaer, A 2016, 'Interaction prediction between groundwater and quarry extension using discrete choice models and artificial neural networks' Environmental Earth Sciences, vol 75, no. 23, 1467. DOI: 10.1007/s12665-016-6268-z

Dekoninck, A, Bernard, A, Barbarand, J, Saint-Bezar, B, Missenard, Y, Lepretre, R, Saddiqi, O & Yans, J 2016, 'Detailed mineralogy and petrology of manganese oxyhydroxide deposits of the Imini district (Morocco)' Mineralium Deposita, vol 51, no. 1, pp. 13-23. DOI: 10.1007/s00126-015-0590-3

Dekoninck, A, Leprêtre, R, Saddiqi, O, Barbarand, J & Yans, J 2016, The high-grade Imini manganese district-karst-hosted deposits of Mn oxides and oxyhydroxides. In: Bouabdellah M., Slack J. (eds) Mineral Deposits of North Africa. Mineral Resource Reviews. Springer, Cham, pp. 575-594. DOI: 10.1007/978-3-319-31733-5_22

Dewaide, L, Bonniver, I, Rochez, G & Hallet, V 2016, 'Solute transport in heterogeneous karst systems: Dimensioning and estimation of the transport parameters via multi-sampling tracer-tests modelling using the OTIS (One-dimensional Transport with Inflow and Storage) program' Journal of Hydrology, vol 534, pp. 567-578. DOI: 10.1016/j.jhydrol.2016.01.049

Geay F, Mellery J, Tinti E, Douxfils J, Larondelle Y, Mandiki SNM, Kestemont P. 2016. Innate immune system modulation and disease resistance in Eurasian perch fed contrasted LC-PUFA dietary contents. Fish & Shellfish Immunology 53:70. DOI: 10.1016/j.fsi.2016.03.078.

Geay F, Tinti E, Mellery J, Michaux C, Larondelle Y, Perpète E, Kestemont P. 2016. Cloning and functional characterization of Δ6 fatty acid desaturase (FADS2) in Eurasian perch (Perca fluviatilis). Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 191:112–125. DOI: 10.1016/j.cbpb.2015.10.004.

Otjacques, W, De Laender, F & Kestemont, P 2016, 'Discerning the causes of a decline in a common European fish, the roach (Rutilus rutilus L.): A modelling approach' Ecological Modelling , vol 322, pp. 92-100. DOI: 10.1016/j.ecolmodel.2015.12.002

Radinger, J, Hölker, F, Horký, P, Slavík, O, Dendoncker, N & Wolter, C 2016, 'Synergistic and antagonistic interactions of future land use and climate change on river fish assemblages' Global Change Biology, vol 22, no. 4, pp. 1505-1522. DOI: 10.1111/gcb.13183

Roland, S, Rorive, A, Capette, L & Hallet, V Carte hydrogéologique de Wallonie, Planchettes Rebecq - Ittre n° 39/1-2. link

Ruthy, I, Dassargues , A, Capette, L & Hallet, V Carte hydrogéologique de Wallonie, Planchettes Natoye – Ciney n° 54/1-2. link

Tramoy, R, Schnyder, J, Nguyen Tu, TT, Yans, J, Jacob, J, Sebilo, M, Derenne, S, Philippe, M, Huguet, A, Pons, D & Baudin, F 2016, 'The Pliensbachian-Toarcian paleoclimate transition: New insights from organic geochemistry and C, H, N isotopes in a continental section from Central Asia' Palaeogeography, Palaeoclimatology, Palaeoecology, vol 461, pp. 310-327. DOI: 10.1016/j.palaeo.2016.08.020

Verhaert, M-A, Bernard, A, Dekoninck, A & Yans, J 2016, 'Characterization and genesis of Cu-Pb-Zn-V-Fe-Mn supergene ore deposits in the area of Bou Arfa (Oriental High Atlas, Morocco)' Geologica Belgica, vol 19, no. 3/4, pp. 302-304.

Yans, J & Dekoninck, A 2016, Ressources du sous-sol wallon : historique, état des lieux et perspectives. in Mines et Carrières. vol. Hors Série 18, 236, Revue de la Société de l'Industrie Minérale, Paris, pp. 5-12. pdf

Khuyen TD, Mandiki SNM, Douxfils J, Cornet V, De Schryver P, Bossier P, Betoulle S, Tort L, Kestemont P. 2016. Physiological and immune pathway responses of rainbow trout juveniles to dietary supplementation with inulin and lactoferrin. Fish & Shellfish Immunology 53:117. DOI: 10.1016/j.fsi.2016.04.101.

Mandiki SNM, Redivo B, Baekelandt S, Douxfils J, Lund I, Höglund E, Kestemont P. 2016. Long-term tryptophan supplementation decreased the welfare and innate immune status of pikeperch juveniles. Fish & Shellfish Immunology 53:113–114. DOI: 10.1016/j.fsi.2016.04.090.

Mellery, J, Geay, F, Tocher, DR, Kestemont, P, Debier, C, Rollin, X & Larondelle, Y 2016, 'Temperature increase negatively affects the fatty acid bioconversion capacity of rainbow trout (Oncorhynchus mykiss) fed a linseed oil-based diet' PLoS ONE, vol 11, no. 10, e0164478. DOI: 10.1371/journal.pone.0164478

Redivo B, Mandiki SNM, Bournonville T, Baekelandt S, Fontaine P, Ledoré Y, Kestemont P. 2016. Characterization of neurophysiological and immune responses of pikeperch juveniles to major stress factors under intensive culture conditions. Fish & Shellfish Immunology 53:72. DOI: 10.1016/j.fsi.2016.03.084.

Schmitz, M, Douxfils, J, Mandiki, R, Morana, C, Baekelandt, S & Kestemont, P 2016, 'Chronic hyperosmotic stress interferes with immune homeostasis in striped catfish (Pangasianodon hypophthalmus, S.) and leads to excessive inflammatory response during bacterial infection' Fish & shellfish immunology, vol 55, pp. 550-8. DOI: 10.1016/j.fsi.2016.06.031

van Aubel, G, Cambier, P, Dieu, M & Van Cutsem, P 2016, 'Plant immunity induced by COS-OGA elicitor is a cumulative process that involves salicylic acid' Plant Science, vol 247, pp. 60-70. DOI: 10.1016/j.plantsci.2016.03.005