Research team

Expertise

Main expertise: Toxicology and ecophysiology of marine and freshwater organisms under changing environmental conditions (due to natural and anthropogenic pressures) with a focus stress physiology, energy metabolism and ionoregulation at different levels of biological organisation: molecular, cellular and organismal. Comparative animal physiology. Techniques: Toxicological tests: bioaccumulation, biomagnification and modes of action Performance tests: Swimming capacity and behaviour, challenge tests Fuel utilisation: Respiration rates and energy stores, metabolomics Ion homeostasis: Ion and toxicant uptake mechanisms, blood electrolytes and acid-base balance Biomarkers: Oxidative stress, stress and defensive proteins (e.g. metallothionein) and enzymes Regulation: stress hormones, transcriptomics, proteomics.

Quantitative extrapolation in ecotoxicology (QTOX). 01/02/2023 - 31/01/2027

Abstract

Reliable assessment of the ecological risks posed by chemicals is a fundamental component of European policies concerned with safe use of chemicals e.g. REACh, The Green Deal, and protection of ecosystem functioning and ecosystem services (Water Framework Directive). Chemical risk assessment typically involves extrapolation of effects observed in-vitro and in-vivo under laboratory conditions to predictions of effects at the ecosystem level. This is a very challenging task and current extrapolation models have limitations, notably due to a number of ecological processes that are disregarded by the models and the paucity of data for parameterisation and validation. QTOX will develop mechanistic knowledge and data efficient modelling tools to bridge the gap between standard toxicity data (typically acute effects ofsingle chemicals) and ecologically relevant end points arising from chronic, time variable exposuresto chemical mixtures. The results will be achieved through an interdisciplinary and intersectoral research and training program in which 10 doctoral candidates will characterise the mechanistic processes describing the successive eventsfrom exposure to ecosystem-level effects and develop models for extrapolation of adverse effects acrosslevels of biological organisation under environmentally realistic conditions. Notably, the effects of chemical mixtures, dynamic exposure conditions and their interaction with climate change scenarios will be characterised in a series of mesocosm experiments at three sites in central and southern Europe. The mesocosm work will serve as a uniting training element and a rich source of data for testing and validating the modelling framework. QTOX will produce an open access toolbox for quantitative extrapolations in ecotoxicology and a cohort of researchers equipped with the knowledge and skills necessary to implement and develop rigorous approaches for predicting adverse effects of chemicals.

Researcher(s)

Research team(s)

Project website

Project type(s)

  • Research Project

Chronic stress in sharks and their relatives: a comparative and ecophysiological approach to finding a biomarker of long-term stress. 01/11/2022 - 31/10/2023

Abstract

Decades of overexploitation and habitat degradation have profoundly impacted sharks and their relatives, leaving 37.5% of all species threatened with extinction. In order to effectively guide and improve conservation efforts, a profound knowledge on the behaviour, ecology, and physiology of elasmobranchs is urgently needed. A key research gap that requires particular attention are the effects of anthropogenic and environmental stressors on these ancient fishes. However, finding biomarkers of chronic stress in sharks and their relatives has proven to be a challenging task due to their unique stress hormone, 1?-hydroxycorticosterone (1?-OHB). In the proposed research project, because the role of 1?-OHB in elasmobranch fishes remains equivocal, I will experimentally determine the utility of 1?-OHB as an indicator for chronic stress in sharks and their relatives, and I will investigate and physiologically and biologically validate the use of elasmobranch teeth as a unique and novel biomarker of long-term stress. Additionally, the metabolic action and energetic cost of chronic stress on these fishes will be evaluated, with a special emphasis on ketone bodies and amino acids, as these can lead to a suite of possible biomarkers to be added to the conservation physiology toolbox for elasmobranch physiology.

Researcher(s)

Research team(s)

Project type(s)

  • Research Project

The analyser - Skalar. 01/06/2022 - 31/05/2024

Abstract

Nutrients are vital, not only for individual organisms but also for entire ecosystems. The SKALAR SAN++ Advanced System allows us to analyze a whole range of nutrients in continuous flow. It is essential for the research of the new research group ECOSPHERE on aquatic and terrestrial ecosystems, where nutrient analysis in water, plants and soil are essential, and for the research group DuEL, where nutrient analysis in wastewater streams and microbial growth media are indispensable. The equipment also delivers analysis services to other research groups and external parties.

Researcher(s)

Research team(s)

Project type(s)

  • Research Project

From exposure to effects of pollutants: a dynamic mechanistic basis. 01/12/2020 - 30/11/2023

Abstract

Since we will be able to re-apply for a MSCA-ITN with the same scope as the unsuccessful application (QTOX: Quantitative extrapolation in ecotoxicology), the SEP funds will be used to obtain results that will strengthen the basis for our proposal. The particular strengths of the SPHERE group in this regard are measurement and modelling of chemical speciation dynamics in the exposure medium, development of novel active passive sampling devices, characterisation of biouptake rates and subcellular compartmentalisation of pollutants. Several ongoing PhD projects in SPHERE are dealing with aspects of these issues. Within the MSCA-ITN we have the ambition to go beyond current empirical ecotoxicological models to establish mechanistic knowledge of the underlying processes in the chain from exposure to effects of pollutants. Recent work in SPHERE has highlighted the physicochemically erroneous nature of widely used equilibrium-based chemical speciation codes, e.g. WHAM, NICA-Donnan, that are used as input to bioavailability and ecotoxicity models, e.g. BLM, Bio-met, PNEC-PRO. Despite the poor physicochemical basis of such models, they are being increasingly incorporated into environmental policy, e.g. water quality guidelines. The SEP will allow us to critically evaluate the results of ongoing SPHERE projects in the context of widely used bioavailability and ecotoxicity models, and thereby take steps towards development of a robust mechanistic foundation for describing the relationships between exposure and effects of pollutants. Beyond the research tasks, we will promote scientific activity in the subject area by chairing sessions on related topics at the SETAC Europe annual conference (ca. 2,000 participants), and will provide training for early stage researchers by running an intensive postgraduate course on Speciation and Bioavailability in 2021 and 2023 (pending possible SARS-CoV-2 restrictions). The course is part of SPHERE's contribution to the MSCA-ITN training programme. The SEP funds will be used to partly support a temporary academic staff member to be involved in supervision of ongoing PhD students in related topics, to perform modelling tasks, and to lead the preparation of the revised MSCA-ITN proposal; technical staff to support experimental tasks and to maintain and run instrumentation; as well as consumables and travel expenses that may arise in executing the research.

Researcher(s)

Research team(s)

Project type(s)

  • Research Project

Unravelling the effects of individual coping style and long-term glucocorticoid up-regulation on cardiac remodelling in Atlantic salmon (Salmo salar). 01/11/2020 - 31/10/2024

Abstract

Chronic stress in fish due to the intensification in aquaculture can lead to reduced performance (metabolism, growth, reproduction) and a compromised immune system, resulting in a decline in fish production yield and fish welfare. In this framework, quantification and subsequent mitigation of chronic stress was shown to be pivotal in a more sustainable aquaculture. Non-specific mortality of salmonids in the seawater-rearing phase is one of the major recurring problems in the aquaculture industry and especially the sudden stress-related mortality of fish ready for slaughter and subsequent economic losses. However, knowledge on the underlying factors causing this mortality are lacking, though it is attributed in large part to cardiac disease which could be linked to chronic stress. Indeed, it was demonstrated that cortisol responsiveness in salmonids is associated with pathological remodelling of the heart and that this stress hormone directly induces such remodelling. The main objective of this study is to unravel the effects of individual coping style and long-term cortisol up-regulation on cardiac remodelling in one of the most important aquaculture species, the Atlantic salmon, Salmo salar, look at the consequences for fish performance and test a potential mitigation strategy.

Researcher(s)

Research team(s)

Project type(s)

  • Research Project

Characterising genetic and phenotypic signatures of fisheries-induced life history evolution in commercially important Malawi cichlid fish. 01/11/2020 - 31/10/2024

Abstract

We currently lack a detailed understanding of how organisms rapidly adapt to environmental changes, which is key in evaluating and predicting human impact on nature, uncovering the genetic basis of adaptive traits, and gaining insight into fundamental evolutionary processes. Evolutionary response to a direct form of human impact, fishing,has often been discussed but evidence from natural systems is scarce. To address this, I will investigate genetic and phenotypic changes in Malawi cichlid fish following ~40 years of intense fishing. In particular, I will address life-history trait changes. Genome sequencing of museum specimens collected before and during fishing will give unprecedented insight into genes under selection. Extensive genomic resources available for Lake Malawi cichlids will allow me to investigate the evolutionary history of genes used in recent adaptation. I will leverage the ease of breeding cichlids in the lab to experimentally quantify genetic and environmental differences in traits implicated in fisheries-induced evolution. Furthermore, I will use state of the art (ancient) DNA and RNA sequencing technologies and bioinformatic methods to identify the genomic signature & molecular pathways involved in rapid life history adaptation. The combination of genome sequencing and controlled breeding experiments will greatly advance our understanding of how genomes can rapidly adapt to fishing and the link between selective pressures, phenotypes and genotypes.

Researcher(s)

Research team(s)

Project type(s)

  • Research Project

Freshwater ecosystems with a burn-out: extra stress caused by heatwaves? 01/10/2020 - 30/09/2024

Abstract

In this project, our specific focus will be directed towards understanding the interaction between climate warming and two prominent stressors in freshwater habitats: eutrophication (as nitrate pollution) and low dissolved oxygen (hypoxia). Freshwater habitats often receive excessive inputs of nitrates from urban and agricultural sources, and nitrogen is considered the main limiting nutrient for primary production. Nitrate pollution is closely linked to a second stressor - hypoxia. Because of the nitrate pollution, rapid, uncontrolled growth of algal blooms is often triggered, and the unnatural density of algal blooms causes light reduction for macrophytes during the day and nightly hypoxia when photosynthesis is not occurring. In the past it has been postulated that many small fish deplete the zooplanktonic grazers such as daphnids under warm and eutrophic conditions, inducing the turbid waters with algal blooms. However, climate change does not only induce steady increases in temperature but is also causing more frequent and severe heatwaves. In this project we postulate that these heatwaves will seriously negatively affect performance and survival of the fish, which in turn will affect shifts in the aquatic food web towards more zooplankton and hence potential less severe algal blooms.

Researcher(s)

Research team(s)

Project type(s)

  • Research Project

PurpleGuppy: Healthy ornamental fish through environment-friendly feed based on purple bacteria. 01/01/2022 - 31/12/2022

Abstract

Ornamental fish is the third and fifth most common group of pets in the United States and the European Union, respectively, with guppy being one of the most popular freshwater tropical fish. This market and associated environmental aspects continue to grow, spurring fish feed suppliers to use novel and ecological ingredients to boost health, fitness and color. Microalgal biomass, astaxanthin and several probiotics such as Pediococcus acidilactici are already available in commercial feed formulations for aquarists. A promising new sustainable ingredient is purple non-sulfur bacteria (PNSB) biomass. Previous research has shown its use as a probiotic and alternative protein source for shrimp and other aquaculture applications. Patents and scientific literature on the implementation of PNSB biomass in ornamental fish feed are limited, except for the research performed by the University of Antwerp. PurpleGuppy aims to further demonstrate and valorize added-value properties of PNSB biomass in ornamental fish feed. Feeding trials with guppies intend to corroborate the health and esthetic benefits of PNSB as a feed ingredient, resulting in feed formulation protocols with an appealing benefit-cost ratio.

Researcher(s)

Research team(s)

Project type(s)

  • Research Project

FWO sabbatical 2021-2022 (Prof. G. De Boeck). 01/08/2021 - 31/07/2022

Abstract

This sabbatical will be an excellent opportunity to explore old and new ideas, bounce these ideas off international peers, look for new collaborations and develop a research strategy for the next decade. Therefore, the focus of my sabbatical leave will revolve around three main action points: 1. Resolve the mystery around the mechanistic basis leading to the unusually high toxicity and bioaccumulation of silver in elasmobranchs and conduct a survey over different species. 2. Explore and familiarise myself with minimally-invasive and in vitro techniques that will not only become a powerful tool in my future research but also fit within the general effort to improve animal welfare following the 3R principle (replacement, reduction, refinement). These techniques are not limited to their use in elasmobranch research, but can be extended to teleosts and other aquatic organisms. 3. On the go, collect elasmobranch tissue samples and data, and explore new collaborations for a future research line which will be developed in the next years on chronic stress indicators in elasmobranchs and teleosts. With continuously ongoing climate change and habitat degradation, understanding the effects and consequences of chronic stress and evaluating stress responsiveness and environmental tolerances relative to environmental change is rapidly gaining importance. It is at the core of conservation physiology which aims to integrate physiological knowledge into ecosystem management and into tools to solve complex conservation problems. In addition, it is essential for assessing animal welfare in fast growing activities such as aquaculture.

Researcher(s)

Research team(s)

Project type(s)

  • Research Project

BOF Sabbatical 2021-2022 - Gudrun De Boeck. 01/08/2021 - 31/07/2022

Abstract

My sabbatical will focus on elasmobranch research. Firstly, I want to resolve the mystery around the mechanistic basis leading to the unusually high toxicity and bioaccumulation of silver (Ag) that has been observed in elasmobranchs (sharks and rays) and conduct a survey on baseline Ag bioaccumulation over different life stages and species. Doing so will also shed more light on the existence and involvement of putative urea back-transporters, and their characteristics and location in epithelial gill cells of elasmobranchs. Secondly, I want to explore and familiarise myself with minimally-invasive and in vitro techniques that will not only become a powerful tool in my present and future research but also fit within the general effort to improve animal welfare according to the 3R principle (replacement, reduction, refinement). These techniques are not limited to their use in elasmobranch research, but can be extended to teleosts and other aquatic organisms. And lastly, conduct some preliminary experiments and explore new collaborations for a future research line which will be developed in the next years on chronic stress indicators in elasmobranchs.

Researcher(s)

Research team(s)

Project type(s)

  • Research Project

AquaPro: Integrated control to produce high-quality microbial protein on food & beverage effluents used as sustainable aquafeed ingredients. 01/11/2020 - 31/10/2021

Abstract

By 2050, the planet will need to carry 9.7 billion people and their gorging consumption, putting major stress on meat production and fisheries alike. Half of the aquatic protein is currently coming from aquaculture, which sources 33% of its feed from wild catch, putting fish stocks and biodiversity at its limits. Single-cell protein (SCP) is proposed as an alternative to traditional aquafeed. This SCP can be produced from local waste streams, which creates a circular solution for the increasing pressure on wild fish stocks. The waste effluents of the economically important food and beverage industries provide major recovery opportunity, as they are produced in vast amounts and typically carry high organic and nutrient loads, while not being contaminated with pathogens or toxic elements. Aerobic heterotrophic bacteria (AHB), present in conventional wastewater treatments, pose an ideal SCP candidate, given their rapid growth rate and high protein content. The AquaPro project aims to establish a quality-steered resource recovery by AHB-based SCP cultivation on a wide variety of food/beverage industrial effluents. An integrated control system based on respirometry in combination with renewable methanol spiking is proposed to steer stability, quality and quantity of the SCP. The high-quality SCP end-product could be valorized as protein ingredient in aquafeed, providing a resource-efficient and sustainable answer to the growing protein gap, within the framework of a circular economy.

Researcher(s)

Research team(s)

Project type(s)

  • Research Project

Development of a guidance document for improving zebrafish welfare in laboratory animal facilities. 01/09/2020 - 31/01/2023

Abstract

About 10-15% of all animals used as laboratory animals in Flanders are fish. While the assessment of animal welfare is well established for mammals, the optimal conditions for guaranteeing fish welfare are less known or documented. A formal framework for optimizing and monitoring zebrafish welfare does currently not exist. This project therefore aims to develop a guidance document providing scientific and practical instructions for improving zebrafish welfare in laboratory animal facilities. The guidance document will be relevant to animal caretakers, technicians, responsible scientists, members of ethical committees, and animal welfare inspectors.

Researcher(s)

Research team(s)

Project type(s)

  • Research Project

PurpleRace: Cost-cutting raceway technology for purple microbiomes, sustainable feed ingredients for healthy fish. 01/01/2020 - 31/12/2021

Abstract

The aquaculture feed and ornamental fish food markets depend mainly on fishmeal as protein source, yet its use is highly controversial as its production relies primarily on fish caught in the wild resulting in overexploitation of natural fish stocks. The use of microbial biomass as protein source for feeds, termed microbial protein, has the potential to mitigate this unsustainable practice. Biomass of purple non-sulfur bacteria (PNSB) is a type of microbial protein with a high protein content, an outstanding protein quality and a high vitamin and pigment content. Its potential use as feed ingredient has been demonstrated, yet research beyond the nutritional value such as health or color improvements is limited or nonexistent. The PurpleRace project is firstly developing a novel production method that will reduce the current high production costs by using raceway technology. Secondly, PurpleRace will provide evidence for the benefits of PNSB as a feed ingredient, resulting in a detailed protocol for the formulation of an ornamental fish food.

Researcher(s)

Research team(s)

Project type(s)

  • Research Project

CALI-capture the light. 01/01/2020 - 31/12/2021

Abstract

The equipment applied for in this application is the Tecan SPARK®, a multimode microplate reader. The instrument reads microtiter plates up to 384 wells in various modes. Equipped with several monochromators, it measures optical density, several fluorescence modes and luminescence. It has an incubator-shaker ranging from 18° to 42°C. Unlike many other readers on the market, it is capable of measuring the quality and quantity of nucleic acids and proteins in volumes down to 2 microliters on 16 samples in parallel. It is a modular system which allows future extension with flash injectors, plate stacker, automatic lid removal etc… Prof. L. Bervoets (promotor), prof. G. De Boeck, and prof. H. Svardal (co-promotors) work in the SPHERE group on the effects of environmental stressors, both natural and anthropogenic, on the performance of aquatic and terrestrial organisms, in vivo and in vitro with an emphasis on mechanisms and ecological relevance. Prof. E. Prinsen (co-promotor) and the IMPRES group study plant stress and energy metabolism, acclimation mechanisms and the modelling of Leaf growth and tip growth and the role of plant hormones therein. All team members have an increasing need of in vitro assays to determine enzymatic activity and several other biomarkers such as hormones and cellular metabolites. The advanced possibilities of the SPARK® instrument offer several advantages, e.g. fluorescence modes, luminescence, scanning mode, etc., compared to the groups' current instruments (>10 years old). Notably, the cooling capacity of the incubator is unique on the market today. The facility for cooling is very important for the groups' research: SPHERE mainly focusses on the aquatic environment, and IMPRES on plants in a temperate climate, hence it is necessary to run assays at temperatures lower than typical room.

Researcher(s)

Research team(s)

    Project website

    Project type(s)

    • Research Project

    Predicting Organismal responses To Eutrophication and Climate warming in Tandem (PROTECT). 01/05/2019 - 31/05/2019

    Abstract

    Worldwide habitat degradation has created a matrix of environmental stressors for species to navigate; but, understanding interactions among stressors is one of the largest knowledge deficiencies in ecological conservation. Anthropogenic eutrophication (hereafter, eutrophication) and climate warming are two of the most pervasive global stressors. The environmental and economic burdens of eutrophication and climate warming in isolation are well documented, with frequent reports of species range shifts and extinctions, fisheries collapses and contamination of drinking water. Eutrophication events are predicted to increase in frequency, duration and intensity under forecasted climate warming. However, it is unknown how climate warming and eutrophication will interact to affect the functional performance of fish. Stressor interactions can reveal 'ecological surprises', where exposure to one stressor may heighten or reduce resilience to another stressor. PROTECT aims to explores how simultaneous exposure to eutrophication and climate warming impacts the physiology, behaviour and fitness of a range of fish species. A mechanistic, experimental approach will be implemented to assess the efficacy of physiological compensation in buffering the negative impacts of these stressors, which unless combated, may lead to cardio-respiratory compromise, impaired swimming and reduced fitness. Comparative studies will aim to reveal mechanisms underlying inter-species differences in susceptibility to eutrophication in a warmer world. This project will unveil crucial data required to incorporate climate warming scenarios into eutrophication control guidelines, ultimately aiding conservation efforts in novel environments.

    Researcher(s)

    Research team(s)

      Project type(s)

      • Research Project

      Adaptive responses of an aquatic vertebrate to chemical pollution. 01/01/2017 - 31/12/2020

      Abstract

      Human-induced pollution features among the greatest challenges that organisms face for survival and adaptation. Aquatic ecosystems have been exposed worldwide to varying degrees of pollution, and the fitness of their communities and populations has been affected to such extent that biodiversity is compromised. We evaluate the potential adaptive response of three-spined stickleback, a model fish, to pollution after multigenerational exposure to mercury and PCB. Both chemicals feature among the most toxic pollutants that bio-accumulate in the food chain. Our first aim will be to test if exposure to metal or PCB pollution in situ has led to divergent phenotypes and genetic backgrounds. The second aim will be to test in the lab and in near-field conditions if pollutant adapted populations exposed to the original or other stressors are more resistant than naive populations. This is of importance considering the future challenges populations are facing. Our approach is unique, because it involves a real scenario of field adapted individuals and because the effects resulting from exposure to pollutants are tested over multiple generations across the full genome and at multiple levels of biological organisation from cell to population. Our findings provide novel interdisciplinary fundamental knowledge on ecotoxicology, physiology and genetics, and benefit the assessment, monitoring and follow-up of a Good Ecological Status of the European aquatic environment.

      Researcher(s)

      Research team(s)

        Project type(s)

        • Research Project

        Mixed metal and temperature stress in aquatic environments establishing functional links across different levels of organisation. 01/01/2016 - 31/12/2019

        Abstract

        The aquatic environment is continuously challenged by anthropogenic stressors of which exposure to mixtures of chemicals is one of the most important. In most cases the resulting environmental impact is caused by a combination of natural and anthropogenic stressors with very different modes of action. In this project we explore the importance and nature of these interactions on three model species and a mesocosm scale simulated ecosystem.

        Researcher(s)

        Research team(s)

          Project type(s)

          • Research Project

          Mechanisms of ammonia transport in marine fish with a different nitrogen metabolism. 01/10/2015 - 30/09/2019

          Abstract

          Ammonia toxicity is a frequent problem in aquatic environments (aquaculture, eutrophication, …) which adversely affects fish performance and welfare. Fish also produce endogenous ammonia in their nitrogen metabolism, and it is their most important nitrogen waste product. Mechanistic strategies in fish gills to cope with ammonia toxicity and transport have fascinated biologists for many decades. The recent discovery of the ammonia transport function of Rhesus (Rh) glycoprotein has added a new major mechanism associated with ammonia handling at piscine gills. It was established that mammalian Rh glycoproteins, linked to antibody production in humans, are members of a protein family that mediates ammonia transport in broad group of organisms, suggesting a long evolutionary history. Also, the Rh family might have undergone some evolutionary changes among piscine phylogeny likely in association with the functional significance of ammonia handling. Among freshwater teleosts, Rh proteins are emerging as vital ammonia conduits, as was also evident from our studies in salmonids and cyprinids. Despite these recent advancements, very limited mechanistic information is available in marine teleosts and in more primitive marine cartilaginous fish such as sharks, rays and chimaeras, who show very different strategies for ionoregulation. Moreover, there is no consensus about the possible linkage of ammonia excretion with ion fluxes (in freshwater or marine fish) and the role the skin in ammonia excretion. Therefore, there is an urgent need to explore the evolution of mechanisms allied with ammonia handling in these different marine fish which possess very diverse ion-regulatory strategies. This project aims at characterizing and localizing Rh protein among the above-mentioned piscine groups, and at unravelling their involvement in ammonia transport. Additionally, it wants to establish possible links between ammonia and ion fluxes as well as the role of the skin in ammonia transport.

          Researcher(s)

          • Promoter: De Boeck Gudrun
          • Co-promoter: Sinha Amit Kumar
          • Fellow: Shrivastava Jyotsna

          Research team(s)

            Project type(s)

            • Research Project

            Biochemical analysis of freshwater crayfish. 01/12/2014 - 30/11/2015

            Abstract

            This project represents a formal research agreement between UA and on the other hand the client. UA provides the client research results mentioned in the title of the project under the conditions as stipulated in this contract.

            Researcher(s)

            Research team(s)

              Project type(s)

              • Research Project

              Research on Ocean Acidification. 09/11/2013 - 08/11/2017

              Abstract

              This project represents a formal research agreement between UA and on the other hand the Government of India. UA provides the Government of India research results mentioned in the title of the project under the conditions as stipulated in this contract.

              Researcher(s)

              Research team(s)

                Project type(s)

                • Research Project

                Ammonia transport in marine piscine groups: physiological and evolutionary role of Rhesus (Rh) glycoproteins. 01/10/2013 - 30/09/2016

                Abstract

                The project focuses on organismal physiology but extends to molecular physiology. Aim is to unravel the mechanisms associated with ammonia excretion in marine teleosts and primitive marine cartilaginous fish by determining the potential role of Rhesus (Rh) glycoproteins and possible linkage with ion transport.

                Researcher(s)

                Research team(s)

                  Project type(s)

                  • Research Project

                  Scaling ecotoxicological effects across levels of organization: towards an ecologically relevant evaluation of mixed toxicity. 01/10/2013 - 30/09/2014

                  Abstract

                  The innovative aspect of our study is that we will perform environmentally relevant exposures under similar conditions (°T, test organisms, duration, mixture of pollutants) at three scales of exposure: in the laboratory, in semi-controlled mesocosms, and in in-situ exposures in the field. This will allow us to compare and connect the data obtained, despite the increasing complexity of confounding factors, and lead to a set of trustworthy biomarkers with ecological relevance.

                  Researcher(s)

                  Research team(s)

                    Project type(s)

                    • Research Project

                    Mesodrome. 26/04/2012 - 31/12/2017

                    Abstract

                    This project represents a formal research agreement between UA and on the other hand the Flemish Public Service. UA provides the Flemish Public Service research results mentioned in the title of the project under the conditions as stipulated in this contract.

                    Researcher(s)

                    Research team(s)

                      Project type(s)

                      • Research Project

                      Preparation of a Biotic Ligand Model (BLM) for the metals cupper and cadmium in marine and estuarine environments by the target species: the European sea bass (Dicentrarchus labrax). 01/01/2012 - 31/12/2012

                      Abstract

                      This study attempt to prepare a BLM for marine and estuarine environments. the aim of this BLM is to provide a model which includes the strong influence of site-specific environmental factors, such as hardness, chemical speciation, pH, temperature and salinity, as well as the strong influence of the physiological characteristics of the organism so that the bioavailability of the metals can be evaluated. Consequently, a possibility may arise of establishing appropriate site-specific water quality standards in the future.

                      Researcher(s)

                      Research team(s)

                        Project type(s)

                        • Research Project

                        The changing world as a stressful environment: combined effects of temperature, hypoxia, carbon dioxide and ammonia on ionoregulation in fish - influence of energy budget and hormonal regulation. 01/10/2011 - 30/09/2013

                        Abstract

                        Fish are especially suitable to study hypoxic effects, very few studies have focussed on ion transport during hypoxia. Little is known on how hypoxia affects the uptake of ions and essential metals at the gill. Regulation and homeostasis of ions and essential metals is highly dependent on energy metabolism and protein metabolism, processes that are severely down regulated during hypometabolism. The aim of the presented research is to study the interacting effects of hypoxia, hypercapnia and ammonia on ionoregulation and uptake, homeostasis and excretion of essential metals with a special focus on the influence of stress and/or ion regulatory related hormones.

                        Researcher(s)

                        Research team(s)

                          Project type(s)

                          • Research Project

                          Integrated performance trade off in cichlid heads: feeding versus mouth brooding. 01/10/2011 - 30/09/2012

                          Abstract

                          This project tries to unravel some of the involved trade-offs, and will analyse the structural, functional and physiological trade-offs that exist in the buccal system of two closely related haplochromine species of Lake Victoria, both maternal mouthbrooders but representing two distinct trophic niches: a biter morph and a suction feeding morph. Trade-offs related to both sexual and trophic dimorphism will be studied in relation to mouthbrooding, with performance analyses to estimate the impact on survival and fitness.

                          Researcher(s)

                          Research team(s)

                            Project type(s)

                            • Research Project

                            Integrated performance trade off in cichlid heads: feeding versus mouth brooding. 01/01/2011 - 31/12/2014

                            Abstract

                            This project tries to unravel some of the involved trade-offs, and will analyse the structural, functional and physiological trade-offs that exist in the buccal system of two closely related haplochromine species of Lake Victoria, both maternal mouthbrooders but representing two distinct trophic niches: a biter morph and a suction feeding morph. Trade-offs related to both sexual and trophic dimorphism will be studied in relation to mouthbrooding, with performance analyses to estimate the impact on survival and fitness.

                            Researcher(s)

                            Research team(s)

                            Project type(s)

                            • Research Project

                            Nutritional and microbiological studies in Larvale aquaculture. 01/01/2010 - 31/12/2019

                            Abstract

                            This is a fundamental research project financed by the Research Foundation - Flanders (FWO). The project was subsidized after selection by the FWO-expert panel. This Scientific Research Community was initiated from the Laboratory for Aquaculture & Artemia Reference Center (ARC, UGent). The research within the ARC has evolved from fundamental and applied research on the cultivation of the brineshrimp Artemia to a multidisciplinary study of larval fish, shellfish cultivation in collaboration with various research groups. The emphasis is currently on host microbial interactions. Given the complexity of the mechanisms involved, it has been found necessary to bundle the expertise in a research community.

                            Researcher(s)

                            Research team(s)

                              Project type(s)

                              • Research Project

                              The changing world as a stressfull environment: combined effects of temperature, hypoxia, carbon dioxide and ammonia on ionoregulation in fish - influence of energy budget and hormonal regulation. 01/10/2009 - 30/09/2011

                              Abstract

                              Fish are especially suitable to study hypoxic effects, very few studies have focussed on ion transport during hypoxia. Little is known on how hypoxia affects the uptake of ions and essential metals at the gill. Regulation and homeostasis of ions and essential metals is highly dependent on energy metabolism and protein metabolism, processes that are severely down regulated during hypometabolism. The aim of the presented research is to study the interacting effects of hypoxia, hypercapnia and ammonia on ionoregulation and uptake, homeostasis and excretion of essential metals with a special focus on the influence of stress and/or ion regulatory related hormones.

                              Researcher(s)

                              Research team(s)

                                Project type(s)

                                • Research Project

                                Marine Teleosts and Elasmobranchs: differences in physiology lead to differences in sensitivity. 01/01/2009 - 31/12/2011

                                Abstract

                                Elasmobranchs possess a unique system for osmoregulation. They are slightly hyperosmotic compared to their environment due to high levels of urea and trimethylamino oxide in their body. Therefore, they absorb water continuously by osmosis and do not have to drink. This system creates an enormous urea gradient at the gills, which is supposedly maintained by urea back-transporters. This study aims at characterizing environmental influences on these transporters.

                                Researcher(s)

                                Research team(s)

                                  Project website

                                  Project type(s)

                                  • Research Project

                                  Defence mechanisms of fish with different sensitivity towards heavy metals: Interaction and dynamics of proteins and hormones. 01/11/2008 - 31/10/2010

                                  Abstract

                                  The aim of this project is to investigate whether gill cells of fish with a different sensitivity towards copper show intracellular differences with regard to the expression of transporters, carriers and metal binding protein, as well as defensive proteins and enzymes involved in oxidative stress, during sublethal copper exposure. The role of the hormonal status on these processes will be examined. The most suitable biomarker will be selected, and an ELISA for this biomarker will be developed.

                                  Researcher(s)

                                  Research team(s)

                                    Project type(s)

                                    • Research Project

                                    Comparative Fish Physiology: Putting Feeding into the Picture. 01/10/2008 - 30/06/2013

                                    Abstract

                                    Feeding has generally been ignored as a contributing factor in fish physiology and ecotoxicology. Nevertheless, it plays a crucial role in ion homeostasis and has clear osmotic benefits. Furthermore, it induces obvious effects on the energy metabolism with coinciding changes in respiratory gas exchange and acid-base balance (e.g. ammonia and urea excretion, alkaline tide). The aim of this project is to investigate the importance of feeding in fish with different ionoregulatory strategies and nitrogen metabolisms.

                                    Researcher(s)

                                    Research team(s)

                                      Project type(s)

                                      • Research Project

                                      Anoxia resistance in vertebrates: metabolomics of brains en hearts that never stop. 01/10/2007 - 30/09/2011

                                      Abstract

                                      The crucian carp can survive for weeks in total anoxia, amongst others because of a unique anaerobic pathway producing ethanol. During this period brain and heart remain fully functional. This study compares the 'metabolomics' of the main organs of the anoxic crucian carp with those of the closely related, but not anoxia resistent, common carp. New methodologies for NMR and data analaysis will ne optimised.

                                      Researcher(s)

                                      Research team(s)

                                        Project type(s)

                                        • Research Project

                                        Identification and characterisation of urea transporters in the gills of the spiny dogfish, Squalus acanthias. 01/07/2007 - 31/12/2011

                                        Abstract

                                        Elasmobranchs possess a unique system for osmoregulation. They are slightly hyperosmotic compared to their environment due to high levels of urea and trimethylamino oxide in their body. Therefore, they absorb water continuously by osmosis and do not have to drink. This system creates an enormous urea gradient at the gills, which is supposedly maintained by urea back-transporters. This study aims at identifying and characterizing these transporters.

                                        Researcher(s)

                                        Research team(s)

                                          Project type(s)

                                          • Research Project

                                          Defence mechanisms against heavy metal exposure in fish with different sensitivities to stress: interactions and dynamics. 01/01/2007 - 31/12/2010

                                          Abstract

                                          The aim of this research is to assess whether gill cells of fish with a different sensitivity to copper exposure show intracellular differences in protein expression patterns of transporters, carriers and metal binding protein as well as in proteins and enzymes involved in the defence mechanisms against oxidative stress. We want to evaluate the dynamics of these patterns in three fish species under sublethal copper exposure and in addition determine the role of the changes in hormonal status on these processes.

                                          Researcher(s)

                                          Research team(s)

                                            Project type(s)

                                            • Research Project

                                            Defence mechanisms of fish with different sensitivity towards heavy metals: Interaction and dynamics of proteins and hormones. 01/11/2006 - 31/10/2008

                                            Abstract

                                            The aim of this project is to investigate whether gill cells of fish with a different sensitivity towards copper show intracellular differences with regard to the expression of transporters, carriers and metal binding protein, as well as defensive proteins and enzymes involved in oxidative stress, during sublethal copper exposure. The role of the hormonal status on these processes will be examined. The most suitable biomarker will be selected, and an ELISA for this biomarker will be developed.

                                            Researcher(s)

                                            Research team(s)

                                              Project type(s)

                                              • Research Project

                                              Animal Physiology. 01/03/2006 - 28/02/2017

                                              Abstract

                                              Because of the variability of oxygen concentrations in aquatic and especially freshwater environments, oxygen has been a major force in the evolution of fishes. Their long evolutionary history, the present different oxygen requirements between species, and the acclimatory responses to hypoxic conditions make fish prime models in the study of oxygen dependent cellular and organismal functions and their regulation. During the last decades, global change events such as slight rises in temperature and increasing eutrofication result in more frequent hypoxic events. For fish, hypoxia results in hyperventilation, changes in the haemoglobin-oxygen binding affinity, and release of stress hormones such as cateoholamines and cortisol. Most of these effects are amplified under increased levels of the greenhouse gas carbon dioxide (hypercapnia). In fish, hypoxia also causes hypometabolism, suppressing energy metabolism, growth and reproduction as a consequence. Despite the fact that fish are especially suitable to study hypoxic effects, very few studies have focussed on ion transport during hypoxia. In red blood cells, transporters are up regulated, but little is known on how hypoxia affects the uptake of ions and essential metals at the gill. Regulation and homeostasis of ions and essential metals is highly dependent on energy metabolism and protein metabolism, processes that are severely down regulated during hypometabolism. The aim of the presented research is to study the interacting effects of hypoxia, hypercapnia and ammonia on ionoregulation and uptake, homeostasis and excretion of essential metals with a special focus on the influence of stress andlor ion regulatory related hormones.

                                              Researcher(s)

                                              Research team(s)

                                                Project type(s)

                                                • Research Project

                                                Copper homeostasis in fish: the role of subcellular partitioning and metal-binding proteins. 01/05/2005 - 31/12/2006

                                                Abstract

                                                The subcellular fractionation of a metal, in casu the essential copper, can be an important factor in modulating the effects that this metal exerts. Proteins involved in copper transport, detoxification and excretion play an essential role. The proposed research will examine the differences in subcellular fractionation and protein binding of copper, and asses their importance in the different way that copper affects two freshwater fish.

                                                Researcher(s)

                                                Research team(s)

                                                  Project type(s)

                                                  • Research Project

                                                  Toxicity identification and evaluation of neuro-active chemicals for the zebrafish. 01/10/2003 - 30/09/2005

                                                  Abstract

                                                  Until recently pharmaceuticals have systematically escaped the attention of environmental toxicologists. Due to the high volumes of pharmaceuticals used in human and veterinary medicine and animal production considerable amounts of drugs can enter the water cycle through a number of different exposure routes, e.g. disposal of waste water during the production process (industrial route) and more important the excretion in sewage after therapeutic use (domestic route). Several studies have already identified a variety of drugs in waste-, surface- and drinking water in the ng-µg/l range. Dispite of 1) worldwide production and consumption of pharmaceuticals, 2) detection of unneglectable concentrations of pharmaceuticals in the environment and 3) the fact that these substances are specifically designed to be biologically very active there is still very little known about the occurence and effect of pharmaceuticals on non-target organisms. In this study we are evaluating the effects of (neuro)pharmaceuticals in a teleost (zebrafish) as model of aquatic non-target species. The modelchemicals, chosen based on their occurrence in the environment, known effects in non-target organisms and the importance of the effected pathways in fish are: diazepam, chlorpromazin, mianserin and ethynylestradiol. The ultimate aim is to elucidate the toxic working mechanisms of pharmaceuticals and to develop relevant biomarkers for the early detection of chronic effects of these substances in fish. A very important point in this research is the investigation for correlation of effects on the biomarker level and effects on higher levels of biological organization. More specific this aim consists of several aspects: 1) development of highly sensitive and specific LC/MS/MS detection protocols for measurement of environmental concentrations and controling experimental exposures, 2) moleculair toxicological characterization of the modelchemicals. In this part cDNA array hybridizations will be applied to study differential gene expression in brain caused by exposure to the model pharmaceuticals, 3) further characterize the differentially expressed genes and test them as potential biomarkers for neurotoxic effects in fish by forming a concentration/respons relationship, 4) correlate the developed moleculair biomarkers to effects at higher levels of biological organization (growth/reproduction/survival, physiology, behavior). The results generated in this research will lead to a better understanding of the ecotoxicology of neuropharmaceuticals and can lead to the development of specific assays for the detection of neurotoxic effects in fish which enable the environmental risk assessment of these chemicals.

                                                  Researcher(s)

                                                  • Promoter: De Coen Wim
                                                  • Co-promoter: De Boeck Gudrun
                                                  • Fellow: Van der Ven Karlijn

                                                  Research team(s)

                                                    Project type(s)

                                                    • Research Project

                                                    Impact assessment and remediation of anthropogenic interventions on fish populations. 01/01/2003 - 31/10/2006

                                                    Abstract

                                                    Researcher(s)

                                                    Research team(s)

                                                      Project type(s)

                                                      • Research Project

                                                      01/10/2001 - 30/09/2003

                                                      Abstract

                                                      Researcher(s)

                                                      • Promoter: De Coen Wim
                                                      • Co-promoter: De Boeck Gudrun
                                                      • Fellow: Van der Ven Karlijn

                                                      Research team(s)

                                                        Project type(s)

                                                        • Research Project

                                                        Species specific differences in energy metabolisme and ionregulation on a cellular level: consequence for heavy metal toxicity. 01/10/2001 - 31/12/2002

                                                        Abstract

                                                        Different fish species show different tolerances towards sublethal Cu-exposure. Differences do not only occure in Cu-uptake, accumulation and excretion,but also in energy metabolism, especially the capacity for metabolic depression, seem to play an important role. The aim of this research is to explore if differences in Cu-metabolism and energy budgets at the issue and cellular level can explain differences in Cu-tolerance in three species of freshwater fish.

                                                        Researcher(s)

                                                        Research team(s)

                                                          Project type(s)

                                                          • Research Project

                                                          Species specific differences in energy metabolisme and ionregulation on a cellular level: consequence for heavy metal toxicity. 01/01/2001 - 31/12/2002

                                                          Abstract

                                                          Researcher(s)

                                                          Research team(s)

                                                            Project type(s)

                                                            • Research Project

                                                            01/10/2000 - 30/09/2004

                                                            Abstract

                                                            Researcher(s)

                                                            Research team(s)

                                                              Project type(s)

                                                              • Research Project

                                                              RAFO-Financial support for conferences for the organisation of the conference 'Symposium for European Freshwater Scientists' (25-28.8.1999). 01/03/1999 - 31/12/1999

                                                              Abstract

                                                              European freshwater scientists have, for long, lacked their own forum at which to discuss and develop their science and at which to discuss possibilities for further cooperation. The intention of the first 'Symposium for European Freshwater Scientists' was to fill this gap, with special attention for a new generation of competent young scientists.

                                                              Researcher(s)

                                                              Research team(s)

                                                                Project type(s)

                                                                • Research Project

                                                                Acid-base regulation in fish: continuous assessment of bloodparameters as a fast tool for monitoring ion- and gas transport disturbances. 01/10/1998 - 31/12/1999

                                                                Abstract

                                                                Oxygen and carbon dioxide transport is essential for the regulation of the acid-base balance in all organisms. In fish, the buffering capacity of blood and tissue is considerably lower compared to higher vertebrates. The surrounding water also limits compensation via respiration due to its higher viscosity. The aim of this research is to study gas and ion transport and acid-base balance in three fish species with different tolerances towards hypoxia when exposed to heavy metals.

                                                                Researcher(s)

                                                                Research team(s)

                                                                  Project type(s)

                                                                  • Research Project

                                                                  Influences of a stressful environment on the swimming capacity of freshwater fish with different tolerances towards hypoxia. 01/05/1998 - 30/04/2000

                                                                  Abstract

                                                                  The aim of the proposed research is to compare the capacity for swimming and critical swimming speed under stressful circumstances in three species of freshwater fish: 1) the rainbow trout Salmo gairdneri, which is sensitive to hypoxia, 2) the common carp Cyprinus carpio, which is hypoxia tolerant, and 3) the crucian carp Carassius carassius, which is anoxia tolerant. Does the different tolerance towards hypoxia explain their tolerances towards pollution?

                                                                  Researcher(s)

                                                                  Research team(s)

                                                                    Project type(s)

                                                                    • Research Project

                                                                    Physiological effects of sublethal copper and aluminum exposure on the energy metabolism of freshwater fish with different tolerances towards hypoxia. 01/10/1997 - 30/09/2000

                                                                    Abstract

                                                                    The aim of the proposed research is to compare the effects of sublethal copper and aluminum exposure on three species of freshwater fish with different tolerances towards hypoxia: 1) the rainbow trout, Salmo gairdneri, sensitive to hypoxia, 2) the common carp, Cyprinus carpio, survives hypoxia for short periods of time, and 3) the crucian carp, Carassius carassius, which can tolerate anoxia for several months. Since the assessed responses are related to the enrgymetabolism, and thus growth and reproduction, the study has an important ecological relevance.

                                                                    Researcher(s)

                                                                    Research team(s)

                                                                      Project type(s)

                                                                      • Research Project