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Publications (99)
Rationale
The analysis of nitrogen isotopes in aqueous dissolved nitrate is an effective method for identifying pollution sources and offers the potential to study the nitrogen cycle. However, the measurement of nitrogen isotope ratios of nitrate still requires extensive sample preparation or derivatization.
Methods
In this study, a modified comme...
Ponto-Caspian gobies became highly abundant in many regions outside their native distribution range (e.g. in the Rhine River system). In the newly invaded habitats, the parasite communities of the invasive gobies are characterized by a lower species richness compared to their native range. Interestingly, acanthocephalans of the genus Pomphorhynchus...
Trophic interactions are crucial for understanding food web complexity and energy flow in ecosystems. Including parasites in these analyses can alter dynamics and challenge ecological assumptions. Compound-specific isotope analysis (CSIA) offers greater precision than bulk SIA by analyzing individual amino acids, providing deeper insights into nutr...
The analysis of nitrogen isotopes in aqueous dissolved nitrate is an effective method for identifying pollution sources and offers the potential to study the nitrogen cycle. However, the measurement of nitrogen isotope signatures of nitrate still requires extensive sample preparation or derivatization. In this study, a modified commercially availab...
While macroinvertebrate dispersal operates at the individual level, predictions of their dispersal capabilities often rely on indirect proxies rather than direct measurements. To gain insight into the dispersal of individual specimens, it is crucial to mark (label) and capture individuals. Isotopic enrichment with ¹⁵N is a non‐invasive method with...
Numerous low-income groups and rural communities depend on fish as an inexpensive protein source worldwide, especially in developing countries. These communities are constantly exposed to various pollutants when they frequently consume polluted fish. The largest river basin in South Africa is the Orange-Vaal River basin, and several anthropogenic i...
Marine ecosystems are continuously under threat due to pollutants, which endanger marine biodiversity. The present study determines the potential use of the parasitic isopod, Cinusa tetrodontis Schjödte et Meinert, 1884, together with its fish host, Amblyrhynchotes honckenii (Bloch) for marine bioaccumulation monitoring. The concentrations of As, C...
Wild animals are usually infected with parasites that can alter their hosts' trophic niches in food webs as can be seen from stable isotope analyses of infected versus uninfected individuals. The mechanisms influencing these effects of parasites on host isotopic values are not fully understood. Here, we develop a conceptual model to describe how th...
Although interest in Acanthocephala seems to have reached only a small community of researchers worldwide, we show in this opinion article that this group of parasites is composed of excellent model organisms for studying key questions in parasite molecular biology and cytogenetics, evolutionary ecology, and ecotoxicology. Their shared ancestry wit...
Anthropogenic activities, including combustion of fossil fuels, coal, and gold mining, are significant sources of mercury (Hg) emissions into aquatic ecosystems. South Africa is a major contributor to global Hg emissions (46.4 tons Hg in 2018), with coal-fired power stations as the main source. Atmospheric transport of Hg emissions is the dominant...
Anthropogenic stressors are causing fundamental changes in aquatic habitats and to the organisms inhabiting these ecosystems. Yet, we are still far from understanding the diverse responses of parasites and their hosts to these environmental stressors and predicting how these stressors will affect host-parasite communities. Here, we provide an overv...
Background
Stone wool is an inorganic mineral insulation material increasingly used to reduce the climate impact of buildings. The acute and chronic ecotoxicological potential of stone wool eluates have been studied in a battery of standardized laboratory ecotoxicological tests. The experiments were conducted with stone wool test materials in fibro...
Stable isotope analysis of individual compounds is emerging as a powerful tool to study nutrient origin and conversion in host-parasite systems. We measured the carbon isotope composition of amino acids and glucose in the cestode Schistocephalus solidus and in liver and muscle tissues of its second intermediate host, the three-spined stickleback (G...
Environmental parasitology developed as a discipline that addresses the impact of anthropogenic activities related to the occurrence and abundance of parasites, subsequently relating deviations of natural parasite distribution to environmental impact. Metals, often considered pollutants, might occur under natural conditions, where concentrations mi...
The overflow of stormwater retention basins during intense and prolonged precipitation events may result in the direct input of particulate pollutants and remobilization of already sedimented particle-bound pollutants to receiving freshwater bodies. Particle-bound pollutants may cause adverse effects on aquatic biota, particularly sediment dwellers...
Stable isotope analysis of individual compounds is emerging as a powerful tool to study nutrient origin and conversion in host-parasite systems. We measured the carbon isotope composition of amino acids and glucose in the cestode Schistocephalus solidus and in liver and muscle tissues of its second intermediate host, the three-spined stickleback (...
Interest in local environmental conditions and the occurrence and behaviour of parasites has increased over the last 3 decades, leading to the discipline of Environmental Parasitology. The aim of this discipline is to investigate how anthropogenically altered environmental factors influence the occurrence of parasites and how the combined effects o...
Interpretation of stable isotope data is of upmost importance in ecology to build sound models for the study of animal diets, migration patterns and physiology. However, our understanding of stable isotope fractionation and incorporation into consumer tissues is still limited. We therefore measured the δ¹³C values of individual amino acids over tim...
Gold nanorods (AuNRs) are promising agents for diverse biomedical applications such as drug and gene delivery, bioimaging, and cancer treatment. Upon in vivo application, AuNRs quickly interact with cells of the immune system. On the basis of their strong intrinsic phagocytic activity, polymorphonuclear neutrophils (PMNs) are specifically equipped...
Physiologically based pharmacokinetic (PBPK) models have been applied to simulate the absorption, distribution, metabolism, and elimination of various toxicants in fish. This approach allows for considering metal accumulation in intestinal parasites. Unlike “semi” physiologically-based models developed for metals, metal accumulation in fish was cha...
Ponto-Caspian gobies became highly abundant in many regions outside their native distribution range (e.g. Rhine River system). In the newly invaded habitats, the parasite communities of the invasive gobies are characterized by a lower species richness compared to their native range. However, acanthocephalans of the genus Pomphorhynchus are highly a...
Worldwide, numerous rural communities and low-income groups depend on fish harvested by subsistence fishers from local rivers and its impoundments as a source of protein. The aim of the present study was to determine the trace element bioaccumulation (As, Cd, Cr, Cu, Ni, Pb, Pt, Zn) in three edible fish species (Cyprinus carpio, Clarias gariepinus,...
Among the parasitic taxa studied for their metal accumulation properties, especially Acanthocephala and Cestoda proved to be promising sentinels for metal pollution. However, studies on metal accumulation are still sparse for other parasite groups, mainly due to their small body size. In the present study, we collected the relatively large-sized mo...
Interpretation of isotope data is of upmost importance in ecology to build sound models for the study of animal diets, migration patterns and physiology. However, our understanding of isotope fractionation and incorporation into different consumer tissues is still limited. We therefore measured the δ ¹³ C values of individual amino acids from muscl...
Background
The artificial mussel (AM) is a passive sampling device that was originally developed for monitoring metal concentrations in the marine environment, but is also increasingly used in freshwater environments. The AM consists of a non-permeable Perspex tube, which is closed on both sides with a semi-permeable membrane. The space in between...
Acanthocephalans belonging to the species Neoechinorhynchus agilis were collected from two mullets, Mugil cephalus and Chelon ramada from Ichkeul Lagoon in northern Tunisia. Collected parasites, as well as tissues of their hosts (muscle, liver and intestine), were analysed for trace elements (silver, arsenic, cadmium, cobalt, copper, iron, manganes...
Clinus superciliosus was collected for element analysis from six localities along the South African west and south coasts. Concentrations in muscle and liver were determined, considering size and sex. No significant positive correlation between size and concentrations were detected, except for Mn and Sn in liver from Simons Town marina, while no si...
A toxicokinetic-toxicodynamic model based on subcellular metal partitioning is presented for simulating chronic toxicity of copper (Cu) from the estimated concentration in the fraction of potentially toxic metal (PTM). As such, the model allows for considering the significance of different pathways of metal sequestration in predicting metal toxicit...
Heavy metals such as zinc cannot be degraded by microorganisms and form long contaminant plumes in groundwater. Conventional methods for remediating heavy metal-contaminated sites are for example excavation and pump-and-treat, which is expensive and requires very long operation times. This induced interest in new technologies such as in situ adsorp...
A toxicokinetic-toxicodynamic model was constructed to delineate the exposure–response causality. The model could be used: to predict metal accumulation considering the influence of water chemistry and biotic ligand characteristics; to simulate the dynamics of subcellular partitioning considering metabolism, detoxification, and elimination; and to...
Fully inorganic, colloidal gold nanoclusters (NCs) constitute a new class of nanomaterials that are clearly distinguishable from their commonly studied metal–organic ligand-capped counterparts. As their synthesis by chemical methods is challenging, details about their optical properties remain widely unknown. In this work, laser fragmentation in li...
Chronic toxicity of copper (Cu) at sublethal levels is associated with ionoregulatory disturbance and oxidative stress. These factors were considered in a toxicokinetic-toxicodynamic model in the present study. The ionoregulatory disturbance was evaluated by the activity of the Na+/K+-ATPase enzyme (NKA), while oxidative stress was presented by lip...
Mining activities in the world’s largest Platinum mining area in South Africa have resulted in environmental contamination with Pt (e.g., the Hex River’s vicinity). The present study compared a Pt mining area with a non-mining area along this river in terms of (1) metal concentrations in different grain size fractions from soils and aquatic sedimen...
Intraspecific diet specialization, usually driven by resource availability, competition and predation, is common in natural populations. However, the role of parasites on diet specialization of their hosts has rarely been studied. Eye flukes can impair vision ability of their hosts and have been associated with alterations of fish feeding behavior....
To reduce direct discharges of surface runoff to receiving waters, separate sewer systems have been implemented, with runoff retention basins (RRB) for pollutant pretreatment by sedimentation and infiltration. However, due to frequent and intense precipitation events, most RRBs are overwhelmed by runoff resulting in overflow into the receiving fres...
The stenohaline zebra mussel, Dreissena polymorpha, is uniquely sensitive to the ionic composition of its aquatic environment. Waterborne copper (Cu) uptake and accumulation in zebra mussels were examined at various conditions in an environmentally relevant range in freshwater, i.e. Cu exposure levels (nominal concentrations of 25 and 50 μg/L), pH...
Background The artificial mussel (AM) is a passive sampling device that was originally developed for monitoring metal concentrations in the marine environment but is also increasingly used in freshwater environments. The AM consists of a non-permeable Perspex tube, which is closed on both sides with a semi-permeable membrane. In the space in betwee...
Background
The artificial mussel (AM) is a passive sampling device that was originally developed for monitoring metal concentrations in the marine environment but is also increasingly used in freshwater environments. The AM consists of a non-permeable Perspex tube, which contains Chelex-100 resin, water diffuses through the semi-permeable membranes...
Due to the increasing consumption of platinum (Pt), especially in automobile exhaust catalysts, environmental concentrations of Pt are of emerging concern worldwide. Limited information exists on environmental concentrations, particularly in Pt mining regions, while South Africa is the world’s main supplier of Pt. Moreover, other metals are also re...
Nanocomposites have been widely applied in medical device fabrication and tissue-engineering applications. In this context, the release of metal ions as well as protein adsorption capacity is hypothesized to be two key processes directing nanocomposite-cell interactions. The objective of this study is to understand the polymer-matrix effects on ion...
Fish strongly rely on olfaction as a variety of essential behaviors such as foraging and predator avoidance are mediated by the olfactory system. Cadmium (Cd) is known to impair olfaction and accumulate in the olfactory epithelium (OE) and bulb (OB) of fishes. In the present study, the acute toxicity of Cd on olfaction in zebrafish (Danio rerio) wa...
Stable isotope analysis offers a unique tool for comparing trophic interactions and food web architecture in ecosystems based on analysis of stable isotope ratios of carbon (¹³C/¹²C) and nitrogen (¹⁵N/¹⁴N) in organisms. Clarias gariepinus were collected from six sites along the Vaal River, South Africa and were assessed for ectoparasites and endopa...
Parasitism is commonly recognised as a consumer strategy, although, the interaction of parasites in communities and ecosystems are generally poorly understood. As parasites are integral parts of food webs, analysis of the trophic interactions between parasites and hosts was assessed through comparison of stable isotope ratios of carbon (¹³C/¹²C) an...
There is increasing evidence that platinum group elements (PGE) are pollutants of emerging concern worldwide. Limited information exists on levels, particularly in regions where PGEs are mined. A passive sampling device (i.e., the artificial mussel (AM)) and transplanted indicator organisms (i.e., the freshwater clam Corbicula fluminalis africana)...
Background
Stable isotope analysis offers a unique tool for comparing trophic interactions and food web architecture in ecosystems. This approach is based on analysis of the stable isotope ratios of carbon (13 C/ 12 C) and nitrogen (15 N/ 14 N) in organisms. Studies comparing stable isotope enrichment in hosts and parasites have shown that parasite...
The Rhine has been severely impacted by non-indigenous free-living and parasite species, largely triggered by the connection of the Ponto-Caspian and the Central European area due to the inauguration of the Main-Danube Canal in 1992. In the present review, we give a brief summary of species invasions in the Rhine with a focus on non-indigenous free...
South Africa is the world’s main supplier of Pt. The Bushveld Igneous Complex in South Africa contains 75% of the world’s Pt resources. Mining of this precious metal requires large volumes of water for production and removal of waste products. Most of this wastewater is discharged into river systems. Although the source of contamination with Pt in...
Wound healing is a complex orchestration of processes involving cell proliferation, migration, differentiation, anabolism, and catabolism in order to restore skin continuity. Within these processes, elements such as metallic ions are involved due to their implications in cell behavior and enzymatic activity regulation. This study analyzed the kinet...
Invasive species are a major threat to ecosystems worldwide. Their effects are versatile and mostly well studied. However, not much is known about the impact of invasion on native parasite communities, although parasites are usually important response variables for ecosystem health. To improve the knowledge on how native fish parasite communities a...
Mechanistic models based on chemical properties of metals and body size have received substantial attention for their potential application to various metals and to different conditions without required calibration. This advantage has been demonstrated for a number of metals, such as Cd and Ag. However, the capacity of metal-specific chemical prope...
Historically, the European Atlantic is probably the most important oil-spill hotspot worldwide. One of the most recent accidents occurred in 2002 when the oil-tanker Prestige sank over the Galician Bank causing two major oil-spills followed by several small leaks until March 2003. This resulted in contamination of virtually all types of marine habi...
Heavy metal pollution and parasites of fish might be very important from human health point of view, as the fish is often one of the major food sources in many regions on the earth. Fish serves as intermediate host for various human related parasites (e.g. trematodes) and similar to other aquatic organism could accumulate pollutants like heavy meta...
Due to the increasing presence of platinum (Pt) in the environment, the caveat arises to identify its toxic potential in species at risk of being exposed – especially those found in aquatic environments where pollutants tend to accumulate. Comprehensive characterisation of possible adverse effects following exposure of aquatic organisms to Pt remai...
Monomeric brominated flame retardants often pose risks to the environment. The new group of polymeric flame retardants is claimed to be a safer alternative due to their high molecular weight and persistence by design. Within this publication, the degradation of a commercially widely applied example of this group - the polymer "Polymeric FR" - was s...
Simultaneous presence of metals and parasites in fish might lead to potential risks to human health. Parasites might influence metal accumulation and disturb detoxification in fish, thereby affecting biomarkers of fish responses as well as metal biomagnification in humans. It is, therefore, of importance to take into account parasite infection when...
In urban areas, the potential of biomass production is rarely utilized, although many biomass sources are located in cities, ranging from road margins to public parks. There is, however, increasing interest in these potential biomass sources, as they are close to consumers and provide options to reduce maintenance costs of urban green areas. We ana...
The analysis of stable isotopes of carbon and nitrogen has been used as a fingerprint for understanding the trophic interactions of organisms. Most of these studies have been applied to free-living organisms, while parasites have largely been neglected. Studies dealing with parasites so far have assessed the carbon and nitrogen signatures in endopa...
A new method is proposed for producing nanoparticle-metal composite powders for laser additive manufacturing of oxide-dispersion strengthened (ODS) alloys. Different composite powders containing laser-generated Y2O3 and yttrium iron garnet (YIG) nanoparticles were produced and consolidated by Laser Metal Deposition (LMD). The structural properties...
Acanthocephalans of the globally distributed genus Pomphorhynchus have been intensively studied during the past decades. In Europe, Pomphorhynchus species have shown a certain degree of variability in their morphological characteristics and behavior. Nowadays two different Pomphorhynchus species, namely P. laevis and P. tereticollis, have been desc...
Despite the advances in our understanding of the ecological importance of parasites that we have made in recent years, we are still far away from having a complete picture of the ecological implications connected to parasitism. In the present paper we highlight key issues that illustrate (1) important contributions of parasites to biodiversity, (2)...
Background
Stable isotope analysis of carbon and nitrogen can deliver insights into trophic interactions between organisms. While many studies on free-living organisms are available, the number of those focusing on trophic interactions between hosts and their associated parasites still remains scarce. In some cases information about taxa (e.g. acan...
Environmental parasitology deals with the interactions between parasites and pollutants in the environment. Their sensitivity to pollutants and environmental disturbances makes many parasite taxa useful indicators of environmental health and anthropogenic impact. Over the last 20 years, three main research directions have been shown to be highly pr...
Many well-established methods for studying the degradation of brominated flame retardants are not useful when working with polymeric and water insoluble species. An example for this specific class of flame retardants is PolyFR (polymeric flame retardant; CAS No 1195978-93-8), which is used as a substituent for hexabromocyclododecane. Although it ha...
Alginate is a widely used hydrogel in tissue engineering owing to its simple and non-cytotoxic gelation process, ease of use, and abundance. However, unlike hydrogels derived from mammalian sources such as collagen, alginate does not contain cell adhesion ligands. Here, we present a novel laser ablation technique for the in situ embedding of gold a...
The dissolved concentrations of Fe, Cu, Zn, and Pb in the Pb exposure experiment for the uninfected (A) and infected (B) chub.
The left Y axis represents the concentration of Fe, Cu, and Zn while the right Y axis represent the concentration of Pb in the tank water.
(TIF)
Mathematical derivation of the metal concentration in the whole fish exposed to fluctuating exposure concentrations.
(DOCX)
The recovery rates of Fe, Cu, Zn, and Pb in three reference materials: IAEA-407 (Fish Homogenate), DORM-2 (Dogfish Muscle Certified Reference Material), and DOLT-3 (Dogfish Liver Certified Reference Material) determined by the ICP-MS.
(DOCX)