New Publications

Recent studies have shown that toxicity of metals to Daphnia magna depends on the temperature. In a population experiment, we investigated if the effect of temperature on nickel (Ni) sensitivity observed on the apical level can be extrapolated to the population level. However, we observed no consistent population-level effects of Ni at concentrations that significantly affected reproduction. An individual-based model (IBM) with the dynamic energy budget (DEB) theory for Daphnia magna was calibrated based on Ni toxicity data at three temperatures (15, 20 and 25°C). Using the model, we confirmed the unexpected absence of Ni effects at the population level. 

Over the past decade, significant advances have been made to unravel molecular mechanisms of stress response in different ecotoxicological model species. Within this study, we focus on population level transcriptomic responses of a natural population of Daphnia magna to heavy metals. We aim to characterize the population level transcriptomic responses, which include standing genetic variation, and improve our understanding on how populations respond to environmental stress at a molecular level.

In this study, we assess the relationship between beta-diversity (measured as Bray–Curtis dissimilarity) and regional productivity (measured as biovolume) under various levels of a stressor flux in meta-ecosystems that were composed of two marine micro-algae communities. We created heterogeneity by exposing one of the two communities to a herbicide and manipulated regional diversity by applying a dispersal gradient, which decreased beta-diversity.
This study recorded temporal and spatial patterns of the FA profiles of two dominant calanoid copepods within the BPNS: Temora longicornis (Müller, 1785) and Acartia clausi (Giesbrecht, 1889). By means of distance-based linear modelling and by applying multi model inference to generalized additive models, environmental stressors were linked to patterns of the FA profiles of these species.

 

Sea spray aerosols (SSAs) have profound effects on our climate and ecosystems. They also contain microbiota and biogenic molecules which could affect human health. Yet the exposure and effects of SSAs on human health remain poorly studied. Here, we exposed human lung cancer cells to extracts of a natural sea spray aerosol collected at the seashore in Belgium, a laboratory-generated SSA, the marine algal toxin homoyessotoxin and a chemical inhibitor of the mammalian target of rapamycin (mTOR) pathway. 

In this study we developed a novel, mechanistic model where we predict effects of Cu on aquatic invertebrate populations (Lymnaea stagnalis – the great pond snail). Lymnaea stagnalis is particularly sensitive species to various metals 
and the precise mechanism for metal toxicity for this species are not fully understood. In this research, we extrapolated Cu toxicity effects from various studies and food sources to the population level. To improve inter-study comparability, we used a biotic ligand model to correct for the water chemistry. At the population level, the range in EC10 decreased significantly compared at the individual level. This model is the first developed at Arche Consulting and the University of Ghent where we promote the use of ecological models for the risk assessment of chemicals.

Over the past decades, the world's oceans and seas have been influenced by several human induced impacts, including climate change. Understanding the impacts of this changing environmental condition in zooplankton communities is crucial, as alterations in the zooplankton communities can affect entire marine ecosystems. Here, we focus on the potential effects of an increase in temperature on the calanoid copepod species, Temora longicornis, the dominant zooplankton species of the southern part of the North Sea. We sequenced the transcriptome (using RNA-seq technology) in T. longicornis, after being exposed to thermal stress, to investigate gene expression differences as a response to temperature fluctuations. 

Polyunsaturated fatty acids (PUFAs) have key biological roles in fish cells. We recently showed that the phospholipid composition of rainbow trout liver cells (RTL-W1 cell line) modulates their tolerance to an acute cadmium (Cd) challenge. Here, we investigated (i) the extent to which PUFAs and Cd impact fatty acid homeostasis and metabolism in these cells and (ii) possible mechanisms by which specific PUFAs may confer cytoprotection against Cd. 
We performed an environmental risk assessment for microplastics (<5 mm) in the marine environment by estimating the order of magnitude of the past, present and future concentrations based on global plastic production data. In 2100, from 9.6 to 48.8 particles m−3 are predicted to float around in the ocean, which is a 50-fold increase compared to the present-day concentrations. From a meta-analysis with effect data available in literature, we derived a safe concentration of 6650 buoyant particles m−3 below which adverse effects are not likely to occur.
The hardness values of a substantial proportion of Australian freshwaters fall below the application boundary of the existing European nickel biotic ligand models (Ni BLMs) of 2 mg Ca/L. Modifications were made to the Ni BLM by increasing the binding constants for Ca and Mg at the biotic ligand to account for softer waters encountered in Australia and the more important competitive effect of Ca and Mg on Ni toxicity.

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