- Topic:Multiple stressors and pollutants
Mixtures of organic micropollutants exacerbated in vitro neurotoxicity of prymnesins and contributed to aquatic toxicity during a toxic algal bloom
This study investigated how organic micropollutants and the algal toxins prymnesins interact as mixtures in water extracts from the Oder River using neurotoxic effects on human nerve cells in vitro. The authors showed that prymnesins dominate the neurotoxic effects, but many of the detected organic micropollutants exacerbate the lethal effect of prymnesins.
Unpredicted ecosystem response to compound human impacts in a European river
The authors have compiled and analyzed the key environmental factors that led to the mass development of the brackish water alga Prymnesium parvum in the Oder in the summer of 2022. The data synthesis shows how multiple stressors combined to allow an alga that normally thrives in stagnant salt water to proliferate en masse in a completely atypical habitat.
Temperatures and hypolimnetic oxygen in German lakes: Observations, future trends and adaptation potential
A study of oxygen and temperature trends in 46 German lakes showed that temperatures have risen mainly at the surface, but not in the deep water. This led to increased stratification and lower oxygen concentrations. Scenarios showed that these effects of climate change on oxygen content could be compensated by reducing nutrients.
Widely used herbicide metolachlor can promote harmful bloom formation by stimulating cyanobacterial growth and driving detrimental effects on their chytrid parasites
The study investigated the effects of the herbicide metolachlor on host-parasite interactions, using the host-parasite system of the toxigenic cyanobacterium Planktothrix agardhii and its chytrid parasite Rhizophydium megarrhizum. Metolachlor promoted cyanobacteria growth and caused multi and transgenerational detrimental effects on parasite fitness. However, these effects are reversible.
Exposure protocol for ecotoxicity testing of microplastics and nanoplastics
Despite the increasing concern about the harmful effects of micro- and nanoplastics (MNPs), so far, there exist no harmonised guidelines for testing the ecotoxicity of MNPs. An international research team with IGB has now developed protocols to assess the toxicity of these substances in soil and aquatic ecosystems.
Time Series of Electrical Conductivity Fluctuations Give Insights Into Long-Term Solute Transport Dynamics of an Urban Stream
A solute transport model was applied to diurnal electrical conductivity fluctuations in a river to obtain long-term time series of transport metrics. The study showed that differences in transport metrics occur in adjacent river reaches and that mowing of macrophytes can increase the transient storage area.
Particle-associated organic contaminant and cytotoxicity transport in a river during storm events
This study investigated the mobilisation and transport of particle-associated organic contaminants and their cytotoxicity in a river during storm events. Cytotoxicity determined in cell-based bioassays correlated linearly with total suspended solids concentration in a river, demonstrating that particle-associated contaminant mixtures can strongly affect river water quality during rain events.
Multispecies assemblages and multiple stressors: synthesizing the state of experimental research in freshwaters
This is a review of multiple-stressor research in freshwaters, particularly studies that have experimentally manipulated multiple stressors and measured responses of multispecies assemblages. There is a gap between biotic interactions under multiple stressors and ecosystem recovery pathways after restoration, indicating a disconnect between multiple stressor research and environmental practice.
Unravelling the role of sulphate in reed development in urban freshwater lakes
The authors analysed data from 14 lakes in the Berlin catchment area for the period 2000 to 2020. They found that if sulphate concentrations had not increased, there would be about 20 per cent more reeds in the sulphate-polluted lakes today.
Large-scale sampling of the freshwater microbiome suggests pollution-driven ecosystem changes
Citizen scientists sampled more than 600 freshwaters in Germany. This unique data set provides evidence of 3 trends: first, microorganisms in the sediment show signs of chemical stress and antibiotic resistance in their genetic material. Second, excessive artificial lighting at night alters the species composition of microorganisms. And third, all studied water bodies emit greenhouse gases.