Trophic transfer effects of PS nanoplastics and field-derived nanoplastics in the freshwater clam Corbicula fluminea.

Plastic pollution is of global concern. Many studies investigated the effect of micro and nanoplatics towards aquatic organisms. However, relatively few studies were assessed on freshwater organisms.

Toxicity of environmental and polystyrene plastic particles on the bivalve Corbicula fluminea: focus on the molecular responses.

Among aquatic organisms, filter feeders are particularly exposed to the ingestion of microplastics (MPs) and nanoplastics (NPs). The present study investigates the effect of environmental microplastics (ENV MPs) and nanoplastics (ENV NPs) generated from macro-sized plastic debris collected in the Garonne River (France), and polystyrene NPs (PS NPs) on the freshwater bivalve Corbicula fluminea. Organisms were exposed to plastic particles at three concentrations: 0.

Experimental testing of two urban stressors on freshwater biofilms.

Aquatic ecosystems and their communities are exposed to numerous stressors of various natures (chemical and physical), whose impacts are often poorly documented. In urban areas, the use of biocides such as dodecyldimethylbenzylammonium chloride (DDBAC) and their subsequent release in wastewater result in their transfer to urban aquatic ecosystems. DDBAC is known to be toxic to most aquatic organisms.

Potential cellular targets of platinum in the freshwater microalgae Chlamydomonas reinhardtii and Nitzschia palea revealed by transcriptomics.

Platinum group element levels have increased in natural aquatic environments in the last few decades, in particular as a consequence of the use of automobile catalytic converters on a global scale. Concentrations of Pt over tens of μg L have been observed in rivers and effluents. This raises questions regarding its possible impacts on aquatic ecosystems, as Pt natural background concentrations are extremely low to undetectable.

Toxicity assessment of environmental MPs and NPs and polystyrene NPs on the bivalve Corbicula fluminea using a multi-marker approach.

Small plastic particles, microplastics (MPs) and nanoplastics (NPs) represent a major threat in aquatic environments. Freshwater organisms are exposed to MPs and NPs, particularly in industrial and urban areas. The present study aimed to compare the toxicity between polystyrene NPs (PS NPs) and environmental microplastics (ENV MPs) and nanoplastics (ENV NPs) generated from macro-sized debris collected in the Garonne River on the freshwater bivalve C.

Transfer and Transcriptomic Profiling in Liver and Brain of European Eels (Anguilla anguilla) After Diet-borne Exposure to Gold Nanoparticles.

A nanometric revolution is underway, promising technical innovations in a wide range of applications and leading to a potential boost in environmental discharges. The propensity of nanoparticles (NPs) to be transferred throughout trophic chains and to generate toxicity was mainly assessed in primary consumers, whereas a lack of knowledge for higher trophic levels persists. The present study focused on a predatory fish, the European eel (Anguilla anguilla) exposed to gold NPs (AuNPs; 10 nm, polyethylene glycol-coated) for 21 d at 3 concentration levels in food: 0 (NP0), 1 (NP1), and 10 (NP10) mg Au kg .

Ecotoxicity of polyethylene nanoplastics from the North Atlantic oceanic gyre on freshwater and marine organisms (microalgae and filter-feeding bivalves).

Each year, 5 to 10 million tons of plastic waste is dumped in the oceans via freshwaters and accumulated in huge oceanic gyres. Under the effect of several abiotic factors, macro plastic wastes (or plastic wastes with macro sizes) are fractionated into microplastics (MP) and finally reach the nanometric size (nanoplastic NP). To reveal potential toxic impacts of these NPs, two microalgae, Scenedemus subspicatus (freshwater green algae), and Thalassiosira weissiflogii (marine diatom) were exposed for up to 48 h at 1, 10, 100, 1000, and 10,000 μg/L to reference polyethylene NPs (PER) or NPs made from polyethylene collected in the North Atlantic gyre (PEN, 7th continent expedition in 2015).

Mercury contamination levels in the bioindicator piscivorous fish Hoplias aïmara in French Guiana rivers: mapping for risk assessment.

In French Guiana, native populations present high level of mercury contamination, which has been linked to the consumption of contaminated fishes. The goal of this study is to undertake a cartography of mercury contamination levels in fishes from the six main Guiana rivers. The selected species for this study is the ubiquitous piscivorous fish Hoplias aimara.

Herbicide toxicity on river biofilms assessed by pulse amplitude modulated (PAM) fluorometry.

The use of Rapid light curves (RLCs) as a toxicity endpoint for river biofilms was examined in this study and compared to "classical fluorescence parameters" i.e. minimal fluorescence (F0), optimal and effective quantum yields of photosystem II (Fv/Fm and ФPSII).

Biosynthesis of gold nanoparticles by the living freshwater diatom Eolimna minima, a species developed in river biofilms.

Testing biotransformation capacities of living aquatic microalgae diatoms to naturally synthetize gold nanoparticles (AuNP) from gold salts and assessing aftereffects on their viability by microscope observations is a great challenge. In this work, a laboratory experiment was conducted, which aimed to observe (i) directly by transmission electronic and light microscopy and (ii) through indirect measurements (UV-visible spectroscopy) the periphytic freshwater diatom Eolimna minima exposed to gold salts. This work revealed the capacity of E.

Genetic and physiological responses of three freshwater diatoms to realistic diuron exposures.

This study examined the effects of diuron on strains of three major freshwater diatom species, Eolimna minima, Nitzschia palea and Planothidium lanceolatum. These species are frequently recorded in the Morcille River, where diuron runs off during phytosanitary treatments of the vineyards around. Here, there were three diatom exposure groups for each species: 0, 1 and 10 μg/L diuron during a 14-day laboratory assessment.

Is the toxicity of pesticide mixtures on river biofilm accounted for solely by the major compounds identified?

Comparative effects of long-term exposure to Polar Organic Chemical Integrative Sampler (POCIS) extracts (PE) and to a reconstituted mixture based on the major compounds quantified in the PE were evaluated on river biofilm communities. The study aimed to characterize the effects of long-term and low-dose exposure to pesticides on natural biofilm communities and to evaluate if the effects due to PE exposure could be explained solely by the major compounds identified in the extracts. Biofilms from an uncontaminated site were exposed in artificial channels to realistic environmental concentrations using diluted PE, with the 12 major compounds quantified in the extracts (Mix) or with water not containing pesticides (Ctr).

Detoxification and recovery capacities of Corbicula fluminea after an industrial metal contamination (Cd and Zn): a one-year depuration experiment.

This study aimed to assess the recovery capacity of the freshwater bivalve Corbicula fluminea subjected to industrial metal discharges (Cd, Zn). After a 24-day exposure in a metal-contaminated river, bivalves were transferred and maintained in the laboratory for one year under metal-free conditions. Metal accumulation, metallothionein production and genetic expressions of genes involved in metal stress were studied.

What are the outcomes of an industrial remediation on a metal-impacted hydrosystem? A 2-year field biomonitoring of the filter-feeding bivalve Corbicula fluminea.

The Riou-Mort watershed (southwest France) exhibits high metal contaminations (Cd and Zn) related to an important mining past. In this context, a remediation process has been implemented in 2007 to reduce the watershed contamination. The aim of this study was to assess the early effectiveness of the remediation process on the hydrosystem contamination state.

Single and mixture effects of pesticides and a degradation product on fluvial biofilms.

The Morcille River located in the Beaujolais vineyard area (Eastern France) is subjected to strong vine-growing pressure leading to the contamination by a range of herbicides and fungicides of the surrounding freshwater environment. Particularly high concentrations of norflurazon, desmethyl norflurazon and tebuconazole were recorded in spring 2010 at the downstream site of the river. Despite their occurrence in rivers, scarce toxicity data are available for these products, in particular in the case of desmethyl norflurazon (main norflurazon degradation product).

Environmental effects of realistic pesticide mixtures on natural biofilm communities with different exposure histories.

This study deals with the use of Polar Organic Chemical Integrative Sampler (POCIS) extracts to assess the impact of low-dose pesticide mixtures on natural biofilm communities originating from either a chronically contaminated or a reference field site. To investigate how natural biofilm communities, pre-exposed to pesticides in situ or not might respond to environmentally realistic changes in pesticide pressure, they were exposed to either clean water or to POCIS extracts (PE) in order to represent toxic pressure with a realistic pesticide mixture directly isolated from the field. The impacts of PE were assessed on structure, physiology and growth of biofilms.

Cadmium decontamination and reversal potential of teratological forms of the diatom Planothidium frequentissimum (Bacillariophyceae) after experimental contamination.

While the induction of teratology by cadmium (Cd) on diatoms is already known, reversal kinetics are not well documented. This study aims to understand the viability of diatoms exhibiting teratological frustules and their reproduction capacities within a Cd-impacted population to predict their return to normal diatom forms. We worked on a frequently encountered species in French hydrosystems: Planothidium frequentissimum (Lange-Bertalot) Round & L.

Recovery potential of periphytic biofilms translocated in artificial streams after industrial contamination (Cd and Zn).

Metal wastes can significantly disturb aquatic communities, particularly photosynthetic organisms, the main primary producers in freshwater running ecosystems. In this study, biofilms and diatoms were used as bioindicators to characterize the kinetics of biofilm recovery. An experimental decontamination study was conducted under laboratory conditions, after biofilm colonisation at a site subject to discharge of industrial metals (Zn and Cd) and in parallel at an upstream site, metal-free, considered as a control.

Remediation of a watershed contaminated by heavy metals: a 2-year field biomonitoring of periphytic biofilms.

This study focuses on an industrial contamination site subjected to remediation processes since 2007 in the Riou-Mort watershed (southwest France). The purpose was to assess the first impacts of remediation on periphytic biofilms, and was performed during two years of biomonitoring. Periphytic biofilms were collected on glass slides immersed 24 days at different sites along the contamination gradient for 12 colonisation cycles.

Development of q-PCR approaches to assess water quality: effects of cadmium on gene expression of the diatom Eolimna minima.

This study was undertaken to develop molecular tools to assess water quality using diatoms as the biological model. Molecular approaches were designed following the development of a rapid and easy RNA extraction method suited to diatoms and the sequencing of genes involved in mitochondrial and photosystem metabolism. Secondly the impact of cadmium was evaluated at the genetic level by q-PCR on 9 genes of interest after exposure of Eolimna minima diatom populations cultured in suspension under controlled laboratory conditions.