Immunomodulatory effects of single and combined exposure to ZnO and TiO nanoparticles on rainbow trout challenged with Aeromonas salmonicida achromogenes.

The increasing release of engineered nanoparticles (ENPs) in aquatic ecosystems stresses the need for stringent investigations of nanoparticle mixture toxicity towards aquatic organisms. Here, the individual and combined immunotoxicity of two of the most consumed ENPs, the ZnO and the TiO ones, was investigated on rainbow trout juveniles (Oncorhynchus mykiss). Fish were exposed to environmentally realistic concentrations (21 and 210 µg L for the ZnO and 210 µg L for the TiO) for 28 days, and then challenged with the pathogenic bacterium, Aeromonas salmonicida achromogenes.

Physiological responses of Atlantic cod to climate change indicate that coastal ecotypes may be better adapted to tolerate ocean stressors.

Healthy ecosystems and species have some degree of resilience to changing conditions, however as the frequency and severity of environmental changes increase, resilience may be diminished or lost. In Sweden, one example of a species with reduced resilience is the Atlantic cod (Gadus morhua). This species has been subjected to overfishing, and with additional pressures such as habitat degradation and changing environmental conditions there has been little to no recovery, despite more than a decade of management actions.

Effects of Environmental Enrichment on Exposure to Human-Relevant Mixtures of Endocrine Disrupting Chemicals in Zebrafish.

Fish models used for chemical exposure in toxicological studies are normally kept in barren tanks without any structural environmental enrichment. Here, we tested the combined effects of environmental enrichment and exposure to two mixtures of endocrine disrupting chemicals (EDCs) in zebrafish. Firstly, we assessed whether developmental exposure to an EDC mixture (MIX G1) combined with rearing the fish in an enriched environment influenced behaviour later in life.

Isolation and characterization of the morphology, size and particle number of rainbow trout (Oncorhynchus mykiss) and zebrafish (Danio rerio) cell line derived large and small extracellular vesicles.

Extracellular vesicles (EVs) are 50-1,000 nm lipid bilayer-bound vesicles, released into the extracellular environment by various cell types for intercellular communication purposes. The quantitative and qualitative characteristics of EVs can be affected by stress and pathological conditions. The majority of extracellular vesicle (EV) studies have been performed on mammalian cell lines or bodily fluids.

Chronic poly(l-lactide) (PLA)- microplastic ingestion affects social behavior of juvenile European perch (Perca fluviatilis).

Juvenile perch were exposed to 2 % (w/w) poly(l-lactide) (PLA) microplastic particles (90-150 μm) in food pellets, or 2 % (w/w) kaolin particles, and a non-particle control food over 6 months. Chronic ingestion of PLA microplastics significantly affected the social behavior of juvenile perch, evident as a significantly increased reaction to the vision of conspecifics. PLA ingestion did not alter life cycle parameters, or gene expression levels.

Influence of natural organic matter on the transformation of metal and metal oxide nanoparticles and their ecotoxic potency in vitro.

Increased use and production of engineered nanoparticles (NPs) lead to an elevated risk of their diffuse dispersion into the aquatic environment and increased concern on unknown effects induced by their release into the aquatic ecosystem. An improved understanding of the environmental transformation processes of NPs of various surface characteristics is hence imperative for risk assessment and management. This study presents results on effects of natural organic matter (NOM) on the environmental transformation and dissolution of metal and metal oxide NPs of different surface and solubility properties in synthetic freshwater (FW) with and without NOM.

Influence of Aging on Bioaccumulation and Toxicity of Copper Oxide Nanoparticles and Dissolved Copper in the Sediment-Dwelling Oligochaete : A Long-Term Study Using a Stable Copper Isotope.

For engineered metal nanoparticles (NPs), such as copper oxide (CuO) NPs, the sediment is recognized as a major compartment for NP accumulation. Sediment-dwelling organisms, such as the worm , will be at particular risk of metal and metal NP exposure. However, a range of complex transformation processes in the sediment affects NP bioavailability and toxicity as the contamination ages.

From cohorts to molecules: Adverse impacts of endocrine disrupting mixtures.

Convergent evidence associates exposure to endocrine disrupting chemicals (EDCs) with major human diseases, even at regulation-compliant concentrations. This might be because humans are exposed to EDC mixtures, whereas chemical regulation is based on a risk assessment of individual compounds. Here, we developed a mixture-centered risk assessment strategy that integrates epidemiological and experimental evidence.

Effects of pesticides and metals on penaeid shrimps in Maputo Bay, Mozambique - A field study.

Estuaries are important nursery areas for many species and these habitats are often affected by anthropogenic activities. We investigate possible negative effects of pesticides and metals on penaeid shrimps in Maputo Bay, Mozambique. Shrimps and water samples were collected in three estuaries and one coastal area for biomarker and chemical analysis.

Exposure of Physalaemus cuvieri (Anura) to benzo[a]pyrene and α-naphthoflavone: Morphofunctional effects on hepatic melanomacrophages and erythrocytes abnormalities.

Benzo[a]pyrene (BaP) is a high-risk contaminant of elevated toxicity. Its biotransformation process occurs as the expression of CYP1A1 increases and produces toxic metabolites. In turn, α-naphthoflavone (aNF) represents an inhibitor of CYP1A1, preventing BaP metabolism.

Thyroid function and immune status in perch (Perca fluviatilis) from lakes contaminated with PFASs or PCBs.

The environment contains a multitude of man-made chemicals, some of which can act as endocrine disruptors (EDCs), while others can be immunotoxic. We evaluated thyroid disruption and immunotoxic effects in wild female perch (Perca fluviatilis) collected from two contaminated areas in Sweden; one site contaminated with per- and polyfluoroalkyl substances (PFASs) and two sites contaminated with polychlorinated biphenyls (PCBs), with one reference site included for each area. The hepatic mRNA expression of thyroid receptors α and β, and the thyroid hormone metabolising iodothyronine deiodinases (dio1, dio2 and dio3) were measured using real-time PCR, while the levels of thyroid hormone T3 in plasma was analysed using a radioimmunoassay.

Enzymatic, morphological, and genotoxic effects of benzo[a]pyrene in rainbow trout (Oncorhynchus mykiss).

Fish have defense systems that are capable of repairing damages caused by xenobiotics like benzo[a]pyrene (BaP), so the aims of this study were to identify BaP toxicity in melanomacrophages (MMs) cytoskeleton, evaluate the melanin area in MMs, and analyze genotoxicity. Rainbow trout juveniles (n = 24) were split in 48h and 7d treatments that received 2 mg/kg of BaP. After the experiment, blood samples were collected and liver was removed, to proceed with the analysis: EROD activity, MMs melanin area quantification, melanosomes movements, and a genotoxicity test.

Bisphenol A and Bisphenol S Induce Endocrine and Chromosomal Alterations in Brown Trout.

Bisphenol A is a widely used compound found in large amount of consumer products. As concerns have been raised about its toxicological and public health effect, the use of alternatives to bisphenol A are now increasing. Bisphenol S is one of the analogues being used as a replacement for bisphenol A despite the fact that little is known about the effects of bisphenol S on living organisms.

Assessing the effects of textile leachates in fish using multiple testing methods: From gene expression to behavior.

The textile industry, while of major importance in the world economy, is a toxic industry utilizing and emitting thousands of chemical substances into the aquatic environment. The aim of this project was to study the potentially harmful effects associated with the leaching of chemical residues from three different types of textiles: sportswear, children's bath towels, and denim using different fish models (cell lines, fish larvae and juvenile fish). A combination of in vitro and in vivo test systems was used.

A multi-biomarker study on Atlantic salmon (Salmo salar L.) affected by the emerging Red Skin Disease in the Baltic Sea.

For half a decade, the Atlantic salmon in the Baltic Sea has been facing severe health issues. Clinical signs like haemorrhage, erosions and ulcerative/necrotic skin conditions in returning adults have been reported from different Swedish rivers. These primary disease signs precede a secondary, terminal fungal infection.

Oxidative stress and biomarker responses in the Atlantic halibut after long term exposure to elevated CO and a range of temperatures.

CO emissions from human activities are increasing, resulting in greater rates of change in the oceans, exceeding any other event in geological and historical records over the past 300 million years. Oceans are warming and pH levels are decreasing. Marine organisms will need to respond to multiple stressors and the potential consequences of global change-related effects in fish needs to be investigated.

Mixture toxicity effects and uptake of titanium dioxide (TiO) nanoparticles and 3,3',4,4'-tetrachlorobiphenyl (PCB77) in juvenile brown trout following co-exposure via the diet.

Titanium dioxide nanoparticles (n-TiO) are among the man-made nanomaterials that are predicted to be found at high concentrations in the aquatic environment. There, they likely co-exist with other chemical pollutants. Thus, n-TiO and other chemical pollutants can be taken up together or accumulate independently from each other in prey organisms of fish.

Endocytosis, intracellular fate, accumulation, and agglomeration of titanium dioxide (TiO) nanoparticles in the rainbow trout liver cell line RTL-W1.

There is increasing evidence that titanium dioxide (TiO) nanoparticles (NPs) present in water or diet can be taken up by fish and accumulate in internal organs including the liver. However, their further fate in the organ is unknown. This study provides new insights into the interaction, uptake mechanism, intracellular trafficking, and fate of TiO NPs (Aeroxide® P25) in fish liver parenchymal cells (RTL-W1) in vitro using high-resolution transmission electron microscopy (TEM) and single particle inductively coupled plasma mass spectrometry (spICP-MS) as complementary analytical techniques.

Size Matters: Ingestion of Relatively Large Microplastics Contaminated with Environmental Pollutants Posed Little Risk for Fish Health and Fillet Quality.

In this study, we investigated biological effects associated with ingestion of polystyrene (PS) microplastic (MPs) in fish. We examined whether ingestion of contaminated PS MPs (100-400 μm) results in chemical stress in rainbow trout (Oncorhynchus mykiss) liver and we explored whether this exposure can affect the oxidative stability of the fillet during ice storage. Juvenile rainbow trout were fed for 4 weeks with four different experimental diets: control (1) and feeds containing virgin PS MPs (2) or PS MPs exposed to sewage (3) or harbor (4) effluent.

Development of three-dimensional (3D) spheroid cultures of the continuous rainbow trout liver cell line RTL-W1.

In vitro experimental systems based on continuous piscine cell lines can be used as an alternative to animal tests for obtaining qualitative and quantitative information on the possible fate and effect of chemicals in fish. However, their capability to reproduce complex metabolic processes and toxic responses as they occur in vivo is limited due to the lack of organ-specific tissue architecture and functions. Here we introduce a three-dimensional (3D) in vitro experimental system based on spheroidal aggregate cultures (spheroids) of the continuous rainbow trout liver cell line RTL-W1 and provide a first description of their structural and functional properties including growth, viability/longevity, metabolic activity, ultrastructure and cytochrome P450 1A (CYP1A) expression determined by bright-field, multi-photon fluorescence and transmission electron microscopy as well as RT-qPCR analysis.

Exposure to a nicotinoid pesticide reduces defensive behaviors in a non-target organism, the rusty crayfish Orconectes rusticus.

Imidacloprid is the most widely used of the nicotinoid insecticides, the fastest growing class of pesticides on the global market. Although less toxic to mammals and birds compared to organophosphates, nicotinoids have the potential to impact non-target invertebrates, especially through sublehal effects on behavior, physiology, reproduction, and development. We investigated the impact of sublethal doses of imidacloprid on the defensive responses of rusty crayfish Orconectes rusticus exposed to 0, 1, 10, and 100 µg•L of imidacloprid for 10 days (n = 7 crayfish per treatment).