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Abstract The gastrointestinal tract (GIT) of fish is a target of contaminants since it can absorb these substances. We evaluated the morphophysiological alterations in the GIT of Sphoeroides testudineus collected in two estuaries presenting differences in their environmental quality (NIA and IA). The intestine was analyzed for histological and neuronal changes; liver and gills for biochemical markers; muscle tissues for neurotoxicity and peripheral blood for genotoxic damage. The results showed alterations in the GIT of the animals collected in the IA, such as muscle tunica and goblet cell density reduction, increased intraepithelial lymphocytes density and changes in neuronal density. Furthermore, changes were observed in MTs and LPO in the gills. Thus, we suggest that TGI is functioning as a barrier that responds to ingested contaminants, in order to reduce their absorption and translocation. Thus, alterations in morphophysiological and enteric neurons in S. testudineus can be used as biomarkers of environmental contamination. Highlights • Animals from anthropic environments presented alterations in the intestinal layers. • Contaminated luminal content changes the chemical code of myenteric neurons. • The biomarkers matrix differentiated the estuaries by the PERMANOVA analysis • The enteric nervous system proved to be a potential biomarker. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate B[ a ]P and low-density polyethylene microplastics (MPs) toxicty, alone and in mixture (0.03 to 30 μg L−1 of B[ a ]P; and 5, 50 and 500 mg L−1 for MPs). Five mg L−1 of MPs is considerably higher than commonly reported environmental concentrations, although it has been reported for marine environments. Individual (sea urchin embryo-larval development and mortality of mysids) and sub-individual responses (LPO and DNA damage in mysids) were assessed. The toxicity increased as the B[ a ]P concentration increased, and microplastics alone did not cause toxicity. B[ a ]P toxicity was not modified by the lowest concentration of MPs (5 mg L−1), but at higher MPs concentrations (50 and 500 mg L−1), the effects of B[ a ]P on sea urchin development and in biomarkers in mysids were diminished. Microplastics interacted with B[ a ]P in seawater, reducing its toxicity, probably due to adsorption of B[ a ]P to the surface of microplastics. [Display omitted] • Microplastics are important carriers of contaminants and can alter their toxicity. • Biological responses in two species of marine invertebrates were assessed. • Microplastics and B[ a ]P interact modifying the toxicity of the isolated elements. • B[ a ]P toxicity was not modified by environmental concentrations of microplastics. • B[ a ]P toxicity decreased at higher concentrations of microparticles. [ABSTRACT FROM AUTHOR]

The goal of the current study was to evaluate different genotoxicity tools in order to assess a marine protected area (MPA) affected by former mining activities and urban settlements. A catfish ( Cathorops spixii ) was analyzed for genotoxic effects at the (i) molecular and at the (ii) chromosomal levels. Through factor analysis, genotoxicity was found to be linked to levels of metals bioaccumulated and PAH metabolites in the bile. Micronucleus and nuclear alteration were less vulnerable to the effects of confounding factors in mildly contaminated areas since they were more frequently associated with bioaccumulated metals than the DNA analysis. The different genotoxicity responses allowed for the identification of sources of pollution in the MPA. This approach was important for detecting environmental risks related to genotoxic contaminants in a mildly contaminated MPA. [ABSTRACT FROM AUTHOR]

Microplastics, including plastic pellets, get stranded on sandy beaches. They persist in the oceans for long periods and frequently carry contaminants. Acute and chronic toxicity has been observed when marine organisms are exposed to high densities of plastic pellets in laboratory assays. We investigated the toxicity of beach-stranded plastic pellets on macrobenthic populations (Excirolana armata ; Crustacea; Isopoda) under natural conditions (in situ). We simulated different pellets densities on a beach not contaminated by pellets, exposing isopods for 6 h and testing possible behavioral responses (i.e. , vertical displacement) and mortality effects. No effect was observed on vertical displacement, but higher mortality was reported for organisms exposed to plastic pellets. The lowest pellet density tested commonly found in coastal areas was sufficient to trigger mortality. We also observed that lethargic individuals (near-death) were preyed on by the healthy individuals remaining in the test chambers. [Display omitted] • Plastic pellets were tested in field ecotoxicological assays for benthic macrofauna. • The presence of few pellets was enough to induce toxicity, regardless of density. • Pellets did not induce mortality in organisms tested individually, only in groups. • Cannibalism and necrophagy events were observed in isopods exposed to plastic pellets. • Intraspecific interactions should be considered for ecotoxicological effects. [ABSTRACT FROM AUTHOR]

Although the simplification of multivariate histopathological data into univariate indices can be useful for the assessment of environmental quality, this implies a great loss of information. The objective of the present study was to evaluate the effectiveness, in the context of environmental quality assessment, of an approach that integrates individual histopathological responses in a discriminated manner with the results of contaminants by means of multivariate analyses. This analysis was compared to the diagnosis of environmental quality provided by the use of the univariate Bernet histopathological index. Contaminant loads (sediments and fish) and the liver histopathology of Cathorops spixii were integrated through multivariate analysis. Integrated individual histopathological responses allowed classifying environmental quality from more to less impacted sites, while the univariate index showed some inconsistencies with chemical loads and allowed identifying only the most impacted site. [Display omitted] • Histological data usually are integrated into univariate indices, implying loss of information • Granulomatosis, parasites, and necrosis were associated with sediment contamination • Malignant neoplasms and other pathologies were associated with contaminants body burdens • Univariate histopathological index showed inconsistencies with chemical data • Multivariate approach allowed classifying sites from better to worse environmental quality [ABSTRACT FROM AUTHOR]

The gastrointestinal tract and its enteric nervous system are the first routes of food and xenobiotics uptake. Considering the importance of this organ, this study evaluated intestinal biomarkers of Sphoeroides testudineus integrating the data to generate tools for pollution assessment. The fish were collected in three sites of São Paulo Coast and their intestines were analyzed for biochemical, histology, and neuronal density and morphometry biomarkers. To evaluate the differences among the data, a PERMANOVA was applied, followed by a FA/PCA. The PERMANOVA indicated differences (P < 0.001) between the regions (RA, A1, and A2). Four factors were extracted from the FA/PCA (62% cumulative), showing that the animals from A2 presented severe alterations, mainly in intestinal morphometry and neuronal density. A1 alterations refer mainly to the increase of neuronal metabolism. Our results also evidence a gradient of environmental quality related to the protection level (AR > A1 > A2). • Ambiental stressors caused increase in intestinal layers and IELs. • Stressors disponibles in water can decrease, generally, the density of enteric nervous system neurons. • Areas with high levels of anthropogenic influences can lead to changes in intestinal peristalsis. [ABSTRACT FROM AUTHOR]

Methods to assess the effects of contaminants on marine organisms typically involve euthanasia to obtain samples, but less invasive techniques may be more appropriate for working with threatened species. In this study, were assessed the biological responses of crabs exposed to microplastics and contaminants of emerging concern. Biochemical and cellular effects (lipid peroxidation, DNA damage, cholinesterase activity, and lysosomal membrane stability) in hemolymph were analyzed in a kinetic study, at 3 and 7 days, in U. cordatus exposed to microplastics spiked with Triclosan (TCS) or 17α-Ethynylestradiol (EE2). The results showed that the contaminants were produced toxic effects in the crabs exposed either to the microplastics alone (oxidative stress, genotoxicity, and neurotoxicity), or to microplastics with TCS or EE2 adsorbed (neurotoxic and cytotoxic). The present study showed the responsiveness of non-lethal analyzes to understanding the biological effects of combined exposure to microplastics and chemical pollution. [Display omitted] • Microplastics and PPCPs effects in crabs were evaluated through hemolymph samples. • Non-lethal biomarkers embrace better bioethical aspects of endangered species. • Virgin microplastic caused oxidative stress, genotoxicity and neurotoxicity. • Microplastics carrying antibacterial and hormone were neurotoxic and cytotoxic. • Our results contribute to the understanding of pollution effects through non-lethal analyses [ABSTRACT FROM AUTHOR]

This study investigated the sublethal effects of environmentally relevant concentrations of DCOIT on the neotropical oyster Crassostrea brasiliana. Gills and digestive glands of animals exposed to increasing concentrations of DCOIT were analyzed for biochemical, cellular, and histopathological responses. Exposure to DCOIT (0.2 to 151 μg L−1) for 120 h triggered oxidative stress in both tissues (through the modulation of GPX, GST, GSH and GR), which led to damage of membrane lipids (increase of LPO and reduction of the NRRT). DCOIT increased histopathological pathologies in gills, such as necrosis, lymphocyte infiltration and epithelial desquamation. This study showed that short term exposure to environmental concentrations of DCOIT causes negative effects on C. brasiliana at biochemical, physiological, and histological levels. Therefore, the use of DCOIT as a booster biocide in antifouling paints should be further assessed, as it may cause environmental hazards to marine organisms. [Display omitted] • DCOIT caused biochemical, cellular, and histopathological effects on C. brasiliana • Digestive gland and gills presented tissue-specific responses at biochemical level • Modulation of antioxidant enzymes led to oxidative stress and lipid peroxidation • DCOIT damaged lysosomal membranes and increases histopathological pathologies • Environmental concentrations of DCOIT are enough to affect C. brasiliana [ABSTRACT FROM AUTHOR]