Exposure to silver and titanium dioxide nanoparticles at supra-environmental concentrations decreased sperm motility and affected spermatozoa subpopulations in gilthead seabream, Sparus aurata.

Marine pollution by nanoparticles (NPs) can be reprotoxic for fish and disturb successful reproduction of wild populations. In gilthead seabream (Sparus aurata), a mild effect on sperm motility was observed after exposure to high concentrations of silver NPs. Considering the great heterogeneity traits within a sperm sample, it is possible that NPs affect spermatozoa accordingly, modulating subpopulation profile.

Silver nanoparticles and silver ions indistinguishably decrease sperm motility in Pacific oysters (Magallana gigas) after short-term direct exposure.

The present study aimed to evaluate the reprotoxicity of environmental (0.25 μg.L) and supra-environmental (25 μg.

Shipping can be achieved but cargo arrives with damage - titanium dioxide nanoparticles affect the DNA of Pacific oyster sperm.

Titanium dioxide nanoparticles (TiO NP) were reported to be reprotoxic in humans and fish. However, the effects of these NP on the reproduction of marine bivalves, namely oysters, remain unknown. Thus, a short-term (1 h) direct exposure of sperm of the Pacific oyster (Crassostrea gigas) to two TiO NP concentrations (1 and 10 mg.

Mercury bioaccessibility in fish and seafood: Effect of method, cooking and trophic level on consumption risk assessment.

The bioaccessible Hg fraction in fish and seafood commonly present in the Mediterranean diet was assessed through three distinct in vitro extraction schemes. Each extraction method provided different results, highlighting the lack of a universal methodology to estimate mercury (Hg) bioaccessibility in those matrices. Bioaccessible Hg fractions ranged from 10 to nearly 90% of total mercury (T-Hg) and increased in predator species (Swordfish - Xiphias gladius, Blue Shark - Prionace glauca and Tuna - Thunnus sp.

Ex vivo exposure to titanium dioxide and silver nanoparticles mildly affect sperm of gilthead seabream (Sparus aurata) - A multiparameter spermiotoxicity approach.

Nanoparticles (NP) are potentially reprotoxic, which may compromise the success of populations. However, the reprotoxicity of NP is still scarcely addressed in marine fish. Therefore, we evaluated the impacts of environmentally relevant and supra environmental concentrations of titanium dioxide (TiO: 10 to 10,000 μg·L) and silver NP (Ag: 0.

Mild Effects of Sunscreen Agents on a Marine Flatfish: Oxidative Stress, Energetic Profiles, Neurotoxicity and Behaviour in Response to Titanium Dioxide Nanoparticles and Oxybenzone.

UV filters are potentially harmful to marine organisms. Given their worldwide dissemination and the scarcity of studies on marine fish, we evaluated the toxicity of an organic (oxybenzone) and an inorganic (titanium dioxide nanoparticles) UV filter, individually and in a binary mixture, in the turbot (). Fish were intraperitoneally injected and a multi-level assessment was carried out 3 and 7 days later.

Advances on assessing nanotoxicity in marine fish - the pros and cons of combining an ex vivo approach and histopathological analysis in gills.

The need to overcome logistic and ethical limitations of in vivo nanotoxicity evaluation in marine organisms is essential, mostly when dealing with fish. It is well established that medium/solvent conditions affect dispersion and agglomeration of nanoparticles (NPs), which represents a constraint towards a solid and realistic toxicity appraisal. In this way the pros and cons of an ex vivo approach, using a simplified exposure medium (seawater) and addressing gills histopathology, were explored.

Rare earth elements in mud volcano sediments from the Gulf of Cadiz, South Iberian Peninsula.

Eight gravity cores (GC) were retrieved from the deep mud volcanoes Sagres, Bonjardim, Soloviev and Porto in the Gulf of Cadiz. Cores with 137 to 317 cm long were sliced in intervals of 15 to 20 cm thickness, and 46 samples were analyzed for grain size distribution, loss on ignition, Al, Fe, Ca, Mg, Mn, Sr, Ba and the rare earth elements (REE) La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu. REE profile normalized to Post-Archean Australian Average Shale (PAAS) was dominated by a mid-REE bulge with a pronounced Eu enhancement.

Addressing the impact of mercury estuarine contamination in the European eel (Anguilla anguilla L., 1758) - An early diagnosis in glass eel stage based on erythrocytic nuclear morphology.

The decline of the European eel (Anguilla anguilla L., 1758) population throughout Europe has been partially attributed to pollution. As glass eel estuarine migration may represent a considerable threat, the impact of mercury (Hg) contamination at this stage was evaluated through an in situ experiment (7days).

Mercury Stable Isotopes Discriminate Different Populations of European Seabass and Trace Potential Hg Sources around Europe.

Our study reports the first data on mercury (Hg) isotope composition in marine European fish, for seven distinct populations of the European seabass, Dicentrarchus labrax. The use of δHg and ΔHg values in SIBER enabled us to estimate Hg isotopic niches, successfully discriminating several populations. Recursive-partitioning analyses demonstrated the relevance of Hg stable isotopes as discriminating tools.

Effect of historical contamination in the fish community structure of a recovering temperate coastal lagoon.

This study aimed to assess the impact of trace element concentrations in fish assemblages of a recovering coastal lagoon. Fish, water and sediment were sampled in winter and summer in the Ria de Aveiro (Portugal). Multivariate analyses were used to examine the relationship between fish assemblages and environmental variables (physical-chemical parameters, contaminants and sediment grain size).

The significance of cephalopod beaks in marine ecology studies: Can we use beaks for DNA analyses and mercury contamination assessment?

Cephalopod beaks found in the diet of predators have been a major source of scientific information. In this study, we evaluated the usefulness of DNA and contaminants analysis (total mercury - T-Hg) in cephalopod beaks in order to assess their applicability as tools in marine ecology studies. We concluded that, when applying DNA techniques to cephalopod beaks from Antarctic squid species, when using flesh attached to those beaks, it was possible to obtain DNA and to successfully identify cephalopod species; DNA was not found on the beaks themselves.

Impairment of mitochondrial energy metabolism of two marine fish by in vitro mercuric chloride exposure.

The goal of this work was to understand the extent of mercury toxic effects in liver metabolism under an episode of acute contamination. Hence, the effects of in vitro mercuric chloride in liver mitochondria were assessed in two commercial marine fish: Senegalese sole (Solea senegalensis) and gilthead seabream (Sparus aurata). Liver mitochondria were exposed to 0.

Mercury accumulation and tissue-specific antioxidant efficiency in the wild European sea bass (Dicentrarchus labrax) with emphasis on seasonality.

The main goal of this study was to assess both mercury (Hg) accumulation and organs' specific oxidative stress responses of gills, liver and kidney of Dicentrarchus labrax with emphasis on seasonality. Fish were collected in cold and warm periods in three stations: reference, moderated and highly contaminated sites. Our results showed that seasonal factors slightly influenced Hg accumulation between year periods (cold and warm) and strongly affected organs' response basal levels.

Mercury biomagnification in a contaminated estuary food web: effects of age and trophic position using stable isotope analyses.

The main aim of this study was to ascertain the biomagnification processes in a mercury-contaminated estuary, by clarifying the trophic web structure through stable isotope ratios. For this purpose, primary producers (seagrasses and macroalgae), invertebrates (detritivores and benthic predators) and fish were analysed for total and organic mercury and for stable carbon and nitrogen isotopic signatures. Trophic structure was accurately described by δ(15)N, while δ(13)C reflected the carbon source for each species.

Trace elements in two marine fish species during estuarine residency: non-essential versus essential.

Trace element levels in fish are of particular interest, owing the potential risk to human health. In accordance, juveniles of Dicentrarchus labrax and of Liza aurata were sampled and arsenic, cadmium, chromium, selenium and zinc were determined in the muscle. The levels of trace elements in muscle demonstrated to be similar for both species and sites, with the exception of selenium levels at reference, which seemed to be higher in D.

Mercury-induced chromosomal damage in wild fish (Dicentrarchus labrax L.) reflecting aquatic contamination in contrasting seasons.

Ria de Aveiro (mainly Laranjo basin, Portugal) has been subjected to mercury contamination from a chlor-alkali plant, currently presenting a well-described mercury gradient. This study aimed to assess mercury genotoxicity in this area by measuring the frequency of erythrocytic nuclear abnormalities (ENA) in the European sea bass (Dicentrarchus labrax), addressing the relation with total mercury concentration in the blood and the modulatory role of seasonal variables. Fish were collected, in warm and cold periods, at three locations differing in their distances to the main mercury source: reference (R), moderately (M), and highly (H) contaminated sites.

Major inputs and mobility of potentially toxic elements contamination in urban areas.

Soil quality in urban areas is affected by anthropogenic activities, posing a risk to human health and ecosystems. Since the pseudo-total concentrations of potentially toxic elements may not reflect their potential risks, the study of element mobility is very important on a risk assessment basis. This study aims at characterising the distribution and major sources of 34 elements in two Portuguese urban areas (Lisbon and Viseu), with different geological characteristics, industrial and urban development processes.

Evaluation of species-specific dissimilarities in two marine fish species: mercury accumulation as a function of metal levels in consumed prey.

The aim of this research was to compare mercury (Hg) accumulation (total and organic) and tissue distribution in two marine fish species with contrasting feeding tactics. Thus, juvenile specimens of European sea bass and Golden grey mullet were surveyed in an estuary historically affected by Hg discharges. Total Hg was preferentially accumulated in intestine, muscle, and liver, whereas gills and brain presented the lowest Hg levels observed in both species.

Fish consumption and risk of contamination by mercury---considerations on the definition of edible parts based on the case study of European sea bass.

In the present study, the risk to humans by consuming European sea bass (Dicentrarchus labrax), captured at three sites along a Hg contamination gradient, was evaluated by comparing muscle and kidney total Hg (T-Hg) levels with the European regulations for marketed fish. Moreover, T-Hg and organic Hg (O-Hg) levels in muscle were compared with the Provisional Tolerable Weekly Intake (PTWI) and the Reference Dose (RfD). Although T-Hg levels in muscle were below the European value allowable for marketed fish, kidney's levels were higher than the set value, stressing the importance of redefining the concept of edible tissue and which tissues should be considered.

Mercury accumulation patterns and biochemical endpoints in wild fish (Liza aurata): a multi-organ approach.

The integration of bioaccumulation and effect biomarkers in fish has been proposed for risk evaluation of aquatic contaminants. However, this approach is still uncommon, namely in the context of mercury contamination. Furthermore, a multi-organ evaluation allows an overall account of the organisms' condition.

Metallothioneins failed to reflect mercury external levels of exposure and bioaccumulation in marine fish--considerations on tissue and species specific responses.

The suitability of metallothioneins (MT) in fish as biomarker of exposure to mercury has been questioned. Therefore, this study aimed at investigating the relationship between external levels of exposure, mercury accumulation and MT content, assessing species and tissue specificities. Two ecologically different fish species--Dicentrarchus labrax and Liza aurata--were surveyed in an estuary historically affected by mercury discharges.

Brain as a critical target of mercury in environmentally exposed fish (Dicentrarchus labrax)--bioaccumulation and oxidative stress profiles.

Although mercury is recognized as a potent neurotoxicant, information regarding its threat to fish brain and underlying mechanisms is still scarce. In accordance, the objective of this work was to assess vulnerability of fish to mercury neurotoxicity by evaluating brain pro-oxidant status in wild European sea bass (Dicentrarchus labrax) captured in an estuarine area affected by chlor-alkali industry discharges (Laranjo Basin, Ria de Aveiro, Portugal). To achieve this goal, brain antioxidant responses such as catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST) activities and total glutathione (GSHt) content were measured.

Lipid peroxidation vs. antioxidant modulation in the bivalve Scrobicularia plana in response to environmental mercury--organ specificities and age effect.

This study aimed at the assessment of mercury burden and its association to damage vs. antioxidant protection in the bivalve Scrobicularia plana environmentally exposed to mercury. Inter-age and organ-specific approaches were applied by using different annual size classes (2+, 3+, 4+ and 5+ year old) and assessing specific organs (gills, digestive gland), respectively.

Mercury organotropism in feral European sea bass (Dicentrarchus labrax).

The knowledge of mercury (Hg) burdens in a wide set of tissues and organs of exposed fish is crucial to understand the internal distribution dynamics and thus predict Hg bioavailability and implications for ecosystem and human health. Total Hg was measured in six tissues of Dicentrarchus labrax captured along an estuarine contamination gradient, revealing the following pattern: liver > kidney > muscle > brain ≈ gills > blood. All of the tissues displayed intersite differences, although brain and muscle seemed to better reflect the extent of contamination.