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Fishes are one of the most important components of the oceans and are exposed to several anthropogenic pressures, namely microplastic (MP), contaminants that are now ubiquitous worldwide. Taking advantage of the 2020 Circumnavigation Expedition carried by the NRP Sagres tall ship of the Portuguese Navy, fish samples from the southern Atlantic ocean were collected to evaluate possible MP contamination. In a total of 14 weeks of campaign, seven large migratory fishes of commercial interest were collected across the middle Atlantic Ocean and along the South American Atlantic coast. All individuals were contaminated with MPs, with an average of 18 ± 11 MPs/fish. In all fish sampled, both the gastrointestinal tract and gills presented MPs, indicating different contamination pathways including via their preys and from surrounding water, respectively. A total of 124 MPs were observed, where 72 % were fibers and 28 % particles, mostly of blue color (85 %), and with rayon and nylon as the most abundant polymers. This study is an important contribution to increase the scientific knowledge of MP contamination in mesopelagic fishes used for human consumption and collected in the open waters, reinforcing the need for further research regarding MP contamination in top predatory species from high trophic levels., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Due to their ubiquitous presence, size and characteristics as ability to adsorb pollutants, microplastics are hypothesized as causing a major impact on smaller organisms, such as plankton. Despite this, there is a need to determine whether these impacts just relate to the environmental presence of the materials or their effects on biological processes. Therefore, we aimed to 1) review current research on plankton and microplastics; 2) compare field and laboratory experimental findings, and 3) identify knowledge gaps. The systematic review showed that 70% of the 147 relevant scientific publications were from laboratory studies and microplastics interactions with plankton were recorded in 88 taxa. Field study publications were relatively scarce and the characteristics of microplastics collected in the field were very different from those used in laboratory experiments thereby limiting the comparison between studies. Our systematic review highlighted knowledge gaps in: 1) the number of field studies; 2) the non-comparability between laboratory and field conditions, and 3) the low diversity of plankton species studied. Furthermore, this review indicated that while there are many studies on contamination by microplastics, the effects of this contamination (i.e., pollution per se) have been less well-studied, especially in the field at population, community, and ecosystem levels., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The presence in EU waters of invasive tetrodotoxin (TTX) -harbouring puffer fishes has been receiving increasingly attention due to potential new threats posed by this potent neurotoxin. The present study investigates the occurrence of tetrodotoxin, saxitoxin (STX), and their analogues in two native puffer fish species from the NE Atlantic. High TTX content was detected by LC-MS/MS in several tissues of the Guinean puffer Sphoeroides marmoratus from Madeira Island (Portugal), reaching concentrations as high as 15 mg TTX kg -1 in the digestive tract of a male specimen and 7.4 mg TTX kg -1 in gonads of a female specimen. Several TTX analogues were also detected, including the 4-epi-TTX, 4,9-Anhydro-TTX, 5- 11- deoxyTTX and 6,11-dideoxyTTX. Although at low levels, STX was detected in liver of the Oceanic puffer Lagocephalus lagocephalus. Trace levels of decarbamoylsaxitoxin (dcSTX) were also observed in L. lagocephalus. This study reports the presence of TTX and STX in native fish from EU waters, highlighting the need for a proper understating of the origin, distribution and fate of these toxins in NE Atlantic., (Copyright © 2019. Published by Elsevier Ltd.)

Estuaries are productive environments used by many fish as nursery grounds. The initial stages of fishes are highly vulnerable to (a)biotic factors, and anthropogenic pressures, influencing fish larvae assemblages along the estuary. Microplastics (MPs < 5 mm) are particularly dangerous to early life stages of fishes because their ingestion can induce gut blockage, limiting food intake or exposing organisms to contamination due to MPs capacity to absorb pollutants. Present work aimed to investigate the contamination of an urban impacted estuary (Douro estuary, NW Portugal) by MPs, and study the abundance and distribution of MPs and fish larvae in this estuary. Monthly sampling surveys were performed from December 2016 to December 2017, in nine stations along the estuary. Sub-surface planktonic horizontal trawls were performed to collect fish larvae and MPs. Planktonic samples were sorted, and fish larvae identified. MPs density was determined using a protocol optimized in our laboratory. A total of 1498 fish larvae belonging to 32 taxa were collected, with a mean density of 11.66 fish larvae 100 m -3 . During the spring-summer period, it was observed the typical increase in the density and diversity of the larval assemblage. Diversity was generally low, with the high dominance of very few taxa, namely the common goby, Pomatoschistus microps. Different types of MPs were found, namely fibers, soft/hard plastic, colorful/transparent plastic, in a total of 2152 particles, with a mean density of 17.06 MPs 100 m -3 . Hard MPs and fibers were the most predominant types, representing 83% of the total MPs collected. In some months the number of MPs surpassed the number of fish larvae, with an average ratio of 1.0 fish larvae:1.5 MPs. Such results are concerning, highlighting that a higher availability of MPs may facilitate their ingestion by fish and therefore increase possible impacts in these communities., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Intake of soil by children and adults is a major exposure pathway to contaminants including potentially toxic elements (PTEs). However, only the fraction of PTEs released in stomach and intestine are considered as bioaccessible and results from routine analyses of the total PTE content in soils, therefore, are not necessarily related to the degree of bioaccessibility. Experimental methods to determine bioaccessibility usually are time-consuming and relatively complicated in terms of analytical procedures which limits application in first tier assessments. In this study we evaluated the potential suitability of a recently developed single extract method (ISO-17586:2016) using dilute (0.43M) nitric acid (HNO 3 ) to mimic the bioaccessible fraction of PTEs in soils. Results from 204 soils from Portugal, Brazil and the Netherlands including all major soil types and a wide range of PTEs' concentrations showed that the extraction efficiency using 0.43M HNO 3 of Ba, Cd, Cu, Ni, Pb and Zn in soils is related to that of in vitro methods including the Simple Bioaccessibility Extraction Test (SBET) and Unified BARGE Method (UBM). Also, differences in the degree of bioaccessibility resulting from differences in parent material, geology and climate conditions did not affect the response of the 0.43M HNO 3 extraction which is a prerequisite to be able to compare results from different soils. The use of 0.43M HNO 3 as a first screening of bioaccessibility therefore offers a robust and representative way to be included in first tier standard soil tests to estimate the oral bioaccessibility., Capsule: The single dilute (0.43M) nitric acid extraction can be used in first tier soil risk assessment to assess both geochemical reactivity and oral bioaccessibility of PTEs., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The development of sustainable shellfish aquaculture is highly dependent on the provision of reliable monitoring and predictive information on the occurrence of harmful algal blooms (HABs). The Portuguese HAB early warning system and shellfish closures presented here is a prototype, developed in the ASIMUTH project. It relies on weekly monitoring data composed of observations of HAB species and toxin concentrations within shellfish, and ocean circulation forecasts generated by an operational oceanographic model. The shellfish harvesting areas comprise coastal areas, estuaries+rías and coastal lagoons. The weekly bulletin characterizes the current shellfish closure situation and next week's forecasts for potentially impacted areas. The period analyzed ranged from 27 July 2013 to 17 March 2014, and describes the first skill assessment of the warning system. The forecast accuracy was evaluated, considering the number of forecasts that were verified to be correct the following week (85%) as well as the number of events not forecasted (false negatives, 12%) and those expected but did not occur (false positives, 3%). Variations were most visible in the first weeks of bulletin implementation and during autumn-winter months. The complementary use of field data, remote sensing and operational models led to more accurate predictions of blooms and range of the event., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The objective of this study was to characterize the link between bioaccessibility and fractionation of mercury (Hg) in soils and to provide insight into human exposure to Hg due to inhalation of airborne soil particles and hand-to-mouth ingestion of Hg-bearing soil. Mercury in soils from mining, urban and industrial areas was fractionated in organometallic forms; mobile; semi-mobile; and non-mobile forms as well as HCl-extractable Hg. The in vitro bioaccessibility of Hg was obtained by extracting soils with (1) a simulated human gastric fluid (pH1.5), and (2) a simulated human lung fluid (pH7.4). Total soil Hg concentrations ranged from 0.72 to 1.8 mg kg(-1) (urban areas), 0.28 to 94 mg kg(-1) (industrial area) and 0.92 to 37 mg kg(-1) (mining areas). Both organometallic Hg as well as 0.1M HCl extractable Hg were lower (<0.5% of total Hg) than Hg extracted by gastric fluid (up to 1.8% of total Hg) and lung fluid (up to 12% of total Hg). In addition, Hg extracted by lung fluid was significantly higher in urban and industrial soils (average 5.0-6.6% of total Hg) compared to mining soils. Such differences were related to levels of mobile Hg species in urban and industrial soils compared to mining soils. These results strengthen the need to measure site-specific Hg fractionation when determining Hg bioaccessibility. Results also show that ingestion and/or inhalation of Hg from soil particles can contribute up to 8% of adult total Hg intake when compared to total Hg intake via consumption of contaminated fish and animal products from contaminated areas., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Organotin compounds such as tributyltin (TBT) are used as antifouling paints by shipping companies. TBT inhibits the aromatase responsible for the transformation of testosterone into estrogen. Our hypothesis is that TBT modulates the vascular reactivity of female rats. Female Wistar rats were treated daily (Control; CONT) or TBT (100 ng/kg) for 15 days. Rings from thoracic aortas were incubated with phenylephrine (PHE, 10(-10)-10(-4) M) in the presence and absence of endothelium, and in the presence of N(G)-Nitro-L-Arginine Methyl Ester (L-NAME), tetraethylammonium (TEA) and apocynin. TBT decreased plasma levels of estrogen and the vascular response to PHE. In the TBT group, the vascular reactivity was increased in the absence of endothelium, L-NAME and TEA. The decrease in PHE reactivity during incubation with apocynin was more evident in the TBT group. The sensitivity to acetylcholine (ACh) and sodium nitroprusside (SNP) was reduced in the TBT group. TBT increased collagen, reduced α1-smooth muscle actin. Female rats treated with TBT for 15 days showed morphology alteration of the aorta and decreased their vascular reactivity, probably due to mechanisms dependent on nitric oxide (NO) bioavailability, K(+) channels and an increase in oxidative stress., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Gymnodinium catenatum, a dinoflagellate species with a global distribution, is known to produce paralytic shellfish poisoning (PSP) toxins. The profile of toxins of G. catenatum is commonly dominated by sulfocarbamoyl analogs including the C3+4 and GTX6, which to date has no commercial certified reference materials necessary for their quantification via chemical methods, such as liquid chromatography. The aim of this study was to assess the presence of C3+4 and GTX6 and their contribution to shellfish toxicity. C3+4 and GTX6 were indirectly quantified via pre-column oxidation liquid chromatography with fluorescence detection after hydrolysis conversion into their carbamate analogs. Analyses were carried out in mussel samples collected over a bloom of G. catenatum (>63×10 3 cellsl -1 ) in Aveiro lagoon, NW Portuguese coast. Concentration levels of sulfocarbamoyl toxin analogs were two orders of magnitude higher than decarbamoyl toxins, which were in turn one order of magnitude higher than carbamoyl toxins. Among the sulfocarbamoyl toxins, C1+2 were clearly the dominant compounds, followed by C3+4 and GTX6. The least abundant sulfocarbamoyl toxin was GTX5. The most important compounds in terms of contribution for sample toxicity were C1+2, which justified 26% of the PSP toxicity. The lesser abundant dcSTX constitutes the second most important compound with similar % of toxicity to C1+2, C3+4 and GTX6 were responsible for approximately 11% and 13%, respectively. The median of the sum of C3+4 and GTX6 was 27%. These levels reached a maximum of 60% as was determined for the sample collected closest to the G. catenatum bloom. This study highlights the importance of these low potency PSP toxin analogs to shellfish toxicity. Hydrolysis conversion of C3+4 and GTX6 is recommended for determination of PSP toxicity when LC detection methods are used for PSP testing in samples exposed to G. catenatum., (Copyright © 2013 Elsevier B.V. All rights reserved.)

An innovative technique for rapid identification and quantification of mercury (Hg) species in soils and sediments was developed using a direct mercury analyser. Speciation was performed by the continuous thermal-desorption of mercury species (temperature range 76-770 °C), in combination with atomic absorption spectrophotometry detection. Standard materials HgCl(2), Hg bound to humic acids and HgS were characterized; thermo-desorption curves of each material showed a well-resolved peak at specific temperature intervals: 125-225 °C, 100-250 °C and 225-325 °C, respectively. Certified reference materials (CRM) BCR(®) 142R, RTC(®) CRM 021, NRC(®) MESS-3 and PACS-2 were tested. Although the CRM were not certified for Hg species, the sum of Hg species obtained was compared to the certified value for total Hg; recoveries were 92%, 100%, 97%, and 95%, respectively. One sediment and three soil samples from mercury contaminated areas (total Hg concentrations 0.067-126 mg kg(-1)) were analysed as well. It was possible to compare peaks of thermo-desorption curves from the samples with those from standard materials and thereby distinguish different Hg species in solid samples. Generally, Hg was present as bound to chloride or humic substances. The precision was satisfactory, as reflected by the relative standard deviations determined for standards and certified reference materials (<11%; n=10)., (Copyright © 2012 Elsevier B.V. All rights reserved.)

A mercury-cell chlor-alkali plant operated in Estarreja (North-western Portugal) for 50 years causing widespread environmental contamination. Although production by this process ceased in 2002, mercury contamination from the plant remains significant. The main objective of this study was to investigate mercury impact on the nearby environment and potential risks to local population. To assess the level of contamination soil samples were collected from agricultural fields in the vicinity of the plant, extending the study by taking samples of the predominant vegetation suitable for animal and human consumption, water samples, and fish species from a nearby coastal lagoon, to gain a preliminary insight into the potential for contamination of the terrestrial and aquatic food web. To determine population exposure to mercury, hair samples were collected from local residents. Total mercury concentration in the 0-15 cm layer of soil was found to be highly variable, ranging between 0.010 and 91 mg kg(-1), although mercury contamination of soils was found to be restricted to a confined area. Lolium perenne roots contained between 0.0070 and 2.0 mg kg(-1), and there is evidence that root systems uptake mercury from the soil. Levels of mercury in the aerial parts of plants ranged between 0.018 and 0.98 mg kg(-1). It appears that plants with higher mercury concentration in soils and roots also display higher mercury concentration in leaves. Total mercury concentration in water samples ranged between 12 and 846 ng L(-1), all samples presenting concentrations below the maximum level allowable for drinking water defined in the Portuguese law (1.0 microg L(-1)). Mercury levels in fish samples were below the maximum limit defined in the Portuguese law (0.5 mg kg(-1)), ranging from 0.0040 to 0.24 mg kg(-1). Vegetables collected presented maximum mercury concentration of 0.17 mg kg(-1). In general, food is not contaminated and should not be responsible for major human exposure to the metal. Mercury determined in human hair samples (0.090-4.2 mg kg(-1); mean 1.5 mg kg(-1)) can be considered within normal limits, according to WHO guidelines suggesting that it is not affecting the local population. Despite being subject to decades of mercury emissions, nowadays this pollutant is only found in limited small areas and must not constitute a risk for human health, should these areas be restricted and monitored. Considering the present data, it appears that the population from Estarreja is currently not being affected by mercury levels that still remain in the environment.

Background: The basolateral complex of the amygdala (BLA) is uniquely affected by steroid hormones. Whereas glucocorticoids (GCs)--the adrenal hormones released during stress--increase the excitability of BLA neurons, estrogen decreases it., Methods: In this study, we used a vector designed to express a chimeric gene that contains the GC-binding domain of the GC receptor (GR) and the DNA binding domain of the estrogen receptor (ER) ("ER/GR") in infected neurons; as a result, it transduces GC signals into estrogenic ones. We microinfused ER/GR bilaterally into the BLA of rats to determine whether it would impair fear conditioning, a valuable BLA-dependent paradigm for studying the neural basis of emotional memory., Results: Expression of ER/GR in the BLA caused robust expression of the transgene and a significant disruption of both auditory and contextual long-term fear memory consolidation, whereas fear learning and post-shock freezing remained intact., Conclusions: These data show that dual gene therapy with ER/GR might be a useful tool for understanding the role of steroid hormones in the storage of traumatic memories.

The presence of paralytic shellfish poisoning (PSP) toxins has not been recorded in the Portuguese coast since 1995. A bloom of Gymnodinium catenatum occurred in the NW coast of Portugal in the autumn of 2005, and PSP profiles were determined in several inshore and offshore shellfish species by HPLC after pre-column oxidation. Most of the species studied contained a complex toxin profile, typically representative of contamination by G. catenatum. However, clams such as Spisula solida contained mainly decarbamoyl toxins, while less extensive transformation was found in Scrobicularia plana. In vitro incubation of S. solida digestive glands with PSP standards revealed a rapid transformation of carbamate and N-sulfocarbamoyl toxins into their corresponding decarbamate analogues. After 24 h, less than 5% of the carbamate or N-sulfocarbamoyl toxins tested remained. After a 24 h in vitro incubation of S. plana digestive glands, no decarbamate analogues were detected. Artificial toxification of S. plana with cultures of G. catenatum revealed the conversion into decarbamoyl analogues progressed slowly: initially dcGTX2+3 and dcSTX accounted only for 5% of total non N-1 hydroxilated toxins, after 6 days these toxins accounted for 41% of the toxin composition. In vitro incubations of digestive glands from other commercial bivalves did not reveal production of decarbamoyl analogues over a 24 h period.