In situ bioassay chambers and procedures for assessment of sediment toxicity with Chironomus riparius

The purpose of this study was to develop an in situ sediment bioassay chamber and respective procedures, suitable for performing toxicity bioassays with benthic invertebrates, using the midge Chironomus riparius. It was also our objective to compare the responses obtained under controlled conditions (laboratory 10-day larval growth and survival test) with those obtained in situ. Clean sand and a formulated sediment were incorporated in the in situ bioassay, along with local sediments, as a way of minimizing natural variability due to physicochemical differences among sediments or due to interactions with indigenous organisms. Recovery of organisms was good (80-100% in the control and reference site), indicating that the developed chamber and protocol were suitable for exposing and retrieving C. riparius in situ. Results also showed differences between responses obtained with formulated and natural sediment in situ, as well as between laboratory and in situ.http://www.sciencedirect.com/science/article/B6VB5-48N2VXR-2/1/4b92092a978e9882e296a0bf4236ff4

Evaluación de la calidad ecológica del estuario del Miño (Peninsula Iberica Noroeste) basada en la concentración de metales en sedimentos y en Corbicula fluminea

The concentrations of metals (Cd, Cr, Cu, Fe, Ni, Pb and Zn) in sediments and the soft tissues of Corbicula fluminea from the Minho estuary (Northwest Iberian Peninsula) were determined to assess the spatial variation of metal bioavailability and to classify the ecological quality of the estuary. Metal concentrations in sediments showed significant spatial variation ( p < 0.0003) and ranged in concentration (dry weight basis) from 0.025-0.36 mg Cd/kg, 7-16 mg Cr/kg, 2.7-24.6 mg Cu/kg, 7.3-45 mg Ni/kg, 4.1-15 mg Pb/kg and 37.3-110 mg Zn/kg. According to the Norwegian Pollution Control Authority metal concentration guidelines for sediments, this first ecological quality classification of the Minho estuary is “Class I/II-Background/Good.” Metal concentrations in the soft tissues of C. fluminea also showed significant spatial variation ( p < 0.0001) and ranged in concentration (dry weight basis) from 1.1-2.5 mg Cd/kg, 1.0-1.8 mg Cr/kg, 34-71 mg Cu/kg, 5.8-11 mg Ni/kg, 0.45-1.3 mg Pb/kg and 136-161 mg Zn/kg. The high Cu concentrations bioaccumulated by C. fluminea in the Minho estuary suggest that the estuary should be classified as “Class II/III-Moderately/Remarkably Polluted.” Thus, the primary contributions of this work are that C. fluminea proved to be a good and adequate biomonitor of metal contamination in the Minho estuary and that it could be used to assess the ecological quality of estuarine ecosystems worldwide.La concentración de metales (Cd, Cr, Cu, Fe, Ni, Pb and Zn) en sedimentos y tejidos blandos de Corbicula fluminea procedentes del estuario del Minho (Noroeste Península Ibérica) fue determinada para evaluar variaciones espaciales en la biodisponibilidad de los metales y para comparar diferentes clasificaciones ecológicas de calidad. Los sedimentos retuvieron metales en rangos (peso seco) entre 0.025-0.36 mg Cd/kg, 7-16 mg Cr/kg, 2.7-24.6 mg Cu/kg, 7.3-45 mg Ni/kg, 4.1-15 mg Pb/kg y 37.3-110 mg Zn/kg, lo que revela una variación espacial significativa (p < 0.0003). Las directrices sobre concentración de metales en sedimentos recomendadas por la Norwegian Pollution Control Authority permitieron obtener una primera clasificación de calidad ecológica del estuario del Miño designada como “Clase I/II-Basal/Buena”. En los tejidos blandos de C. fluminea también se encontraron variaciones espaciales significativas, (p < 0.0001) y sus concentraciones variaron (peso seco) entre 1.1-2.5 mg Cd/kg, 1.0-1.8 mg Cr/kg; 34-71 mg Cu/kg, 5.8-11 mg Ni/kg, 0.45-1.3 mg Pb/kg y 136- 161 mg Zn/kg. Sin embargo, teniendo en cuenta las altas concentraciones de Cu bioacumuladas por C. fluminea el estuario del Miño debería estar clasificado como “Clase II/III-Moderadamente/Notablemente contaminado”. Así, la principal conclusión de este trabajo, es que C. fluminea ha demostrado ser un adecuado indicador de la contaminación en el estuario del Miño y podría ser utilizada para evaluar la calidad ecológica de los ecosistemas estuarinos a nivel mundial

Fate and effects of graphene oxide alone and with sorbed benzo(a)pyrene in mussels Mytilus galloprovincialis

Graphene oxide (GO) has gained a great scientific and economic interest due to its unique properties. As incorporation of GO in consumer products is rising, it is expected that GO will end up in oceans. Due to its high surface to volume ratio, GO can adsorb persistent organic pollutants (POPs), such as benzo(a)pyrene (BaP), and act as carrier of POPs, increasing their bioavailability to marine organisms. Thus, uptake and effects of GO in marine biota represent a major concern. This work aimed to assess the potential hazards of GO, alone or with sorbed BaP (GO+BaP), and BaP alone in marine mussels after 7 days of exposure. GO was detected through Raman spectroscopy in the lumen of the digestive tract and in feces of mussels exposed to GO and GO+BaP while BaP was bioaccumulated in mussels exposed to GO+BaP, but especially in those exposed to BaP. Overall, GO acted as a carrier of BaP to mussels but GO appeared to protect mussels towards BaP accumulation. Some effects observed in mussels exposed to GO+BaP were due to BaP carried onto GO nanoplatelets. Enhanced toxicity of GO+BaP with respect to GO and/or BaP or to controls were identified for other biological responses, demonstrating the complexity of interactions between GO and BaP.This work was funded by the Spanish MINECO (NACE project CTM2016–81130-R) and the Basque Government (grants to consolidated research group IT1302–19 and IT1743–22, and predoctoral fellowship to NGS)

Occurrence and seasonal variation of several endocrine disruptor compounds (pesticides, bisphenols, musks and UV-filters) in water and sediments from the estuaries of Tagus and Douro Rivers (NE Atlantic Ocean coast)

Funding Information: This work was supported by FEDER (Programa Operacional Competitividade e Internacionalização - COMPETE 2020), from PIDDAC through FCT/MCTES project POCI-01-0145-FEDER-028708-PTDC/ASP-PES/28708/2017 , by UIDB/04423/2020 and AgriFood XXI R&D&I project, operation No. NORTE-01-0145-FEDER-000041 , co-financed by the European Regional Development Fund (ERDF) through NORTH 2020 ( Northern Regional Operational Program 2014/2020 ). The Portuguese Foundation for Science and Technology (FCT) supported the contract of Sara C. Cunha (IF/01616/2015), the Ph.D. Grant of Isa Marmelo (DFA/BD/4413/2020) and the contract of Patrícia Anacleto (CEECIND/01739/2017). Other support was provided by the Laboratory of Ecotoxicology and Ecology, Department of Population Studies of the Institute of Biomedical Sciences of Abel Salazar (ICBAS) of the University of Porto , and by the Strategic Funding UIDB/Multi/04423/2019 , UIDB/04423/2020 and LA/P/0101/2020 through national funds provided by FCT and ERDF in the framework of the programme Portugal 2020 to CIIMAR. Publisher Copyright: © 2022 Elsevier B.V.Exposure of aquatic environments to emerging contaminants is a global issue, special relevant in many estuaries due to impacts from anthropogenic activity. The aim of this work was to evaluate thirty-seven endocrine disruptor chemicals (EDCs) from four different classes (pesticides, bisphenols, polycyclic musks and UV-filters) in water and sediment samples collected during one-year in the estuaries of Tagus and Douro Rivers located into the NE Atlantic Ocean coast. EDCs analysis was achieved afterward validation of a gas-chromatography mass spectrometry (GC–MS) method using Dispersive Liquid-Liquid Microextraction (DLLME) as extraction procedure for water samples, and Quick, Easy, Cheap, Efficient, Rugged and Safe (QuEChERS) combined with DLLME for sediments. Tagus estuary presented higher levels of contamination with pesticide residues and bisphenols (BPs) than the Douro estuary in both water and sediment samples. Contrariwise, levels and frequency of polycyclic musks (PCMs) and UV-filters (UVF) were slightly higher in Douro estuary. Levels of pesticide residues in both sediment and water samples, and levels of PCMs and UVF in water samples were higher in warmer seasons (summer and spring) than in colder ones (winter and autumn). The opposite was found in what respect levels of BPs in water and sediment samples, and PCMs and UVF levels in sediment samples. Although the levels found for each contaminant are low, usually in the order of a few ng/mL(g), the presence of a high number of toxic compounds is a source of concern and requires constant monitoring.publishersversionpublishe

Immunotoxicological effects of perfluorooctanesulfonic acid on European seabass are reduced by polyethylene microplastics

Marine environments receive plastic waste, where it suffers a transformation process into smaller particles. Among them, microplastics (MPs; <5 mm) are ingested by aquatic organisms leading to negative effects on animal welfare. The interactions between MPs, contaminants and organisms are poorly understood. To clarify this issue, European seabass (Dicentrarchus labrax L.) were fed with diets supplemented with 0 (control), polyethylene (PE) MPs (100 mg/kg diet), perfluorooctanesulfonic acid (PFOS, 4.83 μg/kg diet) or PFOS adsorbed to MPs (MPs-PFOS; final concentrations of 4.83 μg and 100 mg of PFOS and MP per kg of feed, respectively). Samples of skin mucus, serum, head-kidney (HK), liver, muscle, brain and intestine were obtained. PFOS levels were high in the liver of fish fed with the PFOS-diet, and markedly reduced when adsorbed to MPs. Compared to the control groups, liver EROD activity did not show any significant changes, whereas brain and muscle cholinesterase activities were decreased in all the groups. The histological and morphometrical study on liver and intestine showed significant alterations in fish fed with the experimental diets. At functional level, all the experimental diets affected the humoral (peroxidase, IgM, protease and bactericidal activities) as well as cellular (phagocytosis, respiratory burst and peroxidase) activities of HK leukocytes, being more marked those effects caused by the PFOS diet. Besides, treatments produced inflammation and oxidative stress as evidenced at gene level. Principal component analysis demonstrated that seabass fed with MPs-PFOS showed more similar effects to MPs alone than to PFOS. Overall, seabass fed with MPs-PFOS diet showed similar or lower toxicological alterations than those fed with MPs or PFOS alone demonstrating the lack of additive effects or even protection against PFOS toxicity

Environmental Groundwater Vulnerability Assessment in Urban Water Mines

A multidisciplinary approach was developed to estimate urban groundwater vulnerability to contamination combining hydrogeology, hydrogeochemistry, subterranean hydrogeotechnics, groundwater ecotoxicology and isotope tracers. Paranhos and Salgueiros spring waters in Porto City were used as a case study. Historical and current vulnerability scenarios were compared using hydrogeological GIS-based modelling. Potential contamination sources were mapped around the spring galleries. Most of these were point sources and their potential contamination load was moderate. The ecotoxicological assessment indicated a low acute toxicity potential. Groundwater radionuclides appeared to be mainly controlled by geological factors and biomineralisation. Vulnerability maps suggest that most of the area has a moderate to low vulnerability to contamination. However, some surface sources such as sewage systems cause contamination and contribute to increased vulnerability. This integrated approach was demonstrated to be adequate for a better knowledge of urban hydrogeological processes and their dynamics, and highlighted the importance of a vulnerability assessment in urban areas.info:eu-repo/semantics/publishedVersio

Rapid decline of the greater European peaclam at the periphery of its distribution

Extirpation or even extinction of freshwater invertebrate species is a neglected conservation issue; declines in abundance and spatial distribution for freshwater invertebrates are far less documented than for vertebrate species. In the Minho River tidal freshwater wetlands (northwest of Iberian Peninsula), a rapid decline in density and biomass of the bivalve Pisidium amnicum was recorded at 16 different sites over seven years, from 2004 to 2010, without any sign of a potential recovery. Mean density values reached more than 80 ind.mx2 in 2004, but declined to less than 1 ind.mx2 in 2009 and 2010. An identical declining trend was observed for biomass. A significant reduction in the spatial distribution also occurred. The abiotic changes resulting from the 2005 heat wave and possibly the negative interactions imposed by the non-indigenous invasive bivalve Corbicula fluminea were the main factors responsible for the declining trends. Given the very low density, P. amnicum is facing a serious risk of extirpation in this ecosystem and conservational measures are urgently needed

Effects of temperature in juvenile seabass (Dicentrarchus labrax L.) biomarker responses and behaviour: implications for environmental monitoring

The effects of temperature on European seabass (Dicentrarchus labrax L.) juveniles were investigated using a 30-day bioassay carried out at 18 and 25 °C in laboratory conditions. A multiparameter approach was applied including fish swimming velocity and several biochemical parameters involved in important physiological functions. Fish exposed for four weeks to 25 °C showed a decreased swimming capacity, concomitant with increased oxidative stress (increased catalase and glutathione peroxidase activities) and damage (increased lipid peroxidation levels), increased activity of an enzyme involved in energy production through the aerobic pathway (isocitrate dehydrogenase) and increased activities of brain and muscle cholinesterases (neurotransmission) compared to fish kept at 18 °C. Globally, these findings indicate that basic functions, essential for juvenile seabass surviving and well performing in the wild, such as predation, predator avoidance, neurofunction and ability to face chemical stress may be compromised with increasing water temperature. This may be of particular concern if D. labrax recruitment phase in northwest European estuaries and coastal areas happens gradually inmore warm environments as a consequence of global warming. Considering that the selected endpoints are generally applied in monitoring studies with different species, these findings also highlight the need of more research, including interdisciplinary and multiparameter approaches, on the impacts of temperature on marine species, and stress the importance of considering scenarios of temperature increase in environmental monitoring and in marine ecological risk assessment

Modelos e sistemas de avaliação da toxicidade de substâncias químicas

Tese de doutoramento em Biologia (Ecologia) apresentada à Fac. de Ciências e Tecnologia da Univ. de CoimbraO principal objectivo deste estudo foi desenvolver e investigar as potencialidades de ensaios simples, rápidos e efectivos como alternativa aos testes de toxicidade convencionais. Seleccionaram-se como modelos o crustáceo cladócero Daphnia magna e o rato (Rattus norvegicus), por serem espécies tradicionalmente utilizadas em estudos de toxicidade. Três agentes químicos (3,4-dicloroanilina, paratião e cádmio), considerados como substâncias representativas de diferentes grupos químicos (organoclorados, organofosforados e metais, respectivamente), foram usados como substâncias-teste. Os principais problemas que se levantam em testes de toxicidade com D. magna são: i) a longa duração dos bioensaios crónicos, ii) a avaliação da toxicidade de substâncias consideradas "difíceis" (e.g. paratião) e a escassez de informação fornecida pelos testes agudos baseados na mortalidade. Os resultados obtidos neste estudo sugerem que os efeitos induzidos na primeira ninhada são semelhantes aos efeitos induzidos após 21 dias de teste. Neste trabalho foram também comparados os efeitos da renovação de meio e do uso de um solvente (etanol) na toxicidade letal do paratião para D. magna. Os resultados obtidos indicam que não é necessário o uso de um solvente para se obter a dissolução do paratião até uma concentração de 5 mg/l, a degradação do paratião é negligenciável e as potenciais interacções entre solvente e tóxico não afectam a toxicidade letal do paratião para D. magna em condições experimentais semelhantes às utilizadas. Um dos ensaios agudos testado, o ensaio de inibição da acetilcolinesterase in vivo, apresenta diversas vantagens relativamente ao teste agudo clássico com Daphnia. A toxicidade da 3,4-dicloroanilina, do paratião e do cádmio para ratos Wistar machos foi avaliada utilizando parâmetros hematológicos e bioquímicos como critérios de efeito. Os resultados obtidos indicam que o conjunto de índices utilizados é sensível e suficientemente diversificado para avaliar diversos tipos de efeitos tóxicos. Os resultados obtidos neste estudo sugerem que alguns dos ensaios de toxicidade convencionais podem ser substituídos por alternativas mais simples, rápidas e efectivas