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Trabajo presentado en el workshop "Combined Effects of Climate Change and Pollution by Emerging Contaminants on the Aquatic Environment: Effects on Human and Ecosystem Health", celebrado online el día 29 de noviembre de 2022.

Trabajo presentado en el IX Simpósio de Controle de Qualidade do Pescado (SIMCOPE 2022), celebrado en São Paulo (Brasil) entre el 17 y el 19 de octubre de 2022.

Trabajo presentado en el VIII International Symposium on Marine Sciences (ISMS 2022), celebrado en Las Palmas de Gran Canaria (España) entre el 6 y el 8 de mayo de 2022.

Pharmaceutical drugs in the aquatic medium may pose significant risk to non-target organisms. In this study, the potential toxicity of a mixture of three compounds commonly detected in marine waters (ibuprofen, ciprofloxacin and flumequine) was assessed, by studying bioaccumulation, oxidative stress and neurotoxicity parameters (catalase CAT, superoxide dismutase SOD, glutathione reductase GR, glutathione S-transferase GST, lipid peroxidation LPO, glutathione peroxidase GPX, metallothionein MT and acetylcholinesterase AChE) in the clam Scrobicularia plana. Temporal evolution of selected endpoints was evaluated throughout an exposure period (1, 7 and 21 days) followed by a depuration phase. The accumulation of all drugs was fast, however clams showed the ability to control the internal content of drugs, keeping their concentration constant throughout the exposure and reducing their content after 7 days of depuration. The induction of biochemical alterations (SOD, CAT, LPO, MT, AChE) was observed in gills and digestive gland probably related to an imbalance in the redox state of clams as a consequence of the exposure to the drug mixture. These alterations were also maintained at the end of the depuration week when the high levels of SOD, CAT, GST and LPO indicated the persistence of oxidative stress and damage to lipids despite the fact that clams were no longer exposed to the mixture., This study has been carried out within the research projects (CTM2012-38720-C03-03, CTM2016-75908-R) funded by the Spanish Ministry of Economy and Competitiveness, who also provided a pre-doc grant for Chiara Trombini (BES-2013-063426) and project PID2019-110049RB-100 funded by Ministry of Science and Innovation and ERD funds.

Resumen del trabajo presentado en el Iberaqua-Net: Red Nacional de Ecosistemas Fluviales. Retos y Estrategias de Futuro, celebrado online los días 24 y 25 de noviembre de 2021, Las comunidades acuáticas de los ríos se ven sometidos a impactos como alteraciones del régimen hidrológico natural o de eutrofización procedente de las entradas de aguas residuales y de la agricultura. Estas presiones antropogénicas alteran la composición de especies en diversos grupos taxonómicos, y de manera funcional alteran la estructura de la red trófica debido a cambios en los recursos basales alternativos disponibles para los consumidores. Una proporción elevada de δ15N puede actuar como indicador de contaminación procedente de aguas residuales, debido al enriquecimiento en 15N, reflejándose en los productores primarios y posteriormente en los consumidores de la red trófica. Por ello, identificar las especies que forman la línea base (LB) en una red trófica y analizar sus variaciones a causa de estas presiones, permitiría comprender las posiciones tróficas (PT) de los consumidores e identificar e integrar los impactos procedentes de estas actividades antropogénicas en un ecosistema. Sin embargo, apenas encontramos estudios que estimen esta serie de impactos ecológicos en la dinámica de la red trófica de un río. Esto es relevante en ecosistemas habitados por especies endémicas para poder detectar e informar de alteraciones del régimen hidrológico natural o entradas de aguas residuales y procedentes de la agricultura. En este estudio se analiza la PT estimada de la especie endémica de crustáceo decápodo Dugastella valentina, que habita en los tramos altos de los ríos del levante español y cuyo estatus es “casi amenazada” en la Lista Roja de la UICN. Los resultados muestran cierta superposición entre consumidores primarios e invertebrados depredadores, y un importante grado de omnivoría, alimentándose de algas y detritos. Los valores de δ15N y su PT

15 pages, The environmental state of the world ́s oceans is deteriorating, as the rate, speed and impacts of changes are larger, faster and more imminent than previously anticipated. A myriad of stressors, including those derived from climate change, such as warming, acidification, deoxygenation, and others anthropogenically driven like eutrophication, chemical pollution or proliferation of undesired populations (pathogens, harmful algal and jellyfish, among others) impact the oceans. There is an urgent need to understand the effects of these multiple stressors on ocean health and the implications for human health. In this chapter, we present specific actions required to achieve “healthier oceans”. The accomplishment of this challenge demands a multidisciplinary approach based on ocean monitoring, observation, experimentation and modelling, to assess physicochemical and biological environmental symptoms and to forecast the combined impact/s of the global stressors

Aquatic environments are the recipients of many sources of environmental stress that trigger both local and global changes. To evaluate the associated risks to organisms and ecosystems more sensitive and accurate strategies are required. The analysis of the microbiome is one of the most promising candidates for environmental diagnosis of aquatic systems. Culture-independent interconnected meta-omic approaches are being increasing used to fill the gaps that classical microbial approaches cannot resolve. Here, we provide a prospective view of the increasing application of these high-throughput molecular technologies to evaluate the structure and functional activity of microbial communities in response to changes and disturbances in the environment, mostly of anthropogenic origin. Some relevant topics are reviewed, such as: (i) the use of microorganisms for water quality assessment, highlighting the incidence of antimicrobial resistance as an increasingly serious threat to global public health; (ii) the crucial role of microorganisms and their complex relationships with the ongoing climate change, and other stress threats; (iii) the responses of the environmental microbiome to extreme pollution conditions, such as acid mine drainage or oil spills. Moreover, protists and viruses, due to their huge impacts on the structure of microbial communities, are emerging candidates for the assessment of aquatic environmental health. This study was supported by the Spanish Ministry of Economy and Competitiveness (CTM2016-75908-R), by the Spanish Ministry of Science and Innovation (PID2019-110049RB-I00), by the European Regional Development Fund (UCO-FEDER-1262384-R), and by the Chelonia Association (Mares Circulares project).

Resumen del trabajo presentado en el 14th SETAC Latin America, celebrado de forma virtual del 26 al 29 de septiembre de 2021, The use of non-forced multi-compartmented exposure systems to assess the avoidance behavior of organisms brings a novel perspective about how contaminants affect the spatial distribution of species and their processes of habitat selection. Differently from the standard exposure systems, in a non-forced exposure system organisms are exposed to a chemically heterogeneous scenarios and thus they can move throughout different levels of contamination. In spite of the ecological relevance of this approach, it is still incipient and poorly used in ecotoxicological risk studies. The current study aims to assess how environmentally protective the spatial avoidance in non-forced exposure system is in comparison with the traditional endpoints used in ecotoxicology. For that, we applied two tools: the sensitivity profile by biological groups (SPBG) and the species sensitive distribution (SSD). Three chemically different compounds were selected for this review: copper, glyphosate and silver nanoparticles (Ag-NPs). Considering the hazard concentration for 5% of the species (HC5) avoidance behavior can be considered a very sensitive endpoint. In summary, avoidance behavior in non-forced multi-compartmented exposure systems could be a complementary tool to the ecotoxicological studies because it provides an overview on the level of repellence of contaminants and how they affect the distribution of species under chemically heterogeneous scenarios.

Editors: Antonio Tovar-Sánchez, David Sánchez-Quiles, Julián Blasco. The Handbook of Environmental Chemistry book series (HEC, volume 94), This book provides a comprehensive and authoritative review of the chemical analysis of UV filters in coastal waters and their impact on the marine environment. The sun care is today the most important sector within the cosmetics industry, with annual increases in sales. The main components of sunscreens, organic and inorganic UV filters, have been detected in many coastal regions, with the highest concentrations in coastal areas under high anthropogenic pressure. Moreover, these compounds have been found to be bioaccumulated in aquatic biota causing biological and toxicological responses; some organic UV filters act as endocrine disruptors in aquatic biota, affecting survival, behavior, growth, development and reproduction. On the other hand, inorganic UV filters, mainly based on nanoparticles, have been demonstrated to have various impacts on marine organisms, such as inducing oxidative stress in abalones, accumulating in microalgae, affecting the immune response in mussels, bleaching corals, and genotoxicity in fish, among others. All these effects of sunscreens on the marine environment highlight the need for more stringent and environmentally friendly regulations. This book covers the latest analytical methodologies used in assessing the impact of UV filters impact on marine waters, especially on marine biota, and also critiques the global regulation of UV filters and the environmental risk of using sunscreens. Featuring specific case studies of the environmental effects of sunscreens in the Mediterranean Sea and Hawaii, which highlight the importance of balancing human health with environmental health of coastal ecosystems, it will appeal not only to scientists and students from various disciplines (environmental chemistry, biology, ecology, biogeochemistry, fisheries and climate change among others), but also to environmental managers wanting to promote new restrictive regulations on the use of UV filters, and to professionals from the cosmetic industry interested in the development of eco-friendly sunscreens.

Trabajo presentado en el XX Seminario Ibérico de Química Marina, celebrado en modalidad virtual del 1 al 3 de julio de 2020., Mercury (Hg) is a global pollutant which is widely distributed in the environmental compartments. Its occurrence in oceans and coastal ecosystems is well documented and can be related to natural or anthropogenic sources. The contribution of anthropogenic sources has changed the figures of natural cycles fluxes of Hg on the Earth, increasing its presence from the beginning of industrialization. The main route of Hg exposure to the human being is related to food consumption. Species of larger fish (e.g. tuna, swordfish, etc.) accumulate significant amounts of Hg and mono methylmercury (MMHg) which are a risk for human health. In this work, we have analysed Hg concentrations in muscle and liver in two tuna species (i.e. Thunnus alalunga and Thunnus thynnus) collected in the Gulf of Cadiz. These specimens did not have a commercial size and the weight ranged between 1.12-1.43 kg and 0.22-0.37 kg for T.alalunga and T .thynnus, respectively. Similar Hg concentrations in both target tissues were reported in each species. T. alalunga bioaccumulated higher amounts of Hg in the muscle (0.51-1.22 mg/kg) than T. thynnus, (0.18-0.33 mg/kg). Although, only T. alalunga had concentrations higher than legal limits (1.0 mg/kg). A preliminary exam of the weekly intake of Hg considering both species did not show risk for the general population. However, a more detail exam of Hg intake for fish consumption should be carried out according to the last recommendations of the Spanish Food Security and Nutrition Agency (AESAN, 2019) which reduced the amount recommended for fish consumption with high Hg concentrations, especially for risk groups.

Módulo de ensayo para simulaciones de distribución heterogénea de paisajes en escenarios multi-hábitat para replicación de una pluralidad de condiciones ambientales y distribuciones espaciales, y dispositivo compuesto por una pluralidad de dichos módulos de ensayo. El módulo comprende un cuerpo (1) en cuyo interior se define una cavidad (2) central, con al menos dos canales (4) de paso en la pared (3) lateral. Cada canal (4) comprende una abertura (5) pasante, una ranura (6) definida en el borde perimetral de la abertura (5), y una vertiente (8) que se prolonga en una pendiente ascendente desde la cavidad (2) central hasta la abertura (5). Una cubierta (9) recubre superiormente a las cavidades (2) para evitar la evaporación del contenido, y una pluralidad de compuertas (7) se interpone en los canales (4) para control de la comunicación entre dos módulos contiguos, Consejo Superior de Investigaciones Científicas (España), Aquatic BioTechnology S.L., Universidade de Coimbra, A1 Solicitud de patente con informe sobre el estado de la técnica

Trabajo presentado en el GLOBAQUA workshop (A reconnaissance of trace organic compounds and metals in globaqua river basins: Effects on ecosystems and risk assessment), celebrado en Barcelona el 9 y 10 de noviembre de 2017., The occurrence of metals in environmental compartments is related to both natural processes (weathering, erosion, etc.) and anthropogenicactivities (urban sewage, industrial activities, among others.). Sediment is a key compartment for metal accumulationbecause metals tend to adsorb on particulate material and settling in sediment. Additionally, the sediment has got a high binding capacity for metals and they can be trapped and remain in no bioavailable form. Anyway, the change of physicochemical conditions (redox, resuspension, etc..) can release metals from sediment to the watercolumn, making them bioavailable and thus capable to interact with epibenthic or pelagic aquatic organisms. In the frame of Water Framework Directive (2000/60/EC), hazardous substances, which include metals, must be analysedtoestablish the extent of compliance with environmental quality standards. In order to improve the knowledge about the status of four Mediterranean river basins of Iberian Peninsula (Llobregat, Ebro, Júcar,and Guadalquivir), the SCARCE project was developed (Navarro-Ortega et al., 2012). In the frame of this project, two sediment sampling campaignswere carried out in the four rivers, and 77 sampling stations were monitored. In this work, physicochemical characteristics of the sediment (granulometry, organic matter, organic carbon) and metal concentrations (Ag, Al, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Sr, Pb, Zn) in total and < 63 m fractions were analysed. To establish the ecotoxicological risk associated withmetal pollution in sediment, measured concentrations have been compared with Canadian Sediment Quality Guidelines and other indicesof metal pollution, identifying hotspots in the four river basins and prioritizing metals responsible of risk., This work has been funding by the SCARCE (Consolider-Ingenio 2010 CDS2009-00065) and NET-SCARCE (CTM2015-69780-REDC) projects.

Anthropogenic wastes from different origns (urban, agricultural or industrial activities) have brought severe consequences to the environmental quality of freshwater ecosystems. The impact to aquatic biota linked to contamination has been mainly assessed in function of the toxic (either lethal or sublethal) effects produced on organisms. The ability of organisms to avoid exposure to contaminants, which helps organisms to prevent toxicity, began to be also considered as evidence of environmental risk. The risk associated to the contamination-driven organisms’ spatial displacement can be a serious problem to habitat selection, migration, and (re)colonization processes as well as to the community structure even if no toxic effect at individual level occurs. Theriver inputs of contamination can occur in different zones over its course showing a patchy scenario or a contamination gradient. As organisms exposed to these contamination scenarios can move from contaminated to more favorable habitats, avoiding the contact with the toxic compounds, we have hypothesized that an avoidable discharge can act as chemical barrier causing a habitat fragmentation and affecting the organisms’ displacement (from down to upstream and vice versa). Therefore, the present study aims (i) to verify if the contamination originated from urban and agricultural discharges in a river (i.e. Guadalete River; Southwest Spain) could generate a chemical barrier that restricts the displacement of one of their representative organisms (i.e. the shrimp Atyaephyra desmarestii,and (ii) to discriminate the preference/avoidance response of this species on the effects of the contaminants in water and sediment compartments. Habitat selection assays were performed in a free-choice, multi-compartmented, non-forced exposure system, simulating the spatial arrangement of the samples such as their distribution in the environment, and the freshwater shrimp A.desmarestii, species frequently found in European Rivers (including in the Guadalete River), was used astest organism. Water and sediment samples were collected along Guadalete River, including pristine and sewage-impacted areas (e.g., near the local wastewater treatment plant). Contamination was assessed by measuring a wide range of commonly reported metals and organic contaminants (hydrocarbons, pesticides, pharmceuticals, personal care products, etc.). Results clearly showed that shrimps selected the less contaminated water and sediment samples, indicating that their spatial distribution might be driven by contamination levels. In addition, evidence of habitat fragmentation due to contamination of sediment was observed in the sampling area close to the wasterwater treatment plant. The preference behavior towards some river samples was highly related to contamination levels of water and sediment. Results indicate that contamination might act as chemical barrier causing a spatial isolation of populations., C.V.M. Araújo is grateful to the Spanish Ministry of Economy and Competitiveness for a Juan de la Cierva contract (IJCI-2014-19318). This studywas partially funded by NET SCARCE project (Red Consolider sobre los efectos de la escasez de agua y el cambio global en sistemas fluviales -CTM2015-69780-REDC).

Trabajo presentado en la SETAC Latin America 12th Biennial Meeting ("Bridging the Gap between Science and Governance"), celebrada en Sao Paulo del 7 al 10 de septiembre de 2017., Metals occur in the rocks of the earth and soil, resulting from erosion processes, and its presence in the environment is related to natural cycles. However, other metal sources are related to anthropogenic origin, such as mining, smelters or industrial activities and commercial applications, among others. Metals are transported by different pathways, depending on their physicochemical properties to seawater. Coastal and estuaries are one of the most valuable ecosystems on earth because they provide a wide number of ecosystem services. Nearly half of the world’s population lives near of the coast areas, provoking high pressures in these ecosystems. One of the problems associated with the population increase in coastal areas is pollution. Metal contamination is not a new problem, and episodes of metal pollution have been reported in the scientific literature since the beginning of the industrial revolution. In the last century, many instances of contamination and pollution in coastal areas have been recorded. However, societal changes and the increase of ecological consciousness have generated a tendency to improve industrial processes, lessen residues in production, and focus on a healthy environment. However, in emergent countries, the residues management is a pending task. New technological developments, such as nanotechnology, can represent benefits to human beings, but the release of these engineered nanomaterials and specifically metallic and oxide metal nanoparticles in coastal areas can represent a new source of risks and challenges. Due to the nature of these nanomaterials, new approaches for assessing their toxicity should be implemented. Additionally, the effect of rising temperature and ocean acidification, associated to global climate change, can affect to bioavailability and toxic effects. In this talk, we are going to summarize the problems related to the occurrence of metals (legacy pollutants) in coastal ecosystem and the new challenges associated with the presence of metallic (MeNPs) and metallic oxide (MeOxNPs) nanoparticles in marine ecosystems, focusing on two key trophic levels (phytoplankton and molluscs). The main findings regarding the behavior of nanoparticles and ionic strength (AgNPs), homo and heteroaglomeration processes, effect of UV-A in the toxicity of TiO2 NPs on phytoplankton species and species sensitivity to nanoparticles, among others, will be presented. We will also show the accumulation and elimination strategies (CuONPs, AuNPs), intracellular location and toxicity regarding the mollusc, which was pointed out as a target species for nanotoxicity.

Trabajo presentado en la SETAC Europe 27th Annual Meeting (Environmental Quality Through Transdisciplinary Collaboration), celebrada en Bruselas del 7 al 11 de mayo de 2017., Laboratory aquatic ecotoxicity assays used to provide data for ecological risk assessments assume that, under natural conditions, organisms living in a contaminated habitat are mandatorily and continuously exposed to contaminants. This assumption neglects the ability of the organisms to detect and avoid contamination moving towards less disturbed habitats such as expected in fluvial systems. Along a river, contaminants can be dispersed forming a gradient or even be patchy distributed, conditioning the habitat selection process by organisms as well as their avoidance and preference behavior. Therefore, in the present study, we assessed the avoidance and preference responses of the model fish Danio rerio when exposed to water samples from two Ecuadorian rivers (Pescadillo River and Oro River) with different disturbance levels. A non-forced exposure system, in which water samples from different river points are simultaneously assayed, allowing organisms to move freely between river samples and select the most favorable sample, was used. Results showed that organisms presented a trend to avoid Pescadillo River upstream samples, moving downstream towards to the confluence zone with Oro River. On the other hand, fish exposed to Oro River samples preferred moving upstream. When exposed to samples from both rivers simultaneously, fish tended to prefer Oro River samples. These results leaded us to predict that, as both rivers are connected, fish avoiding environmental disturbers in Pescadillo River would move to Oro River. Therefore, effects of potential stressful conditions present in Pescadillo River that trigger avoidance response by fish may depress fish populations in that river and, indirectly, affect Oro River by inducing an unexpected fish immigration.

Trabajo presentado en la SETAC Europe 27th Annual Meeting (Environmental Quality Through Transdisciplinary Collaboration), celebrada en Bruselas del 7 al 11 de mayo de 2017., Detection of pharmaceuticals in the aquatic environment is an emerging issue of concern. Although the majority of drugs occur in the aquatic environment at trace level (ng L-1 to low μg L-1), most of them have been specifically designed to be biologically active at low concentrations in humans and animals and therefore they can represent a risk for aquatic organisms particularly under chronic exposure. The knowledge on the biological effects of pharmaceuticals on aquatic organisms is still scarce, moreover since these compounds occur in aquatic environment as complex mixtures. Ibuprofen (IBU) is one of the most used non-steroidal anti-inflammatory drugs: its ability to induce toxic effects in aquatic organisms at environmentally relevant concentrations has been widely proven. Ciprofloxacin (CIP) and flumequine (FL) are broad -spectrum antibiotics of the fluoroquinolones class. Fluoroquinolones toxicity was observed in rodents producing among others oxidative stress, cyto and neurotoxicity. However, ecotoxicological effects on aquatic organisms of CIP and FL are practically unknown. In our work biochemical responses related to oxidative stress (CAT, SOD, GR, T-GPx activities and LPO levels), detoxification (GST activity) and neurotoxicity (AchE activity) were studied in the red swamp crayfish Procamabarus clarkii after sub-chronic exposure to 10 and 100 μg L-1 of a mixture of IBU, CIP and FL. Recovery of organisms was also evaluated after 1 week of post-exposure depuration. Additionally transcriptional responses related to antioxidant and stress (CAT, GST, heat shock protein 90HSP90 and metallothioneinsMT), apoptotic (cathepsin-L CatL, 14-3-3 zeta protein14 -3-3ζ), immune (thymosin Thy, toll-like receptorsPcToll) and inflammatory (collagen alpha chain -like proteinColA) processes and neurotransmission modulation (neuropeptide precursor proteinNP, myosuppressin -like neuropeptide precursor MSNP, synaptome-associated proteinSNAP) were evaluated. Results obtained for biomarkers and gene expression indicate a general activation of different oxidative stress related features in both enzymatic and transcriptional responses, particularly at the highest concentration of drugs. Therefore, exposure of pharmaceuticals mixtures to P. clarkii can produce oxidative stress as indicated by enzymatic and transcriptional responses. It has still to be evaluated if these effects can have long term physiological effects on aquatic ecosystems and human health.

Trabajo presentado en la SETAC Europe 27th Annual Meeting (Environmental Quality Through Transdisciplinary Collaboration), celebrada en Bruselas del 7 al 11 de mayo de 2017., Traditional laboratory aquatic ecotoxicity assays aim to assess the potential toxicity of a natural samp le or contaminants on organisms, on which a given response is measured. Organisms are passively and mandatorily exposed to contamination with no possibility to avoid it. This approach, here called forced exposure, allows an obvious concentration-response relationship is derived; although we cannot neglect such direct effects, under natural conditions, mobile organisms can detect contamination and move to more favourable areas, avoiding suffering the toxic effects caused by continuous exposure. In this new scenario, no effect is expected to occur on individuals; therefore, measuring effects down to individual level lacks ecological relevance. When organisms respond to contamination moving towards undisturbed habitats, biological effects will be sensed firstly and more intensely on ecosystems as part (or the entire) population may abandon the disturbed habitat. Therefore, the contamination will affect the spatial distribution of the organisms and the processes of habitat selection (avoidance and recolonization). Secondly, the neighbouring undisturbed habitat, used by organisms as escape area, can be indirectly stressed due to the overpopulation of avoiders. This scenario is hard to be assessed in a forced exposure system. Therefore, a free-choice, multi-compartmented, nor-forced exposure system has been proposed as additional tool able to predict how contamination can affect both avoidance and recolonization responses. By using the non-forced exposure system, it is possible to assess the biological effects caused by a gradient or even patchy contamination up to the ecosystem level. Finally, the non -forced exposure system allows evaluating the environmental fragmentation caused by chemical barrier that contamination can create, blocking the free displacement among habitats. The present study brings a novel tool for ecotoxicity assays in which organisms are not forcedly exposed to contamination, so that avoidance and recolonization responses are added to the ecological risk assessment. The theoretical basis, the oper ational advantages and the ecological relevance of this approach are discussed. Our experience with the non-forced exposure system has shown that this approach can provide important information about the role of the contaminants as habitat disturbers even when individual toxic effects are not detected.

Trabajo presentado en la Final conference of the COST Action ES1205 (Engineered Nanomaterials from Wastewater Treatment & Stormwater to Rivers), celebrada en Aveiro (Portugal) el 7 y 8 de febrero de 2017., Sunscreens is one of largest groups of Personal Care Products (PCPs) used in the market and has increased considerably in recent years, being the coastal zone susceptible to continuous inputs of this emergent pollutant.Sunscreens incorporate in its formulation organic and inorganic UV-filters such as TiO2which are released into aquatic environments. Due to the complexity in their formulations, most of the researches have assessed its toxicity to organisms considering specific compounds, such as benzophenone-3 (BZ-3), octyl methoxycinnamate (OMC), 3-benzylidene camphor (3-BC), 4-methylbenzylidene camphor (4-MBC), isoamyl p-methoxycinnamate (IMC)or p-aminobenzoic acid (PABA). However the toxicity of sunscreens as product in aquatic environment is not frequent assessed. Other lack in the knowledge of toxic effect of UV-filters is that most of studies have been developed to freshwater phytoplankton while investigationsto marine phytoplankton are scarce.The hypothesisof this work is that succession in the phytoplankton community is adversely affected by sunscreens whose composition includes TiO2 as the main inorganic UV-filter, under solar light radiation, and that this effect is mediated by H2O2 production.

Trabajo presentado en la SETAC Latin America 12th Biennial Meeting ("Bridging the Gap between Science and Governance"), celebrada en Sao Paulo del 7 al 10 de septiembre de 2017., Crustaceans may develop biological tolerance when exposed to contaminantion over time, resulting from an adaptation achieved during their life or by genetic selection. Aquatic toxicity occurs through direct absorption of chemicals present in water, sediment or by feeding. In the contaminated mangroves of Cubatão (SP), there are records that the leaves of Rhizophora mangle have high rates of pollutants. These leaves are the main source of food to the Uçá-Crab (Ucides cordatus), a species considered sentinel of this ecosystem,. There are some evidences that U. cordatus has developed biological resistance to the main contaminants present in the mangroves of Cubatão. The objective of the study was to assess if the crabs that live in this contaminated mangrove have a higher biological tolerance comparatively to animals living in a pristine area (Jureia-Itatins). Ninety specimens from Cubatão (CUB) and ESEC Juréia-Itatins (JUR: pristine mangrove) were fed with leavesof R. mangle for 43 days (15 of acclimation: animals fed with uncontaminated leaves). The ex-situ experiment was divided in three treatments: Control (crabs from Juréia fed with uncontaminated leaves), CUB and JUR (crabs from Cubatão and Juréia fed with contaminated leaves, respectively). At seven-day intervals, the genotoxicity (Micronucleus Assay) and cytotoxicity (Neutral Red Assay) were evaluated (T-0, T- 7, T-14, T-21 and T-28). The genetic and physiological effects observed in animals from CUB and JUR treatments were statistically different from those belonging to the Control right after the first week of experiment (T-7) and remained significant throughout the period of 21 days. The physiological effects observed in the animals from CUB and JUR showed no differences during the whole experiment. In relation to genotoxicity, crabs from JUR showed higher effect recorded after 14 days of feeding, remaining stable after this period. However, the animals from CUB showed a significant temporal decrease in the frequency of micronucleated cells, possibly due to the biological genetic adaptation to contaminants found in the leaves. In conclusion, the tolerance and adaptation capacity may vary according to the level of organization analyzed and, possibly, the animals resident in the mangroves of Cubatão have developed genetic mechanisms of tolerance to the main contaminants of this region.

Trabajo presentado en la SETAC Europe 27th Annual Meeting (Environmental Quality Through Transdisciplinary Collaboration), celebrada en Bruselas del 7 al 11 de mayo de 2017., In recent years, the use of personal care products (PCPs) has increased notably. This increase together with growing of human population in coastal areas has provoked a constant entrance of emerging pollutants into the aquatic environments. However, data about bioaccumulation and toxicity of PCPs in aquatic biota are scarce. In this research, the clam Ruditapes philippinarum has been considered as model organism. The aim of this work was to investigate the role of TiO2 nanoparticles in bioaccumulation of organic PCPs and the toxic responses of single and mixture exposure experiments using a battery of antioxidant enzymes (superoxide Oxidase, catalase, total gluthathione peroxidase, Se-dependent glutathione peroxidase and glutathione reductase ) , lipid peroxidation and DNA damage. In the experiment, four treatments, controls and ethanol controls were run in parallel. Two of the four treatments were single treatments, one of the treatment was 100 ppb of TiO2 in form of nanoparticles < 100 nm (TiO2 NPs) and the other one TiO2 in bulk form. The other two treatments were mixture treatment: a) 100 ppb of TiO2 NPs plus 10 ppb of a mix of organic PCPs and b) 100 ppb of TiO2 bulk plus 10 ppb of mix of organic PCPs. The organic PCPs selected were triclosan (antimicrobial), OTNE (fragrance) and benzophenone-3 and octocrylene (UV filters).. Bioaccumulation of inorganic compound such as TiO2 was almost immediate reaching steady stationary over exposure time; and depuration rate was low. Respect to organic compounds in mixtures, triclosan and benzophenone-3 accumulations were mediated by TiO2 and was driven by the size of the particles. TiO2 NPs seems to play a key role in the uptake of organic compounds (“a Trojan horse”), probably due to their high surface area, large pore volume and the presence of high affinity surface hydroxyl groups 1, plus their capacity to stabilize the occurrence of these organic compounds in the cell tissues. NPs provide potential route for the delivery of nanoparticle-associated toxic pollutants to sites where they would not normally reach them. Many NPs, including TiO2 NPs, have shown a tendency to adsorb other pollutants by binding transitional metal and organic pollutants; in addition they have showed the ability to internalize them into the body and cells. The joint action of the organic compound mix and any of the two forms of TiO2 provoked significant (p< 0.01) changes in the activity of antioxidant enzymes compared (EROD, SOD, CAT, T-GPx, Se-GPx, GST and GR). Despite of higher bioaccumulation of triclosan and benzophenone-3 in the TiO2 NPs mixture than TiO2 bulk mixture treatments, toxicity observed could be consequence of compound interactions instead of total bioaccumulation processes., This research has been funded by Junta de Andalucía (PE2011-RNM-7812 project).

Trabajo presentado en la SETAC Europe 27th Annual Meeting (Environmental Quality Through Transdisciplinary Collaboration), celebrada en Bruselas del 7 al 11 de mayo de 2017., In situ observations seem to indicate that the spatial distribution of the snail Olivella semistriata on the Ecuadorian coast (city of Manta) is influenced by urban discharges. Therefore, contamination could determine habitable areas for snails. Firstly, the present study evaluated the ability of O. semistriata individuals to detect local contamination and avoid inhabiting contaminated sediments. Secondly, the ability of snails to recolonize contaminated sediments under recovery was studied. Sediment samples were taken in five points (El Murciélago beach - reference point, El Puerto, La Poza, Río Burro, Los Esteros, and Río Muerto) and evaluated for avoidance and recolonization trials. The tests were performed in a non-forced exposure system in which a contamination gradient was formed by mixing the test sample and the reference sediment. Higher avoidance percentage was observed in the samples of Rio Burro and Rio Muerto. Regarding recolonization tests, the reference sample was always preferred over all test samples. As there is no physical barrier to avoid the displacement of organisms between the studied areas, it is suggested that the absence (visual field observation) of snails in the Rio Burro and Rio Muerto sediments is due to the organisms' ability to avoid those areas. We can conclude that the spatial distribution of the snail may be directly affected by the presence of contaminants in the sediment, by triggering avoidance or even prevent colonization of contaminated areas. Contamination may, therefore, act as a chemical barrier that could cause habitat disruption and isolate populations.

Trabajo presentado en la Final conference of the COST Action ES1205 (Engineered Nanomaterials from Wastewater Treatment & Stormwater to Rivers), celebrada en Aveiro (Portugal) el 7 y 8 de febrero de 2017., Production of engineered nanomaterials (ENM) has increased exponentially in the global market products due to their special physicochemical properties respect to bulk material.The production and application of silver nanoparticles (Ag NPs) in consumer products is primarily related to the well-known antibacterial property of the silver ions (Ag+) released from the ENM surface. Other uses of Ag NPs are electrical devices, detergents, textiles, cosmetics, outdoor paints and agricultural products and water treatment.

Trabajo presentado en el 6th Congress of the Spanish Proteomic Society, celebrado en Cádiz del 15 al 18 de noviembre de 2016., Over the last decades engineered gold nanoparticles (AuNPs) have been developed for and introduced into a growing number of commercial and industrial products. Up to date limited information is available on the ecotoxicological responses in non-target organisms, in par-ticular under environmental relevant concentrations. Notwithstanding their promising applica-tions, increased understanding of their behaviour and effects is required to manage potential risk for non-target organisms.We studied differential protein expression in response to citrate capped AuNPs (21.5 ± 2.9 nm) in the digestive gland of the bivalve Ruditapes philippinarum after 1 and 7 days of expo-sure at an environmental relevant concentration (750 ng L-1), using a 2nd-generation (iTRAQ-8plex) proteomic approach.2200 proteins were identified to be simultaneously expressed in control and treatment and a regularized regression approach (Elastic Net) identified 105 of those to be expressed dif-ferentially. Homology-based functional annotation could be successfully performed for 77% of all sequences and 75% of the differentially expressed sequences and subsequent analysis identified potential enrichment in various stress and injury related functions. Identified pro-teins may be useful as biomarkers of environmental nanoparticle pollution and provide insight about the mode of action of engineered gold nanoparticles.

Trabajo presentado en la NET SCARCE International Conference (Rivers under water scarcity: Threats and Challenges), celebrada en Barcelona el 15 y 16 de noviembre de 2016., When laboratory ecotoxicity assays are employed to assess the quality of fluvial environments, the main goal is to verify how healthy the organisms could be and to identify potentially toxic areas. The traditional mechanism used in laboratory ecotoxicity assays is to expose organisms to samples taken from a specific point of the river and to measure a given response. This exposure system assumes that organisms are passive uptakers of contaminants with no ability to escape from contamination as the contact with the sample (and possible contaminants present in it) is forced and mandatory. Under real situation, such condition is not expected to occur for mobile organisms as it is expected that they move to different areas where contamination levels could be distinct. When this occurs, responses at individual (or lower) level fail in predicting potential risk at higher biological organization such as ecosystem. Although the avoidance by organisms of a disturbed area is a protection mechanismthatpreventstoxic effect at individual level, since an ecosystems level the effects can be quite severe as organisms partially or totally disappeared.By the forced exposure approach is possible to obtain a direct concentration-response relationship, but it presentstwo disadvantages: (i) it only provides information of potential toxicity directly related to individual level (or sub-individual: proteins, gens, cell, tissues), therefore statements about the biological effects at ecosystem level is prevented or hard to be achieved and (ii) it does not consider the ability of the organism to detect and avoid contaminants, nor as contaminants affect the spatial distribution of the organisms.If laboratory ecotoxicity assays are performed with mobile organisms, for a better understanding about the biological effects at ecosystems level, organisms should be exposed simultaneously to different areas and not exclusively to a specific sampled sample. Recently, amulti-compartmented, nor-forced exposure system that allows testing many samples taken along the ecosystems to be studiedhas been developed. In that approach organisms are equally distributed in the system containing different samples (concentrations), whereby they can freely move, and at the end it is possible to check the preferred and avoided areas. This non-forced exposure approach provides information about how contamination can affect the habitat selection patterns by organismsand recolonization processes. The non-forced exposuresystem can also be used to assess effects of a contamination gradient (for specific regions of the river) or of heterogeneously disturbed ecosystems (where contamination patches are formed due to the presence of several discharges along the river).By using the first condition (contamination gradient) it is possible to predict the preferential spatial distribution of organisms along a gradient and to hypothesize from which point populations are not expected to be found. However, by simulating a patchy contamination it is possible to identify less habitable areas and the presence of chemical barriers due to contamination., The present work brings a novel tool for ecotoxicity assays in which organisms can beexposed to different river samplesand can freely move among them, including therefore the concept of habitat selection to ecotoxicological studies.In addition, some results of preliminary studies will be presented and discussed. Finally, a brief discussion about how non-forced system could help predicting the effects of contamination linked to other environmental disturbance factors, such as habitat fragmentation due to presence of reservoirs, will be presented. The recent experience with the non-forced exposure system have shown that this approach can provide important information about the role of the contaminants as habitat disturbers even when individual toxic effects are not detected., CVM Araújo thanks Spanish Ministry of Economy and Competitiveness for the Juan de la Cierva contract (IJCI-2014-19318).

Trabajo presentado en el XIV Congreso Brasileiro de Ecotoxicología (XIV ECOTOX), celebrado en Curitiba del 7 al 10 de septiembre de 2016.

Trabajo presentado en el 30th ESCPB Congress (New European Society for Comparative Physiology and Biochemistry, "Unraveling complexity: from molecules to ecosystems"), celebrado en Barcelona del 4 al 7 de septiembre de 2016., Copper oxide nanoparticles (CuO NPs) are increasingly investigated, developed and manufactured for a wide and promising array of commercial and industrial products. Their increased production use and disposal will eventually lead to their increased release into the aquatic environment and potentially affect non-target organisms within. Although CuO NPs have been identified to be potentially cytotoxic, little is known about their behaviour in the marine environment and its potential influence on their cytotoxicity. We studied aggregation and dissolution kinetics of two commercially available bare copper oxide nanoparticles with nominal similar mean sizes (~ 40 nm), but distinct synthesis processes (wet chemistry and combustion synthesis) in various environmental and experimental relevant conditions. In addition cytotoxicity and DNA damage, as well as gene expression of oxidative stress, inflammatory response, DNA damage repair and cell death mediator markers were studied in Ruditapes philippinarum haemocytes after 24 h in vitro exposure and compared with sub-micron CuO (~ 500 nm) and water soluble Cu treated cells. Our results indicate that aggregating behaviour largely influences the toxicity of CuO NPs by influencing their susceptibility to ion leaching from the particle/aggregate surface. Gene expression analysis identified highly similar modes of action for all tested particulate and ionic Cu forms, further substantiating that nano and bulk CuO toxicity might largely be driven by ionic Cu. In addition our work highlights various differences in the behaviour of CuO NPs in environmental and culture conditions that need consideration when extrapolating results from in vitro to natural (or environmental) conditions.

Trabajo presentado en el 41st CIESM Congress, celebrado en Kiel del 12 al 16 de septiembre de 2016., A lead exposure experiment (7 days) was carried out to determine the biomarker responses in the gills and digestive gland of the clam Ruditapes philippinarum. Non significant response was found in acetylcholinesterase (AChE), catalase (CAT), superoxidase dismutase (SOD) in both gills and digestive gland. On the contrary, phase II antioxidant enzyme (glutathione S -transferase, GST) and antioxidant enzyme, glutathione peroxidase (GPx) have shown significant variation after 7 days of exposure to 100μg/L Pb. GST was induced significantly (p

Trabajo presentado en el International Cool Climate Wine Symposium (ICCWS), celebrado en Brighton del 26 al 28 de mayo de 2016.-- Tardáguila, Javier et al., The VineRobot project has received funding from the European Union’s Seventh Programme for research, technological development and demonstra?on under Grant Agreement No 610953.

Trabajo presentado en el XVIII Seminario Ibérico de Química Marina, celebrado en Alicante (España) de 20 al 22 de julio de 2016., Pharmaceuticals are pollutants of potential concern in the aquatic environment where they are commonly introduced as a complex mixture. In this study we have evaluated the toxic effects produced in clams Scobicularia plana by a mixture of ciprofloxacine, flumequine and ibuprofen, three pharmaceuticals that are produced and used in large quantity and have a wide spread occurrence in aquatic environment. Clams were exposed to two mixture concentrations (at 10 and 100 μg·L-1 levels) during 28 days (21 days of exposure and 7 of depuration) and oxidative and neurotoxic effects were assessed using a multi-biomarker approach: CAT, GR, GPx, GST, SOD, LPO levels and AchE activity were evaluated in gills and digestive gland over time. The present study demonstrated that the combination of three pharmaceutical compounds, particularly at the highest concentration tested, have a considerable effect on the activities of antioxidant and detoxifying enzymes and therefore on the oxidative status of S. plana., This work has been funded by the Ministerio de Economia y Competitividad of the Spanish Government under Project CTM2012-38720-C03-03, and ERF funds.

Trabajo presentado en el 30th ESCPB Congress (New European Society for Comparative Physiology and Biochemistry, "Unraveling complexity: from molecules to ecosystems"), celebrado en Barcelona del 4 al 7 de septiembre de 2016., Titanium dioxide nanoparticles (TiO2 NPs) has become a part of our daily life in the form of drug delivery systems, therapeutics and biosensors, cosmetics, production of paints, coatings, plastics, skin care products, foods, water remediation devices and pharmaceuticals, and the predicted environmental concentrations are the highest in aquatic ecosystems. Although TiO2 has got a limited reactivity, under UV-A radiation can increase adverse effects on organisms, due to its photocatalytic properties; and the occurrence at nanoscale level change its physicochemical properties and toxicity. Phytoplankton is a key trophic level in aquatic ecosystems, and the toxicity provoked by these nanoparticles can affect structure and function of the ecosystems. Two microalgae species, from freshwater (Chlamydomonas reinhardtii) and seawater (Phaeodactylum tricornutum) have been selected for testing toxicity of TiO2 NPs and TiO2 bulk form. Due to their photo-catalytic properties, UV-A effect was checked, also. TiO2 NPs and bulk TiO2 showed a relation between the size of agglomerates (homoagglomerates) and time in freshwater and saltwater but not in ultrapure water. Under both, UV-A and no UV-A treatments, NPs triggered higher cytotoxic responses than conventional bulk material. TiO2 NPs produced higher increasing in ROS production, damage to membrane and quantum yield. The marine microalgae species (P. tricornutum) showed to be more sensitive than the selected freshwater species and higher Ti internalization was reported. Exopolymeric substances (EPS) in the culture media are produced in presence of TiO2 NPs and bulk from microalgae, pointing out a possible defense mechanism, enhancing homoagglomeration and settling processes and reducing bioavailability. In order to assess environmental risk assessment in realistic conditions, UV radiation should be considered as key element in toxicity assay guidelines., This work was supported by Junta de Andalucía PE2011-RNM-7812 project, Spanish National Research Plan (MINECO) CTM2012-38720-C03-03 and FEDER funds European Union.

Trabajo presentado en el Scotland and Valencia workshop on Bayesian Statistics (ScoVa16 Workshop, VABAR), celebrado en Valencia el 28 y 29 de enero de 2016., Among others, proteomic research aims to identify and quantify relative changes in pro-tein abundance between individuals under different circumstances. In ecotoxicology, pro-teomics is applied to test organisms exposed to environmental contaminants, and is es-pecially useful for the evaluation of chronic low-level exposure effects that manifest atmolecular levels of organization. Obtained information can be used to better understandmetabolic pathways and networks the contaminant interferes with, providing a betterknowledge of the mode of action of the contaminant, as well as for contaminant specificbiomarker development for environmental monitoring purposes. In a laboratory-basedexperiment, we exposed the non-target marine bivalve, the Manila clamRuditapes philip-pinarumto an environmentally relevant concentration (0.75μg L−1) of weakly agglomer-ating citrate AuNPs (∼20 nm). An 8-plex iTRAQ-based bottom-up proteomic approachfollowed by tandem mass spectrometry led to the identification and quantitation of 2200expressed proteins. In order to identify statistically significant features, the obtained datawas analysed using multiple contrast analysis corrected by FDR aimed at the control ofthe proportion of false positives among rejected hypotheses. However, the experimentaldesign applied resulted in a higher number of variables than samples or observations lead-ing to an over-conservative approach. Alternatively, the restricted model regressions Lassoand Elastic-Net were applied to provide better information on what proteins differentiatebetween control and treated clams through penalization of the coefficients of the variablesthat are not associated with the response variable zero. Elastic-Net revealed 105 iden-tified proteins of which many were the same as those obtained using multiple contrasts.Ultimately, samples were classified after dimension reduction by PLS-DA. This provideda good classification of the samples, in which all variables are projected along the com-ponents creating the model. Several obtained proteins were related to oxidative stress,inflammatory response and cytoskeleton and correlated with several features identified inq-PCR gene expression analysis carried out on the same samples previously.

Trabajo presentado en el 10th Iberian Congress on Environmental Contamination and Toxicology y el 7th Iberoamerican Congress on Environmental Contamination and Toxicology (CICTA 2015), celebrados en Vila Real (Portugal) del 14 al 17 de julio de 2015., Engineered Gold nanoparticles (AuNPs) are introduced into a growing number of commercial products. Notwithstanding their promising applications, the increased likelihood of their release into environmental compartments and the resulting exposure on the species within needs to be met by an increased understanding of their behaviour and effects. Up to date limited information is available on the ecotoxicological risk for non-target organisms, with the majority of research focusing on magnified expectable environmental concentrations. In our laboratory-based study the bivalve Ruditapes philippinarum was chosen as a model to evaluate differential protein expression of citrate capped AuNPs (21.5 ± 2.9 nm) at an environmental relevant concentration (0.75 μg L-1). We used a 2nd-generation (iTRAQ-8plex) proteomic approach to identify and quantify differently expressed proteins in the digestive gland after 1 and 7 days of exposure in comparison to control organisms.The iTRAQ results demonstrate that the digestive gland is affected by environmentally relevant concentrations of citrate capped gold nanoparticles. Over 2500 proteins involved in a wide range of metabolic pathways and/or physiological processes were identified. Altered proteins may be useful as biomarkers of environmental nanoparticle pollution and provide insight about the mode of action of engineered gold nanoparticles.

Trabajo presentado en el 10th Iberian Congress on Environmental Contamination and Toxicology y el 7th Iberoamerican Congress on Environmental Contamination and Toxicology (CICTA 2015), celebrados en Vila Real (Portugal) del 14 al 17 de julio de 2015., The development of advanced analytical techniques have allowed to detect the occurrence and fate of pharmaceutical compounds in different matrixes such as ground water and sediment, either in their parent compound or in the form of metabolites. Many of these compounds have at least one asymmetrically substituted carbon atom and are, therefore chiral. There are very few studies about the chiral behavior of chemicals in the aquatic environment and the potential negative effects in the organisms. An example of these compounds is Ibuprofen (IB); a widely used nonsteriodal anti-inflammatory drug (NSAIDs). IB is formed by two enantiomer forms: R and S. In order to improve the knowledge about the different ecotoxicological effects that different enantiomeric forms can have in aquatic organisms, we performed a series of toxicity tests on the freshwater shrimp Atyaephyra desmarestii as model organism. A. desmarestii is widely distributed in clean freshwater bodies and has been successfully employed in pharmaceuticals ecotoxicity tests. Selected sublethal endpoints were osmoregulatory capacity and ingestion- and respiration rate as indicators of physiological changes. The shrimps were exposed at IB in its composite form and both enantiomeric forms at environmental relevant concentrations.Given that different enentiomers of a chiral compound can cause different biological effects or the presence of one enantiomer may inhibit the metabolism of the other, it is important know not only the fate but also the effect of these substances in non-target species to improve the environmental risk assessment of chiral compounds.

Trabajo presentado en el 10th Iberian Congress on Environmental Contamination and Toxicology y el 7th Iberoamerican Congress on Environmental Contamination and Toxicology (CICTA 2015), celebrados en Vila Real (Portugal) del 14 al 17 de julio de 2015., Titanium dioxide nanoparticles (TiO2 NPs) are widely used in multitude of applications and present a potential risk due to the release to the marine and freshwater systems.TiO2 NPs have been demonstrated to be toxic to unicellular algae, as they can be adsorbed or internalized by the cells. TiO2 NPs could induce toxicity to aquatic organisms through various mechanisms including physical damage, shading effect, oxidative stress and/or internalization. Surface interactions, such as adsorption of NPs oncells, are important toxicity mechanisms. One of the deleterious could be the increase of cell weight due to the adsorption of NPs, which would sink the floating cells out from the photic zone. On the other hand, different NPs can present different surface properties and aggregation states in the NP-cell suspensions, leading to different NP-cell heteroagglomerations. Water chemistry, such as pH and ionic strength (IS), can also influence the aggregation state of NPs and will thus influence the NPs-Cell.Since sizes of both microorganism cells and NPs aggregates are within the scale of colloids, the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory can be applied to analyze the colloidal behavior of NPs and cells in water. In this study, different freshwater and seawater species of microalgae were chosen in order to investigate interactions between algal cells and TiO2 NPs and TiO2 bulk, as well assedimentation rate of NPs, exposed and non exposed,cells in the water column. This is the first study specifically designed in order to check the NP-cell heteroagglomeration and cells sedimentation in water systems. Our findings show new light on bio-nano interaction.

Trabajo presentado en el 10th Iberian Congress on Environmental Contamination and Toxicology y el 7th Iberoamerican Congress on Environmental Contamination and Toxicology (CICTA 2015), celebrados en Vila Real (Portugal) del 14 al 17 de julio de 2015., Arsenic is a well known toxicant released into the environment through different industrial processes and agricultural usage which environmental concentrations normally between 1 and 10 μg/L reaching milligram concentrations in polluted areas. In the aquatic environment arsenic exists in different chemical forms being arsenate (Asv) is the most common form under oxic conditions. In the present study marine clam Scrobicularia plana was used as a model organism to investigate oxidative stress and bioaccumulation related to Asv exposure. Clams were exposed to two concentrations of Asv (10 and 100 μgL-1) for 14 days and samples were collected after a 1, 7 and 14 days of exposure. Antioxidant biomarker including glutathione S-transferase (GST), glutathione reductase (GR), glutathione peroxidase (GPX), aceticholinesterase (AchE) and superoxide dismutase (SOD) as well as lipid peroxidation (LPO) in gills and digestive glands were analyzed. .SOD activity increased in both tissues after one day of exposure to the highest concentration of Asv . A significant decrease in AchE and GR activities was observed in gills after seven days at both concentrations. Also GR activity decreased in digestive gland at the day 14. On the other hand, GST, GX and LPO didn’t show any significant alteration over time. The results indicate that exposure to environmental concentrations of Asv can induce oxidative stress. The concentration of Asv was determined in clam digestive gland: S. Plana showed a moderate bioaccumulation ability when exposed to both concentrations of Asv. .

Trabajo presentado en el 10th Iberian Congress on Environmental Contamination and Toxicology y el 7th Iberoamerican Congress on Environmental Contamination and Toxicology (CICTA 2015), celebrados en Vila Real (Portugal) del 14 al 17 de julio de 2015., Sediments represent the main sink for pollutants and depending on environmental conditions they can be a source of contaminants to water column. On the other hand, sediments are a component of aquatic ecosystems providing feeding, rearing and spawning areas for multitude of organisms. To establish the quality of sediments and the behavior of contaminants is a challenge for assessing environmental quality and the health of ecosystems. Sediment toxicity testing and bioassays have been defined in restrictive way and they can be applied using different approaches (e.g. evaluate the effect of the contaminants after spiking to artificial or natural sediments or evaluate the effect of the environmental contamination collecting sediments from the field). In both cases, the objective is getting a deeper insight into the biological effects of spiked contaminants or pollutant mixture, respectively. In this presentation both approaches will be considered under the umbrella of sediment toxicity testing. The use of uncommon species (phytobenthos), behavioral response, the effect of geochemical properties to biological responses, the development of sediment quality guidelines and the employment of sediment toxicity tests for assessing the acidification process on metal mobilization have been examined. In summary, sediment toxicity testing is an essential tool to establish the environmental quality of ecosystems and to define strategies for their management in a sustainable way.

Trabajo presentado en el 18th International Symposium on Pollutant Responses in Marine Organisms (PRIMO 18), celebrado en Trondheim (Noruega) del 24 al 27 de mayo de 2015., Hydrothermal vents are extreme environments rich in biodiversity. The polychaete Branchipolymoe seepensis subsists in the palleal cavity of the mussel vent Bathymodiolus azoricus. These scale-worms absorb metal particles deposited in mussel gills surface and their presence has been associated with local environmental characteristics. The goal of this work was to establish a host-symbiont relationship between these two species using oxidative stress as an endpoint in response to metal accumulation., This study is included in the project DEEPFun PTDC/MAR/111749/2009 and NANOECOTOX PTDC/AAC- AMB /121650/2010, funded by Foundation of Science and Technology (FCT).

Trabajo presentado en la SETAC Europe 25th Annual Meeting (Environmental protection in a multi-stressed world: challenges for science, industry and regulators), celebrada en Barcelona del 3 al 7 de mayo de 2015., The production of manufactured nanomaterials has risen exponentially in recent years. Despite this growth, information regarding the fate and behavior of nanoparticles (NPs) in freshwater and marine aquatic ecosystem is still limited. Whiteness, opacity and being a potent photocatalyst are just some of the features that make TiO2 perfect for a wide range of consumer applications such aspaints, coatings, plastics, papers, printing inks, roofing granules, food, medicine, toothpaste, cosmetics and skin-care products(including topical sunscreens). Studies suggest that anatase and rutile have different photocatalytic properties, being anatase more photocatalytic than rutile. However, the mixture of both is the most photocatalytic form of them. In this research, on one hand we have used anatase/rutile NPs with particle size of ≤100 nm, while on the other hand we have used conventional or bulk TiO2. The aim of the current study was to assess the toxicity of TiO2 in an aqueous solution. Two aspects were studied under laboratory conditions, I) NPs and Bulk TiO2 behavior with and without microalgae and II) quantification of intracellular and extracellular NPs and Bulk TiO2. The experiment was performed for two types of microalgae Phaeodctylum tricornutum and Chamydomonas reinhardtii, seawater and freshwater respectively. Both studies were carried out under light (UV-illumination) and white light. As regards TiO2 behaviour, aggregation was accelerated by UV irradiation and ionic strength due to salinity of sea water. UV irradiation is the cause of the formation of hydroxyl groups, which change surface charge and aggregation. Moreover, the presence of algal cells affects the stability of TiO2suspensions. Both, nano and bulk TiO2 formed aggregates during incubation, but NPs TiO2 formed large aggregates trapped almost completely between algae more than bulk TiO2 did. The dispersion of NPs in seawater is likely to be more difficult than in freshwater. It is reasonable to assume that the mechanisms of toxicity of NPs on marine organisms are more complex. Furthermore, the trend of quantification of intracellular and extracellular TiO2 was similar. Within 72 hours of interaction period under UV and white light conditions, a greater proportion of NPs TiO2 was found in the supernatant compared to the surface and interior of the cell. However, the highest concentration of extracellular and intracellular TiO2 showed up with NPs TiO2 under UV conditions.

Trabajo presentado en la SETAC Europe 25th Annual Meeting (Environmental protection in a multi-stressed world: challenges for science, industry and regulators), celebrada en Barcelona del 3 al 7 de mayo de 2015., The effects of pharmaceuticals are usually conducted at non-target species, evaluating a single compound at a time and at fixed environmental conditions; in addition most studies focus on one phase of the life cycle. Although the effects of emergent compounds may not significantly affect larval stages, larval experience may influence juvenile performance and the likelihood of successfully recruitment to the adult population.The objective of this study was to evaluate the effect of single vs mixture toxicity of two pharmaceuticals, Sodium diclofenac (DS) and Clofibric Acid (CA), on larval and juvenile stages of the non-target saltmarsh species Palaemon varians. Experiments also consider the effect of pharmaneuticals and daily variation in temperature with another pharmaceutical more, clotrimazole (CLZ), in order to test whether this compound has similar toxic effect than on Palaemon serratus larvae. We considered cyclic variations in temperature because larvae develop commonly in saltmarshes where water temperature may vary considerably at the daily scale. The individual exposure of DS and CA at environmental concentrations (10 and 20 μg/L) did not have any effect on survival and duration of development. The effects of these PhCs on larvae appeared with the mixture of DS and CA at intermediate doses (234 and 194 μg/L): this mixture increased the duration of development and intermoult duration required to reach the first juvenile stage. The mixture also reduced growth rates at 18ºC leading to a reduction in body mass . At daily variation of temperature, the mixture of the three compounds (DS, CA and CLZ) at intermediate doses increased duration of development and at high doses also decreased larval growth rate and larval body mass. CLZ had toxic effects similar to P. serratus larvae: increased duration of development, decreased growth rate and larval body mass under daily variation of temperature. Some effects of pharmaceuticals appeared later during juvenile phase. This study manifested the importance to test environmental risk assessment taking into account species specific habitat conditions, the mixture of different emergent compounds and consider more than one stage on Non-target Organisms with complex life cycle., Financial support to EGO was given by Marie Curie fellowship and SCARCE (Consolider-Ingenio 2010 CSD2009-00065).

Trabajo presentado en la SETAC Europe 25th Annual Meeting (Environmental protection in a multi-stressed world: challenges for science, industry and regulators), celebrada en Barcelona del 3 al 7 de mayo de 2015., According to the European Water Framework Directive, the assessment of the ecological status of freshwater systems is based on biological, physicochemical and hydromorphological quality. Some studies have observed that biological status is not always in coherence with chemical status, maybe due to the adaptation mechanisms of aquatic organisms under chronic chemical exposure. In these situations, ecotoxicity tests could be useful to resolve these divergences. The use of effect-based monitoring tools has been mentioned in the context on the Common Implementation Strategy (CSI) focused on regulated substances, which involves that many substances are not considered and their contributions to toxicity are lacking. The general aim of this study is to design a methodology to categorize the ecotoxicological status of rivers. The specific aims are: to compare the effectiveness of different ecotoxicity tests performed with freshwater sediments; to evaluate the relation between ecological status, pollutant concentent, their bioavailability, and water and sediment ecotoxicit y; and to develop a general methodology to evaluate the relative contribution of the main pollutants to the toxicity in order to improvemanagement tools. Two sampling campaings were carried out in 2013 and 2014 within the Ebro River (Spain) watershed. Therteen composite samples of sediments were collected and data on the chemical and ecologycal status has been achieved. The ecotoxicity of pore water and whole sediments was evaluated by Vibrio fischeri, Nitzschia palea, Pseudokirshneriella subcapitata, Daphnia magna and Chironomus riparius. In addition, the trace metals bioavailability was calculated by a sequential extraction according to the BCR method. To distinguish the potentially toxic fraction associated to trace metals burden of sediments, an analysis of acid-volatile sulphide and simultaneously extracted metals was performed. The results indicate that the ecotoxicological approach in most of the analyzed sediments is in agreement with their ecological status. This study demonstrates that the integration of chemical, biological and ecotoxicological analyses could be crucial to understand the hazard of pollutants in aquatic ecosystems, especially, in freshwater sediments. Moreover, it corroborates that cost-effective and rapid screening short-term bioas says could be useful to determine the surface water ecotoxicological status.

Trabajo presentado en el ImageNano 2015 (Bringing together Nanoscience and Nanotechnology), celebrado en Bilbao del 10 al 13 de marzo de 2015., The increasing use of nanomaterials in industrial applications for the last decade implies an increase of the concern about potential toxic effects of released engineered nanoparticles to the environment. In fact, aquatic ecosystems are the main receptors of chemical pollution, including nanoparticles. Surface waters and, to a greater extent, oceans, will be the final receptors for all wasted NPs (Fabrega et al., 2011; Gong et al., 2011; Whiteley et al., 2013). The transition from freshwater to estuarine and marine ecosystems represents drastic changes in ionic strength, organic matter and other physicochemical properties, which affect to particle propertiesand their fate and behavior. Nevertheless, knowledge about the effects and the mechanisms of toxicity of the different NPs on the aquatic and, over all, marine biota is quite far away to be complete (Boxall et al.; 2007; Baun et al., 2008; Chinnapongse etal., 2011; Walters et al., 2014). Toxicity of metallic nanoparticles to aquatic organisms seems to be related to the physical and chemical properties of those nanoparticles as well as their behavior in aquatic media where dissolution, aggregation and agglomeration processes occur. These ones affect to metal bioavailability. In this study a review of fate, behavior and toxicity of metallic nanoparticles is carried out taken in account the differences between fresh and marine environment with special emphasis on phytoplankton., This work has been funded by the projects PE2011-RNM-7812 Junta Andalucía and CTM2012-38720-C03-03 Plan Nacional Investigación (MINECO).

Trabajo presentado en el 18th International Symposium on Pollutant Responses in Marine Organisms (PRIMO 18), celebrado en Trondheim (Noruega) del 24 al 27 de mayo de 2015., Lucky Strike hydrothermal vent field is the largest known vent in the Mid-Atlantic Ridge (MAR), characterized by fluids that reach temperatures of 330ºC at 1,700m deep and by high amounts of metals (e.g. Cd, Cu, Fe, Hg, Mn and Zn). The vent polychaete Branchipolynoe seepensis lives in the palleal cavity of the mussel dominant species Bathymodiolus azoricus, cleaning the gills surface from particles in excess. This scale-worm is found more frequently inside the host mussel compared to other scale-worms, probably related with local environmental characteristics. Polychaetes are a very good trace-metal bioindicators, accumulating metals directly related with local metal bioavailability. The aim of this study was to understand the changes in protein expression of the membranar subproteome of polychaetes B. seepensis in response to metal concentration characteristics of Lucky Strike vent sites. Mussels were collected from two sites from Lucky Strike Hydrothermal vent field, Montségur-MS and Eiffel Tower-ET, during BIOBaz mission in August 2013 and polychaetes separated from the mussels. Subcellular fractionation was performed by sequential centrifugation of polychaetes tissues and 2D-SDS-PAGE applied to the membranar subproteome. Metal concentrations were also determined in polychaetes cellular and subcellular fractions by ICP-OES. Protein expression signatures show significant differences in 471 protein spots for B. seepensis between the two vent sites, with 11 specific for Montségur and 382 specific for Eiffel Tower. Common proteins to both sites with the higher change in expression (2-fold or higher) were selected to be identified by MALDI-TOF. Metal concentrations in the cellular (insoluble) and subcellular (thermo labile and heat-stable compounds) fractions were higher in ET and MS, respectively. Data suggests that metal concentrations from both sites reflect the environmental fluctuations between the two microhabitats within the same vent field and are related with the changes found at the subproteome level.

Trabajo presentado en el 14th Deep-Sea Biology Symposium, celebrado en Aveiro del 31 de agosto al 4 de septiembre de 2015., Lucky Strike is the biggest hydrothermal vent field located in the Mid-Atlantic Ridge (MAR) at 1, 700m de pth, characterized by fluid chemistry with high metal concentrations (e.g. Cu, Fe, Mn and Zn), low pH and temperatures of 330ºC. The polychaete Branchipolynoe seepensis live in the palleal cavity of the mussel dominant species Bathymodiolus azoricus. B.seepensis is known by clean the mussel gills surface from particles in excess and its presence is above 85% in Lucky Strike vent field. The aim of this study was to understand, at a membranar subproteome level, if the presence of B.seepensis in vent mussel B.azoricus is a response to high metal concentrations in Lucky Strike vent sites (Montsegur-MS and Eiffel Tower-ET). Mussels and polychaetes were collected from Lucky Strike hydrothermal vent field (MS and ET), in August 2013, aboard the vessel “Pourquoi Pas?”. Subcellular fractionation of polychaetes and mussel gills was performed and 2D-SDS-PAGE applied to the membranar subproteome. Metal concentrations (e.g. Ag, Cd, Cu, Fe and Zn) of both species were also determined in cellular and subcellular fractions by ICP-OES. Protein expression signatures showed significant differences, suggesting intra variation in Lucky Strike field. For B. seepensis 471 different proteins were detected between the two vent sites, 11 specific for MS and 382 specific for ET and 71 and 67 specific proteins for B.azoricus for MS and ET, respectively, out of a total of 176. Common proteins to both sites with the higher change in expression (2-fold or higher) were identified by MALDI-TOF. Metal concentrations in the cellular (insoluble) and subcellular (heat-stable compounds) fractions were higher for both species in ET and MS, respectively. Data suggests that the different metal concentrations found in these species from both sites reflect the environmental chemical fluctuation between the two microhabitats within the same vent field and are related with the changes at the subproteome level. For B.seepensis protein changes are clear, suggesting that polychaetes from ET contain specific proteins that help to deal with excess of metals, regulating the metal accumulation in themussel gills.

Trabajo presentado en el 14th Deep-Sea Biology Symposium, celebrado en Aveiro del 31 de agosto al 4 de septiembre de 2015., Hydrothermal vent biology has been studied in an attempt to understand the mechanisms involved in vent organisms that permit their survival and reproduction in extreme conditions. Symbiosis is very important for the subsistence of these deep-sea organisms. The scale-worm Branchipolymoe seepensis lives in the palleal cavity of the mussel vent Bathymodiolus azoricus, the dominant species in the MAR. Polychaetes are known to absorb particles in excess deposited in mussel gills and at the same time get protection. The aim of this study was to understand the metal accumulation in this symbiosis relationship. Mussels B. azoricus were collected from two sites from Lucky Strike Hydrothermal vent (1700m), Montségur-MS and Eiffel Tower-ET and from Rainbow-Rb hydrothermal vent (2300m) where B. seepensis is present. To compare the interaction between both species, mussels were also collected from Menez Gwen hydrothermal vent (MG2, MG3 and MG4) (850m) where polychaetes are not present. Induction of metallothionein (MT) and lipid peroxidation (LPO) levels were higher in polychaetes from Rb and MS vent sites, while in mussels were higher in the gills followed by the digestive gland and mantle in all vent fields. Enzymatic activities (CAT and GST) showed that mussels had higher CAT activity in digestive gland, followed by gills and mantle, while GST levels were higher in gills. In polychaetes , both CAT and GST activities were higher in ET. Metal concentrations (Ag, Cd, Co, Cu, Fe, Mn and Zn) in the cellular and subcellular fractions determined in mussels tissues and polychaetes whole body by ICP-OES suggest intra-and inter-variation of fluid chemistry between hydrothermal vent sites. The subcellular metal partitioning in polychaetes was higher in insoluble and soluble (thermolabile and heat-stable) fractions from ET, MS and Rb, respectively. In mussel tissues, me tal partitioning was higher in gills and digestive gland. Overall, the data suggest that the presence of the scale-worm is an adaptation to the elevated metal concentrations present in vent sites.

Trabajo presentado en el 10th Iberian Congress on Environmental Contamination and Toxicology y el 7th Iberoamerican Congress on Environmental Contamination and Toxicology (CICTA 2015), celebrados en Vila Real (Portugal) del 14 al 17 de julio de 2015., CO2 capture and storage in sub-seabed geological formations is proposed as one of the potential options to mitigate the abrupt and irreversible consequences of climate change. However, possible CO2 leakages could occur during the injection and sequestration procedure, provoking significant repercussions on marine environment. In this study, we investigate the toxicity effects of acidification derived from possible CO2 leakage events on the European green crab, Carcinus maenas. To this end, a lab-scale experiment involving direct release of CO2 through marine sediment was conducted at expected scenarios of pH values for this kind of events. Crabs were exposed for 10 days to sediments collected from two different coastal areas, one with relatively uncontaminated sediments (RSP) and the other with known contaminated sediments (MZ and ML), under the pre-established pH conditions (8.0-6.1). End points measured were: survival rate, histopathological damages and metal accumulation (Fe, Mn, Cu, Zn, As, Cr, Cd and Pb) in gills and hepatopancreas. Significant associations were observed between pH and the histological damage. Organic matter and organic carbon content as well as Fe, Mn, Cr, Pb, Cd and PAHs concentrations in sediment presented significant correlation coefficients with the damage to gills and hepatopancreas and metal accumulation in both tissues. The results obtained in this study revealed the importance of sediment properties in the biological effects caused by possible CO2 leakage events derived from the implementation of this mitigation option. However, a clear pattern was not observed between metal accumulation in tissues and pH reduction. Animal ́s avoidance behaviour and tolerance degree to acidification may are confounding factors to assess metal bioaccumulation. Further research to find a suitable organism battery, which allows us to predict the possible consequences on human health derived from metal bioaccumulation associated to high CO2 conditions, is required.

Trabajo presentado en el 2nd Marine NanoEcoSafety Workshop (MANET), celebrado en Palermo el 17 y 18 de noviembre de 2014., Gold nanopar ticles (AuNPs) h ave unique physical and chemical properties and are therefore used and developed for a wide r ange of novel applications in medicine, biology and chem istry. However in recent years concern has been raised over their ability to enter cells, organelles and n uclei, and provoke oxidative stress. In a laboratory-based experiment the non -t arget marine bivalve Ruditapes philippinarum was used as a model organismo Uptake, elimination and molec ular effects of ~20 nm citrate AuNPs at 0.75 Ilg 1-1 were studied over 7 days exposure and equal length elimination periodo Our results demonstrate that the AuNPs were readily taken up into the digestive glan d > gilIs. We further observed limited oxidative stress and inflammatory responses. The activity of several antioxidant en zy mes was increased in an organ sp ecific manner, with the digestive gland ex.hibiting the majority of its enzyme activity within 2,1 hours of exposure. Gene expression analysis highlighted the involvement of inflammatory re sponse genes in digestive gland tissue, as measured by changes in T NF-a and Gadd45 expression. Suggesting that one m echanism of citrate AuNP toxicity i5 well described by the oxidative stress par adigm. Further a significant elimination of Au from the digestive tract within t he purification period was observed, with excretion being an important pathway. In conclusiol1, wh ile not producing significant oxidative dam ag e, concern is rajsed regardi ng the effects of ch ronic AuNP exposure.

Trabajo presentado en la Final SCARCE International Conference (River Conservation Under Water Scarcity: Integration of water quantity and quality in Iberian Rivers under global change), celebrada en Tarragona el 20 y 21 de octubre de 2014., According to the European Water Framework Directive (WFD), assessment of surface water status is based on ecological and chemical status that not always are in coherence. In these situations, ecotoxicity tests could help to obtain a better characterization of the ecosystems. The general aim of this work was to design a cost-effective methodology to study the ecotoxicological status of freshwater systems that could be useful and complementary to ecological status defined by the WFD by applying a quality triad integrating chemical, physicochemical, biological and ecotoxicological data. The specific aims of this work have been: (1) to compare the effectiveness and viability of different ecotoxicity tests performed with freshwater sedimen ts (whole sediment and pore water) taking as target organisms different aquatic species, and (2) to evaluate the relationship between ecological status, pollutant concentrations (paying special attention to metals availability), and pore water and sediment ecotoxicity. For this purpose, sediments from thirteen sampling sites within the Ebro river watershed (NE Spain) were collected for ecotoxicity characterization. The ecotoxicity of pore water has been evaluated employing the test organisms Vibrio fischeri, Pseudokirschneriella subcapitata and Daphnia magna, while whole sediment ecotoxicity was evaluated using Vibrio fischeri, Daphnia magna, Nitzschia palea and Chironomus riparius. An analysis of acid-volatile sulfide (AVS) and simultaneously extracted metals (SEM) was performed to evaluate the sediment toxicity associated to bioavailable metals. Moreover, data about priority pollutants defined by the WFD in wate r, sediment and fish as well as data of surface water status of each sampling point were provided by the Monitoring and Control Program of the Ebro Waterbodies. In general terms, whole sediment bioassay s have shown more toxicity than pore water tests. Among the different organisms used, P.subcapitata and C. riparius were the most sensitive in pore water and whole sediment, respectively. Our evaluation of th e ecotoxicological status showed high coincidences with the ecological status, established according to the WFD, especially when ecosystem disruption due to numerous stressors (presence of metals and organi c pollution) was observed. These results allow us to confirm that, when chemical stressors affect the ec osystem functioning negatively, an ecotoxicological approach, provided by suitable bioassays in pore water and whole sediment, could be able to detect these changes with accurate sensitivity., Authors would like to thank the Spanish Ministry of Economy and Competitiveness for its financial support through the project SCARCE (Consolider-Ingenio 2010 CSD2009-00065).

Trabajo presentado en el 18th International Microscopy Congress (IMC-2014), celebrado enn Praga del 7 al 12 dse septiembre de 2014, Because of their prospective widespread use, gold nanoparticles (AuNPs) will certainly accountfor a considerable and persistent nanomaterial input to environmental systems. Thereforeecotoxicological risks in non target organisms associated with AuNPs are showing increasingconsideration. Location of AuNPs has been previously studied in our laboratory analyzing slicesof gills and digestive gland tissues of the bivalbe Ruditapes philippinarum after “in vivo”exposure experiments. Analysis was carried out by TEM of ultrathin tissue’s slices (80 nm)operating at 80 kV [1].In this communication we present the results of investigating the use of an “in vitro”methodology associated to the optimization of the STEM-in-SEM technique for the use of ascanning electron microscope (SEM-FEG) in transmission mode and operated at 20-30 kV.The advantages of STEM-in-SEM over TEM are discussed [2, 3]. The localization of high Znanoparticles in low Z tissue matrices is presented here by using the STEM-in-SEM coupled toEDX analysis as a powerful technique. In addition we have optimized the measurements withthe goal of working with thicker slices. The work with thick samples also avoid the NPsdisplacement during cutting and increase the possibility of finding NPs when working with lowNPs doses (environmental relevant concentrations).For the optimization of measurements conditions, the resolution in our SEM-FEG has beenestimated using Fast Fourier Transform (FFT) algorithms on specific images of our tissue slices.We have used the SMART macro running inside the “SCION Image” program under windows [4,5]. Working at magnifications over 100 kx, for slices thicknesses of 200-300 nm and operatingvoltages of 20-30 kV, leads to resolutions below 10 nm (an adequate value for analyzing AuNPsof 23 nm average diameter).Figure 1 shows a representative image of AuNPs accumulated into the gill tissues after “invitro” exposures. From the obtained images it was possible to localize AuNPs (see also Figure2) associated with vesicles (it can be a large phagosome or also exocytosis). Nanoparticleswere also found in residual bodies (exocytosis).In summary this communications presents new results for “in vitro” fast testing andSTEM-in-SEM imaging of engineered AuNPs in a tissular ecotoxicity model., The authors gratefully acknowledge financial support from the Junta de Andalucia and EU FEDER (project PE2009-FQM-4554 and TEP-217) and the EU FP7AL-NANOFUNC project (CT-REGPOT2011-1-285895).

Trabajo presentado en el XVII Seminario Ibérico de Química Marina (evento que une al IV Congreso de Ciencias del Mar, IV Simposio Internacional de Ciencias del Mar y al Encuentro de la Oceanografía Física), celebrado en Las Palmas de Gran Canaria del 11 al 13 de junio de 2014., The development of the nanotechnology has promoted the use of metal nanoparticles (MNPs) and nano-materials (NMs) for a wide range of areas and applications. In the daily life are being extensively used inhousehold products (cosmetics or sunscreens) or in industrial uses (paints, catalysts, coatings, packagingmaterial, electronics, etc.). Since the NMs are in continuous growth, the emerging market is estimates toexceed one trillion dollars by 2015 (DEFRA, 2007).Nanoparticles (NPs) occurrence in the environment might cause adverse effects over the ecosystemshealth and consequently, these effects need to be assessed. Ecotoxicological methods should be de-veloped in order to assess the NPs risks. Their effect over life is largely influenced not only by theirinteraction with the surrounded aquatic media but also by the physico-chemical properties of the NPs.In aquatic media, the NPs mostly tend to be dissolved in their ions or to suffer different aggregations,which largely determines its toxicity. The extent of this aggregation mainly is dependent on the surfacecharge, particles morphology (shape and size), pH and the ionic strength of the medium. In seawater theincreasing salinity, and therefore ionic strength, reduces the negativity of electrophoretic mobility of theparticles to encourage aggregation (Batley et al., 2013).Most studies have been conducted with freshwater species such asDaphnia magna(Lovern and Kapler,2006) andPimephales promelas(Zhu et al., 2006). Unfortunately, in spite of the high importance intothe trophic structure of ecosystems, just a few marine species and photosynthetic organisms (Navarro etal., 2008) have been checked in these kind of studies.Traditionally, gold nanoparticles (AuNPs) have been widely considered as non-toxic particles althoughtheir potential toxicity has not been fully assessed, yet. On the opposite, the toxicity of the silver nanopar-ticles (AgNPs) has raised an increasing attention. Some of the most important factors related to thetoxicity of both types of NPs are the oxidative stress and the effect on DNA, lipids and certain metabolicactivities (Lapresta-Fernandez et al., 2012). Therefore, an ecotoxicity study was carried out for some living species in the presence of AgNPs,dissolved silver (Agdis) and silver-gold alloy nanoparticles (AuAgNPs). Interestingly, by modifyingthe NPs composition, the toxicity of the NPs can be fine-tuned. In order to assess the toxicity ofAgNPs and Agdis, a 72 hours exposure testing growth inhibition was performed over two marine di-atoms species (Phaeodactylum tricornutumandCylindrotheca closterium) and two freshwater microal-gae species (Chlamydomonas reinhardtiiandNitzschia palea). Moreover, AuAgNPs toxicity responseswere studied inP. tricornutumandN. palea.The results show AgNPs toxicity (in terms of EC50) is smaller with Agdis for all species tested. HigherEC50 is also observed in marine species.N. paleais the most sensitive species (EC50Agdis = 0.081±0.017μM and EC50AgNP = 0.707±0.198μM); whileC. closteriumis the most resistant species(EC50Agdis = 0.043±1.074μM and EC50AgNP = 2.219±0.159μM). In the case of AuAgNPs, theEC50 values found for the random species studied are 3.286±1.217μM for N. palea and 0.990±0.231μM forP. tricornutum.