Coastal and marine pollution in the Anthropocene

The author would like to gratefully acknowledge financial support from the Basque Government through Consolidated Research Group GIC IT1743-22

Morphology and histology of the digestive gland of Oxychilus (Drouetia) atlanticus (Morelet & Drouët) (Gastropoda: Pulmonata).

Little information exists on the histology of Zonitidae digestive system. This study deals with a detailed characterization of the different types of cells comprising epithelium lining the digestive gland of 0xychilus atlanticus. From light and scanning electron microscope (SEM) studies, three types of differentiated cells can be identified in the digestive gland: digestive cells, excretory cells and calcium cells. Digestive cells are the most numerous, and are present in two forms, one believed to be absorbing food material and the other secreting material. Excretory cells are distinguished by having a large central vacuole, containing excretory granules. Calcium cells contain spherules of calcium salts, which have a characteristic birefringence

La enseñanza y aprendizaje de la Geología como vía para desarrollar el pensamiento y las actitudes positivas hacia la ciencia

Carmela García-Marigómez – Universidad de Valladolid - 0000-0002-2642-9265Vanessa Ortega-Quevedo – Universidad Complutense de Madrid - 0000-0002-5742-4678Cristina Gil Puente – Universidad de Valladolid - 0000-0001-5794-5564Recepción: 12.05.2023 | Aceptado: 07.06.2023Correspondencia a través de ORCID: Carmela García-Marigómez - 0000-0002-2642-9265Financiación: Fundación Española para la Ciencia y la Tecnología (FCT-19-14617)Agradecimiento: al Proyecto FECYT “Ciencia con consecuencia: la escuela y los maestros como fuente de cultura y vocaciones científicas” y al Grupo de Innovación Docente #PensaTIC de la Universidad de Valladolid.Área o categoría del conocimiento: Didáctica de las Ciencias ExperimentalesAbstract: The need to promote scientific literacy and the development of high-order capacities to provide a quality response to students in keeping with the new society has produced a growing interest in approaches that show contextualised science and in movements that promote learning to think to learn. Therefore, the objective of this project was to design materials and activities with scientific content from the inquiry point to favour these aspects and encourage vocation. The design to unite research and school reality has been mixed using the LeTiS scale and the qualitative analysis of the students’ production. The study results showed that the designed activities promoted the beginning development of scientific and thinking skills. In addition, it is considered that the proposal applied through a more lasting intervention can improve positive attitudes towards science. In conclusion, it is highlighted that the didactic resources developed were effective, allowing the improvement of the scientific culture and the creation of a culture of thought.Resumen: La necesidad de promover la alfabetización científica y el desarrollo de capacidades de orden superior para dar una respuesta de calidad al alumnado acorde a la nueva sociedad ha producido un creciente interés en enfoques que muestren una ciencia contextualizada y en movimientos que promuevan el aprender a pensar para aprender a aprender. Por lo tanto, el objetivo de este proyecto fue diseñar materiales y actividades de contenido científico desde la indagación para favorecer estos aspectos y, además, estimular las vocaciones. El diseño llevado a cabo para conseguir unir investigación y realidad escolar ha sido mixto a través del uso de la escala LeTiS y en análisis cualitativo de las producciones del alumnado. Los resultados del estudio mostraron que las actividades diseñadas promovían el inicio del desarrollo de destrezas científicas y del pensamiento. Además, se considera que la propuesta aplicada a través de una intervención más duradera puede mejorar las actitudes positivas hacia la ciencia. A modo de conclusión, se destaca que los recursos didácticos elaborados fueron eficaces permitiendo la mejora de la cultura científica y la creación de una cultura de pensamiento.Universidad de ValladolidUniversidad Complutense de Madri

Bioavailability and cellular effects of metals on Lumbricus terrestris inhabiting volcanic soils

Copyright © 2005 Elsevier Ltd. All rights reserved.Whether the radial thickness (RT) of the chloragogenous tissue and intestinal epithelium of earthworms (Lumbricus terrestris) reflects the bioavailability of metals in soils was investigated in two areas, one with active volcanism (Furnas) and another with no volcanic activity since 3 million years ago (Santa Maria), in the Azores. Metal contents in soil samples and earthworms from the two areas were analyzed. Autometallography and measurements of the RT were performed in the chloragogenous tissue and intestinal epithelium. Earthworms from the active volcanic area demonstrated lower RT of chloragogenous tissue and intestinal epithelium as well as higher levels of bioavailable metals, especially Zn and Cd. Comparison of bioavailable metal contents between both areas suggests a higher risk for uptake of potentially toxic metals in the active volcanic area than in the non-active volcanic area, which is reflected by the lower RT of the chloragogenous tissue and intestinal epithelium in the former.Centro de Investigação de Recursos Naturais (CIRN, University of the Azores), Direcção Regional da Ciência e Tecnologia (Government of the Azores), and the ETORTEK program from the Basque Government, through the BERRILUR project (IE03-110). André Amaral was supported by a PhD grant from Fundação para a Ciência e a Tecnologia (SFRH/BD/8186/2002)

Freshwater molluscs from volcanic areas as model organisms to assess adaptation to metal chronic pollution

Copyright © 2006 Elsevier B.V. All rights reserved.Cellular biomarkers of exposure and biological effects were measured in digestive gland of snails (Physa acuta) sampled in sites with 12 andwithout active volcanismin SãoMiguel Island (Azores).Metal content in digestive cell lysosomeswas determined by image analysis 13 after autometallography (AMG) as volume density of autometallographed black silver deposits (VvBSD). Lysosomal structural changes 14 (lysosomal volume, surface and numerical densities – VvLYS, SvLYS and NvLYS−, and surface-to-volume ratio – S/VLYS−) were 15 quantified by image analysis, after demonstration of β-glucuronidase activity, on digestive gland cryotome sections. Additional chemical 16 analyses (atomic absorption spectrophotometry) were done in the digestive gland of snails. The highestmetal concentrations were found 17 in snails from the active volcanic site, which agreed with high intralysomal VvBSD. Digestive cell lysosomes in snails inhabiting sites 18 with active volcanismresembled a typical stress situation (enlarged and less numerous lysosomes). In conclusion, the biomarkers used in 19 this work can be applied to detect changes in metal bioavailability due to chronic exposure to metals (volcanism), in combination with 20 chemical analyses.Centro de Investigação de Re- 430 cursos Naturais (CIRN, University of the Azores) and 431 Direcção Regional da Ciência e Tecnologia (Government 432 of the Azores) and by the Basque Government (ETOR- 433 TEK

Toxicopathic effects of waterborne Cd in sole juveniles, a prospective pollution monitoring sentinel for estuarine ecosystems

Introduction: Estuarine ecosystems are under high anthropogenic pressure and receive a wide Q7 variety of contaminants, including metals. They can remain trapped in estuarine sediments at high concentrations for long periods but eventually they can be released to the overlying water and become toxic for the resident benthic biota. As a consequence, biomonitoring programs surveying the health status of estuaries and coastal areas count with benthic species for the assessment of health disturbances in these specific ecosystems. The present investigation aims at recognizing toxicopathic effects elicited in estuarine life stages of the benthic fish Solea senegalensis on exposure to waterborne Cd, a model compound for metal contamination. Methods: Biological responses to metal exposure were assessed based on the application of a “biomarker + histopathology” approach. Two-year old sole juveniles were exposed to various concentrations of waterborne Cd for 3 and 7 days (Control; Low Cd: 1 µg/l; Mid Cd: 10 µg/l and High Cd: 1000 µg/l). Liver samples were collected for chemical analysis at day 7. Biological samples were collected at days 3 and 7 for biochemical (brain and liver), histochemical (liver) and histopathological analysis (liver, gills and gonad). Results: Brain acetyl cholinesterase was inhibited after 7 days exposure, indicating neurotoxic effects on exposure to 1000 µg Cd/l. Hepatic catalase and glutathione-Stransferase were induced at day 3 and inhibited at day 7, which suggests a bell-shaped response. A dose-dependent lysosomal membrane destabilization in hepatocytes was recorded at day 7. In parallel, histopathological lesions in gills, liver and gonad were more frequent at day 7 in soles exposed to high Cd concentrations. Discussion: Overall, the “biomarker + histopathology” approach revealed that waterborne Cd causes toxicopathic effects in sole juveniles upon exposure to environmentally relevant concentrations (10 µg Cd/l). The effects were clearly time dependent, and thus it is conceivable that more severe biological effects would be elicited by these low concentrations of Cd at longer exposure periods. Therefore, biomarkers and histopathology in combination provide early-warning indications of altered health status after waterborne Cd exposure in sole juveniles, a prospective sentinel for biological effects assessment of metal contamination in pollution monitoring programs in estuaries and coastal areas

Integrative biomarker assessment of the effects of chemically and mechanically dispersed crude oil in Pacific oysters, Crassostrea gigas

International audienceThe impact of dispersed crude oil and dispersant on adult Pacific oysters, Crassostrea gigas, was evaluated through an integrative biomarker approach including (1) biochemical (plasma catecholase- and laccase-type phenoloxidase and superoxide dismutase), (2) histological (digestive cell lysosomal responses, digestive gland histopathology) and (3) physiological (flesh condition index) endpoints in the haemolymph and digestive gland. Adult oysters were exposed to non-contaminated water (control), chemically-dispersed oil (Brut Arabian Light), mechanically-dispersed oil and dispersant (FINASOL®) alone for 2 days, and further depurated in noncontaminated water for 4 weeks. After exposure to chemically and mechanically dispersed oil oysters exhibited induction of plasma laccase-type phenoloxidase and superoxide dismutase activities, enlargement of digestive cell lysosomes, lipofuscin accumulation, reduced neutral lipid content and atrophy of digestive gland diverticula; more markedly on exposure to chemically dispersed oil. From the studied biomarkers, only lysosomal biomarkers were significantly affected after exposure to the dispersant alone. This included lysosomal enlargement, neutral lipid depletion and lipofuscin accumulation in the digestive gland epithelium. A recovery of plasma enzyme activities was observed after 4 weeks of depuration. The integrative biological response index indicated that chemically dispersed oil caused significantly higher stress to C. gigas than the mechanically-dispersed one or the dispersant alone; nevertheless, the response seems to be reversible after depuration

Biological Responses and Toxicopathic Effects Elicited in Solea Senegalensis Juveniles by Waterborne Exposure to Benzo[a]pyrene

Polycyclic aromatic hydrocarbons (PAHs) are priority contaminants in coastal and estuarine ecosystems under anthropogenic pressure. Although PAHs tend to accumulate in the sediment, toxicity for benthic flat fish such as soles may be caused by PAHs released from the sediment to the water column. Within this context, the present investigation aims at recognizing toxicopathic effects elicited after waterborne exposure to benzo[a]pyrene B[a] P, a model individual PAH compound, in juvenile Solea senegalensis. Sole juveniles were exposed to various concentrations of waterborne B[a]P for 3 and 7 days. Brain, liver, gills and gonad were the target tissues selected to determine biochemical and lysosomal biomarkers, and histopathology. Biological responses and toxicopathic effects were consistent with B[a]P concentration and exposure time. From day 3, hepatic catalase inhibition indicated potential oxidative effects of B[a]P. At day 7, contaminant exposure produced hepatic glutathione-Stransferase induction at low concentrations and inhibition at higher levels, evidencing a bell-shaped response. A clear gradient in lysosomal membrane destabilisation was observed in relation with B[a]P concentrations. Histopathological lesions were more frequent at day 7 and at higher contaminant levels. It seems that environmentally relevant waterborne concentrations of B[a]P (1000 ng/l) would suffice to cause toxicopathic effects on sole juveniles in relatively short exposure times. In agreement, the Integrative Biological Response index (IBR/n) indicated a dose-dependent decline in health condition upon exposure to B[a]P (IBR/nHighB[a]P > IBR/nMidB[a]P > IBR/nLowB[a]P > IBR/nDMSO > IBR/nControl). Overall, changes in antioxidant enzymes activity, lysosomal biomarkers and gill and liver histopathology are responsive early-warning signs of health disturbance in sole juveniles exposed to waterborne PAHs.This work was funded by Spanish MINECO (CTM 2012-40203-C02-01, DIAGNOseas-BMW), by the University of the Basque Country UPV/EHU (UFI 11/37) and by the Basque Government through Consolidated Research Groups Grant (IT810-B). TB profited from a PhD Scholarship provided by the Spanish MINEC

Influence of dispersant application on the toxicity to sea urchin embryos of crude and bunker oils representative of prospective oil spill threats in Arctic and Sub-Arctic seas

This study deals with the toxicity assessment of crude and bunker oils representative of prospective oil spill threats in Arctic and Sub-Arctic seas (NNA: Naphthenic North-Atlantic crude oil; MGO: Marine Gas Oil; IFO: Intermediate Fuel Oil 180), alone or in combination with a third-generation dispersant (Finasol OSR52). Early life stages of sea urchin, Paracentrotus lividus, were selected for toxicity testing of oil low-energy water accommodated fractions. A multi-index approach, including larval size increase and malformation, and developmental disruption as endpoints, was sensitive to discriminate from slight to severe toxicity caused by the tested aqueous fractions. IFO (heavy bunker oil) was more toxic than NNA (light crude oil), with MGO (light bunker oil) in between. The dispersant was toxic and further on it enhanced oil toxicity. Toxic units revealed that identified PAHs were not the main cause for toxicity, most likely exerted by individual or combined toxic action of non-measured compounds.The authors would like to gratefully acknowledge financial support from the European Union's Horizon 2020 research and innovation program EU H2020-BG-2005-2 under grant agreement No 679266 (project GRACE), from the Spanish Ministry of Education, Culture and Sport through pre-doctoral fellowship FPU15/05517, from the Spanish Ministry of Economy, Industry and Competitiveness through the project seaDIMENTOX (CTM2017-87766-R) and from the Basque Government through Consolidated Research Group GIC IT810-13 and IT1302-1