Estudio de acumulación de metales pesados en los sedimentos de jaulas de peces de crianza y en puertos de la isla de Tenerife

La contaminación medioambiental es un problema que afecta a todos los países del mundo. Entre los contaminantes ambientales, los metales se consideran uno de los grupos más significativos y preocupantes. Los metales pesados en los ecosistemas acuáticos y en concreto en los ecosistemas marinos, se consideran un riesgo debido a su carácter acumulativo y a su toxicidad. En la isla de Tenerife, las actividades que más contaminación generan o pueden generar en sus costas, son la acuicultura y las actividades portuarias. Para el análisis del impacto producido por estas actividades, en este estudio se lleva a cabo por un lado un estudio granulométrico de los sedimentos y por otro un análisis de los metales pesados (Cd, Co, Cr, Cu, Mn, Ni, Pb y Zn) de los sedimentos bajo jaulas de acuicultura, puertos y playas colindantes a puertos en la islas de Tenerife. Los puntos de muestreo, se establecieron en el nordeste y suroeste de la isla, por ser los lugares donde se encuentran los mayores puertos con actividad de la isla. Cada punto de muestreo contiene 28 muestras: 10 muestras superficiales de 0-2.5 cm, 10 muestras en profundidad de 2.5 a 5 cm y 8 muestras correspondientes un perfil de 0 a 20 cm, dividido en partes de 2.5 cm. En las actividades de acuicultura (nordeste y suroeste), se establecen dos puntos de muestreo, un punto de impacto situado bajo las jaulas y otro control alejado al menos a un kilómetro contracorriente de las jaulas. En el puerto situado en el nordeste (Puerto de Santa Cruz de Tenerife) se establecieron 6 puntos de muestreo dentro del puerto y 4 en las playas colindantes, estableciendo dos puntos de muestreo como zona control en el Espacio Protegido de Anaga. Para el puerto del suroeste (Puerto de Los Cristianos) y debido a su menor extensión se tomaron 3 puntos de muestreo dentro del puerto, 6 puntos en las playas colindantes y 2 puntos de muestreo como zona control en el Espacio Protegido de La Caleta. En el caso de la acuicultura, las muestras localizadas en el impacto presentaron una granulometría más degradada, con mayor proporción de finos. En el caso del área nordeste, la concentración de Cd, Cr, Cu y Ni era más alta en el punto de impacto que en el control, siendo la concentración de Co, Mn, Pb y Zn, más alta en el punto de control que en el impacto. Tan solo se encontraron diferencias significativas entre el Cu y Mn entre ambos puntos. En el caso del suroeste, existe una mayor concentración de Cd, Co, Cr, Cu, Ni, Pb y Zn en el punto de impacto que en el control, siendo tan solo el Mn más alto en el punto de control que en el de impacto. En el suroeste se demostraron diferencias significativas entre el control y el impacto para Co, Cr, Cu y Ni. En cuanto a los puntos de muestreo de puertos y playas colindantes, se encontraron 3 comportamientos predominantes: el primero (menos finos en superficie y mayor diámetro eficaz) correspondiente a los puntos en donde existían una compactación natural del terrenos y no existen alteraciones por estar influenciados por los diques; el segundo (más finos en superficie, y menor diámetro eficaz) correspondiente a los puntos donde existe una continua resuspensión de las partículas más finas por el funcionamientos de las turbinas de los barcos; el tercer con proporciones parecidas de finas y mismo diámetro eficaz causado por el continuo oleaje existente en las playas. La concentración de metales (Cd, Co, Cr, Cu, Ni, Pb y Zn) en el entorno portuario del nordeste era mayor en el puerto que en sus playas colindantes, excepto para el Mn. La menor concentración de estos metales se encontraba en los puntos de control. En cuanto al área suroeste, la zona portuaria presenta mayor concentración de Cr, Cu, Ni y Pb, presentando las playas colindantes a los puertos una mayor concentración de Cd, Co, Mn y Zn. Del mismo modo que en el nordeste, en el suroeste también encontramos la menor concentración de metales en los puntos de control en el espacio protegido

Recycled wastewater as a potential source of microplastics in irrigated soils from an arid-insular territory (Fuerteventura, Spain)

In this work, the occurrence of microplastics (MPs) in irrigation recycled wastewaters (RWWs) and a desalinated brackish water (DBW) from the arid territory of Fuerteventura (Canary Islands, Spain) was studied. Besides, the presence of MPs in two types of soils (sandy-loam and clay-loamy; with no mulch film or fertilization with sewage sludge applied) irrigated with both water qualities was addressed. Results showed the prevalence presence of cellulosic and polyester microfibers (between 84.4 and 100%) of blue and transparent colors (up to 55.6 and 33.3%, respectively), with an average length of 786.9 ± 812.1 μm in the water samples. DBW had the lowest MP concentration (2.0 ± 2.0 items·L−1) while RWW showed concentrations up to 40.0 ± 19.0 items·L−1. Similarities were also observed between the MPs types and sizes found in both soils top layer (0–5 cm), with an average concentration three times greater in soil irrigated with RWW than in soil under DBW irrigation (159 ± 338 vs. 46 ± 92 items·kg−1, respectively). In addition, no MPs were extracted from non-irrigated/non-cultivated soils, suggesting agricultural activities as the unique source of MPs in soils of this arid area. Results show that RWWs constitute a potential source of MPs in irrigated soils that should be considered among other pros and cons linked to the use of this water quality in agricultural arid land

Microplastics in snow of a high mountain national park: El Teide, Tenerife (Canary Islands, Spain)

Human activities have introduced high amounts of microplastics (MPs) into the atmosphere that can be transported long distances and be later deposited in terrestrial and aquatic ecosystems with precipitation (rain or snow). In this work, it has been assessed the presence of MPs in the snow of El Teide National Park (Tenerife, Canary Islands, Spain, 2150–3200 m above sea level) after two storm episodes (January–February 2021). The data set (63 samples) was divided into three groups: i) samples from “accessible areas” (after the first storm episode and in places with a strong previous/recent anthropogenic activity); ii) “pristine areas” (after the second storm episode, in places with no previous anthropogenic activity), and iii) “climbing areas” (after the second storm episode, in places with a soft recent anthropogenic activity). Similar pattern profiles were observed among sampling sites in terms of morphology, colour and size (predominance of blue and black microfibers of 250–750 μm length), as well as in composition (predominance of cellulosic -either natural or semisynthetic-, with a 62.7 %, polyester, 20.9 %, and acrylic, 6.3 %, microfibers); however, significant differences in MPs concentrations were found between samples collected in pristine areas (average concentration of 51 ± 72 items/L) and those obtained in places with a previous anthropogenic activity (average concentration of 167 ± 104 and 188 ± 164 items/L in “accessible areas” and “climbing areas”, respectively). This study shows, for the first time, the presence of MPs in snow samples from a high altitude protected area on an insular territory and suggests that the sources of these contaminants could be atmospheric transport and local human outdoor activitie

Microplastics determination in gastrointestinal tracts of european sea bass (Dicentrarchus labrax) and gilt-head sea bream (Sparus aurata) from Tenerife (Canary Islands, Spain)

Microplastic pollution has an extremely widespread distribution, to the extent that microplastics could be ingested by aquatic organisms, including species of commercial importance for fisheries and aquaculture. In this work, the anthropogenic particles content of the gastrointestinal tracts of 86 individuals of cultivated European sea bass (Dicentrarchus labrax, n = 45) and gilt-head sea bream (Sparus aurata, n = 41) from Tenerife (Canary Islands, Spain) was determined. Samples were bought at local markets and directly transported to the laboratory. After the dissection of the fishes and digestion of the gastrointestinal tracts in 10% KOH (w/v) at 60◦C for 24 h, the digests were filtered (50 µm stainless-steel mesh) and visualized under a stereomicroscope, finding that most of the items were colourless (47.7% for Dicentrarchus labrax and 60.9% for Sparus aurata) and blue (35.3% vs. 24.8%) microfibers, with an average length of 1957 ± 1699 µm and 1988 ± 1853 µm, respectively. Moreover, 15.3% of the microfibres were analysed by Fourier transform infrared spec-troscopy, showing the prevalence of cellulosic fibres together with polyester, polyacrylonitrile, and poly(ether-urethane). This pattern (microplastics shapes, colours, sizes, and composition) clearly agrees with previous studies carried out in the Canary Islands region regarding the determination of microplastics in the marine environmen

Teor de metais pesados nas lamas de tratamento de águas residuais: estratégia de gestão para uma ilha oceânica

In recent years, the generation of sewage sludge has increased worldwide. Correct processing and management of this waste concerns all countries. This work presents a study of metal contents, i.e. of Cd, Pb, Zn, Cr, Cu, and Ni, in sewage sludge from a wastewater treatment plant in the northeastern region of the island of Tenerife. The study aimed at examining the sludge for potential suitability as a farmland fertilizer. Detected metal levels for Pb, Zn, Cr, Cu, and Ni were extremely low (26.44, 544.01, 24.10, 37.05, and 8.04 mg/kg dw [dry weight], respectively). Cadmium levels were under quanti cation limit. Season-dependent, statistically significant differences (p < 0.05) in metal concentrations in sewage sludge were observed for Cu, Ni, Cr, and Pb. Consequently, the application of sewage sludge to fertilize nutrient-deficient agricultural soils and soils degraded by human activity represents a fast and straightforward solution to the lack of such resources, particularly in an oceanic island.Durante los últimos años, la generación de lodos de depuradora ha aumentado en todo el mundo. El tratamiento y la gestión correctos de estos residuos son una cuestión que afecta a todos los países. Este trabajo presenta un estudio del contenido de metales, i.e. Cd, Pb, Zn, Cr, Cu y Ni, de los lodos de depuradora de una planta de tratamiento de aguas residuales situada en la zona noreste de la isla de Tenerife. El estudio tuvo por objeto estudiar los lodos para ver su posible idoneidad como fertilizante agrícola. Los niveles de metal detectados para Pb, Zn, Cr, Cu y Ni fueron extremadamente bajos (26,44, 544,01, 24,10, 37,05 y 8,04 mg/kg [peso seco], respectivamente). Los niveles de cadmio quedaron por debajo del límite de determinación. Se observaron diferencias dependientes de las estaciones que son estadísticamente significativas (p < 0,05) en las concentraciones de Cu, Ni, Cr y Pb. Por consiguiente, el uso de lodos de depuradora para fertilizar suelos agrícolas que son pobres en nutrientes o que han sido degradados por la actividad humana es una solución rápida y sencilla a la escasez de tales recursos, particularmente en islas oceánicas.Nos últimos anos, a produção de lamas de águas residuais aumentou em todo o mundo. O tratamento e a gestão corretos deste resíduo são uma preocupação de todos os países. Este trabalho apresenta um estudo sobre os teores de metais, ou seja, Cd, Pb, Zn, Cr, Cu e Ni, em lamas duma estação de tratamento de águas residuais no nordeste da ilha de Tenerife. O estudo teve como objetivo analisar as lamas quanto à sua potencial adequação como fertilizante de terras agrícolas. Os níveis de metais detetados para Pb, Zn, Cr, Cu e Ni foram extremamente baixos (26,44, 544,01, 24,10, 37,05 e 8,04 mg/kg dw [peso seco], respetivamente). Os níveis de cádmio estavam abaixo do limite de quantificação. Foram observadas diferenças, estatisticamente significativas (p < 0,05), dependentes da estação do ano nas concentrações de Cu, Ni, Cr e Pb. Consequentemente, a aplicação de lamas para fertilizar agriculturas, solos deficientes em nutrientes e solos degradados pela atividade humana representa uma solução rápida e direta para a insuficiência de tais recursos, particularmente numa ilha oceânica

Microplastic pollution in sublittoral coastal sediments of a North Atlantic island: The case of La Palma (Canary Islands, Spain)

In this work, the microplastic content of sediments collected in July 2020 between 5 and 7 m depth was studied in four locations of La Palma island (Canary Islands, Spain). At each sampling location, three samples were taken parallel to the shoreline. The microplastic content in each sampling corer was studied every 2.5 cm depth after digestion with a H2O2 solution followed by flotation in a saturated NaCl solution. Visualization of the final filtrates under a stereomicroscope revealed that all the sediment samples evaluated contained mostly microfibers (98.3%) which were mainly white/colorless (86.0%) and blue (9.8%), with an average length of 2423 ± 2235 (SD) mm and an average concentration of 2682 ± 827 items per kg of dry weight, being the total number of items found 1,019. Fourier Transform Infrared microscopy analysis of 13.9% (n = 139) of the microfibers also showed that they were mainly cellulosic (81.3%). No significant differences were found between the depths of the sediment. However, significant differences were found between the number of fibers from the sampling sites at the east and west of the island. Such variability could be driven by the winds and ocean mesoscale dynamics in the area. This study confirms the wide distribution of microfibers in sediments from an oceanic island like La Palma, providing their first report in marine sediments of the Canary Islands.En prensa3,20

Caracterización de la biomasa de distintas especies de algas, enfocadas al consumo incluyéndolas en alimentos funcionales.

Comunicación en formato posterEn un contexto actual que dificulta el abastecimiento de la población de una manera sostenible, encontramos la necesidad de desarrollar nuevos sistemas de producción de alimentos, apostando en este caso por las algas. Éstas son una fuente segura y ambientalmente sostenible de alimentos y compuestos bioactivos con un alto valor nutricional. Este estudio se enmarca en el contexto del Proyecto ALGAHUB (TED2021- 131555B-C22). Dentro de dicho proyecto, la UMA trabaja en coordinación con la UCA en uno de los subproyectos, enfocado a la innovación y desarrollo de alimentos funcionales en un formato atractivo para el consumidor. Concretamente nuestro grupo se dedica a la caracterización de la composición interna de las algas, en busca de las más interesantes a nivel nutricional y funcional. Por su parte, UJA y UAL van a centrar sus esfuerzos en optimizar las tecnologías de producción a gran escala de la biomasa.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Hypothyroidism confers tolerance to cerebral malaria

The modulation of the host’s metabolism to protect tissue from damage induces tolerance to infections increasing survival. Here, we examined the role of the thyroid hormones, key metabolic regulators, in the outcome of malaria. Hypothyroidism confers protection to experimental cerebral malaria by a disease tolerance mechanism. Hypothyroid mice display increased survival after infection with Plasmodium berghei ANKA, diminishing intracranial pressure and brain damage, without altering pathogen burden, blood-brain barrier disruption, or immune cell infiltration. This protection is reversed by treatment with a Sirtuin 1 inhibitor, while treatment of euthyroid mice with a Sirtuin 1 activator induces tolerance and reduces intracranial pressure and lethality. This indicates that thyroid hormones and Sirtuin 1 are previously unknown targets for cerebral malaria treatment, a major killer of children in endemic malaria areas.This work was funded by grants SAF2017-83289-R to S.A. and A.A., SAF2017-90604REDT to A.A. supported by the The European Regional Development Fund (FEDER) and BIO2016-77430-R to J.M.B. from the Ministerio de Economía y Competitividad; B2017/BMD-3724 to S.A. and A.A. from the Comunidad de Madrid; and CIBERONC CB/16/00228 to A.A. from the Instituto de Salud Carlos III

A nationwide monitoring of atmospheric microplastic deposition

8 Pág.Plastic production continues to increase every year, yet it is widely acknowledged that a significant portion of this material ends up in ecosystems as microplastics (MPs). Among all the environmental compartments affected by MPs, the atmosphere remains the least well-known. Here, we conducted a one-year simultaneous monitoring of atmospheric MPs deposition in ten urban areas, each with different population sizes, economic activities, and climates. The objective was to assess the role of the atmosphere in the fate of MPs by conducting a nationwide quantification of atmospheric MP deposition. To achieve this, we deployed collectors in ten different urban areas across continental Spain and the Canary Islands. We implemented a systematic sampling methodology with rigorous quality control/quality assurance, along with particle-oriented identification and quantification of anthropogenic particle deposition, which included MPs and industrially processed natural fibres. Among the sampled MPs, polyester fibres were the most abundant, followed by acrylic polymers, polypropylene, and alkyd resins. Their equivalent sizes ranged from 22 μm to 398 μm, with a median value of 71 μm. The particle size distribution of MPs showed fewer large particles than expected from a three-dimensional fractal fragmentation pattern, which was attributed to the higher mobility of small particles, especially fibres. The atmospheric deposition rate of MPs ranged from 5.6 to 78.6 MPs m-2 day-1, with the higher values observed in densely populated areas such as Barcelona and Madrid. Additionally, we detected natural polymers, mostly cellulosic fibres with evidence of industrial processing, with a deposition rate ranging from 6.4 to 58.6 particles m-2 day-1. There was a positive correlation was found between the population of the study area and the median of atmospheric MP deposition, supporting the hypothesis that urban areas act as sources of atmospheric MPs. Our study presents a systematic methodology for monitoring atmospheric MP deposition.The authors acknowledge the support provided by Spanish Network of Plastics in the Environment, EnviroPlaNet (www.enviroplanet.net) and the financial support provided by the Spanish Government, Ministerio de Ciencia e Innovación, grants PID2020-113769RB-C21/C22. The authors would like to thank the Interdepartmental Investigation Research Service of the Universidad Autónoma de Madrid (SIDI-UAM and Segainvex) for the use of their infrastructures and their technical support. J.G.S. thanks ACIISI for the contract from the Viera y Clavijo program at the University of La Laguna (85 % co-financed by the European Social Fund).Peer reviewe

Arenas Blancas (El Hierro island), a new hotspot of plastic debris in the Canary Islands (Spain)

[EN] The present work has studied the incidence and type of micro (1-5 mm), meso (5-25 mm) and macroplastics (>25 mm) that have reached Arenas Blancas beach, located in the north coast of El Hierro island, in the Canary Islands (Spain), from October 2019 to May 2020 (13 sampling dates with 3 sampling points each). Taking into consideration the three studied plastic debris fractions (macro, meso and microplastics), a total of 9206 items were found, which had a total weight of 1169.7 g and a concentration of 891.3 ± 91.5 items/m2 (118.3 ± 17.8 g/m2 and 2.3 ± 0.4 g/L). Regarding their colour, most of them were transparent/white/clear, especially in the microplastic fraction in which they accounted for a 68% of the total. Attenuated Total Reflectance Fourier Transform Infrared spectroscopy of meso and microplastic fractions indicated that most of the particles were either polypropylene and polyethylene followed by polystyrene in a much lower amount. In general, the total amount of plastic debris that arrives to the beach by the persistent oceanic current pattern linked to the easternmost branch of the North Atlantic Subtropical Gyre is comparable to those of the most contaminated beaches of the Canary Islands archipelago, suggesting that a new hotspot of plastic debris arrival has been found.Authors would like to thank Julio Herrero Segura (Dirección General de Lucha Contra el Cambio Climático y Medio Ambiente del Gobierno de Canarias), Carlos Samarín Bello (Dirección General de Lucha Contra el Cambio Climático y Medio Ambiente del Gobierno de Canarias), Diana Porto Lozano (Gestión y Planeamiento Territorial y Medioambiental, Gesplan, S.A.), Javier Pérez González (Gesplan, S.A.) y Vicente Benítez Cabrera (Dirección General de Lucha Contra el Cambio Climático y Medio Ambiente del Gobierno de Canarias) for the sampling facilities. J.G.S. would like to thank “Cabildo de Tenerife” for the Agustín de Betancourt contract at the Universidad de La Laguna. Authors acknowledge financial support of the Transnational Cooperation Program Azores-Madeira-Canary Islands for the “IMPLAMAC” project (reference number MAC2/1.1a/265) financed with FEDER funds. Authors would also like to thank the “General Support Research Services (SEGAI)” of the Universidad de La Laguna as well as May Gómez and Alicia Herrera from the EOMAR group at the University of Las Palmas de Gran Canaria, and Andrea Brito from the Universidad de La Laguna.Peer reviewe