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Plastic pollution in oceans and rivers is of growing concern. Aquatic ecosystems play an important role in transport and storage of plastic waste from land-based storage to riverine and marine environments. This focus issue brings together new insights on the sources, transport dynamics, fate, and impact of plastic pollution through aquatic environments. The work collected in this focus issue shows that urban areas, transportation infrastructure, and wastewater treatment plants are consistently identified as sources for micro-, meso-, and macroplastics. Transport dynamics of plastics over land and through rivers were found to be driven by human factors, flood and storm events, and hydrodynamics, and combinations thereof. Most plastics were found not to make it to the open sea, but rather beach, float in coastal waters, or accumulate on land and within river systems. When exposed to the environment, both conventional and biodegradable plastics degrade into smaller pieces. Yet, the degradation and fragmentation of plastics in the environment remain unresolved. Future work should focus on transferability of new river and region specific insights, collection and exploration of large-scale and novel datasets, source and entry point identification, and understanding fundamental transport mechanisms. This focus issue provides new insights on sources, transport, fate, and impact of plastics, but also emphasizes that need for further work on plastics in aquatic ecosystems.

Small microplastics (SMPs) in the gulf of Cadiz was sampled at 5 m depth by pumping it through the ship's pipe system and filtered through a 45 mu m mesh size net. Our study reveals that higher densities have been found (130 mg.m(-3)) compared to other regions worldwide and these densities decreased from the coastline to the outer stations, showing a general coastal gradient influenced by estuarine outflows. SMPs with a size range between 45 and 193 mu m were predominant and most of them composed by polyethylene and polypropylene. The metals associated with the MPs were mainly Na (21.1%), K (11.3%), Fe (8.5%), Ca (2.1%), Cr (1.8%), Zr (13.3%) and Hf (0.7%). The high proportion of Zr compared to Fe, which is different from what can be found in the environment

En el actual trabajo de fin de grado se realiza un estudio de la transmitancia en el espectro del UV y la luz azul de diferentes lentes oftálmicas blancas y de distintas categorías solares, con la finalidad de comprobar que cumplan con la normativa ISO8980-3:2003. Para este fin se ha empleado el espectrorradiómetro LI-COR1800, con el cual se han podido hacer medidas de transmitancia entre los 300 y los 1100 nm. Todos los resultados serán representados a través de gráficas comparativas que se comentarán e interpretarán. Las transmitancias espectrales medidas en el laboratorio señalan que diferentes materiales protegen en mayor o menor medida contra la radiación UV. Los filtros de luz azul son más eficaces en las longitudes de onda más cortas, y no específicamente para las emitidas por los dispositivos electrónicos. Solo una de las lentes oftálmicas probadas presentaba protección contra la región infrarroja. Este hecho podría ser muy relevante, ya que la mayoría de las lentes son tintadas y presentan valores bajos de transmitancia en el rango visible provocando una dilatación pupilar., This undergraduate thesis presents a study of the transmittance of UV and blue light of different ophthalmic lenses. White ophtalmic lenses and different solar categories are tested to check if they comply with ISO8980-3:2003 standard. For this purpose, the LI-COR1800 spectroradiometer is used, measuring spectral radiation between 300 and 1100 nm. All the results will be represented by comparative graphics, which will be discussed and interpreted. The spectral transmittances measured in lab point out different materials protect in greater or lesser extent against UV radiation. Blue light filters are more efficient at shorter wavelengths, not specifically for those wavelengths emitted from electronic devices. Only one of the ophthalmic lenses tested presented protection against the infrared region. This fact could be extremely relevant since most of the lenses are tinted and present low transmittance values in the visible range causing pupil dilation., Departamento de Física Teórica, Atómica y Óptica, Grado en Óptica y Optometría

La economía colaborativa ha tenido un gran crecimiento en los últimos años, especialmente en el transporte y alojamiento colaborativo, los cuales son claves para un sector estratégico como es el turismo. Su importancia es tal que se ha producido una transformación completa de este sector. El desarrollo de la economía colaborativa y su impacto en el turismo comenzó antes de la pandemia, pero se ha visto ralentizada por ella desde el año 2020. Por todo ello, el objetivo principal que se persigue con la siguiente investigación es obtener una panorámica general de la economía colaborativa, y en especial del alojamiento colaborativo, estudiando su relación con el turismo y su situación actual., Grado en Marketing e Investigación de Mercados

El principal objetivo de este TFG es determinar las diferencias entre diferentes fotómetros (CIMEL, PFR y SP1A) situados en un mismo lugar, Ny-Ålesund. También, se determinan las diferencias entre dos fotómetros, CIMEL, situados en dos localizaciones cercanas, Ny-Ålesund y Hornsund. Se presentan en este trabajo comparaciones entre las diferentes estimaciones del espesor óptico del aerosol (AOD) y del exponente de Ångström (AE) tomadas de la base de datos del proyecto europeo Rehearsol en Ny-Ålesund y Hornsund. Se ha tomado como fotómetro de referencia el CIMEL situado en Ny-Ålesund. En el periodo de 2017 al 2018, se observa una sobreestimación del AOD del PFR y una subestimación del AOD del SP1A respecto al de referencia. En cambio, en el caso del AE se obtienen valores en ambos fotómetros, PFR y SP1A, superiores a los del CIMEL. Las comparaciones entre el CIMEL situado en Ny-Ålesund y el situado en Hornsund determinan que, en el periodo de estudio (2017-2020), los valores de AOD son mayores en Hornsund mientras que los valores de AE son menores. Lo que indica que no se miden en ambas localizaciones las mismas masas de aire. Las tendencias observadas tanto anuales como mensuales desde el 2002 al 2020, no son estadísticamente significativas. Aunque, se aprecia una ligera disminución de los valores del AOD en la mayor parte de los instrumentos y longitudes de onda analizados. Se puede concluir que existe una buena concordancia entre los datos obtenidos en los diferentes fotómetros analizados., The main goal of this study is to analyse the differences between the measurements using different collocated photometers (CIMEL, PFR y SP1A) in Ny-Ålesund base. In addition, the differences between two CIMEL photometers situated at two nearby locations, Ny-Ålesund and Hornsund, are determined. A comparison between different estimations of the Aerosol Optical Depth (AOD) and the Ångström Exponent (AE) are shown in this study. Both have been taken from the european proyect Rehearsol’s data base in Ny-Ålesund and Hornsund. The CIMEL from Ny-Ålesund has been used as a reference photometer. In 2017-2018 PFR measured an overestimation in AOD over the reference, meanwhile an underestimation was observed by SP1A. But three instruments present an uncertainty inside the AOD limits established by the World Meteorology Organization. The AE was overestimated in both PFR and SP1A instead. In addition, it has been verified that the exact same air masses were not measured in Ny-Ålesund and Hornsund due to the comparison between the different CIMELs. In the study period, 2017-2020, AOD values are higher in Hornsund while AE values are lower. The trends observed both annual and monthly from 2002 to 2020 are statistically negligible. Even though a slight decrease in AOD is shown in most of the analysed instruments and wavelengths., Departamento de Física Teórica, Atómica y Óptica, Grado en Física

Plastic pollution in the natural environment is causing increasing concern at both the local and global scale. Understanding the dispersion of plastic through the environment is of key importance for the effective implementation of preventive measures and cleanup strategies. Over the past few years, various models have been developed to estimate the transport of plastics in rivers, using limited plastic observations in river systems. However, there is a large discrepancy between the amount of plastic being modelled to leave the river systems, and the amount of plastic that has been found in the seas and oceans. Here, we investigate one of the possible causes of this mismatch by performing an extensive uncertainty analysis of the riverine plastic export estimates. We examine the uncertainty from the homogenisation of observations, model parameter uncertainty, and underlying assumptions in models. To this end, we use the to-date most complete time-series of macroplastic observations (macroplastics have been found to contain most of the plastic mass transported by rivers), coming from three European rivers. The results show that model structure and parameter uncertainty causes up to four orders of magnitude, while the homogenisation of plastic observations introduces an additional three orders of magnitude uncertainty in the estimates. Additionally, most global models assume that variations in the plastic flux are primarily driven by river discharge. However, we show that correlations between river discharge (and other environmental drivers) and the plastic flux are never above 0.5, and strongly vary between catchments. Overall, we conclude that the yearly plastic load in rivers remains poorly constrained.

Fragments of microplastics (< 5mm) found in commercial species of fish, crustaceans, and bivalves, are an issue of global concern. The bioaccumulation of microplastics and other anthropogenic particles in different levels of the food web may provoke unwanted impacts on marine ecosystems and cause pernicious effects on human health. Here, we study the presence of anthropogenic particles and the fraction of microplastics in the target organs of two representative commercial fish species in Spain; the European anchovy (Engraulis encrasicolus) and the European pilchard (Sardina pilchardus). The individuals were sampled along the continental shelf of the Gulf of Cádiz, from the Bay of Cádiz to Cape Santa Maria. The isolation of the microplastics (MPs) was carried out with a complete alkaline-oxidant organic digestion (KOH-H2O2) of the digestive tract, including both the contents ingested and the muscle tissues. Anthropogenic particles were found in all individuals of both species with an average of 8.94 ± 5.11 items·ind-1. Fibres made up 93 % of the items while fragments and films were represented by the remaining 7 %. The average size of the anthropogenic particles was 0.89 ± 0.82 mm. In addition to the fragment and film particles identified as microplastics, 29 % of the fibres were estimated to be microplastics by Fourier-transform infrared spectroscopy (FTIR) analysis. The main polymer found in both species was nylon. No significant correlation was found between the abundance and size of anthropogenic particles ingested and individual size or other body variables. The analysis of similarities (ANOSIM) and the distanced-based multiple linear regression model showed a high homogeneity in anthropogenic particle contamination in both species throughout the study area along the continental shelf of the Gulf of Cádiz.

Fragments of microplastics (<5 mm) found in commercial species of fish, crustaceans, and bivalves, are an issue of global concern. The bioaccumulation of microplastics and other anthropogenic particles in different levels of the food web may provoke unwanted impacts on marine ecosystems and cause pernicious effects on human health. Here, we study the presence of anthropogenic particles and the fraction of microplastics in the target organs of two representative commercial fish species in Spain; the European anchovy (Engraulis encrasicolus) and the European pilchard (Sardina pilchardus). The individuals were sampled along the continental shelf of the Gulf of Cádiz, from the Bay of Cádiz to Cape Santa Maria. The isolation of the microplastics (MPs) was carried out with a complete alkaline-oxidant organic digestion (KOH-H2O2) of the digestive tract, including both the contents ingested and the muscle tissues. Anthropogenic particles were found in all individuals of both species with an average of 8.94 ± 5.11 items·ind−1. Fibres made up 93 % of the items while fragments and films were represented by the remaining 7 %. The average size of the anthropogenic particles was 0.89 ± 0.82 mm. In addition to the fragment and film particles identified as microplastics, 29 % of the fibres were estimated to be microplastics by Fourier-transform infrared spectroscopy (FTIR) analysis. The main polymer found in both species was nylon. No significant correlation was found between the abundance and size of anthropogenic particles ingested and individual size or other body variables. The analysis of similarities (ANOSIM) and the distanced-based multiple linear regression model showed a high homogeneity in anthropogenic particle contamination in both species throughout the study area along the continental shelf of the Gulf of Cádiz.

During the preparation of the Supplementary Data spreadsheet “S. Data 3_Regression data,” the mean and median confidence intervals (CI) of FML (items yr−1) were misplaced in relation to their corresponding river names. The Supplementary Data file has now been updated in the HTML version of the article. This update does not alter the results or conclusions of this article.