The aim of this study was to effectively remove Fe2+ by using ozone microbubbles in bottled mineral water to prevent sediment from occurring during storage and increase shelf life. By considering the characteristics of mineral water with low solubility of ozone and high CO2 content, a suitable ozone injection step was chosen and a new mineral water treatment method using microbubbles was proposed. As a result of the treatment of the bottled mineral water with ozone microbubbles, the concentration of the iron ion was reduced from 0.14 to 0.01 mg L-1, and the shelf life increased to 360 days. During the treatment, the concentrations of K+ and Na+ were almost unchanged, and the deposition time was reduced to one-third compared to the natural oxidation. Fe2 Fe CO content proposed 014 0 14 0.1 001 01 0.0 L1, L1 L 1, 1 L-1 36 days K Na unchanged onethird one third oxidation 0. 00 L- 3

Resumen La cuenca baja del río Acre se ubica en una zona de deforestación con la implementación de pastizales para ganado vacuno en suelos susceptibles a la erosión y clima ecuatorial. La existencia de mataderos y ganado vacuno en el municipio de Boca do Acre, en el estado de Amazonas, es uno de los problemas vinculados a la deforestación en la Amazonía brasileña. Ante este escenario, se presentó una estimación de las pérdidas de suelo con la aplicación de la Ecuación Universal en un sistema de información geográfica. En la metodología, se desarrolló una base de datos con información vectorizada para extraer las áreas de tipos de suelo y cobertura del suelo, incluyendo el análisis espacial de pendientes extraído del modelo digital de elevación. Como resultado del análisis de las áreas por geoprocesamiento y vectorización, se obtuvieron los cálculos de las parcelas de erosión a través de tablas con los parámetros adoptados por los referentes científicos. Se encontró que el 60% de la pérdida de suelo ocurre en el área agrícola en el 11% del territorio de la cuenca, siendo predominantemente en áreas de asentamientos rurales en el estado de Acre. Como resultado de la estimación, la pérdida de suelo en la cuenca baja del río Acre fue de 386.422 t/ha/año, con una producción de 46 millones de toneladas de sedimentos por año.

Abstract The Lower Acre River Basin is located in an area of deforestation with the implementation of pastures for beef cattle ranching in soils susceptible to erosion and equatorial climate. The existence of slaughterhouses and beef cattle in the municipality of Boca do Acre, in the state of Amazonas, is one of the problems linked to deforestation in the Brazilian Amazon. Given this scenario, an estimate of soil losses was presented with the application of the Universal Equation in a geographic information system. In the methodology, a database was elaborated with vectorized information for the extraction of the areas of the types of soils and land cover, including the spatial analysis of slopes extracted from the digital elevation model. Due to the analysis of the areas by geoprocessing occurring by vectorization, the calculations of the erosion plots were obtained through tables with the parameters adopted by the scientific references. It was found that 60% of the soil loss occurs in the area of agriculture in 11% of the territory of the watershed, being predominantly in areas of rural settlements of the state of Acre. As a result of the estimate, soil loss in the Lower Acre River Basin was 386,422 t/ha/year, with a production of 46 million tons of sediment per year.

Resumo A Bacia do Baixo Rio Acre está localizada em uma área de desflorestamento com implantação de pastagens para pecuária de corte em solos suscetíveis à erosão e clima equatorial. A existência de abatedouros e pecuária de corte implantada no município de Boca do Acre, no Amazonas, é um dos problemas vinculados ao desmatamento da Amazônia Brasileira. Diante desse cenário, foi apresentada uma estimativa de perdas de solo com aplicação da Equação Universal em sistema de informação geográfica. Na metodologia, foi elaborado um banco de dados com informações vetorizadas para extração das áreas dos tipos de solos e cobertura da terra, incluindo a análise espacial de declividades extraídas do modelo digital de elevação. Em decorrência da análise das áreas pelo geoprocessamento ocorrer pela vetorização, foram obtidos os cálculos das parcelas de erosão através de tabelas com os parâmetros adotados pelas referências científicas. Foi constatado que 60% da perda de solo ocorrem na área de agricultura em 11% do território da bacia hidrográfica, sendo predominantemente em áreas de assentamentos rurais do estado do Acre. Como resultado da estimativa, a perda de solos na Bacia do Baixo Rio Acre foi de 386.422 t/ha/ano, com uma produção de 46 milhões de toneladas de sedimentos por ano.

Abstract Introduction: Methanogenic archaea (MA), participate in the anaerobic mineralization of organic matter in mangrove sediments, their activity is related to atmospheric warming due to the production of methane; several environmental variables can influence the presence of MA and methane production in these sediments. Objective: To analyze, through culture-dependent techniques, viable methanogenic archaea (VMA) in the sediments, and the production of methane from acetate in different climatic periods in the mangrove El Morro-La Mancha, Veracruz, Gulf of Mexico. Methods: From May to November 2019, following a salinity transect, sediment samples from El Morro-La Mancha mangrove were collected at three locations, in three different climatic seasons, dry (May), rainy (October) and northern (November) (N = 9). VMA in the sediments was quantified using the Most Probable Number (MPN) technique with acetate and methanol as substrates. The influence of sulfate on methane production was analyzed from acetate in microcosm by gas chromatography and the chemical variables of salinity, pH, Eh, carbohydrates, organic content, and carbonates in the sediments were evaluated. Results: The abundance of VMA was 102 to 108 MPN/g of wet sediment, higher than that reported in other studies, this abundance was higher when methanol (104-108 MPN/g sediment) was used as substrate, compared to acetate (102-105 MPN/g sediment); methane production in the microcosms increased in sulfate-free conditions (29.78-929.75 nmol CH4/month) and in the sediments of the rainy season. Conclusion: The influence of the chemical conditions of the mangrove sediments on the methanogenic dynamics is highlighted, determining that in the rainy season, the decrease in salinity, more electronegative Eh, and the increase in organic fractions favored the methanogenesis.

Resumen Introducción: Las arqueas metanogénicas (MA) participan en la mineralización anaerobia de la materia orgánica en sedimentos de manglar, su actividad está relacionada con el calentamiento atmosférico por la producción de metano; diversas variables ambientales pueden influir en la dinámica metanogénica y la producción de metano en estos sedimentos. Objetivo: Analizar, mediante técnicas dependientes de cultivo, la abundancia de las arqueas metanógenas viables (AMV) y la producción de metano en diferentes épocas climáticas en los sedimentos del manglar El Morro-La Mancha, Veracruz, Golfo de México. Métodos: De mayo a noviembre 2019, siguiendo un transecto de salinidad, se recolectaron sedimentos del manglar del Morro-La Mancha, en tres localidades, abarcando tres diferentes épocas climáticas, secas (mayo), lluvias (octubre) y nortes (noviembre) (N = 9), cuantificándose la abundancia de las AMV mediante la técnica del Número Más Probable (NMP) con acetato y metanol como substratos; la influencia de los sulfatos en la producción de metano a partir de acetato en microcosmos, se analizó por cromatografía de gases y se evaluaron las variables químicas de salinidad, pH, Eh, carbohidratos, contenido orgánico y carbonatos en los sedimentos. Resultados: Se determinó una abundancia de AMV de 102 a 108 NMP/g de sedimento húmedo, superior a la reportada en otros estudios, dicha abundancia se incrementó cuando se utilizó metanol (104-108 NMP/g sedimento) como sustrato, en comparación con el acetato (102-105 NMP/g sedimento); la producción de metano en los microcosmos aumentó en condiciones libres de sulfatos (29.78-929.75 nmol CH4/mes) y en los sedimentos de la temporada de lluvias. Conclusión: Se destaca la influencia de las condiciones químicas de los sedimentos del manglar sobre la dinámica metanógena, determinándose que, en la temporada de lluvias, una disminución de la salinidad, Eh más electronegativos y el incremento de las fracciones orgánicas favorecieron la metanogénesis.

This study investigates the role of stable isotope ecology in unconsolidated sediment coastal systems, focusing on scientific production and research trends over time. Existing literature is analyzed to identify knowledge gaps and highlight the significance of stable isotope analysis in understanding coastal ecosystems. A comprehensive bibliometric analysis is employed, utilizing Scopus database to collect and categorize relevant publications on stable isotope ecology. Key indicators are focused on, including publication trends, authorship patterns, and the geographic distribution of research efforts. The temporal scale of studies is systematically analyzed, with attention given to methodological approaches used in these publications. Co-authorships networks and co-occurring keywords are examined to explore the intellectual structure of the field and identify collaborative patterns among authors. Over 140 publications are revealed, attributed to more than 400 researchers, with a significant increase in interest noted over time, particularly in trophic studies involving macrobenthos. Mudflats are identified as a focal point, receiving more attention than sandy beaches. The analysis indicates that seasonality is the predominant temporal scale, while mesoscale studies are observed to be more common in spatial investigations. A plateau in publication growth is noted, probably corresponding with the emergence of alternative methodologies for trophic ecology studies. Major contributions are attributed to France, the United States and Australia. Additionally, fragmented collaboration networks are illustrated through the co-authorship analysis, with limited international engagement among developing nations. Overall, the critical importance of stable isotope ecology in understanding coastal ecosystems is underscored, while the need for methodological diversity and increased collaboration in future research efforts is highlighted.

Abstract This paper presents the results of investigations in the archaeological locality Huaycondo located in the south of Punilla, Córdoba province, Argentina. The field research consisted of prospecting, test pits, and systematic excavations (using Harris matrix). The pottery and lithic material record recovered in one of the sectors, HUAY 2, was techno-morphologically approached and in the case of the ceramics also was stylistically analyzed. The results indicate that HUAY 1 was a roofed space based on the finding of holes that are linked to the placement of poles and a level of sediment compaction. In HUAY 2, activities like knapping, use, and discarding of lithic tools, manufacturing and consumption of pottery vessels and other objects made of clay associated with a level of sediment compaction were carried out. A defined compaction level was not identified in HUAY 3 therefore, the work would have to continue. In the three sectors of the site, radiocarbon dates belong to human occupations from the final late Holocene (ca. 1000-360 BP) were obtained. These domestic spaces, linked to various tasks of manufacturing, processing, consumption, use and disposal of ceramic, lithic, fauna and plant products, constitute forms of social reproduction with local and extra-regional community ties.

Resumen Este trabajo presenta los resultados de investigaciones en la localidad arqueológica Huaycondo, ubicada en el sur de Punilla, provincia de Córdoba, Argentina. La metodología de campo consistió en prospecciones, sondeos y excavaciones sistemáticas (mediante matriz de Harris). El registro material cerámico y lítico recuperado en uno de los sectores, HUAY 2, fue abordado tecno morfológicamente y para el caso de la cerámica, también se analizó estilísticamente. Los resultados indican que el sector 1 (HUAY 1) fue un espacio techado, a partir del hallazgo de orificios que se vinculan con la colocación de postes y un nivel de compactación del sedimento. En el sector 2 (HUAY 2), se llevaron a cabo actividades de talla, uso y descarte de instrumentos líticos, y de manufactura y consumo de recipientes cerámicos y otros objetos producidos en arcilla, asociados a un nivel de compactación del sedimento. En el sector 3 (HUAY 3) no se identificó un nivel de compactación definido, por lo que habría que continuar los trabajos. En los tres sectores del sitio se obtuvieron fechados radiocarbónicos pertenecientes a ocupaciones humanas del Holoceno tardío final (ca. 1000-360 AP). Estos espacios domésticos, vinculados a diversas tareas de manufactura, procesamiento, consumo, uso y descarte de productos cerámicos, líticos, faunísticos y vegetales, constituyen formas de reproducción social con vínculos comunitarios locales y extra-regionales.

ABSTRACT The rock-fluid interaction is associated with formation damage and occurs due to the introduction of foreign fluids that cause chemical and physical imbalances in the rock matrix and in the fluids insides, which reduces the permeability of formation The objective of the research is to evaluate properties of rock-fluid interaction in an improved recovery process. The research is developed on a laboratory scale with injection of chemical formulation, in search of alternatives for the improvement of oil production and the increase of the recovery factor of the reservoirs. Wettability tests and physical-chemical characterization of the injected fluids and effluents (total dissolved solids, density, conductivity, chloride, calcium, magnesium and pH) were carried out before and after contact with the formation. Based on determinations of density, water and sediment content, asphaltenes and rheological behavior, the characterization of the crude oil from the Seboruco well was carried out, as well as the layer water that was analyzed for its ionic composition and its classification. Such tests indicated a heavy and pseudoplastic crude oil, and a sodium hydrocarbonated layer water. The rock-fluid interaction tests showed significant changes in the wettability of the rock, from to oil-wet to water-wet. The analyzes of the effluents corroborated ionic exchange in the rock-fluid system such as: The increases in pH and increased content of chloride, calcium and magnesium obtained during the formulation step, which in some way favored the displacement of crude oil in the porous medium.

RESUMEN La interacción roca-fluido se asocia al daño de la formación y ocurre por introducción de “fluidos extraños” que causan desequilibrios químicos y físicos en la matriz de la roca y en los fluidos en su interior, lo que reduce la permeabilidad de la formación. La investigación tiene como objetivo: evaluar propiedades de interacción roca-fluido en un proceso de recuperación mejorada, a escala de laboratorio, con inyección de formulación química, en búsqueda de alternativas para el mejoramiento de la producción de petróleo e incremento del factor de recobro de los yacimientos. Se realizaron ensayos de mojabilidad y caracterización física y química de los fluidos inyectados y los efluentes (sólidos totales disueltos, densidad, conductividad, cloruro, calcio, magnesio y pH) antes y después del contacto con la formación. Sobre la base de determinaciones de densidad, contenido de agua y sedimento, asfaltenos y comportamiento reológico, se realizó la caracterización del crudo del pozo Seboruco y también del agua de capa que fue analizada en cuanto su composición iónica y su clasificación. Tales ensayos indicaron un crudo pesado y seudoplástico y el agua de capa del tipo hidrocarbonada sódica. Los ensayos de interacción roca-fluido evidenciaron cambios significativos en la mojabilidad de la roca, de oleohumectada a acuohumectada. Los análisis de los efluentes corroboraron intercambio iónico en el sistema roca-fluido como son: los incrementos de pH y aumento de contenido de cloruro, calcio y magnesio, obtenido al paso de la formulación, que en alguna forma favorecieron al desplazamiento del crudo en el medio poroso.

RESUMO Objetivou-se descrever os aspectos metodológicos, operacionais e atravessamentos políticos do projeto ‘Avaliação da contaminação ocupacional, ambiental e em alimentos por agrotóxicos na Bacia do Juruena, Mato Grosso (MT)’, realizado entre 2015 e 2019, em municípios de elevada produção agrícola voltada para o agronegócio: Campo Novo do Parecis, Sapezal e Campos de Júlio. Fundamentada na epidemiologia crítica, na vigilância popular e do desenvolvimento, a pesquisa participativa envolveu a população por meio de articulações com prefeituras, sindicatos e escolas públicas e trabalhadores(as) rurais e urbanos. Coletaram-se amostras de matriz ambiental (água, ar, sedimento), alimentar (hortaliças, commodities e animais) e humanas (sangue e urina) e realizou-se um inquérito populacional das condições de saúde autorreferidas, exposição ambiental, alimentar e ocupacional de trabalhadores(as) e moradores(as). Os dados revelaram um processo de contaminação impositiva em todo o território da bacia do rio Juruena, no ambiente, em alimentos, e o adoecimento agudo e crônico supostamente relacionado com a exposição ambiental e ocupacional aos agrotóxicos. O processo participativo na pesquisa almejou fortalecer a luta por territórios saudáveis e sustentáveis mediante redes cooperativas, vigilância popular de base territorial e das populações expostas aos agrotóxicos, além de outros desdobramentos que modifiquem legislações e processos destrutivos do atual modelo de desenvolvimento. Objetivouse Objetivou se metodológicos Avaliação Juruena MT, MT , (MT)’ 201 2019 agronegócio Parecis Júlio crítica desenvolvimento prefeituras trabalhadoresas trabalhadores as trabalhadores(as urbanos Coletaramse Coletaram água, água (água ar sedimento, sedimento sedimento) hortaliças, hortaliças (hortaliças animais sangue urina realizouse realizou autorreferidas moradoresas. moradoresas moradores . moradores(as) ambiente cooperativas (MT) 20 moradores(as (MT 2

ABSTRACT The aim was to describe the methodological, operational, and political aspects of the project ‘Assessment of occupational, environmental and food contamination by pesticides in the Juruena Basin, Mato Grosso (MT)’, carried out between 2015 and 2019 in municipalities with high agricultural production geared towards agribusiness: Campo Novo do Parecis, Sapezal, and Campos de Júlio. Based on critical epidemiology, popular and developmental surveillance, the participatory research involved the population through links with town halls, unions public schools, and rural and urban workers. Environmental (water, air, sediment), food (vegetables, commodities, and animals), and human (blood and urine) samples were collected, and a population survey was carried out on self-reported health conditions, environmental, food, and occupational exposure of workers and residents. The data revealed a process of imposing contamination throughout the territory of the Juruena River basin, in the environment, in food, and in acute and chronic illnesses supposedly related to environmental and occupational exposure to pesticides. The participatory process in the research aimed to strengthen the struggle for healthy and sustainable territories through cooperative networks, grassroots territorial surveillance, and populations exposed to pesticides, as well as other developments that modify legislation and destructive processes of the current development model. methodological operational Assessment Basin MT, MT , (MT)’ 201 agribusiness Parecis Sapezal Júlio epidemiology surveillance halls schools water, water (water air sediment, sediment sediment) vegetables, vegetables (vegetables commodities animals, animals animals) blood urine collected selfreported self reported conditions residents basin environment networks model (MT) 20 (MT 2

Verlorenvlei is a globally important RAMSAR wetland on the arid west coast of South Africa. A prolonged drought between 2016 and 2021 and increasing competition for water from the agricultural sector resulted in extremely low water levels. We used historical aerial and satellite imagery from 1942 and rainfall and water level data for the past 50 years, to assess habitat changes within the estuarine functional zone of the Verlorenvlei Estuarine Lake. Prior to the drought, lake water levels and water surface area remained stable (1113 ± 27 ha (SE)). Since then, there has been a 64% decrease in open water area, exposing 193 ha of sandbanks, of which 190.9 ha were hyper-sulfidic pyrite-rich. The water in the lower lake was hypersaline (>100), and in the middle, it was acidic (pH<3). The low water level plus sediment and nutrient input from surrounding agriculture resulted in a localised increase in reeds. Additional pressures, such as fires, have reduced the above-ground biomass of reeds and sedges, potentially altering surface morphology and reducing stored carbon. Despite flooding and filling up in June 2023, the lake remained in an acidic state (3.9-4.3). Similar low-lake level, hypersaline and acidic conditions are predicted to become more common under future climate change scenarios where aridity and extreme weather events are anticipated. Inflow of fresh water into the estuary and control of farming practices are required to keep the Verlorenvlei in a functional state, with long-term monitoring necessary to assess the ecological condition in response to restoration actions. SIGNIFICANCE: We assessed the habitat changes in Verlorenvlei, an estuarine lake on the arid west coast of South Africa. Estuarine lakes are scarce, and an extended drought greatly reduced the water surface area, exposing hyper-sulfidic pyrite-rich soils, leading to lake acidification and a negative response from biota. Competition for water from agribusiness and the burning of reeds are added pressures. Subsequent heavy rains have been slow to buffer lake acidity, and the impacts thereof serve as a warning for the management of similar ecosystems and their ecological water requirements, especially under climate change where extreme weather conditions, increased aridity and competition for water are realities.

Abstract Introduction Floods are a common phenomenon in flat ecosystems with deficiencies in river drainage, impacting the local and regional economy. They can be identified and analyzed by remote sensing. Objective The aim of this study was to evaluate the performance of two normalized water indices during periods of maximum and minimum annual precipitation for the identification of flooding in the Salado River Basin, Argentina. Materials and methods The years with maximum and minimum annual precipitation in the period 2001-2020 were derived from satellite estimates of monthly precipitation provided by NASA through Google Earth Engine. Floods were identified using Landsat images, applying two normalized water indices (NDWI -Normalized Difference Water Index- and modified NDWI) to evaluate their performance in generating binary images that better represent the reality of the study area. Results and discussion Both indices showed good capability in identifying permanent or semi-permanent watercourses and water bodies; however, only the NDWI demonstrated higher effectiveness in identifying flooded areas with shallow depths (5 to 15 cm). The use of the Landsat mid-infrared band (1 566 - 1 651 µm) is less sensitive to water sediment load and can reflect subtle differences in it, providing a greater ability to delineate the water-soil boundary. Conclusion The use of NDWI showed a suitable behavior for the identification of flooded areas in very low slope ecosystems

Resumen Introducción Los anegamientos son fenómenos frecuentes en ecosistemas llanos con deficiencias en el drenaje fluvial que afectan la economía local y regional. Estos pueden ser identificados y analizados mediante teledetección. Objetivo Evaluar el desempeño de dos índices normalizados de agua, en épocas de precipitación anual máxima y mínima, para la identificación de anegamientos en la cuenca del río Salado, Argentina. Materiales y métodos Los años con precipitación anual máxima y mínima en el periodo 2001-2020 se obtuvieron de estimaciones satelitales de precipitación mensual provistas por la NASA a través de Google Earth Engine. Los anegamientos se identificaron con imágenes Landsat, a través de la aplicación de dos índices normalizados de agua (NDWI, por sus siglas en inglés -Normalized Difference Water Index- y NDWI modificado) con la finalidad de evaluar su desempeño en la obtención de imágenes binarizadas que representen mejor la realidad del área de estudio. Resultados y discusión Ambos índices tuvieron buena capacidad para la identificación de los cursos y cuerpos de agua permanente o semipermanente; sin embargo, solo el NDWI demostró mayor capacidad para la identificación de áreas anegadas con escasa profundidad (5 a 15 cm). El empleo de la banda del infrarrojo medio de Landsat (1 566 - 1 651 µm) es menos sensible a la carga de sedimentos del agua y es capaz de reflejar diferencias sutiles en ella, lo que proporciona una mayor capacidad para delinear el límite agua-suelo. Conclusión El empleo del NDWI demostró un comportamiento adecuado para la identificación de zonas anegadas en ecosistemas de muy baja pendiente.

Abstract Introduction The lama-bordo systems (LBS) are built in natural watercourses and favor retention of sediment and runoff moisture for the development of agricultural activity. Objective To obtain a model for predicting the volume of soil permanently captured by LBS, based on the morphometric and hydrological characteristics of the micro-watersheds where they have prevailed in the Mixteca Alta of Oaxaca, Mexico Materials and methods The study was carried out in 27 sites where morphometric parameters and hydrological indexes were determined to obtain the volume prediction model by multiple linear regression (backward elimination technique). Results and discussion The systems studied were found in micro-watersheds under conditions that favor sediment transport: elongated shape, areas smaller than 2 km2 with 1st and 2nd order streams, at altitudes above 2 000 m and slopes greater than 10 %. Twelve morphometric parameters and three hydrological indexes characterize these micro-watersheds and explain the physical conditions that allow their establishment, but only four (micro-watershed area, average slope of the mainstream, topographic wetness index and sediment transport index) explain the cumulative sediment volume (R2 = 0.85, P < 0.001). Conclusions The model evaluated for volume estimation is reliable for application at sites under similar conditions.

Resumen Introducción Los sistemas lama-bordo (SLB) se construyen en cauces naturales y favorecen la retención de sedimentos y humedad del escurrimiento para el desarrollo de la actividad agrícola. Objetivo Obtener un modelo de predicción de volumen de suelo captado por los SLB en forma permanente, a partir de las características morfométricas e hidrológicas de las microcuencas donde estos han prevalecido en la Mixteca Alta de Oaxaca, México. Materiales y métodos El estudio se hizo en 27 sitios donde se determinaron parámetros morfométricos e índices hidrológicos que permitieron obtener el modelo de predicción de volumen mediante regresión lineal múltiple tipo backward stepwise. Resultados y discusión Los sistemas estudiados se encontraron en microcuencas bajo condiciones que favorecen el transporte de sedimentos: forma alargada, áreas menores de 2 km2 con corrientes de 1° y 2° orden, en altitudes superiores a los 2 000 m y pendientes mayores de 10 %. Doce parámetros morfométricos y tres índices hidrológicos caracterizan dichas microcuencas y explican las condiciones físicas que permiten su establecimiento, pero solo cuatro (área de la microcuenca, pendiente media de la corriente principal, índice topográfico de humedad e índice de transporte de sedimentos) explican el volumen de sedimento acumulado (R2 = 0.85, P < 0.001). Conclusiones El modelo evaluado para la estimación de volumen es confiable para su aplicación en sitios bajo condiciones similares.

ABSTRACT. Eastern Tropical Pacific (ETP) seagrasses are composed of three genera and four species: Halophila baillonii, Halodule beaudettei, Halodule wrightii, and Ruppia maritima. These are colonizing seagrass species and meadows in the ETP can be ephemeral. Current seagrass distribution in this region remains unknown, with verified extant presence at a limited number of locations and mapping heavily reliant on historical reports. Suitable environmental conditions for seagrasses in the ETP consist of sheltered bays <10 m depth with fine sediment, 19-35 salinity, 26-32°C temperature, and water transparency of up to 10 m Secchi depth. In this region, seagrass organic carbon (OC) biomass pools (<0.2 Mg ha-1) have been reported from three locations, while sediment bulk density (<1.4 g mL-1) and OC (<24 Mg ha-1) have been reported from eight locations, all found on the Pacific coast of Costa Rica. Recent blue carbon reports from the ETP have not been included in global assessments to date. OC sequestration and sediment accumulation rates are currently unknown. Seagrasses provide key ecosystem services yet they are also threatened by anthropogenic and natural stressors. Seagrasses have already disappeared from two locations within the ETP, with restoration efforts currently underway on the northern Pacific coast of Costa Rica. This overview of our current understanding of seagrasses in the ETP and their services highlights the need for further research in this understudied region.

Abstract (Introduction): Coastal areas constitute the interface between land and marine environments, connected through multiple natural and socioecological processes that contribute to human well-being. (Objective): Identify land and marine uses and activities with mutual implications and biophysical processes in the northern region of the Bonaerense Coastal Ecosystem (Argentina), in order to evaluate the degree of compatibility or conflict between these activities, with emphasis on the fishing activity. (Methodology): The land-sea-land (T-M-T) methodological analysis was applied. Uses and activities (U&A) and biophysical processes of marine and land origin were determined. Interactions between marine-land and biophysical processes T-M-T were identified for further categorization and analysis. (Results): A total of 121 U&A sea-land-sea (L-S-L) interactions related to fishing were detected. Medium conflicts were mainly caused by competition for space or resources and were associated with the coexistence of U&A (tourism, fishing, and communication activities), both spatially and temporally. Of the total, 68 negative interactions were observed between biophysical processes and U&A L-S-L, which were linked to climatic events and the effects of climate change (variation in sea surface temperature, atmospheric and oceanic circulation, as well as variations in sediment transport and coastal erosion). (Conclusions): The analysis carried out constitutes an advancement in the study of U&A T-M-T in coastal-marine areas of the Atlantic coast and their interactions, with emphasis on fishing activities, as a contribution to their management with an ecosystemic approach.

Resumen (Introducción): Los espacios litorales constituyen la interfaz entre los ambientes terrestres y marinos, conectados por múltiples procesos naturales y socioecológicos, proporcionando bienes y servicios ecosistémicos para el bienestar humano. (Objetivo): Identificar los usos y actividades tanto terrestres como marinos con implicancias mutuas y los procesos biofísicos en la región norte del Ecosistema Costero Bonaerense (Argentina), con el fin de evaluar el grado de compatibilidad o conflicto entre estas actividades, con énfasis en el sector pesquero. (Metodología): Se aplicó el análisis metodológico tierra-mar-tierra (T-M-T). Se determinaron los usos y actividades (UyA), así como procesos biofísicos de origen marino y terrestre. Se identificaron las interacciones entre UyA marinos y terrestres, y procesos físicos T-M-T, para su posterior categorización y análisis de las interacciones previamente identificadas. (Resultados): Se notaron 121 interacciones de UyA T-M-T vinculadas con la pesca. Predominaron los conflictos medios por competencia de espacio o recursos y se relacionaron con la coexistencia espacial y temporal de UyA (turísticas, pesquera y comunicaciones). Se detectaron 68 interacciones negativas entre los procesos biofísicos y UyA asociados a eventos climáticos e impactos derivados del cambio climático (modificaciones en la temperatura superficial del mar, circulación atmosférica y oceánica, así como variaciones en el transporte de sedimentos y erosión costera). (Conclusiones): El análisis efectuado constituye un avance en el estudio entre UyA T-M-T en zonas litorales costero-marinas de la costa atlántica y de sus interacciones, con énfasis en la actividad pesquera, como aporte a la gestión de aquellos, con un enfoque ecosistémico.

ABSTRACT The aim of this study was to assess the deposition rates (Td) of mineral aeolian sediments in a forest patch in the semiarid Pampas agroecosystem and to analyze the seasonal variability of such deposition. The average Td was 520.15 kg ha-1 year-1 with high interannual variability. In spring-summer, Td was higher than in autumn-winter. Air temperature and average maximum wind speed influenced Td more significantly. However, the soil cover and management of the agricultural fields surrounding the forest would determine the production of sediment from wind erosion and consequent deposition within the forest. These results show the importance of maintaining forest patches within the agricultural matrix in the semi-arid environment, since they retain eolian sediments that would eventually be deposited on the forest soil, minimizing the negative impacts of wind erosion processes on these ecosystems.

RESUMEN El objetivo de este estudio fue determinar las tasas de sedimentación (Td) de sedimentos eólicos minerales en un parche de bosque del agroecosistema del semiárido pampeano y analizar la variabilidad estacional de dicha sedimentación. La Td media fue 520,15 kg ha-1 año-1 con alta variabilidad interanual. En primavera-verano, Td fue superior que en otoño-invierno. La temperatura del aire y velocidad media máxima del viento influenciaron de forma más significativa a Td. Sin embargo, la cobertura del suelo y el manejo de los campos agrícolas que rodean al bosque determinarían la producción de sedimentos a partir de la erosión eólica y consecuente sedimentación dentro del bosque. Estos resultados muestran la importancia de mantener los parches de bosques dentro de la matriz agrícola en el semiárido, los cuales retienen sedimentos eólicos que finalmente se depositarían en el suelo forestal, minimizando los impactos negativos que los procesos de erosión eólica tienen en estos ecosistemas.

ABSTRACT Introduction: The discharge of hospital wastewater leads to the establishment of microorganisms from human biota in aquatic ecosystems. This is risky, as there is the possibility of horizontal gene transfer of antibiotic resistance genes from bacteria to other bacterial strains in the aquatic ecosystem and the environment in general, contributing to the expansion of bacterial resistance to antibiotics and the therapeutic ineffectiveness of these medicines. Objective: To demonstrate the environmental risk due to discharge of wastewater from a hospital into an urban river in Santa Clara, Cuba. Materials and Methods: Bacteria were isolated from sediment and soil from the banks of the Bélico river and their resistance to parenteral antibiotics for intra-hospital use employed between 2015 and 2019 was determined. If positive, the environmental risk of these medicines in terrestrial surface waters was estimated, and the resistance of in-hospital strains was assessed. Results and Discussion: All isolated bacterial strains were resistant to at least one of the parenteral antibiotics for intra-hospital use employed in the period under study. All antibiotics were environmentally risky in terrestrial surface waters. There was a high antibiotic resistance of the strains isolated from hospitalized patients. Conclusions: The discharge of untreated wastewater into the Bélico river led to the establishment of bacterial strains which can have a negative impact on the environment, including human health.

RESUMEN Introducción: El vertimiento de aguas residuales hospitalarias conduce al establecimiento de microorganismos de la biota humana en ecosistemas acuáticos. Lo anterior es riesgoso, al existir la posibilidad de transferencia génica horizontal de genes de resistencia de antibióticos de las bacterias a otras cepas bacterianas del ecosistema acuático y del ambiente en general; contribuyendo a la expansión de la resistencia bacteriana a antibióticos y la inefectividad terapéutica de estos medicamentos. Objetivo: Demostrar el riesgo ambiental por vertimiento de aguas residuales de un hospital a un río urbano en Santa Clara, Cuba. Materiales y Métodos: Se aislaron bacterias del sedimento y suelo de la ribera del río Bélico y se determinó su resistencia a los antibióticos parenterales de uso intrahospitalario empleados entre 2015 y 2019. De ser esta positiva, se estimó el riesgo ambiental de estos medicamentos en aguas superficiales terrestres y se valoró la resistencia de cepas intrahospitalarias. Resultados y Discusión: Todas las cepas bacterianas aisladas fueron resistentes al menos a uno de los antibióticos parenterales de uso intrahospitalario empleados en el período objeto de estudio. Todos los antibióticos resultaron ambientalmente riesgosos en aguas superficiales terrestres. Existió una elevada resistencia microbiana a antibióticos en las cepas aisladas de pacientes hospitalizados. Conclusiones: El vertimiento de las aguas residuales sin tratar al río Bélico, condujo al establecimiento de cepas bacterianas que pueden tener un impacto negativo en el ambiente, incluyendo la salud humana.

Abstract: The study was conducted at the Jalpan de Serra dam, Querétaro, Mexico. In a mountain watershed with a history of artisanal mining activity in the upper part, runoff feeds the reservoir, transporting mining tailings. The Jalpan dam has been used for drinking water supply, agricultural irrigation activities and recreational purposes as a Ramsar site. The reason for the study has been the relevance and social impact of the reservoir sediments as a source of diffuse pollution. The objective was to determine the concentration of arsenic, cadmium and lead in the sediment and to evaluate the level of risk to human health and the environment. The methodology consists of the analysis by atomic absorption carried out in three sites sampled in the superficial layer of 10 cm depth, samples obtained with a PVC tube of 7 cm diameter, identified, preserved for transfer and digested with nitric acid. The results show mean arsenic concentrations of 4.278 mg/kg, cadmium 0.323 mg/kg and lead 4.873 mg/kg. In conclusion, the sediment analyzed does not represent a risk to human health or the environment of the reservoir according to NOM-147-SEMARNAT/SSA1-2004. This investigation demonstrates the lack of a policy or standard that establishes permissible limits for heavy metals in sediment.

Resumen: El estudio ha sido realizado en la presa Jalpan de Serra, Querétaro, México. En una cuenca de montaña con antecedentes de actividad minera artesanal en la parte alta, la escorrentía alimenta el embalse, transportando relaves mineros. La presa Jalpan se ha empleado para abastecimiento de agua de consumo humano, actividades de riego agrícola y fines recreativos como sitio Ramsar. El motivo de estudio ha sido la relevancia e impacto social que tienen los sedimentos del embalse como fuente de contaminación difusa. El objetivo ha sido conocer la concentración de arsénico, cadmio y plomo en el sedimento y evaluar el nivel de riesgo para la salud humana y del ambiente. La metodología consiste en el análisis por absorción atómica realizada en tres sitios muestreados en la capa superficial de 10 cm de profundidad, muestras obtenidas con un tubo de PVC de 7 cm de diámetro, identificadas, conservadas para su traslado y digeridas con ácido nítrico. Los resultados muestran concentraciones medias en arsénico de 4.278 mg/kg, cadmio 0.323 mg/kg y plomo 4.873 mg/kg. En conclusión, el sedimento analizado no representa riesgo para la salud humana o entorno del embalse según la norma NOM-147-SEMARNAT/SSA1-2004. Esta investigación evidencia la falta de una política o norma que establezca los límites permisibles de metales pesados en sedimentos.