http://hdl.handle.net/10256/11212 2025-06-27T14:32:39Z http://hdl.handle.net/10256/26673 Anàlisis de la relació llacuna-aqüífer de tres basses ubicades al Baix Ter Mateos Gasquet, Marc Coastal lagoons are masses of water that stand out for their ecosystemic importance and for their great biodiversity, but also for their vulnerability to impacts. These lagoons are characterized by their relationship with maritime waters, as they are a transitional element between terrestrial space and the sea. However, this work has focused on studying the relationship between the lagoon and the groundwater. The study has focused on the Baix Ter area, specifically on the Pletera natural area. La Pletera is a system of restored wetlands, which suffered strong human pressure during the eighties, the result of an urban project. The entire coastal lagoon system was restored through two LIFE projects. For this study, three of the six gaps that make up this network have been chosen. The lagoons studied are Fra Ramon (FRA) of natural origin, M03 and L04 both of artificial origin, created within the framework of the two LIFE projects. The aim of this work is to determine its relationship with the aquifer, as well as the hydrogeological state. To achieve the objectives of the study, methods have been carried out that evaluate the surface-subterranean relationship of the aquifer. The methods used have been those of mass balances, concentration monitoring, mathematical models and heat tracers. Regarding the results, it has been determined through meteorological and piezometric data that the study area suffers from very significant water stress at the time of analysis. It has also been seen through the evolution of the lagoons that the water in the lagoons is maintained mainly by underground contributions throughout the year, except when there are periods of precipitation. In addition, it has been determined that at the depth of Fra Ramon (FRA) stratification occurs during the autumn and winter weather seasons. Other results show the evolution of ions (Cland SO42-), alkalinity, nutrients (TN, PT, TOC and PT/PO43-), which have reaffirmed the stratification in Fra Ramon (FRA). The isotopes (δ18O and δD) have shown that all the lakes suffer the same evaporation and that in the summer months or close to them, evaporation is much more accentuated, on the other hand, in the winter or autumn months, it is less. Finally, with principal component analysis (PCA), some of the observed results have been confirmed. In general, this work has made it possible to determine that the lagoons receive an underground contribution most of the year, except when precipitation occurs, that the situation can be reversed. In addition, it has been established that the lagoon with the most salinity is M03, and the one with the least salinity is L04; Coastal lagoons are masses of water that stand out for their ecosystemic importance and for their great biodiversity, but also for their vulnerability to impacts. These lagoons are characterized by their relationship with maritime waters, as they are a transitional element between terrestrial space and the sea. However, this work has focused on studying the relationship between the lagoon and the groundwater. The study has focused on the Baix Ter area, specifically on the Pletera natural area. La Pletera is a system of restored wetlands, which suffered strong human pressure during the eighties, the result of an urban project. The entire coastal lagoon system was restored through two LIFE projects. For this study, three of the six gaps that make up this network have been chosen. The lagoons studied are Fra Ramon (FRA) of natural origin, M03 and L04 both of artificial origin, created within the framework of the two LIFE projects. The aim of this work is to determine its relationship with the aquifer, as well as the hydrogeological state. To achieve the objectives of the study, methods have been carried out that evaluate the surface-subterranean relationship of the aquifer. The methods used have been those of mass balances, concentration monitoring, mathematical models and heat tracers. Regarding the results, it has been determined through meteorological and piezometric data that the study area suffers from very significant water stress at the time of analysis. It has also been seen through the evolution of the lagoons that the water in the lagoons is maintained mainly by underground contributions throughout the year, except when there are periods of precipitation. In addition, it has been determined that at the depth of Fra Ramon (FRA) stratification occurs during the autumn and winter weather seasons. Other results show the evolution of ions (Cland SO42-), alkalinity, nutrients (TN, PT, TOC and PT/PO43-), which have reaffirmed the stratification in Fra Ramon (FRA). The isotopes (δ18O and δD) have shown that all the lakes suffer the same evaporation and that in the summer months or close to them, evaporation is much more accentuated, on the other hand, in the winter or autumn months, it is less. Finally, with principal component analysis (PCA), some of the observed results have been confirmed. In general, this work has made it possible to determine that the lagoons receive an underground contribution most of the year, except when precipitation occurs, that the situation can be reversed. In addition, it has been established that the lagoon with the most salinity is M03, and the one with the least salinity is L04 2025-02-01T00:00:00Z http://hdl.handle.net/10256/26672 Agroecologia i sobirania alimentària a Catalunya ; alternatives al sistema alimentari globalitzat : un nou concepte agroecològic d’hort urbà Divison Sotodosos, Alexandre The study analyzes the impacts of the globalized food system at a global level, conducting a more detailed examination of the situation in Catalonia and exploring viable alternatives to ensure a more sustainable and resilient model. The negative effects of the globalized model have been studied, including greenhouse gas emissions, biodiversity loss, and soil erosion, as well as the growing dependence on food imports, which creates significant vulnerability to global crises. In contrast, realistic alternatives have been sought to reduce the current impact on the planet. Agroecology emerges as a viable and necessary alternative to mitigate these effects and ensure a fairer and more sustainable food system. This model promotes crop diversification, reduces dependence on chemical inputs, and strengthens short food supply chains, supporting local farming and reducing the ecological footprint. Additionally, concrete initiatives have been analyzed that contribute to strengthening food sovereignty in Catalonia as well as in other countries. This study also examines the fundamental role of urban gardens, not only as food production spaces but also as tools to promote sustainability, social cohesion, and resilience to climate change. Furthermore, an innovative combination with mushroom cultivation is proposed, which could enhance the efficiency of these spaces and diversify food production in urban environments. The conclusions suggest that the transition to an agroecological model is key to achieving real food sovereignty and long-term sustainability. However, to accomplish this, public policies that support small-scale producers, better land-use planning, and a firm commitment to environmentally respectful production systems are essential 2025-02-01T00:00:00Z http://hdl.handle.net/10256/25991 De quina manera es poden detectar i localitzar els nius de vespa asiàtica (Vespa velutina)? Tous Tito, Marina The Asian hornet, Vespa velutina, is a species of hornet that has been declared an invasive species in Spain and has been established in Catalonia and across Europe for several years. This species presents both ecological and economic problems, particularly due to its predation on pollinators, which seriously threatens the apiculture industry. Currently, the most used method for controlling this species is nest removal. However, using only this practice is not enough for its control. In general, this species tends to build nests in the canopy of tall trees (over 10 meters). Nest activity decreases as temperatures drop, to the point that in winter, the wasps die and the nests become empty. It is during this time when deciduous trees lose their leaves, making nests more visible, even though they are already vacant. For this reason, the solution to prevent this species from proliferating further relies on early detection of these nests. With this approach, nests can be detected while they are still active, especially before future queens leave the nest to form new colonies. This study identifies several nest detection methods to be able to compare them and thus determine which is most suitable for improving control of this species. To compare the different methods, a matrix is created that considers environmental, economic, and social factors. Among the methods, it has been concluded that the one that best meets the proposed requirements is a marking and tracking method presented by Sandra V. RojasNossa. This method compared to others, it is more economical, provides acceptable results, and is environmentally respectful and ethically responsible. However, for those seeking better results in less time and with a higher budget, the most suitable method is radiotelemetry, as it is more effective but also entails high costs 2024-07-01T00:00:00Z http://hdl.handle.net/10256/25990 Paràsits i patologies de la gamba blanca (Parapanaeus longirostris) i el seu potencial ús com a sentinelles de l’impacte ambiental Pons Tadeo, Júlia Cai The white shrimp (Parapenaeus longirostris) is a key fishery resource in some regions of the Mediterranean, being one of the commercial species with the highest revenues, but despite its economic importance, it is very little studied compared to other commercial species. For this reason, this study aims to improve the understanding of the threats and diseases that can impact the natural populations of white shrimp, susceptible to various infections that can cause severe symptoms and mortality. During the month of February, white shrimp samples were collected in two areas of the Catalan coast, Barcelona and La Rápita, characterized by presenting different degrees of pollution. Through the dissection of the specimens, macroscopic examination, histological analysis and quantitative analysis of various biological parameters, the presence and diversity of parasites has been studied, possible diseases and alterations have been detected, and the health status of the populations of this species in both locations has been compared based on the condition index. The most notable macroscopic alterations have been melanosis and calcification of the exoskeleton. However, these conditions are considered normal post-mortem processes originating during the handling and storage of the samples, and do not pose a direct risk to the health of the shrimp. A remarkable aspect has been the detection of ciliated protozoa in the shrimp from Barcelona, while these microorganisms have been observed in smaller quantities in the samples from La Rápita. The presence of these parasites could be indicative of water pollution or poor quality in certain areas of the Barcelona coast. However, it will be necessary to deepen the identification and study of these parasites to determine their pathogenic capacity and their potential as a bioindicator. Finally, it has been seen that although the shrimp from Barcelona have a slightly smaller body size than those from La Rápita, the lowest condition index has been recorded in the samples from the latter location, which suggests that the physiological state of the individuals from La Rápita is worse. In fact, in this area all the recorded histopathologies (encapsulations, cysts and hemocyte infiltrations) have also been detected, which could be related to both environmental factors and possible pathogenic organisms to which the shrimp are exposed. In general, the study has revealed the presence of some pathogens and alterations in the analyzed samples, but the evidence of pathogens associated with the white shrimp found so far is scarce. In addition, no serious lesions or pathologies have been detected in the examined specimens, which could be indicative that the white shrimp populations are not affected by diseases that can compromise their survival. However, further research is needed, expanding the number of samples and conducting seasonal monitoring, to obtain a more complete and representative view of the health status of this fishery resource on the Catalan coast 2024-07-01T00:00:00Z