14 resultados para Subtropical estuary
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Estuaries are perhaps the most threatened environments in the coastal fringe; the coincidence of high natural value and attractiveness for human use has led to conflicts between conservation and development. These conflicts occur in the Sado Estuary since its location is near the industrialised zone of Peninsula of Setúbal and at the same time, a great part of the Estuary is classified as a Natural Reserve due to its high biodiversity. These facts led us to the need of implementing a model of environmental management and quality assessment, based on methodologies that enable the assessment of the Sado Estuary quality and evaluation of the human pressures in the estuary. These methodologies are based on indicators that can better depict the state of the environment and not necessarily all that could be measured or analysed. Sediments have always been considered as an important temporary source of some compounds or a sink for other type of materials or an interface where a great diversity of biogeochemical transformations occur. For all this they are of great importance in the formulation of coastal management system. Many authors have been using sediments to monitor aquatic contamination, showing great advantages when compared to the sampling of the traditional water column. The main objective of this thesis was to develop an estuary environmental management framework applied to Sado Estuary using the DPSIR Model (EMMSado), including data collection, data processing and data analysis. The support infrastructure of EMMSado were a set of spatially contiguous and homogeneous regions of sediment structure (management units). The environmental quality of the estuary was assessed through the sediment quality assessment and integrated in a preliminary stage with the human pressure for development. Besides the earlier explained advantages, studying the quality of the estuary mainly based on the indicators and indexes of the sediment compartment also turns this methodology easier, faster and human and financial resource saving. These are essential factors to an efficient environmental management of coastal areas. Data management, visualization, processing and analysis was obtained through the combined use of indicators and indices, sampling optimization techniques, Geographical Information Systems, remote sensing, statistics for spatial data, Global Positioning Systems and best expert judgments. As a global conclusion, from the nineteen management units delineated and analyzed three showed no ecological risk (18.5 % of the study area). The areas of more concern (5.6 % of the study area) are located in the North Channel and are under strong human pressure mainly due to industrial activities. These areas have also low hydrodynamics and are, thus associated with high levels of deposition. In particular the areas near Lisnave and Eurominas industries can also accumulate the contamination coming from Águas de Moura Channel, since particles coming from that channel can settle down in that area due to residual flow. In these areas the contaminants of concern, from those analyzed, are the heavy metals and metalloids (Cd, Cu, Zn and As exceeded the PEL guidelines) and the pesticides BHC isomers, heptachlor, isodrin, DDT and metabolits, endosulfan and endrin. In the remain management units (76 % of the study area) there is a moderate impact potential of occurrence of adverse ecological effects and in some of these areas no stress agents could be identified. This emphasizes the need for further research, since unmeasured chemicals may be causing or contributing to these adverse effects. Special attention must be taken to the units with moderate impact potential of occurrence of adverse ecological effects, located inside the natural reserve. Non-point source pollution coming from agriculture and aquaculture activities also seem to contribute with important pollution load into the estuary entering from Águas de Moura Channel. This pressure is expressed in a moderate impact potential for ecological risk existent in the areas near the entrance of this Channel. Pressures may also came from Alcácer Channel although they were not quantified in this study. The management framework presented here, including all the methodological tools may be applied and tested in other estuarine ecosystems, which will also allow a comparison between estuarine ecosystems in other parts of the globe.
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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Gestão e Sistemas Ambientais
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Dissertation submitted to the Faculty of Sciences and Technology of New University of Lisbon for obtaining the degree of Master in Environmental Management Systems
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The section at Cristo Rei shows sandy beds with intercalated clayey lenses (IVb division from the Lisbon Miocene series) that correspond to a major regression event dated from between ca. 17.6 and 17 Ma. They also correspond to a distal position (relatively to the typical fluviatile facies in Lisbon), nearer the basin's axis. Geologic data and paleontological analysis (plant fossils, fishes, crocodilians, land mammals) allow the reconstruction of environments that were represented in the concerned area: estuary with channels and ox-bows; upstream, areas occupied by brackish waters where Gryphaea griphoides banks developped; still farther upstream, freshwaters sided by humid forests and low mountain subtropical forests under warm temperate and rainy conditions, as well as not far away, seasonally dry environments (low density tree or shrub cover, or steppe).
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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia do Ambiente, perfil de Engenharia Ecológica
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World Transport Policy & Practice, Vol.6, nº2, (2000)
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Estuaries and other transitional waters are complex ecosystems critically important as nursery and shelter areas for organisms. Also, humans depend on estuaries for multiple socio-economical activities such as urbanism, tourism, heavy industry, (taking advantage of shipping), fisheries and aquaculture, the development of which led to strong historical pressures, with emphasis on pollution. The degradation of estuarine environmental quality implies ecologic, economic and social prejudice, hence the importance of evaluating environmental quality through the identification of stressors and impacts. The Sado Estuary (SW Portugal) holds the characteristics of industrialized estuaries, which results in multiple adverse impacts. Still, it has recently been considered moderately contaminated. In fact, many studies were conducted in the past few years, albeit scattered due to the absence of true biomonitoring programmes. As such, there is a need to integrate the information, in order to obtain a holistic perspective of the area able to assist management and decision-making. As such, a geographical information system (GIS) was created based on sediment contamination and biomarker data collected from a decade-long time-series of publications. Four impacted and a reference areas were identified, characterized by distinct sediment contamination patterns related to different hot spots and diffuse sources of toxicants. The potential risk of sediment-bound toxicants was determined by contrasting the levels of pollutants with available sediment quality guidelines, followed by their integration through the Sediment Quality guideline Quotient (SQG-Q). The SQG-Q estimates per toxicant or class was then subjected to georreferencing and statistical analyses between the five distinct areas and seasons. Biomarker responses were integrated through the Biomarkers Consistency Indice and georreferenced as well through GIS. Overall, in spite of the multiple biological traits surveyed, the biomarker data (from several organisms) are accordant with sediment contamination. The most impacted areas were the shipyard area and adjacent industrial belt, followed by urban and agricultural grounds. It is evident that the estuary, although globally moderately impacted, is very heterogeneous and affected by a cocktail of contaminants, especially metals and polycyclic aromatic hydrocarbon. Although elements (like copper, zinc and even arsenic) may originate from the geology of the hydrographic basin of the Sado River, the majority of the remaining contaminants results from human activities. The present work revealed that the estuary should be divided into distinct biogeographic units, in order to implement effective measures to safeguard environmental quality.
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A bone breccia from Goldra, near Loulé, is studied. It corresponds to the infilling of a karst depression, consisting of: rather worn and probably transported dolomite pebbles at the bottom; accumulations of frequently burnt bone scraps, much broken and with acute edges (no transport), certainly debris of human food, suggesting habitat level (s); in association with the former, stone (flint, quartz, quartzite, graywacke) rather uncharacteristic artifacts that seem compatible with middle and upper Paleolithic, or with Epipaleolithic; and small mammal teeth and bones. Fauna includes an extinct species, Microtus brecciensis recognized for the first time in Portugal. It is not older than Riss-Wiirm interglacial, and may be of this age or later, maybe that of one of wurm's first interstades. Fauna points out to a varied landscape with open country and woods; and to a rather warm and dry temperate, or dry subtropical mediterranean climate. Climate differences should not be significant in comparison with the extant situation. The presence of the mammal species found so far is consistent with modern distribution.
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The synthetic study of the uppermost Cretaceous of the Beira Litoral (fauna, flora) confirms its upper Campanian-Maastrichtian age. It shows the presence of a tropical to subtropical climate in an area constituted by a low coastal plain only occasionally linked to the sea, saturated with fresh water and possessing accordingly, a predominantely freshwater fauna (Viso, Aveiro); this plain changed towards the interior into a drier more forested zone with a more abundant terrestrial fauna which includes mammals (Taveiro). A thorough study of the chelonian Rosasia, abundant on the coastal plain, was made possible thanks to the discovery of a skull: it demonstrates that the genus belongs to the family Bothremydidae, revalided here. The composition of this family is presented, its phylogenetic and paleobiogeographic relation with the other pleurodires are analyzed, and its diagnosis established. The family is constituted of three groups; Rosasia belongs to one of these, the Bothremys group.
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New Middle Pliocene ichthyofauna (2.4-2.2 Ma) from central-eastern Italy (Samoggia Torrent, Bologna) are described. These ichthyolites were found in a rather thin laminated layer that was deposited after the 2.4 Ma climatic crisis. The origin of this deposit, in which 31 taxa have been classified, is to be related to anoxic events on a regional and, probably, supraregional scale. This ichthyofaunistic association, which consists of living genera, is characterized by a clearcut predominance of mesopelagic species. The palaeoclimatic characters of these ichthyofauna indicate subtropical-type waters, while from a palaeobiogeographic point of view there is a close relationship with the present-day Atlantic-Mediterranean bioprovince. The Samoggia deposit has yielded six taxa that are absent or only occasionally present in the Mediterranean: one of these, Spratelloides gracilis, is exclusive of the Indo-Pacific bioprovince.
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Thesis submitted to the Faculdade de Ciências e Tecnologia to obtain the Master’s degree in Environmental Engineering, profile in Ecological Engineering
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Dissertação apresentada como requisito parcial para obtenção do grau de Mestre em Ciência e Sistemas de Informação Geográfica
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The synthetic study of the uppermost Cretaceous of the Beira Litoral (fauna, floral confirms its upper Campanian-Maastrichtian age. It shows the presence of a tropical to subtropical climate in an area constituted by a low coastal plain only occasionally linked to the sea, saturared with fresh water and possessing accordingly, a predominantely freshwater fauna (Viso, Aveiro); this plain changed towards the interior into a drier more forested zone with a more abundant terrestrial fauna which includes mammals (Taveiro). A thorough study of the chelonian Rosasia, abundant on the coastal plain, was made possible thanks to the discovery of a skull: it demonstrates that the genus belongs to the family Bothremydidae, revalided here. The composition of this family is presented, its phylogenetic and paleobiogeographic relation with the other pleurodires are analyzed, and its diagnosis established. The family is constituted of three groups; Rosasia belongs to one of rhese, the Bothremys group.
Resumo:
New Middle Pliocene ichthyofauna (2.4-2.2 Ma) from central-eastern Italy (Samoggia Torrent, Bologna) are described. These ichthyolites were found in a rather thin laminated layer that was deposited after the 2.4 Ma climatic crisis. The origin of this deposit, in which 31 taxa have been classified, is to be related to anoxic events on a regional and, probably, supraregional scale. This ichthyofaunistic association, which consists of living genera, is characterized by a clearcut predominance of mesopelagic species. The palaeoclimatic characters of these ichthyofauna indicate subtropical-type waters, while from a palaeobiogeographic point of view there is a close relationship with the present-day Atlantic-Mediterranean bioprovince. The Samoggia deposit has yielded six taxa that are absent or only occasionally present in the Mediterranean: one of these, Spratelloides gracilis, is exclusive of the Indo-Pacific bioprovince.