999 resultados para ambientes aquáticos


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A espécie Eichhornia crassipes (Pontederiaceae) é uma macrófita aquática conhecida popularmente como aguapé. É utilizada na descontaminação de ambientes aquáticos poluídos, pois possui alta capacidade de absorver e tolerar elevadas quantidades de íons metálicos. Segundo estudos, o cádmio é um dos metais mais absorvidos por essa espécie, que apresenta maior acúmulo em raízes em relação às partes aéreas. O objetivo desse trabalho foi verificar se a produção de antocianinas do aguapé é alterada pela presença de íons Cd(II) nos tecidos. Foram realizados experimentos in vivo submetendo os espécimes à solução nutritiva contendo ou não íons cádmio. Os extratos metanólicos acidificados com HCl das raízes foram analisados por CLAE-UV e fracionados por CC (C18 e Sephadex), seguidos por CLAE semipreparativa. Após as análises por CLAE-DAD-EM foi possível propor a estrutura de duas antocianidinas: delfinidina e delfinidina substituída por um grupo metoxílico (C16H13O8, 333,0609)

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As an effect of the imbalance caused by the damming of rivers and pollution, it has been observed a growing aquatic plants infestation in reservoirs for the generation of electricity. In addition to power generation, these sites have also been used for various other purposes, including recreation, attracting water and navigation. Thus it is important to evaluate these water bodies periodically, in order to verify the leading conditions to the growth of algae, plants and other organisms. In this sense, Remote sensing technology can be a valuable tool for mapping and monitoring the occupation of land in the vicinity of the water body and the optical properties of water, to provide subsidies for the effective management of these aquatic environments. This paper aims to perform the monitoring of the occurrence of aquatic plants in Salto Grande Hydropower Reservoir, located in Americana (SP) and, periodically, map the occupation of land in the vicinity of the water body, through multispectral images taken by sensors on the satellites Landsat series in seven consecutive years: 2004, 2005, 2006, 2007, 2008, 2009 and 2010. The adopted methodological procedure included the images data and the classification of multispectral images to map, every year, the location and extension of the area infested by aquatic plants and the occupation of land

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Aquatic ecosystems are suffering many impacts caused by human activities resulting from the activities occurring around them. With technological progress observed in recent years, this environment has received large amounts of chemicals from industries, agriculture and urban area that affect the aquatic biota. Among these sources of contamination, the oil industry has contributed to the pollution of aquatic environments with both effluents as produced water well as oil spills and their derivatives having toxicity to various organisms. With all the environmental issues has increased concern about water quality and has been used ecotoxicological tests with aquatic organisms to ecosystems to assess the toxicity of chemicals present in the water. In this context the microcrustacea Daphnia similis stands out as a freshwater organism very representative of the aquatic fauna of rivers and high sensitivity to environmental impacts. Thus, the present study aimed to evaluate the lethal toxicity of crude oil and produced water on this microcrustacea. The results showed that the microcrustacea presented high sensitivity to contaminants primarily crude oil. There was also the influence of environmental variables pH and temperature on the survival of organisms

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Pós-graduação em Biometria - IBB

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Despite remarkable significance of Pantanal for the conservation of aquatic birds, the status of their populations, the spatiotemporal patterns of distribution and habitat use and structure of communities are little known. Thus, we studied three aquatic environments (Negro river, bays and salines) from 2007 to 2009 in the Nhecolandia Pantanal to verify the distribution and composition of aquatic birds and also if there is significant seasonal influence on these aspects. We adopted the transect method (288 hours of sampling) and recorded 135 species (7.834 individuals). The Negro river showed the highest diversity, while the salines the lowest. The similarity of aquatic bird communities was higher between bays and salines, followed by Negro river and bays and lower between salines and Negro river. The equidistribution is more variable in the salines and more stable in the Negro river. The environments strongly differ from each other in aquatic bird composition in space (habitat use and distribution) and time (seasonal water fluctuations). The diversity of bird community in the dry season varies significantly in the salines, followed by the bays and more stable in the Negro river. The Negro river, regardless of large annual amplitude of flow, is more seasonally stable since its riparian vegetation is continuous (not isolated) and constant. These aspects provide better conditions to stay all year, contributing to decrease the seasonal nomadic tendencies of aquatic birds. Finally, all these data provide strong arguments to the preservation of all phytophysiognomies in the Nhecolandia sub-region of Pantanal, but with special attention to the salines widely used by many flocks of aquatic birds (mainly in the dry season) and migrant and/or rare species restricted to this habitat.

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Parque das Neblinas (PN) is a 2,800 ha nature reserve contiguous with an Atlantic Forest fragment known as Parque Estadual da Serra do Mar located in the municipality of Bertioga, in the state of São Paulo, Brazil. The area originally contained Eucalyptus trees grown for paper pulp production. The aims of the study were the following: (1) to characterize the diversity of the bird community in PN; (2) to compare bird species observed in PN to species found in the Atlantic Forest; and (3) to list the percentages of species endemic to the Atlantic Forest and present in PN. Quantitative surveys used the point count method. The number of avian species recorded in PN totaled 222, of which 150 (66.4%) were associated with forest environments, 66 (29.3%) with open areas, and 10 (4.3%) with aquatic environments. The quantitative survey recorded 141 species and 2,527 contacts in 120 samples for an average of 21.05 contacts per sample. The general diversity index was H´=3.82. The study identified 15 bird species that actively participated in mixed flocks and 25 species endemic to Atlantic Forest, two of which present some kind of concern relating to conservation. Areas with Eucalyptus trees and a dense understory displayed the greatest bird species diversity, as opposed to areas with less developed or non-existent understories.

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV