27 resultados para Ciências do mar e das zona costeiras

em Universidade Federal do Rio Grande do Norte(UFRN)


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Despite being areas of socioeconomic and ecological importance, the reef environments in northeastern Brazil have been suffering with cluttered tourism impacts, such as trampling, activity that leads to decrease in abundance of organisms, especially benthic, and loss of biodiversity. The objectives of this study were 1) to characterize the benthic community in the shallow sandstone reef of Pirangi/RN, identifying patterns of zonation, and 2) evaluate its process of structuring under different degrees of impact of trampling, providing information to the proper use of the area. Data on abundance of organisms, the percentage coverage of the substrate and physic-chemical parameters were collected. The formation of two zones on the reef was observed: one that considers submerged areas and ones with shorter time of exposure, lower roughness and higher heterogeneity in the coverage of the substrate, with a predominance of sand, foliose algae, rodolit, being related to organisms such as gastropods, crabs and sea-urchin; the second zone comprises areas with longer time of exposure, greater roughness and predominance of bedrock uncovered, being associated with organisms such as barnacles, gastropods, bivalves and crabs. It is concluded that the studied reef presents its own zonation pattern, influenced by both the time of immersion and the substrate characteristics, such as roughness and type of coverage. To answer the second objective of this study, four experimental blocks were mounted on each of the three areas of different intensities of trampling, containing the following treatments: control (isolated from trampling), shaved isolated, trampling and shaved trampling, with data collection by 11 months. The data in abundance, diversity indices and living coverage of the substrate were compared between areas and treatments. The results showed that at the trampling areas, at the end of the experiment, differences were observed between the intensities of the impact, where higher values of abundance and richness of mobile fauna and richness of live coverage (ANOVA, p <0.05) were found in the area of higher trampling intensity. For fauna withdrawal of trampled scraped treatments, it was observed in the area of greatest impact that the abundance of small benthic invertebrates is more than three times smaller than that at the area of intermediate trampling (ANOVA, p <0.05). Initial isolated areas and final ones differed only as to the percentage of live coverage, with an increase of 35% at the end of this experiment. As for the areas that were completely scraped and isolated at the end of the experiment was observed an increase in the percentage of live coverage of 11.11% compared to the initial amount in the area of intermediate impact and 37.5% in the area with greater impact, indicating recovery of the area. It is suggested that the current use of the reef of Pirangi be reviewed, with a decentralization of trampling, or a decrease in visits, so that it does not occur at high intensities

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Beachrocks são rochas sedimentares formadas pela cimentação de sedimentos praiais por carbonato de cálcio em especial, calcita e/ou aragonita em zona de estirâncio. A ocorrência dessas rochas é bastante comum em diversas partes do globo, sobretudo em regiões com latitudes inferiores a 40º. O Rio Grande do Norte possui grande quantidade de beachrocks, os quais afloram tanto em regiões costeiras quanto em zona costa-afora. Os depósitos de beachrocks de zona costeira do referido estado têm sido estudados por diversos autores, os quais abordaram os mais variados temas desde o início do século XX. Por outro lado, os depósitos de zona costa-afora apesar de terem sido estudados por poucos autores têm ganhado atenção apenas nos últimos anos. Porém, nenhum trabalho até o presente fez algum tipo de estudo comparativo de cunho geológico entre os corpos de beachrocks presentes em ambas as zonas: costeira e costa-afora. Sendo assim, a presente dissertação teve o intuito de correlacionar os corpos de beachrocks que afloram em zona costeira aos que estão atualmente dispostos em zona costa-afora, próximo a isóbata de 25 m, levando em consideração seus aspectos petrográficos, diagenéticos e sedimentológicos. Para isso, foram percorridos cerca de 260 km de litoral, correspondendo ao trecho entre os municípios de Extremoz e Tibau, em busca de afloramentos de beachrocks. Seções colunares foram confeccionadas e amostras coletadas em estações de amostragem representativas da zona costeira, ao passo que da zona costa-afora apenas seções delgadas foram analisadas. Trabalhos disponíveis na literatura sobre o tema e área em pauta também foram utilizados. A partir dos dados levantados, observou-se que os beachrocks são formados por diferentes camadas ao longo de um perfil vertical. Estas camadas são claramente identificadas em afloramento pela diferença existente na composição, textura e estruturas sedimentares peculiares a cada uma delas. Seções delgadas foram confeccionadas e analisadas a partir de amostras coletadas nas diferentes camadas de diversos afloramentos. Um afloramento foi escolhido como afloramento modelo sendo este o de São Bento do Norte por apresentar a maior espessura de rocha aflorante (1,9 m). Este tem sido muito bem estudado tanto no corrente trabalho quanto em trabalhos de outros autores. A este foram comparados todos os outros afloramentos analisados. A partir da análise micropetrográfica, foram identificadas 03 microfácies para os beachrocks do Rio Grande do Norte, sendo elas: Quartzarenítica (< 2,9% de bioclastos), Quartzarenítica Bioclástica (entre 3 e 9,9% de bioclastos) e Bio-quartzarenítica (> 10% de bioclastos). Associando essas microfácies às análises sedimentológicas realizadas foi possível propor que as microfácies Quartzarenítica e Bio-quartzarenítica foram depositadas em zona de estirâncio enquanto que a microfácies Quartzarenítica Bioclástica foi depositada em zona de face litorânea superior. A história diagenética dos beachrocks estudados é marcada por quatro principais processos: compactação mecânica, cimentação, dissolução e geração de porosidade secundária, e oxidação. Dentre esses, o processo de cimentação é o mais importante, sendo caracterizado por precipitação de cimento de calcita rica em Mg sob cinco morfologias, a saber: cutículas criptocristalinas, franjas prismáticas isópacas, calcita espática microcristalina, calcita espática equante e agregados pseudo-peloidais. Todas estas morfologias foram formadas durante o estágio de eodiagênese, nas zonas freática marinha ativa ou freática meteórica ativa, corroborando assim com a idéia de que beachrocks têm sua litificação completa a pequenas profundidades. Associando as análises microfaciológicas às diagenéticas foi possível sugerir que a sucessão vertical de camadas vista em alguns beachrocks costeiros representam registros de variações de mais alta frequência do nível do mar durante o Holoceno. A partir daí, baseando-se em informações obtidas através de curvas de variação do nível do mar relativo no Holoceno para o Rio Grande do Norte, disponíveis na literatura, e na correlação aqui realizada entre os beachrocks costeiro e aqueles de zona costa-afora, foi possível inferir que estes últimos representam uma antiga linha de costa formada a idades relativas superiores a 7.000 anos A.P

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Oligoplites palometa (Cuvier) and Oligoplites saurus (Bloch & Schneider) (Osteichthyes: Carangidae) are coastal pelagic fish species. The objective of this study was to investigate the effect of parasitism by isopods and the reproductive biology of the leather jack, Oligoplites spp. A total of 113 individuals of Oligoplites spp (35 of O. saurus and 78 of O. palometa) were captured during the period between January, 2005 and July, 2007 from the coastal waters of Natal, RN. The morphometric and meristic characters were registered; macroscopic analyses were done to collect the isopod parasites and the gonads were observed to verify the reproductive aspects. The crustacean isopod parasite, Cymothoa spinipalpa (Isopoda: Cymothidae) was encountered on the tongue in the oral cavity in both fish hosts. The parasitic indices of C. spinipalpa showed high values of prevalance of 51,4% for O. saurus and 64,1% for O. palometa. The host presented significant correlations between body mass and body length of O. palometa and the number of parasites. Body lengths of female C. spinipalpa were small due to the limited space available in the oral cavity of the host. There was a significant difference in the sex ratio of O. palometa, males outnumbered the females. The isopod parasites showed specificity to the oral cavity of hosts. Macroscopic analyses of gonads showed four stages of gonadal development for both sex of O. palometa: immature, maturing, mature and spent

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Coleodactylus natalensis Freire, 1999, an endemic species of Atlantic Forest fragments around the Natal municipality, Rio Grande do Norte State, Brazil, has as type locality the Parque Estadual Dunas de Natal (05º48 S to 05º53 S and 35º09 W to 35º12 W), one of the largest restinga (herb and shrub association on sand dunes along the Brazilian coastline) associate fragment, surrounded by urban zone, placed on setentrional Atlantic Forest limits. We made estimates on populational density, spatial distribution, habitat and microhabitat preferences and feeding ecological aspects like sazonal and sexual variations on diet, prey electivities and niche breadth. We randomly sampled ninety-six 50m2 quadrants in each of the four habitats identified in the study area. Were collected 49 specimens and their stomach contents were analyzed; prey items found were correlated with leaf-litter invertebrates from habitat samples. We found a 98,5 ± 75,5 individuals/ha density, in grouped distribution pattern on densest habitats and random distribution on others habitats. This species lives mostly on leaf-litter in forest habitats, in higher humidity points, with lower temperatures, deeper leaf litter and lower sea level elevations than the randomly chosen points in the study area. Isopoda and Aranae were the most important prey categories in numeric, frequency and volumetric terms. Niche breadth has an intermediate value and was variable in sexual and in habitat terms. There was no correlation between morfometric measures and prey size on diet. The C. natalensis population studied seems to be diet opportunist, although selects larger prey items. The Parque Estadual das Dunas do Natal has several indications of anthropic pressure from the surrounding urban area that may affects the local C. natalensis population. Thus, the fragility of this species calls for urgent conservation efforts

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The marine fish white mullet, Mugil curema Valenciennes, 1836 (Osteichthyes: Mugilidae) exhibits a wide geographical distribution, being common in the Brazilian coast and is an important component of the artisanal fisheries. The objective of this study was to investigate the reproductive biology of M. curema in the coastal waters of Rio Grande do Norte. Fish samples were captured on a monthly basis during August, 2008 to July, 2009. The fish specimens were numbered, weighed, measured, dissected and their gonads were removed, weighed, their sex and gonadal development were identified. The length-weight relationship was determined for males and females. The sex ratio, the size at first gonadal maturation and gonadosomatic index (GSI) were calculated and ovarian development was investigated using macroscopic and histological techniques. The fecundity, spawning type and the reproductive period of the species were determined. A total of 366 specimens (186 males and 180 females) were captured. The sex ratio was 1:1 and the females were heavier than males. The estimated values of the angular coefficient for both sexes suggest that the species has isometric growth. The size at which 50% of the population began the process of maturation was 25.9 cm of total length for grouped sex. The macroscopic characteristics of the ovaries showed four stages of development: immature, maturing, mature and spent. However, the microscopic characteristics of the ovaries showed five stages of development: immature, early maturing, late maturing, mature and spent. The development of oocytes indicated five phases: Chromatin-nucleolus (phase I), initial perinucleolar (phase II), final perinuclear (phase II), formation of vitelline vesicle or yolk (phase III), vitellogenic (phase IV) and complete vitellogenesis (phase V). The species has a prolonged spawning period, with two peaks coinciding with the rainy season.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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Trata-se de um coorte prospectivo com amostras de leite de 28 mães da zona rural da Paraíba, durante diferentes dias de amamentação exclusiva, com objetivo de avaliar através do ensaio imunoenzimático a presença de imunoglobulina A secretora (sIgA) total e específica contra antígenos de Escherichia coli enteropatogênica (EPEC) e Shigella flexneri. A reatividade dos anticorpos foi analisada pelo Western blot . Os resultados mostram presença da sIgA em todas as amostras, com medianas no colostro de 8,092 g/L(4,546-17,252) e leite de 0,695g/L (0,020-2,830). As medianas nos títulos de colostro de IgA anti-EPEC foi 41 (1-659) e anti-Shigella flexneri de 18 (1-4727) enquanto no leite anti-EPEC foi de 8 (1-288) e anti-Shigella flexneri de 6 (1-450). Houve grandes variações entre as mães e entre os dias de amamentação. No Western blot os anticorpos sIgA reagiram com proteínas de EPEC e Shigella flexneri, destacando-se a fração antigênica de 94kDa, correspondente a intimina. Os resultados mostram que a presença de sIgA total e de anticorpos IgA contra EPEC e Shigella flexneri no colostro e leite de mães residentes em zona rural, com precárias condições sócioeconômica e sanitárias, não diferem de estudos realizados com populações de área urbana e reforçam a importância do leite materno na defesa contra infecções entéricas. Apesar da ausência na literatura de estudos avaliando o perfil de anticorpos sIgA no leite de mães residentes em zona rural do Brasil, os resultados demonstraram que a presença de sIgA total e de anticorpos IgA contra EPEC e Shigella flexneri no colostro e leite de mães residentes em zona rural, com precárias condições sócio-econômica e sanitárias, não diferem de estudos realizados com populações de área urbana e reforçam a importância do leite materno na defesa contra infecções entéricas

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Conselho Nacional de Desenvolvimento Científico e Tecnológico

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The Pitimbu River is located at the oriental portion of the State of Rio Grande do Norte, including three importants cities named Macaíba, Parnamirim e Natal. Although its high importance as a water source, which supplys great part of the South Zone of the Natal city, this river receives a large quantity of domestic and industrial waste water without treatment. The Pitimbu River headhas its river-head located in the city of Macaiba, goes through Parnamirim, then it flowing into at the Jiqui Lake in Natal. The aim of this study was to evaluate, qualitatively and quantitatively, the environmental quality of the Pitimbu River by genotoxicity bio-assays, which are important tools for genetics toxicological evaluation. In this work, five samples sites, distributed along the river, were used to collect water samples. Another point site, located near Jiqui lake, was used to collect drinkable water, which was treated by CAERN, the water treatment entreprise of Rio Grande do Norte. The following assays where used to evaluate the quality of these samples: Allium cepa assay; Comet assay; Micronuclei (MN) assay; and Ames test. For the Allium cepa assay, sixteen specimes where used for each water sample from the sample sites. In this assay both microscopic, like cytogenetic damage, and macroscopic aspects, as morphological variation were evaluated. Red blood cells from periferical blood of the Crenicichla menezesi native specie were used not only for the MN assay, but also for the Comet assay. These fishes were collected at different points on the Pitimbu River and the negative control was developed using fishes of the same species that were bring to the laboratory and maintained for 100 days in the optimal experimental conditions. For the Ames test, TA100, YG1042, TA98 and YG1041 strains were used in the directed method without metabolic activation. The results found by the Allium cepa assay showed that two water sample sites induced increase of mitotic index (IM). Additionally, compared to the control, all the water samples increased the chromossomal aberrations frequency and/or micronucleus. Among the sample sites, two also showed an abnormal growth rate in its root and two samples induced morphological alteration. With the MN test in red blood cells, a high frequence of MN was observed in tree sample. By comparing all the results obtained on the water sample points and with the negative control, a significant variation on the MN frequency was observed. Positive results were also observed for the same sample to water test by the Comet assay. These results allow concluding that the proposed specie Crenicichla menezesi has a good profile as a bio-indicator for the evaluation of environmental water quality and the MN and comet test can be usuful for in situ evaluation. By the Ames test, it was possible to detect the mutagenic activity on the waters from the Pitimbu River in different levels of mutagenicity. This result suggests that this river has several substances that induced changes directly to the DNA. The mechanisms involved to this phenomenon could be by both processes, by changing of the reading frame and by nucleotide substitution. These data set indicate the presence of mutagenic agents, which can represent in risk to biot and human beens

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This research focuses on the fishery activity, aligned to knowledge of past generations, and the transformation to those who depend on this activity for their livelihood, at the seashore community of Pitangui in Extremoz municipality, which lies 40 km away from Natal, seat of the state of Rio Grande do Norte. The intense modernization which has taking place during the last few years may be considered the result of a number of economic, social and cultural factors, as the introduction of new fishery technology. On the other hand, the present study seeks to show how this changing process happened, and to what extent those affected understand and evaluate this transformation. The methodology to carry out the ethnographic work was mainly adopted by qualitative methods and techniques - by participant observation, oral history, photography and the audiovisual records besides reference to data extracted under quantitative methods, as an important instrument of analyses. This induces a conclusion that the transformation of the community is a consequence of the globalized market, though still tied up to specific local relations. The emerging results are: the use of new fishery technology, and new ways of orientation and navigation; the opening to new jobs and occupational activity, the re-order of space s appropriation; changing sociability, larger access to consumer goods, besides bringing on some new conflicts land appropriation and the fishery and the protection of the environment. All this comprehended as a result of the movement of the local relations participating in the global spaces

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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The accelerated pressure of use and occupation of Rio Grande do Norte coastline in the last two decades presented the tourism as its main vector, having as a consequence a strong, articulated and growing real estate speculation of this area. In the Natal County there is a Zona Especial de Interesse Turistico II (Special Zone of Tourism Interest II) (ZET-II), consisted of urban beaches with approximately 8.5 km that is an important seashore of the city. The purpose of this research was identification, characterization and assessment of the process of use and occupation of dunes fields emphasizing the role of ZET-II, whereas the specific goals was the analysis of weather, geology and geomorphology, characterization of use and occupation of soil, and elaboration of an environmental diagnosis with identification and description of its mains consequences. The result of this work was the delineation of geologic-geomorphological map of the area with identification of principals units, determining its use and occupation, the measurement of the area already occupied by equipments, besides the description of the environmental impacts on dune fields: devastation, coastline erosion, ocean pollution by sewer and pluvial waters, contamination of groundwater, distribution inadequate of solid residues, landscape degradation, and occupation of seashore through the privatization of public areas. Concluding that the degrading changes occurred in this areas are resulting from the nature of use and urban seashore regulations, which have been diminishing the natural aspect, altering the landscape definitely, compromising the quality of hydro resources and altering its use, privatizing the areas between tides, complicating the population access and obstructing the scenery visualization of dunes and ocean. There is an urgent necessity of improvement of public politics in order to improve the strategies and organization of use and occupation of space urban-coastline

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La enseñanza desarrolló, así como los métodos y las técnicas de enseñar. Aquí el he/she piensa un método instrucción, en que el estudiante está más de un oyente simple: además la parte íntegra, él se llama para intervenir continuamente, mientras tocando una parte ancho, interactivo e involucrando, del contextualização del tema para ser trabajado -inclusivo, asocie día a día al his/her y contextual al programa de la disciplina de Química, hasta la manera como ese tema debe explorarse. La leche, el tema pone en correlación al origen del grupo de los estudiantes seleccionados, fue explorado, dentro de una visión sistémica, bajo el punto de vista de la composición de las propiedades de la industrialización y de la comercialización. Buscando prever los caminos de la construcción y organización del conocimiento de los estudiantes, se usó el modelo de administración mental de Antoine de La Garranderie y la teoría de aprender de Ausubel. El conocimiento de los estudiantes se supervisó antes, durante y al final de las actividades desarrolladas, práctica que permitió verificar la evolución y el nivel de asimilación conceptual de éstos con respecto al tema en el estudio. El análisis de los resultados obtenidos, después de la aplicación de una encuesta que contempla veinte asuntos, todo pertinentes al tema, demostró un nivel del uso sobre el promedio, lo que merecido la pena el método de enseñanza propuesta

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To clarify the functional mechanisms of habitat use is necessary to analyze it in conjunction with the conduct performed by animals. The occurrence, distribution and use of space are characteristic of a species resulting from habitat selection that is in search of conditions favorable to its survival. One can relate the physical and biological factors of the environment with the ecological characteristics of the species, since these factors act by regulating the ecological success of organisms, and from there you can get important information about the habitat use and behavior of individuals. This study aimed to characterize the use of habitat and diurnal activity expressed by the Guiana dolphin, Sotalia guianensis in an estuarine area of Sergipe state, Brazil, analyzing the influence of tide and time days on the occurrence of animals and behavior s state, and group s size and composition in this cetacean species. From March 2009 to February 2010, focal groups observations of dolphins were made from fixed - point and records snapshots of data taken every 5 min. in the interval from 6 a.m to 6 p.m, in alternating shifts. The results showed that the constant presence of animals in the area of the Sergipe River estuary indicates that this is an important area of occurrence of S. guianensis, which use the region mainly in the morning, at low tide and as a feeding. As in other regions of northeastern Brazil, small groups formed 2-12 individuals were most common, with adults and immatures. The high frequency of immature animals may indicate that this area of the estuary is used as brood area and parental care of pups and young animals, since the immature animals were very associated with adults and monitoring the activities of foraging / feeding may be related to a form of learning or training of such behavior

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The estuaries are important investigation zones of the actual morphodynamic and of depositional facies of recent geological history. They are constituted in important receptor means of the coastal area sediments, where the evolutionary processes occur quickly. They are also attractive means for the development of anthropic activities, which in a disordered way interfere in the active processes in the sedimentary balance of the coastal areas. Among the human interventions, the alterations of the depositional environment of mangroves in areas of tropical estuary is deserving relevance, whose implications for the environment estuarine and the coastal adjacent, they are still far to be known. Due to the interest of the sedimentologic component in the comprehension of the processes linked to the evolution of the environments estuarine and coastal adjacent, this work, aimed at the understanding of the morphodynamic coastal phenomena that comprise the region of estuarine influence of the River Curimataú / RN. It was also evaluated in the morphodynamic context the implications due to alterations of the depositional environment of mangrove by anthropic activity. The Curimataú Estuary, located in the south portion of the oriental coast of Rio Grande do Norte, in the last decades has been objective of the overwhelming occupation of the shrimp farm in areas of mangroves, which were implanted with perspectives of development in a short to medium period. On the other hand, the estuary and its region of coastal influence lacks enough information to subsidize the planning and reorganization more effective of the surrounding activities. Thus, it was intended with this work to give a contribution target tothe maintainable use of the coastal resources of this region. A series of studies using data of orbital and acoustic remote sensing, as of sediments sampling, were executed in the gutter of the estuary. The obtained results starting from the interpretation of bathymetric maps, echo sounder graphics and of distribution of sediments made possible the location of the estuary based in morpho-sedimentar criteria. The estuarine tidal flat was dissected in environments of intertidal mangroves, supratidal mangroves and apicuns with base in the integration of data of sensor optic and of radar following by the field control. The adjacent coast that is influenced by the Curimataú estuary, was segmented according to their geomorphologic characteristics, where each segment had a point of observation of the beach morphodynamic, during the period from january/2001 to february/2002. Once every month, beaches profiles, collections of sediments in the beach zones, as measurement of hydrodynamic parameters were executed. The results of the observations of the tidal environment showed that the area of estuarine influence of the Curimataú begins to suffer negative sedimentary taxes, where in some beaches, the erosive processes are already observed. The granulometric characteristics of the beach sediments start to tend for the increase of thin sand in the erosive periods. The destruction of the depositional environments of mangroves of the Curimataú estuary, to the construction of shrimp farms, can be providing the diminution of the tidal prism of the estuary, enlarging the effects of the local increasing of the sea level, through the smaller supplying of sediments to the adjacent coast. Besides this, it was verified the possibility of the sanding of the tidal channel in the margins of the destroyed areas of mangroves, where very high taxes of sedimentation of thin materials were estimated in case of these areas were preserve