Processos sócio-ambientais relacionados às situações de degradação na região do Rio Doce, Natal/RN

Natal is a medium-sized coastal city (800.000 inhabitants), capital of the State of Rio Grande do Norte, in the Northeast of Brazil. According to statistics published by the IBGE (2000), the area of Natal that stretches from Redinha to Lagoa Azul holds about 12% of the municipal population. Part of this area is bordered by a watercourse, the Rio Doce, which has been afflicted by a range of socio-environmental problems over the years. This study was carried out with the aims of 1) identifying the socio-environmental processes related to urban expansion, with an emphasis on those causing environmental degradation in this region; b) analysing the perception of the target population in relation to the environment it occupies; and c) determining the socioeconomic profile of the local residents and the sanitary facilities available to them. A survey was carried out by conducting interviews and completing questionnaires with the residents to assess the situation both qualitatively and quantitatively in the communities of Caiana, Pajussara Sítio, Gramoré Povoado and Gramoré Sítio, as well as by conducting bibliographical and documentary research. It was discovered that the sanitary conditions of the riverside dwellers are precarious and only 1% of the houses in the suburbs mentioned are connected to the public sewers. It was established that the Rio Doce is intensively exploited through the extraction of sand for the building trade, irrigation of riverside vegetable plots and use of the water for bathing, washing of clothes and leisure. It was also found that about 40% of the population resident in this area has migrated from the rural zone, which is one of the factors rendering it difficult for them to adapt to the urban setting. Such information can be of use to the authorities in the environmental planning of these districts and their sustainable development

A biotecnologia vegetal como alternativa para a cotonicultura familiar sustentável

This paper aims to describe the familiar cotton culture in the districts of Tangará and Triunfo Potiguar, located in the state of Rio Grande do Norte. It relates specific problems that small cotton agriculturists face in the cotton production and sale as well as their perception in relation to public policies that have been put into practice in these districts. The research revealed soils with potentiality for the cotton culture, but that are not being cultivated for anything else but subsistence, not being able to become productive, specifically through the cotton culture. That activity should be practiced so that it preserves the environment and the familiar farmers themselves, since it was verified they are constant1y exposed to health problems due to insecticides use. In what refers to fomentation policies it was observed that bureaucracy delays the liberation of the money destined to production, seeds delivery and other actions related to production and commercialization. Some procedures such as information and training about productivity development and attention with the environrnent and infrastructure are recommended. The results indicate lack of investments, rural credit and technical help, main1y in Triunfo Potiguar. There is unanimity, from the rural farmers of that district in what refers to the desire of improving the production and remaining in that activity. In this sense, the contribution of this research for the most appropriate culture production can be materialized through the technique of tissue's culture, aimed at obtaining plants that are resistant to diseases. The data indicated that the hormonal supplementations used induced regenerative calluses making in vitro morphogenesis possible in alI tested varieties. The use of the activated coal antioxidant was efficient, reducing oxidation, however not suppressing it. The results lead to an opportunity for the familiar tàrmers from Rio Grande do Norte enlarge the cotton culture, because to obtain plants that are resistant to diseases implies in insecticides reduction, propitiating smaller impact to the atmosphere and less cost

Caracterização sócio-ambiental do bairro de Felipe Camarão- Natal/ RN

The rapid growth of the Brazilian cities in the latest years has brought a series of problems regarding housing policies and, therefore, the provision of dwellings for the low-income class people. Following the pattern of other capital cities, Natal has repeated the pattern of urbanization practiced in the country, which concentrates the low-income class inhabitants in specific zones of the city known as peripheries or even in a dwelling place for less-favored classes such as Felipe Camarão, which is one of ten boroughs belonging to the western administrative zone, a region which has historically received less attention from the public administrators towards infrastructure investments. Based on those aspects, the general objective of this work is to investigate which main social-environmental alterations have resulted from the processes of urbanization and field occupation in that area. The specific objectives are concerned with verifying 1) the process of urbanization and the process of dividing urban soil from the 1960s; 2) the current configuration of the public spaces in the borough; 3) the process of the deprivation of the original landscape characteristics of Environmental Protection Zones; 4) the dynamics of land occupation which are predominant in dune areas; 5) the dynamics of land occupation which are predominant in mangrove areas; 6) and the destruction of green covering on the land with its consequent alteration of the local floristic pattern. The methodology consisted of in-loco visits; the application of questionnaires as community research; a survey of bibliography published by the organisms and institutions in charge of carrying out the city hall s environmental and housing policies; and descriptive statistics of the collected data. Concerning the pattern of occupation which is predominant in the borough, the treatment of space dispensed by the local dwellers has culminated in the emergence and consolidation of environmental alterations which are clearly different from common occurrence in both the building area represented by housing complexes and in the green areas represented by dunes and mangroves. The data show that there was the predominance of the irregular land occupation process over the official housing policy during the population settlement which contributed with a series of frequent and foreseeable problems in the dynamics of urbanization of poverty such as invasions and appropriations of land parcels, the beginning of irregular arrangement of streets, the formation of villages and slums, which are full of self-constructed housing units, and the occupation and degradation of susceptibly fragile environmental areas such as the dune slopes and the mangroves

Impactos sócio-econômicos e ambientais da introdução da Tilápia do Nilo, Oreochromis niloticus, em açudes públicos do semi-árido nordestino, Brasi

The stocking of exotic fish, especially the tilapia, has become a common practice in the public reservoirs of the Brazilian semi-arid region. The stocking of tilapias has had as its main aim the improvement of the fisheries in the reservoirs and consequently the improvement of the socio-economic conditions of the families that have fishing as the main source of income. However, the environmental risks associated with this practice are high and can lead to a loss in aquatic biodiversity and to changes in the quality of the water. The object of this work was to quantify the socio-economic and environmental effects of the introduction of the Nile tilapia in the public reservoirs of the semi-arid northeastern Brazil. The analysis of the fish yield of 100 public reservoirs from 1970 to 2000 demonstrated that the introduction of the Nile tilapia apparently contributed to an increase in the total fish yield from the late 1970 s until the mid-1980 s. Nevertheless, from that time onwards the fish yield in these reservoirs has fallen into decline to levels inferior to those observed prior to the introduction of the tilápia. The analysis of the fishing activity statistics of the Gargalheiras reservoir located in the city of Acari, Rio Grande do Norte, demonstrated that the introduction of the Nile tilapia in the reservoir has not significantly increased the fish yield, the gross overall income, the gross per capita income nor the number of fishermen actively fishing in the reservoir. On the other hand, the analysis of the fishing activity statistics of the Gargalheiras reservoir has revealed a significant reduction in the captures of other commercially important fish species after the introduction of the tilapia. This result suggests that the Nile tilapia could have negatively affected other species of fish in the reservoir, contributing to the decline in their stocks. In order to assess the perception of the fishermen concerning the effects of the Nile tilapia over other species of fish and the quality of the water, questionnaires containing open and multiple choice questions were applied with 30 fishermen from the colony of the Gargalheiras reservoir. The great majority of the local fishermen stated that the tilapia is currently the most important species of fish to those who depend on fishing as a source of income and that they have not caused damage to other species of fish nor to the quality of the water in the reservoir. However, the results of the present work indicate that the alleged socio-economic benefits, employed to justify the introduction of the Nile tilapia in the reservoirs, are overestimated while the environmental impacts of the introduction of this exotic species are underestimated

Hábito alimentar e percepção ambiental : um estudo de caso com estudantes do Ensino Médio em Natal-RN

This study has as objective to examine the level of perception of high school students from two private schools in Natal-RN about the existence of a direct link between alimentary habit and its effects on environmental. The research was lead with 433 students, who had their school alimentary habits investigated according to the 24-hour recall method and presents the results of data collection from their opinions on participating in the generation of industrialized solid residues and their yearnings about the improvements of the standard of the food offered in the school. The students show a high rate of grading age for level at school, traditional family structure, riding, predominantly, by car or by bus in the house-school-house way, have generally all three important meals at home, feed frequently at their school, getting it from their won school, which included, mainly, soft drinks and fried or grilled appetizers; show a good knowledge about selective collectors, however with a high variation in their correct use. They show significant approval in the existence of a connection between their alimentary habits and debased effects about environmental and consider their food compounds at school could improve the offering of health/natural food, slowing industrialized foods, which are highly used, sometimes. The study on the students knowledge and concern level with regard to the interface alimentary habit-environmental impact allowed delimitating some of the mainly involved components in the alimentary choices of the same students in the school environment, what might help to develop a set of proposals that stimulates the formation of a responsible consumption standard among teenagers and the need of a consideration about the consequences of their choices

Diversidade de anfíbios anuros na Serra da Mantiqueira na região do Pico dos Marins

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Oferta de micro-hábitats artificiais em riachos degradados: respostas das comunidades de peixes e macroinvertebrados

Pós-graduação em Biologia Animal - IBILCE

Four year multitrophic food web: source food web description, methodology accuracy and species diversity

Food webs have been used in order to understand the trophic relationship among organisms within an ecosystem, however the extension by which sampling efficiency could affect food web responses remain poorly understood. Still, there is a lack of long-term sampling data for many insect groups, mainly related to the interactions between herbivores and their host plants. In the first chapter, I describe a source food web based on the Senegalia tenuifolia plant by identifying the associated insect species and the interactions among them and with this host plant. Furthermore, I check for the data robustness from each trophic level and propose a cost-efficiently methodology. The results from this chapter show that the collected dataset and the methodology presented are a good tool for sample most insect richness of a source food web. In total the food web comprises 27 species belonging to four trophic levels. In the second chapter, I demonstrate the temporal variation in the species richness and abundance from each trophic level, as well as the relationship among distinct trophic levels. Moreover, I investigate the diversity patterns of the second and third trophic level by assessing the contribution of alfa and beta-diversity components along the years. This chapter shows that in our system the parasitoid abundance is regulated by the herbivore abundances. Besides, the species richness and abundances of the trophic levels vary temporally. It also shows that alfa-diversity was the diversity component that most contribute to the herbivore species diversity (2nd trophic level), while the contribution of alfa- and beta-diversity changed along the years for parasitoid diversity (3rd level). Overall, this dissertation describes a source food web and bring insights into some food web challenges related to the sampling effort to gather enough species from all trophic levels. It also discuss the relation among communities associated with distinct trophic levels and their temporal variation and diversity patterns. Finally, this dissertation contributes for the world food web database and in understanding the interactions among its trophic levels and each trophic level pattern along time and space

Fragmentação florestal afeta a distribuição e ocorrência da acarofauna (Arachnida ; Acari) associada a vegetação

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influência do aquecimento nas interações entre detritívoros e decompositores aquáticos e no funcionamento do ecossistema bromelícola

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Eutrofização e capacidade de carga de fósforo de seis reservatórios a bacia do Rio Seridó, região semi-árida do Estado do RN

The eutrofization is a natural process of accumulation of nutrients in aquatic´s body that it has been accelerated for the human´s actives, mainly the related with the activities of camp, industrial and the inadequate disposition of the domestic sewage. The enrichment of the aquatic´s body with nutrients, mainly the nitrogen and the phosphorus, and the consequent proliferation of algae and Cyanobacteria can commit the quality of the water for the public provisioning, for the fish farming and for other ends. The problem becomes more critical when there is a shortage of water naturally as in the semi-arid area of the Brazilian northeast. Before that problem this work had as objective evaluates the trophic state of six reservoirs of the basin of River Seridó of Rio Grande of Norte and also estimate the capacity of load of match of the reservoir and risk probabilities based on the established limits by the resolution Conama 357/05. The results demonstrate that the six reservoirs are eutrofization, with concentration of total phosphorus and cloro a in the water upster to 50 e 12 μg l-1. The results show that space homogeneity exists in the state trophic of the reservoirs, but a significant variation interanual in function of the increase of the concentrations of nutrients and decrease of the transparency of the water with the reduction of the body of water accumulated in the reservoirs.The results of the simulation risk estocastic show that the reservoirs could receive annually from 72 to 216 Kg of P, assuming a risk of 10% of increasing in more than 30 μg l-1 the annual medium concentrations of total match in the water of these reservoirs. This load could be high in until 360 kg of P a year in case the managers assume a risk of 10% of increasing in more than 50 μg l-1 the annual medium concentrations of total phosphorus in the waters of these reservoirs

Investigação e avaliação da toxicidade aguda dos agrotóxicos mais utilizados no cinturão verde da Grande Natal (RN, Brasil) para o peixe-zebra (Danio rerio Hamilton Buchanan, 1822, Teleostei, Cyprinidae

The objectives of this research were to investigate the agrotoxic most used in the Gramorezinho region in the green belt of Natal, and to evaluate the acute toxicity of these, based on the LC50-48h values estimated in tests for Danio rerio, internationally used as test organism. The acute toxicity tests were performed under laboratory conditions, according to standardized methods (ABNT/NBR/15088/04) for this species. The LC50-48h estimated to Tamaron BR was 352.89 mg.L-1, which characterizes that as practically non-toxic, according to toxicological classes cited by Zucker. For Decis 25EC, the LC50-48h estimated was 0.0004156 mg.L-1 (4.156 X 10-4 mg.L-1), which classifies it as highly toxic to this species

Avaliação da qualidade da água do Rio Piranhas-Açu/RN utilizando a comunidade de macroinvertebrados bentônicos

The biomonitoring technique for water quality in water bodies has been incorporated increasingly in management of the natural resources, using mainly indices of its aquatic community characteristics. In Brazil the first efforts to use this technique was restricted to the South and the Midwest region of this country. Located in the northeast region, this study was conducted at Rio Grande do Norte state and had as main objective the assessment of water quality in the Piranhas-Açu river using benthic macroinvertebrates community as biological indicators. Thus, were applied two biotic indices, the BMWP (Biological Monitoring Working Party score system) and the IBF (Family Biotic Index). According the requirements of these indices, two periods of sampling were determined as basic methodology, in dry seasons of 2006 and 2007. The sampling sites were around the municipalities of Açu, Ipanguaçu, Alto do Rodrigues and Pendências. Physical-chemical measurements; a protocol of rapid assessment of diversity of habitats, and determination of the degree of tolerance of each taxon to organic pollution were also performed. The most abundant organisms found in the river were tolerant with the prevalence of Chironomidae (Diptera) and Melanoides tuberculata. This results, together with those ones got in indices application, showed a considerable organic pollution in the four sample places and the reaches were classified as modified to impacted. According to the used indices, this study suggest that this river have significant alteration in the biotic community and water quality on the organic pollution, and this fact, occurs in the reach of the river further downstream, where were expected a good water quality. Considering these results, measures aiming the conservation of this water body are needed regarding as it is inserted into a fragile ecosystem with dry season phenomenon, and the water of this river has extremely importance for the local economy

Determinação da toxicidade aguda e caracterização de risco ambiental do herbicida Roundup (glifosato) sobre três espécies de peixes

Considering their commercial importance, as these are the species of freshwater fish more commercialized in Brazil, their occurence in different kinds of aquatic environments (lakes, rivers and dams) and for being tolerant to a wide range of variation of various physical parameters and chemical water, the fish species Oreochromis niloticus, Cyprinus carpio and Colossoma macropomum were chosen for this study, furthermore, to test the toxicity we used the herbicide Roundup. The fingerlings of tilapia (Oreochromis niloticus), commun carp (Cyprinus carpio) and tambaqui (Colossoma macropomum) were submitted to the herbicide roundup in the following concentrations: 0.0 (control); 18,06; 19,10; 20,14; 21,18 and 22,22 mg.L-1, 0.0 (control); 13,89; 14,86; 15,83; 16,81 and 17,78 mg.L-1, and 0.0 (control); 18,06; 19,10; 20,14; 21,18 and 22,22 mg.L-1, respectively, three for 96 hours. The LC50 - 96h for O. niloticus, C. carpio and C. macropomum was 21,63, 15,33 and 20,06 mg.L-1 of the herbicide roundup, respectively. The results show that this herbicide is classified as slightly toxic to the three species. The values of dissolved oxygen, pH and temperature recorded in the aquarium control and aquarium experimental of the three fish species have remained without significant variations during the tests, which reduces the possibility of death caused by sudden variations of these parameters during the 96 hours the experiment. The values of LC50 between different species of fish were observed, noting that the species O.niloticus, C. carpio and C. macropomum showed no expressive differences. The values of environmental risk of Roundup were calculated to obtain more stringent parameters in assessing the dangerousness of those on nontargets. The risk of environmental contamination by Roundup for the Nile tilapia, common carp, and tambaqui are low for the lowest application rate (1 L.ha-1) and depths (1.5 and 2.0 m). The dilution of 100%, the highest recommended dose (5 L.ha-1) and depths (1.5 and 2.0 m) the risk is moderate for the three species. The values of the Risk Ratio (QR) were greater than 0,1, indicating that the values of the CAE and LC50 are above acceptable levels and there is a need, this study, a refinement in ecotoxicological tests

Efeito dos nutrientes (nitrogênio e fósforo) sobre o desenvolvimento da Gracilaria birdiae: crescimento e possível uso como biofiltro

Marine shrimp farming has grown exponentially during the last years in Brazil. In spite of the promising economical situation, this activity is facing an increasing criticism due to its environmental impact. Thus, the necessity of alternatives to mitigate environmental degradation caused by this activity. An alternative that is being studied is the policulture that is the integrated culture of two or more organisms, normally one of them a filtering organism. Among filtering organisms, macroalgae are very practicable because they are efficient in the removal of the exceeding nutrients of the water and do not leave residues in the water. Besides, the integrated culture with macroalgae allows the economical exploration of the seaweed (for the manufacture of jelly and jam, for the dairy industry, pharmaceuticals, etc.) along with possibility of a sustainable aquaculture. In the present experiment, the development of the seaweed Gracilaria birdiae, the influence and tolerance of this species to the environmental parameters, and its absorption efficiency in relation with the three kinds of macronutrients (NH4+, NO3- and PO4-3) found in the effluents of marine shrimp farming was studied. The experiment was divided in two parts: a laboratorial part and one part carried under natural conditions. The water used in the laboratory trial was collected in the shrimp ponds of Tecnarão farm and distributed in aquaria containing 20 g of G. birdiae. In the field trial, 0.5 kg of G. birdiae was inserted in PVC cages cultivated in the farm. The results of the study showed a modest growth of G. birdiae, probably due to its low tolerance to highly eutrophicated environments. However, the removal of nutrients was very expressive. Ammonia was reduced in approximately 34 %. Ortho-phosphate showed a reduction of 93.5 %. The capacity of biofiltration of the NO3- by the macro algae was of 100 %, showing that G. birdiae is a seaweed-filtered with a high level of removal for this nutrient under laboratorial conditions. In spite of the low growth of the macro algae in the experiment, the results in relation to the removal of nutrients of the water was encouraging, suggesting that this species can be an efficient biofilter and thus, a strong candidate to be used in a sustainable aquaculture