Made available in DSpace on 2014-12-17T14:33:03Z (GMT). No. of bitstreams: 1 FabianaOA.pdf: 1147219 bytes, checksum: 82a575e2220e5c6ece53b3d6ec73aede (MD5) Previous issue date: 2009-04-06 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The increasing of pollution in aquatic ecosystems in the last decades has caused an expansion of eutrophication and loss of water quality for human consumption. The increase of frequency and intensity of cyanobacteria blooms have been recognized as a major problem connected to water quality and eutrophication. The knowledge of environmental factors controlling these blooms is a key step towards the management for recovering aquatic ecosystems from eutrophic conditions. Primary productivity in aquatic ecosystems is dependent on light and nutrients availability. In the present work we evaluated the relative importance of the concentration of major nutrients, such as phosphorus and nitrogen, and light for phytoplankton growth in the main water reservoir of Rio Grande do Norte State, named Engenheiro Armando Ribeiro Gon?alves (EARG), which is an eutrophic system, dominated by potentially toxic cyanobacteria populations. Limitation of phytoplankton growth was evaluated through bioassays using differential enrichment of nutrients (N and/or P) under two light conditions (low light and high light) and monthly monitoring of chlorophyll-a and nutrients (total nitrogen and phosphorus) concentrations, and water transparency (Secchi depth) at the pelagic region. Our results confirm that EARG reservoir is an eutrophic system with a low water quality. Results of bioassays on the growth of phytoplankton limitation (N or P) were conflicting with the results predicted by the TN:TP ratios, which indicates that these ratios were not a good indicator of algal growth limitation. Nitrogen was the limiting nutrient, considering both frequency and magnitude. Light and hidrology affected phytoplankton response to nutrient enrichment. The extreme eutrophic conditions of this reservoir, dominated by cyanobacteria blooms, demand urgent managing strategies in order to guarantee the multiple uses for this system, including water supply for human population. Although nitrogen is the limiting nutrient, an effective management program must focus on the reduction of both phosphorus and nitrogen input / O aumento da polui??o nos ecossistemas aqu?ticos nas ultimas d?cadas tem causado uma expans?o da eutrofiza??o e perda da qualidade da ?gua para o consumo humano. O aumento da freq??ncia e intensidade de flora??es de cianobact?rias tem sido reconhecido com o principal problema ligado a eutrofiza??o e qualidade da ?gua. O conhecimento dos fatores ambientais que controlam essas flora??es ? um passo fundamental para a gest?o de recupera??o de ecossistemas aqu?ticos eutrofizados. A produtividade em ecossistemas aqu?ticos ? dependente da disponibilidade de luz e nutrientes. No presente trabalho, n?s avaliamos a import?ncia relativa da concentra??o dos principais nutrientes (nitrog?nio e f?sforo) e da luz para o crescimento fitoplanct?nico no principal reservat?rio do estado do Rio Grande do Norte, o reservat?rio Engenheiro Armando Ribeiro Gon?alves (EARG), que ? um sistema eutrofizado, dominado por cianobact?rias potencialmente t?xicas. A limita??o do crescimento fitoplanct?nico foi avaliada atrav?s de bioensaios usando enriquecimento diferencial de nutrientes (N e/ou P) sob duas condi??es de luz (baixa e alta luz) e monitoramento mensal das concentra??es de nutrientes (nitrog?nio e f?sforo totais), clorofila a e transpar?ncia da ?gua (profundidade de Secchi) na regi?o pel?gica. Nossos resultados confirmaram que o reservat?rio EARG ? um sistema eutr?fico com baixa qualidade da ?gua. Os resultados dos bioensaios sobre a limita??o do crescimento fitoplanct?nico foram contradit?rios com os resultados preditos pelas raz?es NT:PT, o que indica que essas raz?es n?o s?o um bom indicador da limita??o do crescimento. O nitrog?nio foi o nutriente limitante, tanto em freq??ncia quanto em magnitude. A luz e o regime hidrol?gico afetaram a resposta do fitopl?ncton ao enriquecimento com nutrientes. As condi??es eutr?ficas deste reservat?rio, dominado por flora??es de cianobact?rias, demanda estrat?gias de manejo a fim de garantir os usos m?ltiplos neste sistema, incluindo o abastecimento de ?gua para o consumo humano. Embora o nitrog?nio seja o nutriente limitante, um programa de manejo efetivo dever? focar sobre a redu??o da entrada de f?sforo e nitrog?nio

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-04-15T23:04:38Z No. of bitstreams: 1 MarianaRodriguesAmaralDaCosta_DISSERT.pdf: 2488995 bytes, checksum: c1bb8bd3c6d969c70744bfd049bfdd73 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-20T21:52:13Z (GMT) No. of bitstreams: 1 MarianaRodriguesAmaralDaCosta_DISSERT.pdf: 2488995 bytes, checksum: c1bb8bd3c6d969c70744bfd049bfdd73 (MD5) / Made available in DSpace on 2016-04-20T21:52:13Z (GMT). No. of bitstreams: 1 MarianaRodriguesAmaralDaCosta_DISSERT.pdf: 2488995 bytes, checksum: c1bb8bd3c6d969c70744bfd049bfdd73 (MD5) Previous issue date: 2014-03-20 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A eutrofiza??o artificial ? uma das grandes amea?as ? qualidade ambiental de ecossistemas aqu?ticos em todo o mundo. As expectativas dos cen?rios clim?ticos futuros para regi?es ?ridas e semi?ridas s?o per?odos de secas mais intensas e frequentes, aumentando ainda mais o risco de eutrofiza??o e de flora??es de cianobact?rias. Muitas t?cnicas de restaura??o de lagos eutrofizados foram propostas para reduzir as cargas de nutrientes e melhorar a qualidade da ?gua. Uma t?cnica bastante utilizada ? a biomanipula??o por remo??o de peixes que v?m se mostrando eficiente em lagos eutr?ficos de regi?es temperadas. Trabalha mos a hip?tese de que a remo??o de peixes bent?v oros bioturbadores reduz a biomassa total do fitopl?ncton e altera a composi??o dos grupos funcionais fitoplanct?nicos , refletindo na melhora d a qualidade da ?gua . Assim , este estudo teve como objetivo avaliar o impacto da biomanipula??o na din?mica e estr utura d os grupos funcionais fitoplanct?nicos e n a qualidade da ?gua. Aplicamos a t?cnica da biomanipula??o no lago artificial ESEC, regi?o semi?rida do nordeste brasileiro e analisamos as vari?veis f?sicas e qu?micas da ?gua e a din?mica dos grupos funcion ais fitoplanct?nicos, mensalmente durante o per?odo de novembro de 2012 a agosto de 2013. Com a remo??o dos peixes bioturbadores, observamos um aumento significativo na zona euf?tica, na riqueza de esp?cies fitoplanct?nicas e o recrutamento de grupos funci onais fitoplanct?nicos de algas verdes (grupos F e J) indicadoras de boa qualidade ambiental. Por?m, n?o observamos diferen?as significativas na concentra??o de f?sforo total e na biomassa e diversidade fitoplanct?nica. O efeito da seca severa na regi?o du rante o estudo foi evidente , proporcionando uma redu??o dr?stica no n?vel de ?gua que influenciou na disponibilidade de recursos e afetou a comunidade fitoplanct?nica antes da biomanipula??o . Para avaliar o efeito de uma seca severa sobre a din?mica dos gr upos funcionais fitoplanct?nicos e testar se per?odos de seca s?o favor?veis ? domin?ncia de cianobact?rias, estudamos dois lagos artificiais vizinhos (ESEC e Pocinhos) no semi?rido tropical durante maio de 2012 a fevereiro de 2013. Observamos uma diferenc ia??o temporal das vari?veis abi?ticas e do fitopl?ncton causada pela seca severa. Ambos os lagos apresentaram redu??o de 2 metros do n?vel da ?gua e aumento nos valores de condutividade, turbidez, nas concentra??es de nutrientes e redu??o da transpar?ncia da ?gua, durante o per?odo da seca severa. Por?m, a comunidade fitoplanct?nica respondeu diferente ?s condi??es ambientais dependendo da profundidade de cada lago. O mais profundo (Pocinhos) aumentou a biomassa total do fitopl?ncton e apresentou domin?nci a do grupo funcional de cianobact?rias heterocitadas formadoras de flora??o (grupo S N ) e o lago menos profundo (ESEC) reduziu a biomassa total e apresentou domin?ncia de grupos funcionais de algas flageladas com metabolismo mixotr?fico (grupos W 1 e W 2 ) . Su marizando, o conhecimento sobre os efeitos da biomanipula??o por remo??o de peixes bent?voros bioturbadores em um lago raso no semi?rido tropical ainda ? incipiente e o estudo possui limita??es devido ao evento de seca prolongada durante o per?odo de estud o . Sendo assim, ? necess?rio um monitoramento em longo prazo para investigar os reais efeitos da biomanipula??o no funcionamento do ecossistema. Al?m disso, per?odos de seca podem ter efeitos antag?nicos (aumento ou redu??o) na biomassa total , bem como na composi??o dos grupos funcionais fitoplanct?nicos, que nem sempre levar? ? domin?ncia de cianobact?rias. / The artifi cial eutrophication is one of the biggest t h reat for the quality of aquatic ecosystems in the whole world. The expectations for the future climatic scenarios in arid and semi - arid regions are intense and frequent droughts enhancing the risk of eutrophicati on and cyanobacterial blooms. Restoration techniques of eutrophic lakes were proposed to reduce nutrient loading and improve the water quality. A successful technique used in temperate regions is the biomanipulation by benthivorous fish removal . Our hypoth esis is that the benthivorous fish removal reduces phytoplankton total biomass and change the composition of phytoplankton functional groups, improving water quality. The aim of the study was evaluate the impact of biomanipulation on phytoplankton function al groups and in the water quality. We applied the technique of biomanipulation in the artificial lake ESEC, in a semi - arid region of Brazil and analyzed the physical and chemical variables and the dynamic of phytoplankton functional groups monthly during November 2012 to August 2013. With the removal of benthivorous fish we observed a significant increase of the euphotic depth, phytoplankton richness and the recruitment of green algae (groups F and J ), indicators of good water quality. However, we did not observe significant differences on total phosphorous concentration and on phytoplankton biomass and diversity. The drought effect in the region during the study was evident , promoting a drastic reduction on water level which influenced the availability of resource and affected phytoplankton community before the biomanipulation. To evaluate the effect of severe drought on the dynamic of phytoplankton functional groups and test if the drought periods are favorable to dominance of cyanobacterial groups, we stu died two artificial neighbors lakes (ESEC and Pocinhos) in a semi - arid tropical region during May 2012 to February 2013. We observed a temporal differentiation of biotic and abiotic variables caused by drought. Both lakes presented reduction of 2 meters of water level and increase on conductivity, turbidity, nutrients concentration and a reduction on water transparency, during the severe drought. The deeper lake (Pocinhos) increased phytoplankton total biomass and presented cyanobacterial functional group d ominance (group S N ) and the shallower lake (ESEC) reduced phytoplankton total biomass and presented dominance of mixotrophic and flagellate functional groups (groups W 1 e W 2 ). Summarizing, the knowledge of the effects of benthivorous fish removal in semi - a rid tropical lakes still unknown and this study had limitations caused by the impact of drought. Thus, it is necessary a long term monitoring to investigate the real effects of biomanipulation on the functioning of the studied ecosystems. Otherwise, period s of drought could have opposite effects (increase or reduction) on total biomass and composition of phytoplankton functional groups. Drought not always leads to dominance of cyanobacterial groups.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-07-06T20:31:23Z No. of bitstreams: 1 FabianaOliveiraDeAraujoSilva_TESE.pdf: 783632 bytes, checksum: d5a28b9c131a2a8187ccb70b95821d14 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-07-08T17:34:29Z (GMT) No. of bitstreams: 1 FabianaOliveiraDeAraujoSilva_TESE.pdf: 783632 bytes, checksum: d5a28b9c131a2a8187ccb70b95821d14 (MD5) / Made available in DSpace on 2016-07-08T17:34:29Z (GMT). No. of bitstreams: 1 FabianaOliveiraDeAraujoSilva_TESE.pdf: 783632 bytes, checksum: d5a28b9c131a2a8187ccb70b95821d14 (MD5) Previous issue date: 2015-02-03 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / A eutrofiza??o ? a causa mais comum de deteriora??o da qualidade da ?gua no mundo. Este processo se d? pela entrada excessiva de nutrientes, nitrog?nio e f?sforo, nos corpos aqu?ticos causando flora??es de algas e cianobact?rias. Em lagos rasos esses efeitos s?o mais complicados devido a uma maior intera??o do corpo aqu?tico com o entorno, com o ar e o sedimento. Existem v?rias t?cnicas de restaura??o de lagos eutrofizados, com uma vasta gama de resultados bem sucedidos, mas no Brasil h? apenas um ?nico caso de restaura??o bem sucedida: o lago Parano? em Bras?lia. A regi?o semi?rida brasileira possui milhares de lagos artificiais, regionalmente chamados de a?udes, em sua maioria rasos e eutr?ficos. A eutrofiza??o desses corpos aqu?ticos ? documentada e o fitopl?ncton desses ambientes ? frequentemente dominado por cianobact?rias potencialmente t?xicas. O principal objetivo desta tese de doutorado ? testar diferentes t?cnicas de restaura??o da qualidade da ?gua que possam ser facilmente aplicadas em lagos rasos do semi?rido brasileiro. Resultados de um experimento em laborat?rio sugerem que a aplica??o de argila adsorvente de f?sforo associada a um coagulante ? base de alum?nio ? uma t?cnica efetiva na remo??o do f?sforo reativo sol?vel e na diminui??o da taxa de crescimento da Cylindrospermopsis raciborskii, cianobact?ria potencialmente t?xica que domina nos reservat?rios do semi?rido brasileiro, mas que esse efeito ? dependente da biomassa no momento da aplica??o da t?cnica. Os resultados de um experimento de campo realizado em mesocosmos num lago raso eutrofizado demonstraram que a aplica??o de coagulante ? base de alumn?nio em conjunto com a da remo??o de peixes bent?voros ? mais eficiente na remo??o de f?sforo total e clorofila-a da coluna de ?gua do que a aplica??o isolada de apenas uma dessas t?cnicas. Por fim, testes de laborat?rio demostraram que o coagulante ? base de alum?nio apresentou um bom desempenho em remover turbidez e f?sforo total em testes de bancada com ?gua de seis reservat?rios do semi?rido, sendo a efici?ncia reduzida com o aumento da biomassa de clorofila e pH. Os resultados deste estudo mostram que ? poss?vel melhorar a qualidade da ?gua de reservat?rios eutrofizados no semi?rido brasileiro atrav?s do controle da carga interna de nutrientes seja pela precipita??o e inativa??o do f?sforo no sedimento, como tamb?m pela inibi??o da libera??o do f?sforo no sedimento por peixes bioturbadores, e que os resultados s?o aditivos quando as t?cnicas s?o aplicadas em conjunto. / Eutrophication is the most common cause of water quality degradation in the world. This process occurs by excessive nutrients inputs, nitrogen and phosphorus, to the aquatic systems resulting in algal and cyanobacterial blooms. In shallow lakes these effects are pronounced due to the higher interaction of the lake with watershed, air and sediment. There are innumerous restoration techniques of eutrophied lakes with a range of successful results but there is only one case of successful lake restoration in Brazil: Parano? Lake in Bras?lia city. The Brazilian semiarid region has many artificial lakes, named a?udes, which are mostly eutrophic and shallow lakes. The eutrophication in these lakes is reported and the phytoplankton community is dominated by potentially toxic cyanobacteria species, mainly Cylindrospermopsis raciborskii. The aim of this thesis is to test techniques for water quality management which can be easily applied in Brazilian semiarid lakes. Results from a laboratory experiment suggest that the addition of a phosphorus sorbent clay associated with an aluminium based coagulant is an effective technique in removing soluble reactive phosphorus and reducing C. raciborskii growth rate ? cyanobacteria potentially toxic dominant in reservoirs of Brazilian semiarid ? but this effect is dependent on the biomass in the application moment. Results from a field experiment in mesocosm in a eutrophied lake showed that the addition of aluminium based coagulant and removal of benthivorous fish is more efficient in removing total phosphorus and chlorophyll-a from water column than the isolated application of one of the techniques. Lastly, laboratory tests showed that aluminium based coagulant exhibited good performance in removing turbidity and total phosphorus from water of six reservoirs but the efficiency was reduced by algal biomass and pH. The results of this study showed that the improvement in water quality of eutrophied reservoirs in semiarid region is possible through internal loading control by phosphorus precipitation and inactivation in sediments or inhibition of phosphorus release by benthivorous fishes, and also that these results show are additives in water quality improvement.

Made available in DSpace on 2014-12-17T15:03:22Z (GMT). No. of bitstreams: 1 FaranciscoRSF_restricoes.pdf: 1206510 bytes, checksum: bdf6c5d3c8390b9e1ea63d1d4080d1ed (MD5) Previous issue date: 2008-12-15 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Eutrophication has been listed as one of the main problems of water pollution on a global level. In the Brazilian semi-arid areas this problem takes even greater proportions due to characteristical water scarcity of the region. It is extremely important to the predictive eutrophication models development and to the reservoirs management in the semi-arid region, studies that promotes understanding of the mechanisms responsible for the expansion and control of algae blooms, essential for improving the water quality of these environments. The present study had as its main aims, evaluate the temporal pattern of trophic state, considering the influence of nutrients (N and P) and the light availability in the water column in the development of phytoplankton biomass, and perform the mathematical modelling of changes in phosphorus and chlorophyll a concentrations in the Cruzeta man-made lake located on Serid?, a typical semi-arid region of Rio Grande do Norte. To this, a fortnightly monitoring was performed in the reservoir in 05 stations over the months of March 2007 to May 2008. Were measured the concentrations of total phosphorus, total organic nitrogen, chlorophyll a, total, fixed and volatile suspended solids, as well as the measure of transparency (Secchi) and the profiles of photosynthetic active radiation (PAR), temperature, pH, dissolved oxygen and electrical conductivity in the water column. Measurements of vertical profiles have shown some periods of chemical and thermal stratification, especially in the rainy season, due to increased water column depth, however, the reservoir can be classified as warm polimitic. During the study period the reservoir was characterized as eutrophic considering the concentrations of phosphorus and most of the time as mesotrophic, based on the concentrations of chlorophyll a, according to the Thornton & Rast (1993) classification. The N:P relations suggest N limitation, conversely, significant linear relationship between the algae biomass and nutrients (N and P) were not observed in our study. However, a relevant event was the negative and significant correlation presented by Kt and chlorophyll a (r ? = 0.83) at the end of the drought of 2007 and the rainy season of 2008, and the algal biomass collapse observed at the end of the drought season (Dec/07). The equation used to simulate the change in the total phosphorus was not satisfactory, being necessary inclusion of parameters able to increase the power of the model prediction. The chlorophyll a simulation presented a good adjustment trend, however there is a need to check the calibrated model parameters and subsequent equation validation / A eutrofiza??o tem se apresentado como um dos principais problemas de polui??o aqu?tica a n?vel global. No semi-?rido brasileiro este problema toma propor??es ainda maiores devido a escassez de ?gua caracter?stica da regi?o. Torna-se extremamente relevante para o desenvolvimento do modelos preditivos de eutrofiza??o e para a gest?o dos reservat?rios da regi?o semi-?rida, a realiza??o de estudos que propiciem a compreens?o dos mecanismos respons?veis pela expans?o e controle de flora??es de algas, fundamentais para a melhoria da qualidade da ?gua desses ambientes. Diante disso, o presente estudo teve como objetivos principais, avaliar o padr?o temporal do estado tr?fico, considerando a influ?ncia dos nutrientes (N e P) e a disponibilidade de luz na coluna d ?gua no desenvolvimento da biomassa fitoplanct?nica, e realizar a modelagem matem?tica da varia??o das concentra??es de f?sforo e clorofila a no a?ude Cruzeta localizado na regi?o do Serid?, regi?o t?pica do semi-?rido do Rio Grande do Norte. Para tanto, foi realizado o monitoramento do reservat?rio com amostragens de ?gua quinzenais em 05 pontos de coleta ao longo dos meses de mar?o de 2007 a maio de 2008, sendo determinadas as concentra??es de f?sforo total, nitrog?nio org?nico total, clorofila a, e s?lidos suspensos totais, fixos e vol?teis, al?m da medida de transpar?ncia (Secchi) e dos perfis de radia??o fotossinteticamente ativa (RFA), temperatura, pH, oxig?nio dissolvido e condutividade el?trica na coluna d ?gua. As medi??es dos perfis verticais realizados evidenciaram alguns per?odos de estratifica??o t?rmica e qu?mica, notadamente no per?odo chuvoso, devido a maior profundidade da coluna d ?gua, no entanto o reservat?rio pode ser classificado como pol?mitico quente. Durante o per?odo estudado o reservat?rio caracterizou-se como eutr?fico considerando-se as concentra??es de f?sforo e mesotr?fico na maior parte do tempo, com base nas concentra??es de clorofila a, segundo a classifica??o de Thornton & Rast (1993). As raz?es N:P observadas sugerem limita??o por N, opostamente, rela??es lineares significativas entre a biomassa de algas e os nutrientes (N e P) n?o foram observadas no nosso estudo. Entretanto, chamou aten??o a rela??o negativa e significativa apresentada pelo Kt e clorofila a (r?=0.83) no final do per?odo de estiagem de 2007 e per?odo chuvoso de 2008, e do colapso da biomassa algal observado no final do per?odo de estiagem (dez/07). A equa??o utilizada para simular a varia??o do f?sforo total n?o apresentou ajuste satisfat?rio, sendo necess?rio portanto, inser??o de par?metros capazes de elevar o poder de predi??o do modelo. A simula??o para clorofila a apresentou uma boa tend?ncia de ajuste, entretanto h? necessidade de verifica??o dos par?metros calibrados no modelo e posterior valida??o da equa??o

Made available in DSpace on 2014-12-17T15:03:30Z (GMT). No. of bitstreams: 1 JoseNPO_DISSERT.pdf: 2861087 bytes, checksum: 5501c10c7323ae1724c567209f6872ed (MD5) Previous issue date: 2012-06-15 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In semiarid region of northeast Brazil, the majority of reservoirs used for public supply has suffered degradation of water quality affected by diffuse pollution from agricultural and livestock areas of the watershed and by hydrologic regime peculiar to the region, characterized by a rainy season with higher volumes stored in reservoirs and a dry season with a reduction in water level due to high evaporation and increase of eutrophication. The Dourado reservoir, located in Currais Novos city, semiarid region of Rio Grande do Norte state, is one example of a water supply reservoir that can have degradation of water quality and impracticability of their use, due to the high external input of nutrients from non-point sources of watershed during the rainy season and increasing of eutrophication due to decrease the stored volume during the dry period. This study aimed to investigate and quantify diffuse pollution and the hydrologic regime of semiarid region in order to establish standards regarding the water quality of Dourado reservoir. The study period was between the months of May 2011 to March 2012. The diffuse pollution was quantified in terms of watershed from the mass balance of phosphorus in the reservoir, as in relation to areas under different types of land use within the riparian zone of the reservoir from the assessment of soil chemical properties and losses of phosphorus in each area. The influence of hydrological regime on water quality of the reservoir was evaluated from the monthly monitoring of the morphometric, meteorological and limnological features throughout the study period. The results showed that the reservoir has received a high load of phosphorus coming from the drainage basin and presents itself as a system able to retain some of that load tributary, giving an upward trend of the eutrophication process. Diffuse pollution by nutrients from areas under different types of land use within the riparian zone of the reservoir was higher in areas under the influence of livestock, being this area considered a potential diffuse source of nutrients to the reservoir. Regarding the water regime during the rainy season the reservoir was characterized by high concentrations of nutrients and small algal biomass, while in the dry season the reduction of volume and increase of the water retention time of the reservoir, contributing to the excessive growth algal biomass, favoring an increase in eutrophication and deterioration of water quality. In synthesis the water quality of Dourado reservoir is directed by diffuse pollution coming from the drainage basin and the hydrological regime of the peculiar semiarid region, where the rainy season is characterized by high input of allochthonous compounds from the tributaries and erosion of the soil in the reservoir riparian zone, and the dry season characterized by reducing the storage volume due to high evaporation, high residence time of water and consequent degradation of water quality due to the increase of eutrophication process / Na regi?o semi?rida do nordeste do Brasil a maioria dos reservat?rios utilizados para abastecimento p?blico vem sofrendo degrada??o da qualidade da ?gua, influenciados pela polui??o difusa de ?reas agr?colas e de pecu?ria da bacia de drenagem e pelo regime hidrol?gico peculiar da regi?o, caracterizado por um per?odo de chuva com maiores volumes armazenados nos reservat?rios e um per?odo de seca com redu??o do n?vel da ?gua devido ? intensa evapora??o e aumento do processo de eutrofiza??o. O reservat?rio Dourado, localizado no munic?pio de Currais Novos, regi?o semi?rida do estado do Rio Grande do Norte ? um exemplo de manancial de abastecimento que pode apresentar degrada??o da qualidade da ?gua e inviabiliza??o do seu uso, devido ao elevado aporte externo de nutrientes a partir de fontes n?o-pontuais da bacia de drenagem durante o per?odo chuvoso e aumento do processo de eutrofiza??o devido a diminui??o do volume armazenado durante o per?odo de seca. Este trabalho teve como objetivo investigar e quantificar a polui??o difusa e o regime hidrol?gico da regi?o semi?rida a fim de estabelecer padr?es referentes ? qualidade da ?gua do reservat?rio Dourado. O per?odo de estudo foi compreendido entre os meses de maio de 2011 a mar?o de 2012. A polu??o difusa foi quantificada tanto em rela??o ? bacia de drenagem, a partir do balan?o de massa de f?sforo no reservat?rio, como em rela??o a ?reas sob diferentes tipos de uso do solo na zona rip?ria do reservat?rio a partir da avalia??o dos atributos qu?micos do solo e das perdas de f?sforo em cada ?rea. A influ?ncia do regime hidrol?gico na qualidade da ?gua do reservat?rio foi avaliada a partir do monitoramento mensal das vari?veis morfom?tricas, meteorol?gicas e limnol?gicas do reservat?rio ao longo do per?odo de estudo. Os resultados mostraram que o reservat?rio recebeu uma elevada carga de f?sforo advinda da bacia de drenagem e se apresentou como um sistema capaz de reter parte desta carga afluente, conferindo uma tend?ncia ao aumento do processo de eutrofiza??o. A polui??o difusa por nutrientes a partir de ?reas sob diferentes tipos de uso do solo na zona rip?ria do reservat?rio foi maior na ?rea sob influ?ncia da pecu?ria, sendo essa ?rea considerada uma potencial fonte difusa de nutrientes para o reservat?rio. Em rela??o ao regime hidrol?gico, durante o per?odo de chuva o reservat?rio foi caracterizado por elevadas concentra??es de nutrientes e reduzida biomassa algal, enquanto que no per?odo de seca a redu??o do volume e o aumento do tempo de reten??o da ?gua do reservat?rio contribuiu para o crescimento excessivo da biomassa algal, favorecendo o aumento do processo de eutrofiza??o. Em s?ntese a qualidade da ?gua do reservat?rio tropical Dourado ? direcionada pela polui??o difusa oriunda da bacia de drenagem e pelo regime hidrol?gico peculiar da regi?o semi?rida, onde o per?odo chuvoso ? caracterizado pelo elevado aporte de compostos al?ctones provenientes dos rios tribut?rios e da eros?o do solo na zona rip?ria do reservat?rio, e o per?odo seco caracterizado pela marcante redu??o do volume armazenado devido ? intensa evapora??o, alto tempo de resid?ncia da ?gua e a consequente degrada??o da qualidade da ?gua devido ao aumento do processo de eutrofiza??o

Made available in DSpace on 2014-12-17T15:03:32Z (GMT). No. of bitstreams: 1 HerisonAO_DISSERT.pdf: 3081759 bytes, checksum: 59a4bbd5e10be405adf04193c0181a31 (MD5) Previous issue date: 2013-09-06 / The building of water reservoirs has become a solution for water scarcity of the semiarid regions, however, the land use and occupation near the margins of the reservoirs have been causing serious damage to water quality, harming their use. This paper aims to analyze the land use and occupation in the margins of the Northeast reservoir and evaluate their influence on the water quality, to identify the areas and activities that represent an higher risk of contamination to the reservoir. The study was conducted at the reservoir Dourado, located in the city of Currais Novos - RN, during the period from August 2012 to February 2013. Were defined six areas regarding the land use and occupation, then, Water samples were collected from the margins in these areas for the characterization of water quality. The results showed that almost all Permanent Preservation Areas (PPA) from the reservoir is degraded, increasing the susceptibility of large input of nutrients and contaminants loads. The water reservoir showed low quality, being with strong evidence of eutrophication due to the nutrient accumulation arising from the activities surrounding the reservoir, mainly from agriculture and Livestock. The Areas 1 and 2 are the areas that present a greater risk of reservoir degradation, because are the possible major sources of nutrients (phosphorus total, orthophosphate and nitrate), however, due to the small size of the reservoir, any compound that reaches its margins ultimately affects the water quality of the same / A constru??o de reservat?rios de ?gua se tornou uma solu??o para a escassez de ?gua das regi?es semi?ridas, por?m, a ocupa??o e o uso dos solos pr?ximos ?s margens dos reservat?rios v?m causando s?rios danos a qualidade da ?gua, chegando a prejudicar o seu uso. Este trabalho tem como objetivo analisar o uso e ocupa??o do solo das margens de um reservat?rio nordestino e avaliar a sua influ?ncia sobre a qualidade da ?gua, visando identificar as ?reas e as atividades que representam um maior perigo de contamina??o ao reservat?rio. O trabalho foi realizado no reservat?rio Dourado, localizado no munic?pio de Currais Novos RN, durante per?odo de agosto de 2012 a fevereiro de 2013. Foram delimitadas seis ?reas quanto ao uso e ocupa??o do solo, em seguida, foram coletadas ?guas das margens dessas ?reas para a caracteriza??o da qualidade da ?gua. Os resultados mostraram que quase toda a ?rea de Preserva??o Permanente (APP) do reservat?rio esta degradada, aumentando a susceptibilidade de entrada de grandes cargas de nutrientes e de contaminantes. A ?gua do reservat?rio apresentou baixa qualidade, estando com fortes ind?cios de eutrofiza??o devido ao ac?mulo de nutrientes advindos das atividades realizadas nas margens do reservat?rio, principalmente da agricultura e da cria??o de animais. As ?reas 1 e 2 s?o as ?reas que apresentam um maior risco de degrada??o do reservat?rio, pois s?o as poss?veis maiores fontes de nutrientes (fosforo total, ortofosfato e nitrato), por?m, devido ao pequeno tamanho do reservat?rio, qualquer tipo de composto que chegue em sua margem acaba influenciando na qualidade da ?gua do mesmo

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-14T22:36:28Z No. of bitstreams: 1 LeonardoRafaelMedeiros_DISSERT.pdf: 2075288 bytes, checksum: 2bc53649b8f302a0ac6c99aad966ca6a (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-16T20:04:47Z (GMT) No. of bitstreams: 1 LeonardoRafaelMedeiros_DISSERT.pdf: 2075288 bytes, checksum: 2bc53649b8f302a0ac6c99aad966ca6a (MD5) / Made available in DSpace on 2017-03-16T20:04:47Z (GMT). No. of bitstreams: 1 LeonardoRafaelMedeiros_DISSERT.pdf: 2075288 bytes, checksum: 2bc53649b8f302a0ac6c99aad966ca6a (MD5) Previous issue date: 2016-12-28 / A eutrofiza??o artificial tem sido considerada um problema de grande preocupa??o nos ecossistemas aqu?ticos em todo o mundo. Desde 1960, os avan?os cient?ficos t?m sido feitos a fim de desenvolver t?cnicas que atenuem os efeitos da eutrofiza??o. V?rios procedimentos f?sicos, qu?micos e biol?gicos podem ser usados e combinados para recuperar lagos de flora??es de cianobact?rias, como a aplica??o de um floculante combinado com argila natural ou modificada. No entanto, a efic?cia dos solos de regi?es ?ridas na mitiga??o de flora??es ? desconhecida para lagos artificiais brasileiros. Neste artigo, apresentamos uma an?lise bibliom?trica da evolu??o de publica??es sobre flora??es de cianobact?rias e identificamos registros que diretamente objetivam superar a ocorr?ncia dessas flora??es. Al?m disso, avaliamos, por meio de experimentos laboratoriais, o efeito do uso combinado do floculante policloreto de alum?nio (PAC) e um solo local do entorno do lago (LS), como lastro, no controle de flora??es de cianobact?rias em um lago raso da regi?o semi?rida do Brasil. A pesquisa bibliom?trica foi conduzida com o banco de dados "Web of Science" atrav?s da fun??o de busca ?TS = ((cyanobacteri* or blue green algae or cyanoprokariote or cyanophyceae) and (mass accumulation or bloom or domina*))?, de 1969 a junho de 2016. Realizamos uma an?lise de freq??ncia de palavras-chave e quantificamos o n?mero de registros com uma abordagem de restaura??o. Al?m disso, foram realizadas tr?s s?ries de experimentos em tr?s momentos com flora??es diferentes em composi??o e biomassa no Reservat?rio Armando Ribeiro Gon?alves. Nossa pesquisa revelou que os estudos sobre as flora??es de cianobact?rias aumentaram exponencialmente e seu impacto quantitativo nas ci?ncias aqu?ticas aumentou significativamente ao longo dos anos (F = 97,52; p <0,0001). Os EUA se destacam como a na??o mais produtiva, seguida pela China e pa?ses europeus. A China aumentou impressionantemente sua contribui??o para essa ?rea, superando os EUA nos ?ltimos cinco anos. Estudos sobre Microcystis e toxinas, tais como microcistinas, s?o tend?ncias de investiga??o, devido a sua omnipresen?a e suas consequ?ncias negativas hist?ricas. Tamb?m enfatizamos a necessidade de mais estudos com o objetivo de desenvolver t?cnicas para resolver e/ou mitigar a quest?o das flora??es. Em vista disso, nossos experimentos revelaram que o uso de PAC e LS teve um efeito not?vel na biomassa de cianobact?rias da coluna de ?gua em todas as amostragens, reduzindo at? 90% a concentra??o de clorofila-a. O uso de LS sozinho foi ineficiente para remover a biomassa de algas azuis. Em duas amostragens, a combina??o de floculante e lastro apresentou a mesma efic?cia que o uso apenas de PAC. Mesmo assim, o uso de LS ? importante para garantir a sedimenta??o. Combinado com PAC, o LS foi um lastro t?o eficiente em remover cianobact?rias quanto uma argila modificada comercialmente dispon?vel (Phoslock?). Embora LS in natura tenha liberado quantidades consider?veis de f?sforo e n?o apresentou capacidade de adsor??o de P, tal argila conseguiu adsorver quantidades moderadas de f?sforo dissolvido ap?s a mat?ria org?nica ter sido removida por muflagem. Este estudo mostra que LS ? uma alternativa economicamente vi?vel e sustent?vel para ser utilizada como a??o de manejo em reservat?rios apresentando flora??es na regi?o semi?rida do Brasil. / Artificial eutrophication has been considered a problem of major concern in aquatic ecosystems around the world. Since 1960, scientific advances have been made in order to develop techniques that mitigate the effects of eutrophication. Several physical, chemical and biological procedures can be used and combined to recover lakes from cyanobacterial blooms, such as the application of a flocculant combined with natural or modified clay. However, the efficacy of local dryland soils in mitigating blooms is unknown for Brazilian manmade lakes. In this paper, we present a bibliometric analysis of the evolution of publications about cyanobacterial blooms and identify records that directly aim to overcome the occurrence of these blooms. Also, we evaluate, through laboratory experiments, the effect of the combined use of flocculent polyaluminum chloride (PAC) and a local soil from the lake catchment (LS), as ballast, in controlling cyanobacterial bloom in a shallow lake of the semiarid region of Brazil. The bibliometric research was conducted with the ?Web of Science? database through the search function ?TS = ((cyanobacteri* or blue green algae or cyanoprokariote or cyanophyceae) and (mass accumulation or bloom or domina*))?, from 1969 to June 2016. We performed a keyword frequency analysis and quantified the number of records with a restoration approach. Besides, three sets of experiments were performed in three sampling occasions with different bloom compositions and biomass in Armando Ribeiro Gon?alves Reservoir. Our study revealed that studies about cyanobacterial blooms increased exponentially and their quantitative impact on the aquatic sciences increased significantly along the years (F = 97.52; p < 0.0001). The USA stands out as the most productive nation, followed by China and European countries. China has impressively increased its contribution to this area, surpassing the USA in the last five years. Studies about Microcystis and toxins, such as microcystins, are trends in research, due to their ubiquitousness and historical negative consequences. We also emphasize the need for more studies aiming at developing techniques to solve and/or mitigate the issue of blooms. In view of this, our experiments revealed that the use of PAC and LS had a remarkable effect on cyanobacterial biomass in the water column in all samplings, reducing up to 90% top chlorophyll-a concentration. The use of LS alone was inefficient to settle blue-green-algal biomass. In two samplings, the combination of flocculant and ballast exhibited the same efficacy as the use of solely PAC. Even so, the use of LS is important to ensure sedimentation. Combined with PAC, LS was as efficient a ballast to remove cyanobacteria as a commercially available modified clay (Phoslock?). Althugh LS in natura released considerable amounts of phosphorus and did not present P adsorption capacity, it managed to adsorb some dissolved phosphorus after organic matter was removed through muffling. This study shows that LS is a cheap, feasible and environment-friendly alternative to be used as a management action in reservoirs undergoing blooms in the semiarid region of Brazil.

Made available in DSpace on 2014-12-17T14:01:57Z (GMT). No. of bitstreams: 1 AnaCatarinaLR.pdf: 1581949 bytes, checksum: d36f953346d69da5932504873625ff62 (MD5) Previous issue date: 2008-07-03 / ?The aims of this study were: i) assessing the trophic state of the Mendubim reservoir (semi-arid, Rio Grande do Norte, Brazil; 05? 38 99,0 S 36?55 98,0 W) based on chlorophyll-a, total phosphorus and nitrogen concentrations and water transparency; ii) relating the patterns of temporal variation of zooplankton and phytoplankton to the trophic state of the reservoir and iii) investigating the carrying capacity of the reservoir for cage fish farming. The samplingwas done monthly from July 2006 to July 2007 in three stations at the reservoir: next to the dam (barrage), in the central region and in the mouth of the main tributary. The abiotic and biotic variables analyzed were: Secchi depth, volatiles and fixed suspended solids, chlorophyll-a, total phosphorus and nitrogen, TN:TP ratio and mesozooplankton and phytoplankton composition and biomass. The results showed that the reservoir can be considered as mesotrophic with mean concentrations of total nitrogen, phosphorus and chlorophyll-a equal to 1711, 1 ?g.L-1, 30,8 ?g.L-1 and 5,62 ?g.L-1 respectively. The Cyanophyceae class was the most representative in terms of density, with the presence of potentially toxic species such as Microcystis aeruginosa, Planktothrix planctonica, Cylindrospermopsis raciborskii, Aphanizomenon sp. ,Aphanocapsa delicatissima and Pseudanabaena acicularis. Among the zooplankton, the genus Notodiaptomus presented the largest biomass values. Overall, our results show that the light limitation should explain the weak relationship between chlorophyll-a and total phosphorus and nitrogen concentrations. We concluded that the water of Mendubim reservoir is suitable for intensive fish cage aquaculture. Based on the carrying capacity calculations for this reservoir, we found that the maximum sustainable yield of tilapias in cages in the reservoir is 126 ton per year assuming a factor of food conversion of 1.5: 1.0 and a phosphorus content in the fish food of 1% / ?Os objetivos do presente estudo foram: i) avaliar o estado tr?fico do reservat?rio Mendubim (semi-?rido, Rio Grande do Norte, Brasil; 05? 38 99,0 S 36?55 98,0 W ) com base nas concentra??es de clorofila-a, f?sforo e nitrog?nio total, e na transpar?ncia da ?gua; ii) relacionar os padr?es de varia??o temporal da composi??o e biomassa do fitopl?ncton e zoopl?ncton ?s varia??es do estado tr?fico do reservat?rio e iii) investigar a capacidade de suporte do reservat?rio para o desenvolvimento de atividades de piscicultura em tanques-redes. Para tanto, foram realizadas amostragem mensais no per?odo de julho/2006 a julho/2007 em tr?s pontos de coleta, sendo um pr?ximo ? barragem, outro na regi?o central do reservat?rio e o terceiro na desembocadura do principal tribut?rio. As vari?veis bi?ticas e abi?ticas analisadas foram: profundidade e transpar?ncia da coluna d??gua, concentra??es de s?lidos fixos e vol?teis em suspens?o, clorofila-a, nitrog?nio e f?sforo total, raz?o NT:PT, composi??o e biovolume do fitopl?ncton, composi??o e biomassa do mesozoopl?ncton. Os resultados obtidos mostraram que o reservat?rio em estudo pode ser considerado mesotr?fico com concentra??es m?dias de nitrog?nio total, f?sforo total e clorofila-a igual a 1711,1?g l-1 , 30,8 ?g l-1 e 5,62 ?g l-1 respectivamente. A classe Cyanophyceae foi a de maior representatividade em termos quantitativos, com a presen?a de esp?cies potencialmente t?xicas, tais como Microcystis aeruginosa, Planktothrix planctonica, Cylindrospermopsis raciborskii, Aphanizomenon sp., Aphanocapsa delicatissima e Pseudanabaena acicularis. Quanto ? comunidade zooplanct?nica, o g?nero Notodiaptomus, foi o que apresentou maiores valores de biomassa. De um modo geral, os resultados encontrados mostram que a limita??o do crescimento algal por luz, ? uma poss?vel explica??o para as fracas rela??es entre as concentra??es de clorofila-a e de f?sforo e nitrog?nio total no ambiente. Com isso, conclu?mos que as ?guas do reservat?rio Mendubim se encontram apropriadas para a produ??o de pescado num regime intensivo de cultivo em tanques-rede. Com base nos c?lculos da capacidade de suporte do ambiente, verificamos que a produ??o m?xima sustent?vel de til?pias em tanques-rede no reservat?rio ? da ordem de 126 toneladas por ano assumindo um fator de convers?o alimentar de 1,5:1,0 e um conte?do de f?sforo na ra??o de (1,0%)

Made available in DSpace on 2014-12-17T14:01:58Z (GMT). No. of bitstreams: 1 MargaridaLMNS.pdf: 1054716 bytes, checksum: bc213979524001331468154edb0d566e (MD5) Previous issue date: 2008-02-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work aimed to study the structure and dynamic of Phytoplankton and Bacterioplankton in a complete cycle of shrimp cultivation (Litopenaeus vannamei) and determine the environmental factors responsible for the structural changes of these communities. The study was realized in a saltwater shrimp farm (Maca?ba, RN), between September/2005 and February/2006, and in a freshwater shrimp farm (Cear? Mirim, RN), between May/2007 and September 2007. The samplings were collected weekly in saltwater farm and every fifteen days in freshwater farm. Total phosphorus, chlorophyll a and environmental parameters (pH, dissolved oxygen, salinity, temperature, depth and water transparency) were measured. Qualitative and quantitative analysis of the phytoplankton and bacterioplankton were carried out. The Shannon-Wiener ecologic indexes of diversity and the Pielou equitability indexes were calculated to the phytoplankton. Bacterial density was determined by epifluorescence microscopy. The data were statistically analyzed by Pearson correlation and t-Test. Chlorophycea were predominat in salt water and in the captation/drainage point (24 to 99%). Diatoms had higher wealth. The species Choricystis minor had the highest occurrence (100%) and dominance (90-100%), thus showing its adaptation to the high temperatures, salinity and low water transparency conditions. Filamentous Cyanobacteria like Oscillatoria sp., Pseudoanabaena sp. and Phormidium sp. had constant levels. The negative correlation between chlorophycea and water transparency, and the positive correlation between chlorophyll a and salinity, showed that the phytoplankton was well adapted to the low transparency and to the high salinity. The bacterioplankton was negatively correlated with the total phosphorus and salinity. In freshwater, Cyanobacteria were predominant (>80%), presenting some producers of toxins species like Microcystis sp., Aphanizomenon sp., Cylindrospermopsis raciborskii e Anabaena circinalis. Cyanobacterial density and total phosphorus and chlorophyll a concentrations exceeded the maximum value allowed by legislation. The means of total phosphorus varied from 264 to 627 Wg.L-1 and the means of chlorophyll a oscillated between 22 and 182 Wg.L-1. The phytoplankton species were selected by low availability of the light, high pH, temperature and high availability of total phosphorus. The bacterioplankton showed high densities (5,13 x 107 to 8,50 x107 Bac.mL-1). The studied environments (ponds and rivers) presented a high level of trophic state based on the high concentrations of chlorophyll a and total phosphorus and cyanobacteria dominance. The composition of species in the ponds and rivers was similar, as well as high concentrations of total phosphorus and chlorophyll a, highlighting the pollution caused by the discharges of the farms in natural environment / O presente trabalho teve como objetivo estudar a estrutura e din?mica do fitopl?ncton e bacteriopl?ncton em ciclos completos de cultivos de camar?o (Litopenaeus vannamei), determinar os fatores ambientais respons?veis pelas mudan?as estruturais destas comunidades. O estudo foi realizado em duas fazendas de camar?o: uma de ?gua salgada (Maca?ba, RN) entre setembro de 2005 a fevereiro de 2006 e outra de ?gua doce (Cear? Mirim, RN), durante o per?odo de maio de 2007 a setembro de 2007. As coletas tiveram periodicidade semanal no viveiro de ?gua salgada e quinzenal no viveiro de ?gua doce. Foram determinadas clorofila-a e f?sforo total e par?metros ambientais foram medidos (pH, oxig?nio dissolvido, salinidade, temperatura, transpar?ncia e n?vel da ?gua). An?lises qualiquantitativas do fitopl?ncton e bacteriopl?ncton foram realizadas. Os ?ndices ecol?gicos de diversidade de Shannon-Wiener e equitabilidade de Pielou foram calculados para a comunidade fitoplanct?nica. A densidade bacteriana foi realizada por microscopia de fluoresc?ncia. Os dados foram analisados estatisticamente atrav?s da correla??o de Pearson e teste t. No viveiro de ?gua salgada e no ponto de capta??o-drenagem as clorof?ceas foram dominantes (24 % -99%) e as diatom?ceas tiveram maior riqueza. A esp?cie Choricystis minor foi a esp?cie de maior ocorr?ncia (100%) e domin?ncia (90-100%), mostrando-se bem adaptada a condi??es de altas temperaturas e salinidade e baixa transpar?ncia da ?gua. Cianobact?rias filamentosas como Oscillatoria sp., Pseudoanabaena sp. e Phormidium sp. foram constantes. A correla??o negativa, entre o grupo clorof?cea e a transpar?ncia, e positiva, entre clorofila-a e salinidade, demonstrou que o fitopl?ncton esteve bem adaptado ? baixa transpar?ncia e elevada salinidade. O bacteriopl?ncton correlacionou-se negativamente com a salinidade e f?sforo total. No viveiro de ?gua doce, cianobact?rias foram dominantes (>80%), apresentando algumas esp?cies produtoras de toxinas como Microcystis sp., Aphanizomenon sp., Cylindrospermopsis raciborskii e Anabaena circinalis. A densidade de c?lulas de cianobact?rias, os n?veis de f?sforo e clorofila-a excederam o valor m?ximo permitido pela legisla??o. Os valores m?dios do f?sforo total nos ambientes estudados foram de 264 a 627 Wg.L-1e para clorofila-a foi de 22 a 182 Wg.L-1. As esp?cies do fitopl?ncton foram selecionadas pela baixa disponibilidade de luz, alto pH, temperatura e elevada disponibilidade de f?sforo total. O bacteriopl?ncton apresentou elevada densidade (5,13 x107 a 8,50 x107 Bac.mL-1). Os ambientes estudados (viveiros e rios) configuram elevado estado de trofia, com base nas altas concentra??es de clorofila-a e f?sforo total e domin?ncia de cianobact?rias. A composi??o de esp?cies nos viveiros e nos rios (ponto de capta??o/drenagem) foi semelhante, assim como altos valores de concentra??es de f?sforo e clorofila-a, evidenciando o efeito poluidor das descargas dos viveiros no ambiente natural

Made available in DSpace on 2014-12-17T14:01:58Z (GMT). No. of bitstreams: 1 ThiagoPNM.pdf: 364395 bytes, checksum: d196df37d1feef6ed3e5d5cd9f931834 (MD5) Previous issue date: 2009-02-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / 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 Serid? 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 &#956;g 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 &#956;g 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 &#956;g l-1 the annual medium concentrations of total phosphorus in the waters of these reservoirs / A eutrofiza??o ? um processo de ac?mulo de nutrientes em ambientes aqu?ticos que tem sido acelerado pelas atividades antr?picas, principalmente as relacionadas com as atividades agropastoris, industriais e a disposi??o inadequada dos efluentes dom?sticos. O enriquecimento do ambiente aqu?tico com nutrientes, principalmente o nitrog?nio e o f?sforo, e a conseq?ente prolifera??o de algas e cianobact?rias podem comprometer a qualidade da ?gua para o abastecimento p?blico, para a piscicultura e para outros fins. O problema se torna mais cr?tico quando h? naturalmente uma escassez de ?gua como na regi?o semi-?rida do nordeste brasileiro. Diante dessa problem?tica este trabalho teve como objetivo avaliar o estado tr?fico de seis reservat?rios da bacia do Rio Serid? no Rio Grande do Norte e tamb?m mensurar a capacidade de carga de f?sforo dos reservat?rios visando o seu enquadramento segundo a resolu??o CONAMA 357/05. Os resultados demonstram que os seis reservat?rios encontram-se eutrofizados, com concentra??es de f?sforo total e clorofila a na ?gua superiores a 50 e 12 ?g l-1 respectivamente. Os resultados mostram que existe uma homogeneidade espacial, mas uma significativa varia??o interanual no estado tr?fico dos reservat?rios em fun??o das varia??es do volume de ?gua acumulado nos reservat?rios. Os resultados da simula??o estoc?stica de risco mostram que os reservat?rios com maior capacidade de carga poderiam receber anualmente at? 216 Kg de P, assumindo um risco de 10% de aumentar em mais de 30 ?g l-1 as concentra??es m?dias anuais de f?sforo total na ?gua destes reservat?rios. Esta carga poderia ser elevada em at? 360 kg de P por ano caso os gestores assumam um risco de 10% de aumentar em mais de 50 ?g l-1 as concentra??es m?dias anuais de f?sforo total nas ?guas destes reservat?rios