M.Sc. (Zoology) / The production of nanoparticles started as early as 1990s (Alkilany & Murphy, 2010). Nanoparticles are utilised in a range of products such as electronics, optics, textiles, medical, devices, cosmetics, food packaging, water treatment technology, fuel cells, catalysts, biosensors and agents for environmental remediation (Handy et al., 2008). Unlike natural particles, which dissolve or aggregate and are often temporary in the environment, engineered nanoparticles (ENPs) maybe persistent due to the stabilization properties of their capping agent (surfactant or organic material). Thus, there is growing concern about the production and fate of ENPs in the environment (Handy et al., 2008).As ENPs pass through the water system they become exposed to different salinities, ionic concentrations and pH changes (Lapresta-Fernández et al., 2012). During this process the ENPs are degraded, transported, altered and accumulated in various ways. Nanoparticles have been found to aggregate in various organelles, for example endocytotic vesicles (Elsaesser & Howard, 2011; Lapresta-Fernández et al., 2012), cytoplasm and the perinuclear region (Mirkin et al., 2010). This can take place via ingestion, endocytosis and or by diffusion (Nowack & Bucheli, 2007). The major question is are NPs toxic and are they more toxic than their metal salts? While bulk gold is distinguished as a chemically inert and a non-toxic substance, (Alkilany & Murphy, 2010) GNPs may be toxic due to their different physicochemical properties such as small particle size, configuration, charge and specific surface area and easy surface alterations (Cho et al., 2009; Goodman et al., 2004; Lapresta-Fernández et al., 2012)...

The Reserve concept, introduced in the National Water Act, has led to an increasing use of biomonitoring techniques to assess the current ecological status of rivers in South Africa. The ecological status of a river provides vital information necessary to establish the amount and quality of water needed by the aquatic ecosystem. If the amount and quality of water is inadequate, then the water resource will not be able to provide the necessary goods and services to their respective water users. The biomonitoring of rivers gained impetus with the establishment of the River Health Programme (RHP) and its various objectives. The RHP led to the development and refinement of a range of biomonitoring indices to assess various components of the aquatic ecosystem. The components used to assess the current ecological status of a river include the physical habitat, riparian vegetation, water quality, as well as the macro-invertebrate and fish communities. The Mvoti River, in the vicinity of Stanger, is subjected to extensive water abstraction, which is then utilised for irrigation, industrial use, urban water requirements and various domestic uses by informal settlements. Previous studies on the river indicated that it is in a severely degraded state, especially below the confluences of the Nchaweni and Mbozambo rivers. Thus, this assessment of the current ecological status of the Mvoti River was undertaken to possibly identify the main causes of the degraded state. The study was undertaken during the high (February) and low flow (August) periods in 2005. Selected monitoring sites included sites used in previous studies on the Mvoti River as well as sites on the Nchaweni and Mbozambo tributaries. The methodology for this study was to implement the various indices used in the RHP for the different ecosystem components. The habitat indices implemented in this study were the Habitat Quality Index (HQI) and Integrated Habitat Assessment System (IHAS). Physicochemical water analyses were done during each sampling period to assess the water quality against the South African Water Quality Guidelines. The biotic indices used included the South African Scoring System 5 (SASS5) index to assess the macro-invertebrate community and the Fish Assemblage Integrity Index (FAII) to assess the fish community. Additionally, the newly developed EcoStatus indices for the fish and macro-invertebrate communities were implemented on the available fish and macro-invertebrate data. These indices were developed mainly to be used in Reserve determination assessments, where the assessments are built around the integration of all ecosystem components into a single value for the ecological status. The fish index is termed the Fish Response Assessment Index (FRAI) and the macro-invertebrate index the Macro-invertebrate Assessment Index (MIRAI)…. Multivariate statistical analyses were performed on the water quality as well as the macroinvertebrate and fish communities to establish any temporal and spatial trends together with any dominating water quality variables responsible for species composition at the different sites. PRIMER and CANOCO computer software were used to construct hierarchical clusters and NMDS plots for the biotic communities, while RDA and PCA bi-plots were used to represent the water quality variables and their effects on the biotic community structure. The Mvoti River is in a seriously degraded state and this degradation was particularly evident during the low flow period below the Sappi Stanger mill and the Stanger Sewage works effluent discharge points. The degraded state of the river is caused by the multitude of impacts on the river, which includes the local land-use, upstream land-use and effluent discharges in the vicinity of Stanger. The water quality in the vicinity of Stanger was in a poor state during the low flow, while the high flow was only slightly better. The upstream site is in a fair condition but, after the Nchaweni and Mbozambo rivers enter the Mvoti River, the water quality decreases. The variables found to be problematic included microbiological variables, chlorides and electrical conductivity in the Mvoti River. High nutrient values were found together with very high electrical conductivity in especially the Nchaweni River tributary. The lower Mvoti River contains very little habitat of good quality to support the biotic communities. The habitat is generally degraded due to the destruction of the riparian zone and the dominance of alien vegetation in the form of reeds. This, together with land-use and water abstraction activities, has caused high sediment loads in the lower Mvoti River which are continually moving. The IHAS and HQI results indicated the habitat in the lower Mvoti River is in a modified condition. The statistical analysis of the macro-invertebrate data showed that a definite spatial variation existed while no significant temporal variation was identified. There is a difference in the community structure between the Mvoti River and its tributaries, with the tributaries containing a very poor diversity. This lowered species diversity was attributed to the effects of, specifically, chlorides on the community structure but the origin of the chlorides could not be linked specifically to the Sappi Stanger mill’s activities. The SASS5 was similar with the Mvoti River sites having slightly higher scores, placing it in either a B or C class while most of the tributaries had a Class D. The community structure in the tributaries responded to nutrients and chlorides and these variables reduced the numbers of sensitive species and allowed hardy taxa to flourish. The results of the MIRAI index provided the same categories as identified by the SASS5 index. The fish community structure showed the same spatial differences identified in the macroinvertebrate communities, with the tributary sites containing different community structures than those found in the Mvoti River. The Mvoti River fish community is in a modified state with the majority of fish sampled being tolerant with very few sensitive species present. The FAII scores for the Mvoti River was a Category C, while the tributary sites scored a Category D or lower. The fish community is affected by the poor water quality, habitat and flow modifications in the lower Mvoti River. The FRAI index provided the lower Mvoti River and its tributaries with the same categories as identified with FAII. Overall, the Mvoti River is in a seriously degraded state with even the reference site being subjected to impacts that could potentially be harmful to the ecosystem. The ecological state of the river decreases as it moves past Stanger and is subjected to the impacts from the Nchaweni and Mbozambo rivers in the form of nutrients and salinity concentrations. The impacts on the Mvoti River have a multitude of different sources and if the aquatic ecosystem is to improve, only a collective effort will be of any value. / Prof. V. Wepener

Anecdotal evidence suggested that immature lemon sharks (Negaprion brevirostris) occur at the Chandeleur Islands in southeastern Louisiana. From May 2009 to August 2011, the Nekton Research Laboratory at the University of New Orleans regularly sampled habitats at the Chandeleur Islands to confirm the presence of immature individuals of this species. During these efforts, 147 immature lemon sharks (neonates, young-of-the-year, and juveniles) were collected. Each shark was PIT tagged and a tissue sample was taken for genetic analyses. Sizes ranged from 56 – 177 cm total length. Sharks showed a preference for sandy substrate and smaller individuals showed significant preference for shallow waters. Collection data for N. brevirostris were obtained from various locations around the Gulf of Mexico for comparison. Based on a review of current literature, collection data, and microsatellite analysis it was possible to classify the Chandeleur Islands as an elasmobranch nursery ground under the definition presented by Huepel et al. (2007). Current literature and high densities of N. brevirostris suggests that the Chandeleur Islands are the only area in the northern Gulf of Mexico where neonatal and YOY lemon sharks have been recorded. Results from a combination of SPOT 5 satellite tags, PIT tags, and FLOY tags show that immature N. brevirostris at the Chandeleur Islands remain in the vicinity of the islands for several months. The abundance of juvenile sharks across years provides evidence of continuous use of these islands as a pupping area. Genetic analysis supports this information with 7 of 15 mothers returning across years. The combination of this information indicates that the Chandeleur Islands are the northern- and western-most documented nursery ground for this species. Special care should be given to this habitat as CPUE for N. brevirostris decreased significantly during this research following the 2010 Deepwater Horizon disaster and subsequent oil prevention measures. Genetic research indicates a high level of inbreeding and genetic separation between the Chandeleur Islands population and other known populations in Florida, Belize, and the Bahamas.

Dans les écosystèmes aquatiques, l'activité anthropique, mais aussi le contexte naturel induisent chez les organismes aquatiques des situations de stress multiples. Parmi les sources potentielles de perturbation, trois d'entre elles, d’origine chimique, ont été étudiées : contamination métallique, une contamination par un herbicide, par un mélange d’alkylphénols polyéthoxylés et enfin une contamination par un produit pétrolier. Cette démarche entre dans le cadre de la directive européenne REACh (Registration Evaluation Autorisation of CHemicals) mais aussi de la directive cadre eau DCE (directive 2000/60/CE) du parlement Européen et du Conseil établissant une politique communautaire dans le domaine de l'eau. Il s’agit en fait d'évaluer la pertinence d’une série d’indicateurs précoces de pollution (ex : biomarqueurs) afin de prédire l'effet des substances chimiques lors de contaminations chroniques ou ponctuelles du milieu aquatique. Une approche intégrée des interactions des substances ou produits sélectionnés sur la réponse génétique, protéique, cellulaire, histologique et individuelle chez la truite arc-en-ciel, Onchorynchus mykiss, a été entreprise en mésocosmes ouverts et dynamiques et en laboratoire. In vivo, une étude multimarqueurs sur des truites juvéniles femelles diploïdes a été menée à chaque exposition, de 21 ou 28 jours, et durant une période de « récupération » afin d'estimer les effets sur la physiologie des truitelles. Le mélange de nonylphénols polyéthoxylés et l’essence utilisés pour les expositions montrent ainsi des effets qui perdurent jusqu’à la fin de cette période de « récupération ». Les mésocosmes, utilisés lors de cette thèse, offrent des conditions favorables au maintien et à la croissance de truites juvéniles. (...) Dans une démarche de recherche de biomarqueurs d’effets chez une espèce modèle, transposer ces travaux chez des poissons (mâles et femelles) à des stades de développement différents pourrait ainsi permettre d’isoler les paramètres les plus pertinents, à chaque stade ou pour l’ensemble du cycle de l’espèce, afin d’apporter de nouveaux outils pour la surveillance des milieux aquatiques. / In the aquatic ecosystems, anthropic activity, but also natural environment induce several kind of stress in aquatic organisms. Among the potential sources of stress, three chemicals were studied here: a metal, a bipyridylium herbicide, a mixture of nonylphenol polyethoxylate and an oil product exposure. This study enters within the framework of the European directive REACh (Registration Evaluation Authorization of CHemicals) but also of the Directive Cadre Eau, DCE (directive 2000/60/CE) of the European Parliament. The aim is to evaluate the relevance of an early pollution indicator pool (biomarkers) in order to predict chemical substance effects during chronic exposure or after specific contaminations of the aquatic compartment. An integrated approach of the substance effects on the genetic, proteinic, cellular, histological and individual answers in the rainbow trout, Onchorynchus mykiss, were undertaken in open and dynamic mesocosms and also laboratory. In vivo, a multibiomarker study on female juvenile trout was done at each exposure, over 21 or 28 days, followed by a period of “recovery». The mixture of nonylphenol polyethoxylate and the gasoline used for the exposures thus show effects which perdurent until the end of this period of “recovery. The mesocosms used in this study offer favorable conditions for juvenile survival and growth. (...) In addition to the assessment of the measurement robustness and the biomarker relevance, we compared the data obtained in this study with the in vivo tests and those obtained using in vitro tests. This approach made possible to highlight coherent answers between in vitro the tests and in vivo markers. But in vitro tests are only one preliminary approach to quickly seek a specific toxic action. The modulation monitoring of key genes in the fish reproduction function, during a gasoline exposure, offers complementary informationabout the pollutant mode of action. We noted that the effects of the contamination on the hormonal rates were differed in time compared to the modulation of the gene transcription. In order to bring new tools for the monitoring, in a model species, of the aquatic environment,transposing this work in male and female fish at different developmental stages would enableisolating still most relevant parameters.

Resumo: As macrófitas, apesar da enorme importância na dinâmica do ambiente aquático, quando formam extensas e densas colonizações promovem uma série de prejuízos ao ambiente e aos usos múltiplos dos reservatórios. Nestas situações, há a necessidade de redução de seu tamanho populacional, seja reduzindo as condições favoráveis ao crescimento, seja por meio do controle direto das plantas. Dentre as macrófitas aquáticas que proporcionam estes tipos de problemas, o aguapé (Eichhornia crassipes (Mart.) Solms) é considerada como a mais importante. O diquat tem sido muito utilizado para o controle desta planta, devido seu baixo custo, eficácia e rapidez de controle e baixa toxicidade no ambiente aquático. O objetivo do presente trabalho foi o de avaliar as possíveis alterações causadas pelo controle de Eichhornia crassipes sobre algumas características de qualidade da água em mesocosmos. Para tanto, cinco situações experimentais foram estudadas: (i) CPCH - mesocosmo colonizado por aguapé o qual foi controlado pela aplicação do herbicida diquat; (ii) CPCG - mesocosmo colonizado por aguapé o qual foi morto por congelamento; (iii) CPSH - mesocosmo colonizado com aguapé, sem controle; (iv) SPCH - mesocosmo sem macrófitas e com aplicação de diquat na superfície da água e (v) SPSH - mesocosmo sem macrófitas aquáticas e sem aplicação. O herbicida diquat foi utilizado na dose de 7,0 L/ha, na formulação comercial Reward. A temperatura foi mais elevada nos mesocosmos sem plantas, devido à maior incidência de raios solares na coluna d'água. A presença da cobertura de macrófitas reduziu a concentração de diretamente na lâmina d'água não promoveu qualquer efeito significativo consistente ao longo do período experimental quando comparado com o mesocosmo sem colonização e sem aplicação... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract : Besides its high importance to the dynamic of the aquatic environment, dense colonization of aquatic plants promote several problems to the ecological equilibrium and to the multiple use of the water body. Under these conditions, control measures are required aiming to reduce the size of the macrophyte populations. Among the more important aquatic weeds, the waterhyacinth (Eichhornia crassipes (Mart.) Solms) is considered as major problem and it control is necessary in several sites of the world. The herbicide diquat has been used in the waterhyacinth control due to low cost, high efficacy, quickness of action and environmental safety. Aiming to evaluate the effects of the waterhyacinth control and the diquat use on some water characteristics, a trial was carried out, under mesocosm conditions, analyzing the following experimental situations: (i) CPCH - mesocosm colonized by waterhyacinth which was controlled by diquat spraying at 7,0 L/ha of Reward®; (ii) CPCG - mesocosm colonized by waterhyacinth which was killed by freezing; (iii) CPSH - mesocosm colonized by waterhyacinth, without control; (iv) SPCH - mesocosm without aquatic weeds and spray of diquat on the water surface, and (v) SPSH - mesocosm without aquatic weeds. The water temperature was higher in the mesocosms without waterhyacinth colonization due to the radiation penetration in the water column. The waterhyacinth covering reduced the dissolved oxygen concentration, the pH and the amplitud of water temperature variation. When the waterhyacinth population started the senescence process the electric conductivity increased. The diquat application on water surface did not promoted any expressive effect on water features comparing with the water without herbicide spraying. The waterhyacinth control by diquat or by freezing promoted... (Complete abstract click electronic access below) / Orientador: Dagoberto Martins / Coorientador: Robinson Antonio Pitelli / Banca: Fernando Tadeu de Carvalho / Banca: Mario Sergio Tomazela / Banca: Guilherme Luis Guimarães / Doutor

Conventional ecotoxicological tests (forced exposure) are an important tool when what is sought are the possible acute and chronic effects of environmental pollutants on each individual that is exposed. The disadvantage of this approach lies in the fact that the organisms are kept enclosed within containers of the same concentration for several hours and / or days. The forced exposure test has no ecological relevance when the modeled environment exhibits a contamination gradient and organisms can move along this gradient. In many aquatic ecosystems, it is common to observe a contamination gradient, with concentrations decreasing with distance from the discharge zone, so that organisms do not necessarily exhibit continuous and forced exposure to the contaminant. The objective of this work was to analyze how aquatic pollutants (e.g Triclosan, Bisphenol, Atrazine and Copper) influence the dispersion / habitat selection pattern of two species of fish: Poecilia reticulata and Danio rerio, using a static system (non-forced exposure) with several compartments, forming a gradient of contamination with the compound to be analyzed. All pollutants tested triggered an avoidance response in fish at environmentally relevant concentrations. The concentrations that caused avoidance on the organisms are lower than those that cause sub-lethal effects on aquatic organisms, including fish. We also find in one of our approaches the potential for the formation of a chemical barrier (habitat fragmentation) by the release of pollutants into the water bodies, reducing the migration potential of aquatic organisms. Finally, one of the most important findings is the interaction of the species with each other when exposed to a pollution gradient. In this case, the presence of one species interfered in the distribution of the other (reduction of the migration potential), when both were in the same system. Thus, the non-forced approach demonstrates to be a powerful tool in the evaluation of environmental risk, complementary to the traditional ecotoxicological tests / Os testes ecotoxicológicos convencionais (exposição forçada) são uma ferramenta importante quando o que se busca são os possíveis efeitos agudos e crônicos dos poluentes ambientais sobre cada indvíduo que é exposto. A desvantagem dessa abordagem está no fato de que os organismos são mantidos enclausurados dentro de recipientes com uma mesma concentração por várias horas e/ou dias. O teste de exposição forçada não tem relevância ecológica quando o ambiente modelado apresenta um gradiente de contaminação e os organismos podem se mover ao longo deste gradiente. Em muitos ecossistemas aquáticos, é comum observar um gradiente de contaminação, com as concentrações diminuindo com a distância da zona de descarga, de modo que os organismos não apresentam obrigatoriamente uma exposição contínua e forçada ao contaminante. Desta forma, este trabalho teve como objetivo a análise de como os poluentes aquáticos (e.g. Triclosan, Bisfenol, Atrazina e Cobre) influenciam o padrão de dispersão / seleção de habitat por duas espécies de peixes: Poecilia reticulate e Danio rerio, utilizando um sistema estático (não forçado) com vários compartimentos, formando um gradiente de contaminação com o composto a ser analisado. Todos os poluentes testados dispararam uma resposta de fuga nos peixes em concentrações ambientalmente relevantes. As concentrações que causaram a fuga dos organismos são menores do que aquelas que causam efeitos sub-letais em organismos aquáticos, incluindo peixes. Encontramos também em uma de nossas abordagens o potencial de formação de uma barreira quimica (fragmentação de habitat) pela liberação de poluentes nos corpos hídricos, reduzindo o potencial de migração dos organismos aquáticos. Por fim, um dos achados mais importantes está na interação das espécies entre si quando expostas a um gradiente de poluição. Nesse caso, a presença de uma espécie interferiu na distribuição da outra (redução do potencial de migração), quando ambas se encontravam no mesmo sistema. Sendo assim, a abordagem não forçada demonstra ser uma ferramenta poderosa na avaliação de risco ambiental, complementar aos testes ecotoxicológicos tradicionais

Orientador: Archimedes Perez Filho / Coorientador: Waterloo Pereira Filho / Banca: Ailton Luchiari / Banca: Albano Schwarzbold / Banca: Sergio dos Anjos Ferreira Pinto / Banca: Fabiano Tomazini da Conceição / Resumo: A construção de barragem é uma intervenção antrópica na rede de drenagem que altera o fluxo natural da água. O presente trabalho caracterizou e analisou a estruturação limnológica e espectral na escala espaço-temporal nos reservatórios das Usinas Hidrelétricas (UHE) Passo Real e Dona Francisca do rio Jacuí - RS, e a relação com as bacias hidrográficas que os compõem no Alto Jacuí. A hipótese foi a de que ocorrem diferenças nas propriedades ópticas da água na escala espaço-temporal de reservatórios em função das próprias características e de suas bacias hidrográficas. Os procedimentos metodológicos foram: 1) adquirir dados limnológicos (transparência Secchi, temperatura, total de sólidos em suspensão - TSS, carbono orgânico dissolvido e clorofila a) e de espectrorradiometria de campo (dados hiperespectrais) do período de fevereiro de 2009 a março de 2010; 2) construção de um banco de dados com os elementos da bacia hidrográfica (geossistema e sistema socioeconômico) e as variáveis limnológicas na perspectiva espaço-temporal; 3) identificação das fragilidades da bacia hidrográfica e as características dos reservatórios que interferem na qualidade da água; 4) relacionar os dados espectrais com os dados limnológicos para verificar o potencial destes no monitoramento dos reservatórios. Os resultados mostraram que a bacia hidrográfica do reservatório Passo Real, com relevo colinoso, apresenta dominância de uso do solo com agricultura, com destaque para as culturas da soja no verão e trigo no inverno. O reservatório Dona Francisca, na base da série em cascata de reservatórios, recebe o tributário Jacuizinho, cuja bacia hidrográfica é de relevo de morros, os principais usos da terra são florestas e campos. A temperatura da água para ambos os reservatórios é inferior a 20ºC nos meses de inverno... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The building of a dam is an anthropic intervention in the drainage system that changes the natural water flow. This work has characterized and analyzed the limnological and spectral structure on a spatial and temporal scale of the freshwater reservoirs Hidropower Plants (HPP) Passo Real and Dona Francisca of the river Jacuí - RS and, the relationship with the hydrographic basins that make up on the Alto Jacuí. The relationship with the hydrographic basins that make they up on the Alto Jacuí. The hypothesis was that the optical proprieties varies on the spatial and temporal scale as a function of the own reservoir proprieties as well of the hydrographic basins. The methodological procedures were: 1) limnological data acquisition (Secchi transparency, temperature, total of suspended solids - TSS, dissolved organic carbon and chlorophyll a) and field spectroradiometry (hyperspectral data) of the period from February 2009 to March 2010; 2) data base elaboration with the hydrographic basin elements (geosystem and social-economic system) and the limnological variables at the spatial and temporal perspective; 3) identification of the fragility areas of the hydrographic basin and the reservoir characteristics that affect the water quality; 4) relation analysis between the spectral and the limnological data to verify the potential of these to reservoir monitoring. The results showed that Passo Real reservoir hydrographic basin, with a hilly relief, has land use predominance of agriculture, especially for crops such as soybean in the summer and wheat at the winter season. The Dona Francisca reservoir, which is in the basis of the sequence of reservoirs, receives the tributary named Jacuizinho, has a relief characterized by hills and land use with predominance of forest and open fields. In both reservoirs the water temperature is... (Complete abstract click electronic access below) / Doutor

Orientador: Antonio Fernando Monteiro Camargo / Banca: Irineu Bianchini Júnior / Banca: Dalva Maria Silva Matos / Banca: Fábio Cop Ferreira / Banca: Tadeu de Siqueira Barros / Resumo: Este trabalho teve como principal objetivo avaliar questões referentes à avaliação da qualidade ecológica de ambientes aquáticos, com ênfase em macrófitas aquáticas. Inicialmente fizemos uma análise cienciométrica a fim de verificar o panorama global dos estudos sobre qualidade ecológica e índices de integridade biótica e tentamos fornecer uma visão geral sobre os ecossistemas, organismos e regiões que mais utilizam esses indicadores, bem como uma análise crítica sobre as tendências, aplicações e limitações dessa abordagem. Nossos resultados indicam que há uma falta de uniformidade na distribuição do número de estudos por continente, principalmente em regiões tropicais. Além disso, poucos estudos consideram mais do que um grupo de organismos para avaliar a qualidade ecológica de ambientes aquáticos. Em seguida, utilizamos dados de macrófitas aquáticas presentes na bacia hidrográfica do Rio Itanhaém, situada no litoral sul do Estado de São Paulo, para desenvolver mais dois estudos. O primeiro deles avaliou a influência das variáveis ambientais sobre a riqueza de espécies e riqueza de formas de vida, com o intuito de verificar quais fatores naturais e antropogênicos são mais importantes na estruturação da assembleia de macrófitas aquáticas. Tanto fatores naturais quanto antrópicos foram responsáveis por explicar a riqueza de espécies e formas de vida nos ambientes aquáticos estudados. Por fim, nós exploramos o uso de macrófitas aquáticas como indicadoras da integridade ecológica dos ambientes aquáticos da bacia do Rio Itanhaém, a fim de desenvolver um índice multimétrico. Nossos resultados mostraram que a estrutura da assembleia de macrófitas é distinta em locais degradados e não impactados, permitindo o desenvolvimento do índice. Embora o processo de validação do índice não tenha apresentado bons resultados, este estudo permitiu um melhor entendimento das condições ecológicas... / Abstract: This study aimed to evaluate issues related to ecological quality of aquatic environments, with emphasis in aquatic macrophytes. Initially we developed a scientometric analysis in order to verify the global view of the studies dealing with ecological quality and index of biotic integrity (IBI), and try to provide an overview of ecosystems, organisms and regions that mostly used these indicators, as well as a critical analysis of the trends, applications and limitations of this approach. Our results indicate a lack of uniformity in the distribution of the number of studies by continent, mainly in tropical regions. Moreover, few studies have focused in more than one biological group to assess the ecological quality of aquatic environments. After, we used macrophyte aquatic data from Itanhaém River Basin, located in the south littoral of São Paulo State, to develop two more studies. First, we evaluated the influence of environmental variables on species richness and life form richness in order to verify which natural and anthropogenic factors are most important in structuring the plant assemblages. Both natural and anthropogenic factors were responsible for explaining the species richness and life forms richness in aquatic environments studied. Finally, we explored the use of macrophytes as indicators of the river ecological conditions in tropical rivers, in order to develop a multimetric IBI. Our results showed that the macrophyte assemblage structure is distinct in degraded and undisturbed sites, allowing the development of an IBI. Although the validation of the IBI has not shown good results, this study allowed a better understanding of ecological conditions in these aquatic environments and consists in a relevant contribution for future studies involving assessment and biomonitoring in tropical aquatic ecosystems / Doutor

O presente trabalho teve o objetivo testar os efeitos da complexidade do substrato e do tipo de mesohabitat (remanso e corredeira) sobre a riqueza, a abundância e a composição de Chironomidae (Diptera) em riachos. O experimento foi realizado em 12 riachos do Brasil Central, onde em cada mesohabitat (remanso e corredeira) foram colocadas duas bandejas de plástico, uma contendo substrato com alta complexidade e outra contendo substrato com baixa complexidade. Estes substratos permaneceram no riacho durante 20 dias. Os efeitos da complexidade do substrato e dos mesohabitats não foram significativos nem sobre a riqueza padronizada nem sobre a abundância, por outro lado, o efeito do mesohabitat foi significativo sobre a composição faunística. O primeiro eixo da DCA (33% da variabilidade) separou claramente a fauna de remansos da de corredeiras. A análise de espécies indicadoras mostrou que Chironomus sp., Ablabesmyia sp.1, Ablabesmyia sp.2, Djalmabatista sp., Fittkauimyia sp., Labrundinia sp. indicaram o remanso, e Paratendipes sp., Polypedilum sp.2, Pentaneura sp., Rheotanytarsus sp.1, Corynoneura sp.2, Cricotopus sp.2, Lopescladius sp., Nanocladius sp.2, Parametriocnemus sp. e Thienemanniella sp. indicaram a corredeira. / The present study had the aim to test the effects of the substrate complexity and of the mesohabitat (pools and riffles) on the richness, abundance and composition of Chironomidae (Diptera) in streams. The experiment took place in 12 streams of Central Brazil. In each stream, two plastic trays were put in each one of the two studied mesohabitats (pool and riffle), one with higher complexity substrate and one with lower complexity substrate. These substrates were kept in the streams for 20 days. The effects of substrate complexity and of mesohabitat were not significative neither on the standarized richness nor on the abundance. On the other hand, the effect of mesohabitat was significative on the faunistic composition. The first axis of DCA (33% of variability) separated cleanly the fauna in pools from those in riffles. The indicator species analysis showed that Chironomus sp., Ablabesmyia sp.1, Ablabesmyia sp.2, Djalmabatista sp., Fittkauimyia sp., Labrundinia sp. indicated pools, and Paratendipes sp., Polypedilum sp.2, Pentaneura sp., Rheotanytarsus sp.1, Corynoneura sp.2, Cricotopus sp.2, Lopescladius sp., Nanocladius sp.2, Parametriocnemus sp. and Thienemanniella sp. indicated riffles.

O monitoramento de corpos hídricos receptores de efluentes pode ajudar na manutenção e conservação desses locais, pois os poluentes podem alterar o equilíbrio, a estrutura e o funcionamento do ecossistema. Neste aspecto, o estudo em sedimentos é importante ao permitir uma avaliação mais abrangente do ecossistema aquático, onde diferentes contaminantes podem estar associados ao sedimento em concentrações superiores às das águas, podendo resultar em impactos negativos à biota aquática, a depender da biodisponibilidade. A cidade de Cubatão abriga um dos maiores pólos industriais do Brasil, onde a descarga constante de efluentes industriais e domésticos no rio Cubatão e seus afluentes acabou ocasionando um panorama de degradação dos rios. A Bacia do Rio Cubatão esta localizada entre a Grande São Paulo e a Baixada Santista, com área de 177 km2, aproximadamente. O rio Cubatão é o principal rio da região, abastecendo as cidades de Cubatão, Santos, São Vicente e parte dos municípios de Praia Grande e Guarujá. Além do abastecimento de água para a população, o rio também abastece o pólo industrial de Cubatão. O objetivo deste trabalho foi avaliar efeitos agudos e crônicos de amostras de água e de sedimento do rio Cubatão e dois de seus afluentes (Perequê e Pilões), por meio de ensaios ecotoxicológicos. Os organismos aquáticos empregados nos ensaios foram Ceriodaphnia dubia e Vibrio fischeri para avaliação de água e Hyalella azteca para avaliação de sedimento integral. A análise de crescimento corpóreo destes últimos também foi realizada. Além disso, foram realizadas Análises Químicas Instrumentais e Análise por Ativação Neutrônica em amostras de sedimentos. O estudo foi realizado entre 2010 e 2011, totalizando quatro campanhas. Foram coletadas amostras de água em nove pontos da Bacia do Rio Cubatão, e amostras de sedimento em seis pontos. Através dos ensaios realizados com V. fischeri pôde ser verificada toxicidade em todos os pontos amostrados com valores de CE(I)50 que variaram entre 31,25% e 71,61%. Os resultados obtidos com exposição de C. dubia não identificaram toxicidade, com base na análise estatística utilizada (Teste t por bioequivalência). Os ensaios de toxicidade para efeitos agudos do sedimento integral em H.azteca resultaram em toxicidade para as amostras de P2 e P5 (2ª e 4ª campanhas), com uma mortalidade superior a 50% dos organismos expostos. A análise de crescimento corpóreo identificou menor crescimento corpóreo nos organismos expostos ao sedimento coletado em P4 e P5. Com relação aos sedimentos coletados no ponto P5, os compostos endrin, dibenzeno(a,h)antraceno e antraceno ultrapassaram os valores recomendados pela Resolução Conama 344/04. Os resultados das Análises por Ativação Neutrônica evidenciaram maior contaminação por metais nos sedimentos originários de P5 e PI. / The monitoring of water quality on rivers where wastewaters are discharged may be important for the general conservation once many pollutants may alter the ecosystem balance, and life functioning. To study sediments contamination is an important tool that allows a more comprehensive assessment of the aquatic ecosystem, since many contaminants can be associated to the sediment in higher concentrations than in water and may result in negative impacts on aquatic biota. The Cubatão district is one of the largest industrial centers of Brazil. The usual discharge of industrial effluents and domestic sewage into Cubatão and its tributaries ended up causing serious waterways degradation. Cubatão River Basin is located between São Paulo and Baixada Santista (coast), covering approximately 177km2 area. Cubatão River as the main water source for the region, suppling water to Cubatão and its industrial area, and also to Santos, São Vicente and partially to Praia Grande and Guarujá municipalities. The objective of this study was to assess the toxicity for aquatic organisms concerning water and sediment sampled at Cubatão and at two tributaries (Perequê and Pilões). Chemical determinations were included in order to try identify the possible relation between biological effecs. Ceriodaphnia dubia and Vibrio fischeri were used for evaluation of water effects while Hyalella azteca were exposed to the sediments. Biometric analysis were performed on Hyalella azteca. Furthermore, chemical identification by Chromatography and Neutron Activation Analysis were carried out in sediment samples. Through V. fischeri toxicity response it could be noted signs of effects once the EC(I)50 ranged from 31.25% up to 71.61%. C. dubia results were negative to the same samples, based on statistical analysis (test \"t\" for bioequivalence).Through acute toxicity responses when H. azteca was exposed to sediments, toxicity was identified in samples from P2 and P5 (2nd and 4th campaigns): mortality exceeding 50% of exposed organisms. The biometric analysis for the H. azteca growth showed lower values for organisms exposed to sediments from P4 and P5. Chemical analysis evidenced endrin, dibenzo(a, h) anthracene and anthracene at sediments from P5, values which are not in accordance with the Conama 344/04; Neutron Activation Analysis showed high concentrations of metals for samples from the sites P5 and PI.