Phosphorus is an essential element since it controls primary productivity in aquatic ecosystems and its excess can lead to eutrophication in receiving systems. The aim of this project was to determine phosphorus distribution in biotic and abiotic nutrient pools of two KwaZulu-Natal estuaries. Samples of dissolved inorganic phosphorus (DIP), particulate phosphorus (PP), phytoplankton, microphytobenthos, zooplankton, macrozoobenthos and sediment were collected in the temporarily open/closed Mpenjati (MP) and permanently open Mlalazi Estuary (ML) during May (ML), September (MP) and November (ML+MP) using standard methods. Chlorophyll a concentrations as well as species richness, abundance and biomass of zooplankton and macrozoobenthos were analysed. Living and non living nutrient pools were analysed for phosphorus and were compared between stations, sampling sessions, estuaries and taxa. Zooplankton abundance and biomass in the Mlalazi Estuary was higher during May than November. In the Mpenjati Estuary highest zooplankton abundance and biomass was recorded during September than November. No significant differences were apparent in abundance (p = 0.217) and biomass (p = 0.974) of zooplankton between the two estuaries. Macrozoobenthos abundance and biomass in the Mlalazi Estuary was higher during May than November. In the Mpenjati Estuary macrozoobenthos abundance and biomass was higher during November than September. Significant differences in abundance (p = 0.003) and biomass (p = 0.020) were apparent between the estuaries. Sediment to a depth of 10 cm comprised the highest phosphorus biomass than any other nutrient pool in both Mlalazi (4871.1 mgP·m⁻² ± 5888.9 SD) and Mpenjati (2578.6 mgP·m⁻² ± 1828.0 SD) estuaries followed by DIP (120.5 mgP·m⁻² ± 177.7 SD and 5.9 mgP·m⁻² ± 6.1 SD respectively). In both estuaries, the lowest phosphorus biomass was contained in zooplankton with both estuaries containing zooplankton P biomass of 0.001 mgP·m⁻² ± 0.002 SD. Particulate phosphorus and DIP concentrations were higher in the upper reaches in both estuaries indicating that rivers were the main sources of this nutrient in these systems. The Mlalazi Estuary had higher nutrient levels than the Mpenjati Estuary. Such elevated nutrients can be enhanced by the continuous river flow into the permanently open estuary. In both estuaries, no significant differences were apparent in zooplankton and macrozoobenthos P content between different taxa. / M.Sc. University of KwaZulu-Natal, Durban 2013.

Thesis (Ph. D.)--Miami University, Dept. of Botany, 2008. / Title from second page of PDF document. Includes bibliographical references (p. 86-88).

Submitted by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-12T12:18:43Z No. of bitstreams: 1 MELLO_Bruno Gomes_2014.pdf: 2169418 bytes, checksum: 157bccc008d9bb3bac70c082f1d983c3 (MD5) / Approved for entry into archive by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-12T12:18:51Z (GMT) No. of bitstreams: 1 MELLO_Bruno Gomes_2014.pdf: 2169418 bytes, checksum: 157bccc008d9bb3bac70c082f1d983c3 (MD5) / Approved for entry into archive by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-12T12:19:00Z (GMT) No. of bitstreams: 1 MELLO_Bruno Gomes_2014.pdf: 2169418 bytes, checksum: 157bccc008d9bb3bac70c082f1d983c3 (MD5) / Made available in DSpace on 2017-01-12T12:19:08Z (GMT). No. of bitstreams: 1 MELLO_Bruno Gomes_2014.pdf: 2169418 bytes, checksum: 157bccc008d9bb3bac70c082f1d983c3 (MD5) Previous issue date: 2014-05-22 / Não recebi financiamento / The growing interest in studies of functional diversity allows to address the relationship between the functional characteristics of species with variations in the environment attempt to understand the organization of biological communities. We examined the relationship between physical and structural characteristics of 19 stretches of headwater streams in the Atlantic Forest and morphological characteristics related to swimming ability of fish species. The environment was described by altitude, distance from species pool, substrate composition and depth of the channel. The functional characteristics were described by 11 morphological measurements. The RLQ analysis was used and the first two axes explained 97.8% of the total variation. The first axis was interpreted as the action of the altitudinal/longitudinal gradient in the structuring of assemblies of fish which varied with morphological measurements of length of caudal fin and caudal peduncle. We can say that there are two distinct assemblies positioned at the extremes of the environmental gradient separated by capacity of swimming of the species. Within these groups we can say that on a local scale the physical structure of the channel generates subgroups related to the use of the niche, suggesting the action of environmental filters. Thus, we present evidence that environmental attributes of headwaters of the Atlantic Forest are related to the structure of the assemblies of fishes that inhabit these environments. / O crescente interesse por estudos de diversidade funcional permite abordar a relação entre as características funcionais das espécies com variações no ambiente buscando entender a organização das comunidades biológicas. Nós examinamos a relação entre as características físicas e estruturais de 19 trechos de riachos de cabeceira na Mata Atlântica e as características morfológicas relacionadas com a capacidade de natação das espécies de peixes. O ambiente foi descrito quanto à altitude, distância da fonte de espécies, composição do substrato e profundidade do canal; enquanto que as características funcionais foram descritas por 11 medidas morfológicas. Utilizamos uma análise RLQ e os dois primeiros eixos explicaram 97,8% do total da variação. O primeiro eixo foi interpretado como a ação do gradiente altitudinal/longitudinal na estruturação das assembleias de peixes que variou com as medidas morfológicas de comprimento da nadadeira e pedúnculo caudal. Podemos afirmar que existem duas assembleias distintas posicionadas nos extremos do gradiente ambiental separadas pela capacidade de deslocamento das espécies. Dentro destes grupos podemos dizer que em escala local a estrutura física do canal gera subgrupos relacionados ao uso do nicho, sugerindo a ação de filtros ambientais. Desta forma, apresentamos evidências de que a estrutura das assembleias de peixes está relacionada com atributos ambientais de riachos de cabeceira da Mata Atlântica.

Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Two methods for predicting regions susceptible to invasion by alien aquatic animals were developed for southern Africa (excluding Zimbabwe and Mozambique). In the "traditional" (data-poor) approach, distributions of three categories of alien "indicator" species (warm mesothermal, cold stenothermal and eurytopic) were compared to seven existing biogeographical models of distribution patterns of various animals in southern Africa. On the basis of these comparisons a synthesis model was developed which divided southern Africa into seven regions characterised by their susceptibility to invasion by alien aquatic animals with particular habitat requirements. In the "data-rich," geographic information systems (GIS) approach, the distribution of trout (Oncorhynchus mykiss and Salmo trutta) in selected "sampled regions" was related to elevation (as a surrogate of water temperature) and median annual rainfall (MAR) (as a surrogate of water availability). Using concentration analysis, optimum conditions for trout were identified. Regions within a larger "predictive area" which satisfied these conditions, were plotted as a digital map using the IDRISI package. Using this method seven models of potential trout distribution were generated for the following regions: northern Natal (two); southern Natal/Lesotho/Transkei (three), eastern Cape (two) and western Cape (two). Since two of the models were used to refine the methods, only five models were considered for the final assessment. In a modification of the GIS method, another model of potential trout distribution, based on mean monthly July minimum air temperature and MAR parameters, was developed for the region bounded by 29º - 34º S and 26 º - 32°E. This model showed marked similarities to another model, developed for the region bounded by 29 º - 32°S and 26º - 32°E, which was based on elevation and MAR parameters. The validity of the models developed was assessed by independent experts. Of the six models considered, four received favourable judgements, one was equivocal and one was judged to be poor. Based on these assessments it was concluded that the GIS method has credibility and could be used to develop a "data-rich" model of the susceptibility of southern Africa to invasion by alien aquatic animals. This method represents an alternative to the bioclimatic matching approach developed by scientists in Australia. The GIS method has a number of advantages over the "traditional" method: it is more amenable to testing, has greater flexibility, stores more information, produces images of a finer resolution, and can be easily updated. The traditional method has the advantage of being less expensive and requiring a less extensive database.

Thesis (M.S.)--Joint Program in Physical Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 1999. / Includes bibliographical references (leaves 92-100). / The linkage between physics and biology is studied by applying a one-dimensional model and a two-dimensional model to the Sargasso Sea and the Gulf of Maine- Georges Bank region, respectively. The first model investigates the annual cycles of production and the response of the annual cycles to external forcing. The computed seasonal cycles compare reasonably well with the data. The spring bloom occurs after the winter mixing weakens and before the establishment of the summer stratification. Sensitivity experiments are also carried out, which basically provide information of how the internal bio-chemical parameters affect the biological system. The second model investigates the effect of the circulation field on the distribution of phytoplankton, and the relative importance of physical circulation and biological sources by using a data assimilation approach. The model results reveal seasonal and geographic variations of phytoplankton concentration, which compare well with data. The results verify that the seasonal cycles of phytoplankton are controlled by both the biological source and the physical advection, which themselves are functions of space and time. The biological source and the physical advection basically counterbalance each other. Advection controls the tendency of the phytoplankton concentration more often in the coastal region of the western Gulf of Maine than on Georges Bank, due to the small magnitude of the biological source in the former region, although the advection flux divergences have greater magnitudes on Georges Bank than in the coastal region of the western Gulf of Maine. It is also suggested by the model results that the two separated populations in the coastal region of the western Gulf of Maine and on Georges Bank are self-sustaining. / by Caixia Wang. / M.S.

M.Sc. (Zoology) / The Limpopo Province covers an area of 12.46 million hectares and these accounts for 10.2 per cent of the total land area of the Republic of South Africa. The province is endowed with abundant agricultural resources and it is one of the country’s prime agricultural regions noted for the production of fruits and vegetables, cereals, tea, and sugar. A key feature of the agricultural industry of Limpopo Province is its dualism. There are two distinct types of agricultural production systems. The large scale commercial farming system occupies approximately 70% of the total land area. The smallholder farms are located mostly in the former homeland areas and they cover approximately 30% of the provincial land surface area. The town of Thohoyandou, with its surrounding villages, is the area of greatest human concentration in the Luvuvhu Catchment and subsistence farming is about a third of the total agricultural component. It is important to study the effects of agricultural inputs (e.g. fertilizers and sediment loads) on aquatic ecosystems in order to fully understand the processes involved of these stresses on aquatic ecosystems. Knowledge of these impacts toward the environment and human health is often limited due to lack of capacity building, especially among small scale farmers. Ten bio-monitoring sites were studied on five systems in the Vhembe district. The sites were sampled during the low flow period of November 2011 and the high flow period of April 2012. Sampling sites were selected to present conditions in the Mutale, Mutshindudi and Tshinane Rivers upstream and downstream of the potential influence of small scale agricultural activities...

Substantial amounts of methane are sequestered in naturally occurring ice-like formations known as gas hydrates. In particular, oceanic gas hydrates are globally distributed in complex heterogeneous ecosystems that typically occur at depths exceeding 300 m. Gas hydrates have received attention for their potential as an alternative energy resource, as marine geohazards, and their role in cycling of greenhouse gases. In addition, chemosynthetic communities often play a vital role in the cycling and sequestration of carbon emanating from cold hydrocarbon seeps surrounding hydrate sites. Research efforts are presently striving to better understand the significance and complexity of these ecosystems through the establishment of seafloor observatories capable of long-term monitoring with integrated sensor networks. In this thesis, infrared (IR) spectroscopy has been implemented for the investigation of molecular-specific signatures to monitor gas hydrate growth dynamics and evaluate carbonate minerals, which are intimately connected with complex chemosynthetic processes occurring in these harsh environments. The first fundamental principles and data evaluation strategies for monitoring and quantifying gas hydrate growth dynamics utilizing mid-infrared (MIR) fiber-optic evanescent field spectroscopy have been established by exploiting the state-responsive IR absorption behavior of water. This has been achieved by peak area evaluation of the O-H stretch, H-O-H bend, and libration modes and assessing peak shifts in the 3rd libration overtone and libration bands during the formation and dissociation of simple clathrate hydrates of methane, ethane, and propane formed from aqueous solution. Hydrate growth and monitoring was facilitated with a customized pressure cell enabling operation up to ~5.9 MPa with spectroscopic, temperature, pressure, and video monitoring capabilities. Furthermore, the initial feasibility for extending the developed IR spectroscopic hydrate monitoring strategies into oceanic gas hydrate ecosystems has been demonstrated through the evaluation of potential spectroscopic interferences from sediment matrices in samples collected from two hydrate sites in the Gulf of Mexico (GoM). With exception of the libration band, the primary IR absorption features of water are readily accessed within hydrated sediment samples. Additional consideration for potential long-term hydrate monitoring applications revealed that the collection of approx. 2 IR spectra per day should enable direct insight into the temporal dynamics of hydrates...

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Uma grande variedade de produtos que estão presentes no cotidiano da população é continuamente lançada nos ecossistemas aquáticos. Esses produtos contêm compostos de diferentes classes, como fármacos, hormônios, produtos de cuidados pessoais, entre outros. O crescente interesse por essas substâncias ocorre principalmente porque elas podem exibir atividade biológica em concentrações muito baixas, da ordem de µg L-1 e ng L-1 . Portanto, neste trabalho, foi avaliada a presença e determinada a concentração de 20 microcontaminantes, pertencentes a diferentes classes (antiinflamatórios, reguladores lipídicos, antimicrobianos, antissépticos, hormônios sexuais e cafeína), no rio Palmital, localizado na Região Metropolitana de Curitiba. Para investigar a presença desses poluentes, foi realizado o monitoramento ao longo de quatro coletas, em sete pontos de amostragem no rio Palmital. As amostras coletadas foram submetidas ao processo de extração em fase sólida e posteriormente os compostos foram determinados utilizando cromatografia em fase líquida com detector de arranjo de diodos e cromatografia em fase gasosa hifenada a espectrometria de massas. A validação da metodologia utilizada baseou-se nos padrões estabelecidos pela Agência Nacional de Vigilância Sanitária e pelo Instituto Nacional de Metrologia. O método de extração e quantificação foi eficiente para a determinação desses analitos em amostras de água. Dentre os contaminantes analisados, a Cafeína foi detectada em quase 100% das amostras e teve a concentração mais elevada (3,58 µg L-1 ). Entre os produtos farmacêuticos investigados, o cetoprofeno esteve presente em 27 das 28 amostras analisadas, porém em concentrações mais baixas (concentração máxima de 0,18 µg L-1 ) que os demais fármacos; o ácido acetilsalicílico teve a maior concentração (2,31 µg L-1 ) seguida do paracetamol (1,28 µg L-1 ). Concentrações significativas de hormônios também foram quantificadas no rio Palmital, assim como os parabenos e triclosan indicando uma possível influência antrópica no ambiente aquático estudado. Observou-se que ocorreram mudanças associadas a variações sazonais, sendo que em período de estiagem (outubro/2016 e julho/2017), as concentrações foram mais elevadas para a maioria dos contaminantes analisados no rio Palmital. Com o tratamento estatístico dos dados foi possível verificar uma relação entre os contaminantes emergentes estudados em conjunto com as concentrações de Namoniacal e ortofosfato. Os resultados indicaram que o rio Palmital apresentou grande influência antrópica, possivelmente aporte de efluentes domésticos provenientes de áreas densamente povoadas, as quais possuem um serviço de coleta e tratamento de esgoto que não atende a todos os domicílios. / A wide variety of products present in the daily life of the population is released into aquatic ecosystems. These products contain compounds of different classes, such as pharmaceuticals, hormones, personal care products, among others. The growing interest in these substances occurs mainly because they may exhibit biological activity at very low concentrations of the order of μg L-1 and ng L-1 . Thus, it was evaluated in the presence and concentration of 20 microcontaminants belonging to different classes (anti-inflammatories, lipid regulators, antimicrobials, antiseptics, sex hormones and caffeine) in the Palmital River, located in the Metropolitan Region of Curitiba. In order to investigate the presence these pollutants, monitoring was carried out over four samplings at seven points on the Palmital River. The collected samples were submitted to extraction in solid phase and analyzed by liquid phase chromatography with diode array detector and gas chromatography tandem mass spectrometry. The validation of the methodology used was based on the standards established by the Agência Nacional de Vigilância Sanitária and the Instituto Nacional de Metrologia. The extraction and quantification method were efficient for the determination of these analytes in water samples. Among the contaminants analyzed, Caffeine was detected in almost 100% of the samples and had the highest concentration (3.58 μg L-1 ). Among the investigated pharmaceutical products, ketoprofen was present in 27 of the 28 analyzed samples, but in lower concentrations (maximum concentration of 0.18 μg L-1 ) than the other drugs; acetylsalicylic acid had the highest concentration (2.31 μg L-1 ) followed by paracetamol (1.28 μg L-1 ). Significant concentrations of hormones were also quantified in the Palmital river, as well as the parabens and triclosan indicating a possible anthropic influence in the aquatic environment studied. It was observed that changes were associated with seasonal variations, and in the drought period (October / 2016 and July / 2017) the concentrations were higher for most of the contaminants analyzed in the Palmital River. With the statistical treatment of the data it was possible to verify the relation between the emerging contaminants studied together with the concentrations of Nammonia and Orthophosphate. The results indicated that the Palmital River presents a great anthropic influence, possibly due to the contribution of domestic effluents from densely populated areas, which have a sewage collection and treatment service that does not serve all households.

A busca por ideias, modelos e paradigmas computacionais biologicamente inspirados e plausíveis sempre atraiu o interesse de cientistas da computação, especialmente na área de Computação Natural. Além disso, o conceito de otimização pode ser abstraído de vários processos naturais como, por exemplo, na evolução das espécies, no comportamento de grupos sociais, na dinâmica do sistema imunológico, nas estratégias de busca por alimento e nas relações ecológicas entre populações de animais. Com o melhor de nosso conhecimento, os ecossistemas naturais e seus conceitos ainda não foram explorados computacionalmente no contexto de otimização de funções e, portanto, eles são abordados nesta tese. Este trabalho destaca as principais propriedades de ecossistemas naturais que podem ser importantes para a construção de ferramentas computacionais para resolver problemas complexos de otimização. Também, a modelagem computacional para tais funcionalidades são introduzidas. A principal discussão apresentada nesta tese refere-se ao uso cooperativo de populações de soluções candidatas, co-evoluindo em um contexto ecossistêmico. Com esta analogia, cada população comportar-se de acordo com uma estratégia de busca específica que é empregada na evolução das soluções candidatas. Além da possibilidade de utilizar diferentes estratégias de busca cooperativamente, esta analogia abre a possibilidade de inserção de conceitos ecológicos no processo de otimização, permitindo o desenvolvimento de novos sistemas de otimização biologicamente inspirados e plausíveis. O potencial de alguns conceitos ecológicos é apresentado em um algoritmo canônico ecologicamente inspirado, chamado ECO (Ecological-inspired Optimiaztion algorithm). Alguns algoritmos baseados em população são utilizados para compor a abordagem proposta. Os problemas resolvidos nesta tese são várias funções contínuas de benckmark com um número alto de dimensões ($D = 200$) e o problema de predição de estrutura de proteínas para o modelo 2D AB. Além disso, o uso de dinâmica populacional para auto-regular o tamanho das populações; o uso de modelos heterogêneos com diferentes estratégias de busca; e o uso de agrupamento hierárquico para ajustar dinamicamente a formação de habitats e probabilisticamente definir as topologias de comunicação são alguns estudos de caso investigados. Os resultados obtidos se mostraram promissores considerando a aplicação do ecossistema computacional. Finalmente, conclusões e várias ideias para pesquisas futuras são apresentadas. / The search for plausible biologically inspired ideas, models and computational paradigms always drew the interest of computer scientists, particularly those from the Natural Computing area. Also, the concept of optimization can be abstracted from several natural processes, for instance, in the evolution of species, in the behavior of social groups, in the dynamics of the immune system, in the food search strategies and in the ecological relationships of different animal populations. To the best of our knowledge, ecosystems and their concepts have not been explored computationally in the context of function optimization and, therefore, they are addressed in this thesis. This work highlights the main properties of ecosystems that can be important for building computational tools to solve complex problems. Also, it is introduced the computational modelling for such biologically plausible functionalities (e.g., habitats, ecological relationships, ecological succession, and another). The main discussion presented in this work relates to the cooperative use of populations of candidate solutions, coevolving in an ecological context. With this ecology-based analogy, each population can behave according to a specific search strategy, employed in the evolution of candidate solutions. In addition to the possibility of using different optimization strategies cooperatively, this analogy opens the possibility of inserting ecological concepts in the optimization process, thus allowing the development of new bio-plausible hybrid systems. The potentiality of some ecological concepts is also presented in a canonical Ecology-inspired Algorithm for Optimization, named ECO. Some population-based algorithms are used to compose the ecology-based approach. The problems solved in this thesis are several continuous benchmark functions with a high number of dimensions ($D = 200$), and the protein structure prediction problem for the 2D AB model. Also, the use of population dynamics to self-regulate the size of populations during ecological successions; the use of heterogeneous models embedding different search strategies into the system; and the use of hierarchical clustering to dynamically adjust the habitats formation and probabilistically define the habitats communication are some case studies investigated. Results were promising concerning the application of the proposed computational ecosystem for optimization. Finally, concluding remarks and several ideas for future research are presented.