Lake Victoria is the largest lake by area in Africa as well as the source of River Nile. The lake has undergone environmental changes during the last four decades, particularly rise in its trophic condition and decline in oxygen level, which affects the water quality and fish population. Carbon (C), nitrogen (N) and phosphorus (P) are three vital elements required for algal growth that affect eutrophication in lakes. The aim of the study is to examine the P concentrations in sediment cores retrieved from the catchment around Lake Victoria, and compare this with data on N and C concentrations from the same samples. The results show that there is a difference in P levels between the urban versus rural sites. Moreover, concentrations for P, N and C are generally high in younger sediments (near surface samples), meaning that nutrients have most likely been added due to anthropogenic activities in the catchment. In addition, factors like erosion and weathering are also likely to have contributed to nutrient inputs, and thereby the eutrophic status in Lake Victoria.

In this study, I examined water chemistry of 31 Canadian Shield lakes in relation to catchment characteristics to test the hypothesis that Shield lakes with more marble may exhibit iron (Fe) deficiency and, hence, be more vulnerable to eutrophication. I performed a diatom-based paleolimnological reconstruction of one of these lakes (Heney Lake), which was subjected to anthropogenic stresses including a fish farm. Results suggest that the presence of marble influenced lake chemistry, including lowering the ratio of Fe: P. The reconstruction of historical P concentrations was not statistically possible but past Fe could be inferred, which no previous study has attempted. Certain eutrophication-associated diatom species suggest that logging and European settlement beginning in the early XXth century led to a slight increase in nutrient concentrations. However, a more important diatom species shift was likely related to climate change, as observed in other temperate lakes worldwide.

Water eutrophication is a major problem of pollution of water resources, which is caused by excessive nutrient inputs to the water. This study deals with the organization of institutions around the water source as possible cause of the decreasing status of water quality. The method of institutional analysis IAD framework examines the control, disposition and execution of the actors' rights in the Macha Lake in regard to the possible application of community ownership approach. The applied method shows that the administration of the Macha Lake is fragmented into many stages, where each individual has limited powers that are in the approval process depending on other actors. However, here we encounter a major moral attitude of the local community. Further analysis finds that any made efforts to improve the quality of the water are only focused in the treatment of the water of the lake and not in the correction and 6 more regulation of his sources. The cause of the eutrophication and subsequent steps must be performed at the level of the entire watershed, not just locally.

Orientador: Maria José Brito Zakia / Banca: Carolina Bozetti Rodrigues / Banca: Iraê Amaral Guerrini / Resumo: O conceito de microbacias hidrográficas reflete a sensibilidade ao regime de precipitação e uso alternativo do solo da área de drenagem. Neste sentido, ao pensar em planejamento territorial, a conservação das microbacias hidrográficas é o que garante o suprimento da quantidade e qualidade do corpo de água à jusante. Assim, sabendo que a exportação dos nutrientes em uma microbacia hidrográfica está relacionada ao manejo exercido na área, e em que, ao depender da sua concentração no sistema aquático pode gerar um processo de degradação ambiental, o objetivo deste trabalho foi avaliar a dinâmica de parâmetros de qualidade da água e a oscilação do índice de estado trófico em duas microbacias hidrográficas. As microbacias estão sob diferentes coberturas de vegetação, e enquanto uma possui vegetação nativa do bioma Mata Atlântica, a outra possui predominância de florestas plantadas de Pinus. Foram coletados dados durante uma série histórica de dez anos (2005 - 2015), com frequência de observação quinzenal. As variáveis aferidas foram os nutrientes nitrato, fósforo, potássio, cálcio e magnésio, assim como parâmetros físicos de sólidos suspensos totais, turbidez e cor aparente. O monitoramento dos parâmetros de qualidade é fruto do Programa Cooperativo sobre Monitoramento e Modelagem de Bacias Hidrográficas (PROMAB) do Instituto de Pesquisas e Estudos Florestais (IPEF). Neste estudo observou-se que apesar do regime de precipitação condicionar a flutuação de alguns nutrientes, a mobil... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The concept of catchments reflects the sensitivity of the precipitation regime and the alternative use of soil in the drainage area. In this sense, when thinking about territorial planning, the conservation of watersheds is what guarantees the supply of the quantity and quality of the water body downstream. Thus, knowing that the export of nutrients in a watershed is related to the management in the area, and that, depending on its concentration in the aquatic system can generate an environmental degradation process, the objective of this work was to evaluate the parameters dynamics of water quality and the oscillation of the trophic state index in two catchments. The watersheds are under different coverages of vegetation, while one of the watershed is surrounded by vegetation native to the Atlantic Forest biome, the another is predominantly planted pine forests. Data were collected during a ten - year historical series (2005 - 2015), with frequency of biweekly observation. The measured variables were nitrate, phosphorus, potassium, calcium and magnesium nutrients, as well as physical parameters of total suspended solids, turbidity and apparent color. The monitoring of the quality parameters is the result of the Cooperative Program on Monitoring and Modeling of Watershed of the Forest Research Institute. In this study it was observed that although the precipitation regime conditions the fluctuation of some nutrients, the mobility of the elements can be in function of the solubility and reactivity with the water. No water quality depreciation was observed by forest ... / Mestre

Considerando a importância da represa do Lobo, os indícios de eutrofização encontrados na área e tendo a recreação como seu principal uso, buscou-se, neste trabalho, avaliar a qualidade da água nos rios tributários e na represa, e sua adequação a balneabilidade. Para os afluentes do sistema, estimando-se, ainda, a contribuição dos mesmos ao aporte de materiais à represa, foram amostrados o córrego do Geraldo, a confluência dos córregos Água Branca e Limoeiro, o rio Itaqueri (antes da mineradora), o ribeirão do Lobo, o córrego das Perdizes, avaliando-se parâmetros físicos, químicos e biológicos da água e a vazão dos rios, em dois períodos (agosto/setembro e dezembro) de 2002. Os resultados, com base no índice de estado trófico, indicam que a maioria dos tributários, com exceção do córrego Água Branca (eutrófico), é oligotrófico. Na represa o estudo teve avaliações mensais para alguns parâmetros (nutrientes totais e dissolvidos, clorofila total e material em suspensão) e semanais para outros (pH, condutividade elétrica, temperatura da água, oxigênio dissolvido e coliformes fecais) ao longo de um ano (dezembro de 2001 a dezembro de 2002), em nove pontos, abrangendo a região de foz do rio Itaqueri, córrego do Geraldo e ribeirão do Lobo, quatro pontos distribuídos na praia do balneário Santo Antônio e um ponto a jusante da represa. A foz do rio Itaqueri apresentou-se meso-eutrófica no período, enquanto os outros pontos avaliados, oligotróficos. Apesar da condição favorável apresentada, a análise temporal dos dados (com estudos realizados nos últimos 30 anos), mostra uma evidente e preocupante alteração nas condições originárias desse sistema, indicando um evidente processo de eutrofização do reservatório, associado aos usos e ocupação da bacia hidrográfica (resíduos domiciliares, turismo, agricultura e pecuária). Em relação a balneabilidade os principais pontos de contaminação fecal na represa são as entradas dos tributários, enquanto o corpo da represa foi considerado excelente em todo o período amostrado. O córrego Água Branca, como corpo receptor do esgoto de Itirapina, é o mais comprometido dos corpos de água avaliados, além de ser o principal contribuinte de nutrientes e coliformes fecais para a represa do Lobo, através do rio Itaqueri. / Considering the importance of the Lobo reservoir, the sights of eutrophication found in the area and having recreation as its main usage, it has been tried, in the following paper, to evaluate the water quality in the tributary rivers and also in the reservoir as well as its adequacy to balneability. As main tributaries of the system, estimating yet their contribution to the input of materials to the reservoir, there have been sampled the Geraldo river, the meeting of Água Branca and Limoeiro rivers, the Itaqueri river (before the mining plant), the Lobo river, the Perdizes river, evaluating their physical, chemical and biological parameters and the rivers leakage during two different periods of time (August/September and December) from 2002. The results, which are based in the amount of trophic state, show that most of the tributaries, excepting the Água Branca river (eutrophic) are oligotrophic. In the reservoir, the evaluation has been more systematic, with monthly evaluations to some parameters (amount of total nutrients and dissolved nutrients, total chlorophyll and suspended material) and weekly evaluation to others (pH, electrical conductivity, water temperature, dissolved oxygen and fecal coliforms), during the period of one year (December, 2001 to December, 2002), in nine sites considering the region of the mouth of the rivers Itaqueri, Geraldo and Lobo, four sites along the beach of balneário Santo Antônio, and one site at the upper part of the reservoir. The mouth of the Itaqueri river has been meso-eutrophic throughout the period, while the other evaluated sites have been oligotrophic. In spite of the favorable condition showed by the IET, the timing analyses of the data (based on studies done in the last 30 years) shows a clear and worrying change in this system original conditions, related mainly to the increase of nutrients and its consequences, indicating a clear process of eutrophication of the system, what may be associated to the usages and occupation of the river basin (homes wasting material, tourism, agriculture and cattle-raising). Relating to balneability, the main sites of fecal contamination in the reservoir are the tributaries entrances (in the Itaqueri river the contamination happens due to Itirapina\'s sewer system), while the reservoir body has been considered excellent throughout all the sampled period. The Água Branca river, as receptor of the Sewer treatment station and also the sewer from two Itirapina\'s prisons, is the most risking one from the water bodies evaluated, besides being the main contributor of nutrients and fecal coliforms to the Lobo reservoir through the Itaqueri river.

The Red Sea is one of the warmest, saltiest, and most oligotrophic seas in the world that supports a healthy and extremely diverse coral reef ecosystem. Increasing development along the Saudi Arabian coast may increase eutrophication due to impacts of human population and also oil pollution from increased shipping traffic and refinery activity. The risk of oil pollution combined with increased eutrophication due to coastal development provides a clear stressor interaction which is vastly understudied. Individually, these stressors are known to negatively impact coral reproduction, recruitment, and growth. This study focuses on reef settlement and recovery following experimentally-simulated disturbance scenarios. Carbonate recruitment tiles were placed on the reef and exposed to four treatments: control, nutrient enrichment with slow-release fertilizer, tiles soaked in crude oil, and a combination treatment of nutrient enrichment and oil-coated tiles. At periods of 3, 6, 9, 14, and 17 weeks, tiles were collected to classify the settled community and measure oxygen production. Oil, nitrate, and phosphate were the biggest determining factors predicting settlement and oxygen production of the different treatments. The oil treatment had the least overall settlement and oxygen production, whereas the nutrient treatment had the most turf algal recruitment and oxygen production. The combination treatment had an antagonistic effect on algal growth: the nutrients facilitated growth on the otherwise toxic oiled tiles.

Mountains play an important role in providing water resources from snow and ice to downstream urban population centers. In Utah, USA, nearly 86% of the state's population resides in the rapidly growing urban corridor along the Wasatch Front. Water along the Wasatch Front is stored in several deep reservoirs in the Provo River Watershed. Additions of nutrients, into these reservoirs, may stimulate the growth of primary producers (e.g., total phytoplankton and cyanobacteria) potentially attenuating water quality. To determine the influence of nutrients on primary producers in the Provo River's reservoirs, identify whether cyanobacteria are transported downstream, and quantify nutrient thresholds that regulate phytoplankton responses, we monitored and experimentally manipulated total phytoplankton and cyanobacteria in rivers and reservoirs. We found that total phytoplankton biomass (measured as chlorophyll a concentrations) was correlated with the total phosphorus (TP) in the Jordanelle Reservoir and the outflow from the Jordanelle Reservoir. Cyanobacteria biomass (measured as phycocyanin concentration) was correlated with dissolved inorganic N (DIN):SRP in the Deer Creek Reservoir and river sites below the Deer Creek Reservoir. Based on next generation sequencing 16S rDNA of all waters evaluated, the relative abundance of cyanobacteria within bacterial communities was extremely low, with the highest relative abundance of cyanobacteria present in the reservoirs being 10.7% for Deer Creek and 5.5% in Jordanelle during the late summer. Of the 25 genera of cyanobacteria that were found across all waters, five species have the ability to produce cyanotoxin: Microcystaceae; Aphanizomenon MDT14a; Aphanizominon NIES81; and Planktothrix NIVA-CYA. Season determined bacterial community composition in the river and reservoir over the almost two years of sampling with bacterial communities being distinct between the limnetic location in Deer Creek Reservoir to the outflow into the river immediately below the dam. We found no difference between the bacterial communities in the limnetic zone in Jordanelle and the river site directly below Jordanelle Dam. In the nutrient starvation bioassays, cyanobacteria and total phytoplankton responded to the nutrient additions, but there were no specific nutrient thresholds where pigment concentrations leveled out even as nutrient concentration increased. However, when P was added as SRP treatments both total phytoplankton and cyanobacteria concentrations increased, especially in the highest SRP treatment (0.08 mg/L) without any N addition. The addition of N alone did not influence total phytoplankton until there was at least 0.2 mg/L of P added. Further, cyanobacteria required at least 0.2 mg/L of SRP before responding to N levels above 0.8 mg/L. Thus, a nutrient threshold to maintain the reservoir at its current state would be 0.2 mg/L P and between 0.3 and 0.8 mg/L DIN. Our results identify that the water within the reservoirs and rivers are extremely clean and is in no immediate risk of extensive total phytoplankton or cyanobacterial blooms with P being the dominant driver of primary producer activity.

Master's thesis deals with water utilization in exposition of arctic wolf and canadian beaver in ZOO Brno. Theoretical part describes water utilization in ZOO and processes in water connected with nutrient enriching and uprising of water bloom. Practical part focuses on monitoring water quality in April and May 2012 and concept to solute water filtration in ponds.

Around 70% of the world is covered with water but only 2.5% of it is freshwater and even less is available for the ecosystem and humanity. The limited available fresh water is facing increasing challenges from water pollutions and eutrophication is one of the major concerns worldwide. The reason of eutrophication is the presence of excessive amounts of phosphorus and nitrogen in water bodies, which may cause algal blooms and a variety of harms to aquatic ecosystem in association with algal blooms. Among these two components, phosphorus plays a major role in eutrophication control and recovery since atmospheric N2 can be fixed by biological nitrogen fixation (BNF) processes and is therefore of little meaning to control. In this study, we investigated for the first time the potential of using controlled growth of algae and, in particular, filamentous cyanobacterium Spirulina platensis, for eutrophic water restoration. This study investigated the algal cell growth, algal by-product production, and removal of phosphate by S. platensis at different phosphate levels in artificial wastewaters and eutrophic waters. Results indicate that S. platensis could remove 90.17% of phosphorus from artificial wastewaters containing 10 mg/L phosphate in a 16-day cultivation period. When tested for eutrophic water restoration, S. platensis was able to convert hypo-eutrophic, eutrophic, and meso-eutrophic waters to oligotrophic water. It was shown that by using 100- micron nylon mesh cloth we could keep biomass concentration to be lower than 0.30±0.02 g/L. In the meantime, light/dark tests indicate that the dissolved oxygen level would not go below the hypoxic level, i.e., 4 mg/L after a 12-hour dark period at biomass concentration up to 1 g/L. These results indicate that it is possible to use S. platensis for both control of point source discharge and eutrophic water restoration.

Eutrophication is an increase in primary plant nutrients (Nitrogen [N] and Phosphorus [P]) in oceans, estuaries and lakes. The consequences of eutrophication are harmful algal blooms (HABs), resulting in algal toxin production and the depletion of oxygen as the extensive biomass decays. P is often the limiting nutrient and is viewed as a significant environmental problem. Most of the excess P that enters aquatic ecosystems originates from anthropogenic sources such as fertilizers, sewage, animal wastes, compost, crop residues, and wastewater. Over time, one of the main reservoirs of P becomes organic P (Po). We investigated the chemical nature and dynamics of P in cyanobacteria, horse manure, stormwater treatment areas, and rice fields. To better understand the chemical nature of P, the identification of specific P compounds was required, which was achieved through 31P nuclear magnetic resonance (NMR) spectroscopy. We investigated how paramagnetic metals and quadrupolar nuclei cause severe line broadening, peak shifts, and decreased the signal to noise ratio. Results revealed that certain Po forms are readily bioavailable to Microcystis aeruginosa. Additionally, the potential heterotrophic use of the organic portion (e.g., glucose, glycerol) of these P compounds are indicated for the growth and persistence of Microcystis aeruginosa. We showed that the cultivation of rice (Oryza sativa L.) had been found to effectively reduce P from agrarian soil and water through plant uptake and, therefore, minimizing downstream eutrophication. Soil, water, sugarcane, and rice plants at two different stages were analyzed for twelve different elements. Finally, we examined how a “relic” agrarian ditch in Stormwater Treatment Area 1 East (STA-1E) can be used for the retention and sequestration of P and other nutrients. The STAs were established to capture P from agricultural and other sources before reaching the Everglades. Retained P is primarily stored in the wetland soils and sediments, generated through a collection of interrelated physical, chemical, and biological processes. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection