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Eutrophication is a global environmental problem, which in Sweden is predominantly in the south of Sweden where there are large agricultural areas. Skellefteå is a small town on the northern coast which has eleven water bodies classified as “poor ecological status” of which Uttersjöträsket is one of them according to the water authorities. Uttersjöträsket has a requirement to achieve good ecological status by 2021. Uttersjöträsket’s agriculture land is from at least 1716 according to historical maps. To be able to restore a eutrophic lake the source of the phosphorus load must be identified.To determine the natural state for Uttersjöträsket the sediment record could be studied. For example, earlier studies have been made in Kassjön in Umeå were they conclude that the beginning of the agriculture area started in the 12th century, which means that Uttersjöträsket could have had agriculture land since before 1716. The municipality of Skellefteå made contact with residents in the area who formed a water group to work towards achieving the goal by 2021. This report will form the basis for the water group to take appropriate measures to reduce the bloom of cyanobacteria and to achieve good ecological status. The conclusions of this report are based on analysis of data and results from previous studies of eutrophic lakes. Many different methods must be done to have a long-lasting impact and to achieve good ecological status in Uttersjöträsket. The focus of the actions should be on the ditch between Yttersjön and Uttersjöträsket as the highest phosphorus load is in that catchment.

This study focuses on Long Pond, a groundwater-fed sinkhole lake in Georgia, which does not exhibit any evidence of eutrophication drivers despite high concentrations of sedimentary phosphorus (P) (> 3000 mg/kg P) in the recent sediment record. Chemical analyses have shown a strong correlation (r2>0.99) between P and aluminum (Al) throughout the core, suggesting Al plays a significant role in sequestering most of the P, and limiting its availability to phytoplankton, thereby inhibiting eutrophication. The purpose of this study is to decipher P and Al physicochemical associations in the sediments. After the samples were fractionated into amorphous and non-amorphous phases, the correlation was maintained in both phases. Evidence suggests two modes of Al-P associations: a sorption and/or co-precipitation occurring mostly in the amorphous phase and a mode whereby Al and P are being inputted to the lake bound together.

Lake Victoria (LV), is the largest tropical fresh water lake. It is however facing a myriad of challenges like eutrophication, introducing species, mass extinction and climate change. Eutrophication has mostly been seen as a result of non-point pollution from upstream agricultural areas. However, studies have found that atmospheric deposition could perhaps be the greatest cause of nutrient loading in the lake. Our study looked at black carbon as one of the factors favoring eutrophication in LV. Black carbon is a product of incomplete combustion of biomass or fossil fuel. Biomass burning is prevalent in many areas of Africa and our results have shown a great spatial and temporal variability in its concentration in sediments. The sedimentation rates calculated after analyzing 210Pb activity were 0.87, 0.53 and 0.35 g cm-2 yr-1 while the average black carbon concentrations were 4.6, 2.1 and 6.9 mg g-1 for Siaya, Kisumu and Busia, respectively. These results provided valuable information when compared to past historical events in the Lake region especially eutrophication. The study also found that soot BC has been increasing in the past 100 years suggesting the input from fossil fuels. This study elucidates the complexity of drivers of eutrophication in Lake Victoria. Nitrogen and Phosphorous from the upstream agricultural sites has long been seen as the main cause of eutrophication. Through this study we find that soot deposition in the lake coincides with the period of increased primary productivity. The Total Organic Carbon and Total Nitrogen were also analyzed and have shown increased remarkable increase with time. All these geochemical variables are a testament to the increased role of human activities on the lake’s productivity. While other studies on soot in marine environments have associated bacterial growth to nutrients attached to soot black carbon. We correlate the concentration of soot in Lake Victoria basin to blooming of cyanobacteria.

This paper is about analyzing water quality of a stream that flows in southwest of Swedencalled Hasslebäcken. The stream is a tributary of Suseån and has its springs in the naturereserve Biskopstorp and flows through a mixed landscape of mostly spruce forests andagriculture land. Little is known about Hasslebäcken and its water and therefore a study by request of Suseåns vattenråd was performed. The study consisted of analyzing the water ofphosphorous, nitrogen, pH, suspended particles and conductivity. To broaden the examination of water quality sampling of benthic macroinvertebrates and two index (ASPTindex and Shannon’s diversity index) of water quality were used. Another part of the study were to search for fish barrier in the stream and to evaluate the possibilities for troutspawning and habitats. The whole stretch of the stream were examined and eleven differentsampling sites were used. The results show that Hasslebäckens upper parts have low levelsof nutrients while the lower parts show intermediate to extremely high levels. The indexresults points at low ecological values for Shannon and high ecological values for ASPT. Thisis normal for a stream that flows through an agricultural landscape. The results concerning pH show a lower pH in the upper parts than in the lower parts. This is also normal for a stream in a production forest of spruce in these parts of Sweden. Hasslebäcken also have several fish barrier that prevent various fish species to migrate up along the stream from thesea. The evaluation of trout habitats and spawning area show decent possibilities for successful reproduction and growth.

Three north central Texas reservoirs (Grapevine Reservoir, Lake Ray Hubbard, Lewisville Reservoir) were investigated in order to characterize the nutritional ecology, phytoplankton community structure, and primary productivity within the trophogenic zones of each. Emphasis was placed on elucidating the relative influences of the major nutrients (C, N, P, Fe, Si) and various other physico-chemical parameters on phytoplankton community biomass, structure, and productivity. Extensive physical, chemical, and biological analyses consisting of approximately eighty parameter measurements were made on each of twenty-three integrated water samples (surface to three meters) taken from the three reservoirs during the period July, 1971 to June, 1972. New methods which were employed included a high-intensity ultraviolet photocombustion procedure for the determination of total nitrogen, phosphorus, and iron, and an in vitro oxygen method for estimating community metabolism. General chemical and physical regimes are described for the three reservoirs, and various interrelationships discussed. Phytoplankton communities are delineated on bases of species composition, volume, diversity, pigments, and metabolism data. The more salient biotic and physico-chemical interrelationships are examined within the context of the limiting nutrient controversy.

This bachelor thesis is about the possibility of restoring a eutrophic bay in the Baltic Sea. Today the Baltic sea is affected by unnatural amounts of nutrients which affects the ecology in a negative way. To restore the ecology of the Baltic sea national, international and local actions must be undertaken. The case-study of this essay is about the project “Rädda Burgsviken” that is doing local efforts when trying to save the bay from eutrophication. Thepurpose is to see how effective local actions are when trying to achieve a good ecological balance in the bay. Furthermore, the purpose is to acknowledge which actions are effective and what they require to be executed and sustained. The essay is based on a qualitative text analysis and qualitative interviews with two central respondents. The result of this essay indicates that the actions been made have a good or potential good outcome and that they must cooperate with the local area regarding tourism and business because they are dependent on each other.

In the eutrophic waters of the Indian River Lagoon (IRL), decreases in overall shellfish size have been reported, which may be related to coastal acidification. To understand the relationship between acidification and eutrophication, water samples from 20 sites spanning the IRL were collected and analyzed for dissolved nutrients and omega values in spring (dry season) and fall (wet season), 2016-2017. Additionally, three sites were sampled weekly to observe temporal variability of nutrients and omega values. For the IRL-Wide sampling, sites with higher dissolved nutrient concentrations showed lower omega values with significant negative relationships. Both sampling programs showed an overall positive linear relationship between salinity and omega values. This work suggests that salinity and dissolved nutrients have implications for acidification in the IRL and must be considered for future water quality, shellfish and coral reef restoration. / Includes bibliography. / Thesis (M.F.A.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Increasing demands for improved water quality in receiving waters, effluent reclamation and reuse have prompted wide interest in the use of wetlands for the treatment of wastewater. Over a four year period, domestic sewage effluent was treated using a range of gravel based, subsurface flow constructed wetland systems. Weekly samples at inlet and outlet points were assayed for suspended solids, biological oxygen demand, organic carbon, total kjeldahl nitrogen, ammonium, nitrate/nitrite, phosphorus, dissolved oxygen, temperature, pH and faecal coliform levels. The wetland system received secondary treated effluent for three years and primary settled effluent for one year. The potential of constructed wetland systems for nitrogen removal and potential pathogen reduction was investigated. Nitrogen removal was characterised by estimation of potential nitrification and denitrification rates within the system. Disinfection performance of the wetland system was assessed by enumeration of faecal indicator bacteria in the system influent and effluent, as well as with distance along the length of the system. The removal rate was estimated, considering influent and effluent faecal coliform concentrations as well as system hydraulic retention time and temperature. / Master of Science (Hons)