Paleolimnology of selected Precambrian Shield lakes /

The analysis of fossil diatoms and Mallomonas assemblages in a 2.85 m sediment core revealed that a series of distinct floristic changes have occurred in the development of Found Lake, a small Shield lake in southern Ontario. Climatic and vegetational changes in the lake's watershed were closely associated with successional changes in the lake's biota. Nutrients released by the deciduous component of the Found Lake watershed appeared to be especially important in determining diatom and Mallomonas standing crop. The top 20 cm of sediment of 3 ,Shield lakes was then investigated using close interval (1 cm) analyses of diatoms, Mallomonas scales, pollen grains and sedimentary phosphorus. Found and Jake Lake are adjacent to Highway 60, whereas Delano Lake has been undisturbed and was used as a control. Dramatic changes in the diatom and Mallomonas communities were recorded in the Found and Jake Lake stratigraphies and could be closely associated with known historical events. Increased turbidity and nutrient enrichment were believed responsible for these successional changes. In addition, diatom and Mallomonas standing crop increased substantially following road construction in Found Lake's drainage basin. Meanwhile, no. sharp changes in diatom or Mallomonas communities were recorded in the recent sediments of the control (Delano) lake. The use£ulness o£ Synuracean scales as paleoindicators, as well as the importance o£ sectioning cores at close intervals during transition periods in a laker's development, was stressed.

Variação e tendências dos parâmetros de qualidade de água do ecossistema aquático da microbacia hidrográfica Córrego da Onça no município de Ilha Solteira/SP

Pós-graduação em Engenharia Civil - FEIS

Effects of biodegradable detergents in the accumulation of lipofuscin (age pigment) in gill and liver of two neotropical fish species

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparison of aquatic food chains using nitrogen isotopes.

Recent studies have shown the utility of delta(15)N to model trophic structure and contaminant bioaccumulation in aquatic food webs. However, cross-system comparisons in delta(15)N can be complicated by differences in delta(15)N at the base of the food chain. Such baseline variation in delta(15)N is difficult to resolve using plankton because of the large temporal variability in the delta(15)N of small organisms that have fast nitrogen turnover. Comparisons using large primary consumers, which have stable tissue isotopic signatures because of their slower nitrogen turnover, show that delta(15)N increases markedly with the human population density in the lake watershed. This shift in delta(15)N likely reflects the high delta(15)N of human sewage. Correcting for this baseline variation in delta(15)N, we report that, contrary to expectations based on previous food-web analysis, the food chains leading up to fish varied by about only one trophic level among the 40 lakes studied. Our results also suggest that the delta(15)N signatures of nitrogen at the base of the food chain will provide a useful tool in the assessment of anthropogenic nutrient inputs.

Urban development modifies lake food webs in the Pacific Northwest

Thesis (Master's)--University of Washington, 2015

Lake LaVerne Watershed Project Progress Report: Project Number 1415-007, Final Report, June 30, 2016

This application targets a critical need for low maintenance and inexpensive treatment solutions to encourage landowners and resource managers to enhance the water quality of small ponds and lakes. Many rural and urban small ponds and lakes across Iowa and the region have eutrophic conditions with high levels of nutrients and low levels of oxygen. Story SWCD teamed with Iowa State University (ISU) researchers propose to address this need through the construction and monitoring of a vegetated floating island (VFI) system on ISU's iconic Lake LaVerne. VFI's are hydroponically-vegetated islands that reduce nutrient loading directly from pond and lake water (rather than from soil adjacent to the pond). Urban watershed assessment on the ISU campus has already led to reductions in stormwater runoff to the lake but eutrophic conditions persist and are well documented. The VFI will function as a public art attraction for the entire 2015 growing season during which time monitoring will occur to quantify nitrogen, phosphorus and carbon changes in the lake. Tens of thousands of visitors to the ISU campus and Lake LaVerne will interact with this installation using promotional signage on site, public events and interactive social media throughout the project. Water quality and vegetation analysis will quantify nutrient uptake by the island vegetation and thus determine its effectiveness for use in other similar water bodies in Iowa.

Realizing 'four comforts' in the urban fringe : the case of White Horse Lake Eco-creative City Project, Hangzhou, China

This article examines a cultural and creative industries park project – the White Horse Lake Ecocreative City on land outside the urban centre of Hangzhou, China, which uses an imaginary rural lifestyle as its key attraction. By analysing government policies and development plans, and through interviews with initiators, managers and creative practitioners, the article first assesses the geographical position, that is, the impact of locality with regard to both hard and soft infrastructure of the project; it then examines the synergies and tensions embedded in the strategic goals, that is, to build the right city for ‘four comforts’ (siyi, 四宜) – for residence, for business, for travel and for culture. The article concludes that Chinese-style cultural conversion remains locked in a top-down ideological framework, one that rural residents and the new ‘creative class’ are expected to respect.

Coastal management measures for the lower Maumee Watershed, Lake Erie

In January 2006 the Maumee Remedial Action Plan (RAP) Committee submitted a State II Watershed Restoration Plan for the Maumee River Great Lakes Area of Concern (AOC) area located in NW Ohio to the State of Ohio for review and endorsement (MRAC, 2006). The plan was created in order to fulfill the requirements, needs and/or use of five water quality programs including: Ohio Department of Natural Resources (DNR) Watershed Coordinator Program; Ohio EPA Great Lakes RAP Program; Ohio DNR Coastal Non-point Source Pollution Control Program; Ohio EPA Total Maximum Daily Load Program; and US Fish & Wildlife Service Natural Resources Damage Program. The plan is intended to serve as a comprehensive regional management approach for all jurisdictions, agencies, organizations, and individuals who are working to restore the watershed, waterways and associated coastal zone. The plan includes: background information and mapping regarding hydrology, geology, ecoregions, and land use, and identifies key causes and sources for water quality concerns within the six 11-digit hydrological units (HUCs), and one large river unit that comprise the Maumee AOC. Tables were also prepared that contains detailed project lists for each major watershed and was organized to facilitate the prioritization of research and planning efforts. Also key to the plan and project tables is a reference to the Ohio DNR Coastal Management Measures that may benefit from the implementation of an identified project. This paper will examine the development of the measures and their importance for coastal management and watershed planning in the Maumee AOC. (PDF contains 4 pages)

Modelling phosphorus dynamics in multi-branch river systems: A study of the Black River, Lake Simcoe, Ontario, Canada

High rates of nutrient loading from agricultural and urban development have resulted in surface water eutrophication and groundwater contamination in regions of Ontario. In Lake Simcoe (Ontario, Canada), anthropogenic nutrient contributions have contributed to increased algal growth, low hypolimnetic oxygen concentrations, and impaired fish reproduction. An ambitious programme has been initiated to reduce phosphorus loads to the lake, aiming to achieve at least a 40% reduction in phosphorus loads by 2045. Achievement of this target necessitates effective remediation strategies, which will rely upon an improved understanding of controls on nutrient export from tributaries of Lake Simcoe as well as improved understanding of the importance of phosphorus cycling within the lake. In this paper, we describe a new model structure for the integrated dynamic and process-based model INCA-P, which allows fully-distributed applications, suited to branched river networks. We demonstrate application of this model to the Black River, a tributary of Lake Simcoe, and use INCA-P to simulate the fluxes of P entering the lake system, apportion phosphorus among different sources in the catchment, and explore future scenarios of land-use change and nutrient management to identify high priority sites for implementation of watershed best management practises.

Paleolimnologically inferred eutrophication of a shallow, tropical, urban reservoir in southeast Brazil

We studied the eutrophication history of a tropical shallow reservoir in the So Paulo metropolitan region, southeast Brazil. We analyzed grain size, geochemistry, diatom assemblages, and land-use records in a sediment core from the reservoir to infer its trophic state history during the last similar to 110 years (1894-2005). Eighty diatom species were observed in the core and shifts in the relative abundances of planktonic and benthic taxa indicate major limnological changes associated with complex interactions between hydrologic factors and eutrophication. Discostella stelligera was associated with deforestation and water physical changes whereas Aulacoseira granulata, a species abundant throughout the core, was mostly associated with high flux conditions and erosion events, regardless of trophic state. Eutrophication was triggered by construction of the city zoo (1958) and installation of the So Paulo State Department of Agriculture (1975) within the Gar double dagger as watershed, and increasing loads of untreated sewage from these institutions. The data suggest that deterioration in water quality began after similar to 1975 and markedly accelerated after similar to 1990. The reservoir has been hypereutrophic since 1999. Steady increases in geochemical proxies for trophic state, along with a decrease in C/N ratios, indicated higher nutrient concentrations and the prevalence of autochthonous production towards the core top. Appearance of Achnanthidium catenatum similar to 1993 highlighted the onset of a marked eutrophication phase. The subsequent dominance of Planothidium rostratum and Cyclotella meneghiniana suggested a sharp shift to a hypereutrophic state since 1999. Land-use history proved valuable for validating the chronology and interpreting anthropogenic impacts. Multi-proxy analysis of the sediment record provided an effective tool for tracking ecological shifts in the reservoir ecosystem. This study provides the first reconstruction of lake eutrophication history in Brazil and highlights the importance of hydrological/physical changes as drivers of diatom assemblage shifts in reservoirs, which may confound trophic state inferences based on shifts in the planktonic/benthic diatom ratio.

Perfluorinated compounds in environmental matrices of Lake Victoria Gulf

ABSTRACT One of the major ecological challenges on Lake Victoria resources is the existence of “hot spots”, caused by human waste, urban runoff, and industrial effluents. The lake is tending towards eutrophication which is attributed to the increasing human population in its watershed. A report of the levels of perfluorooctane sulfonate and perfluorooctanoic acid in environmental matrices of Lake Victoria is presented, and the management implication of perfluorinated compounds and similar potential organic pollutants examined. Two widely consumed and economically important fish species namely Lates niloticus (Nile perch) and Oreochromis niloticus (Nile tilapia) were obtained from Winam gulf of Lake Victoria, Kenya, and analysed for perfluorooctane sulfonate and perfluorooctanoic acid in muscles and liver using liquid chromatography coupled with mass spectroscopy. Variability in the concentrations of perfluorooctanoic acid or perfluorooctane sulfonate in river waters (range perfluorooctanoic acid 0.4 – 96.4 ng/L and perfluorooctane sulfonate < 0.4 – 13.2 ng/L) was higher than for Lake waters (range perfluorooctanoic acid 0.4 – 11.7 ng/L and perfluorooctane sulfonate < 0.4 – 2.5 ng/L respectively). Significant correlations were tested between perfluorinated compounds levels in sediments, fish and water. Wastewater treatment plants and other anthropogenic sources have been identified as significant sources or pathways for the introduction of perfluoroalkyl compounds into Lake Victoria ecosystem. In this study, elevated concentrations of perfluorooctanoic acid and perfluorooctane sulfonate was found in two wastewater treatment plants (WWTPs) in Kisumu, City of Kenya. An alternative analytical method to liquid chromatography/ mass spectroscopy for analysis of perfluorocarboxylic acids in abiotic and biotic matrices where high concentrations are expected is also presented. Derivatisation of the acid group to form a suitable alkyl ester provided a suitable compound for mass spectroscopy detection coupled to gas chromatography instrumental analysis. The acid is esterified by an alkyl halide i.e benzyl bromide as the alkylating agent for Perfluorocarboxylic acids quantification. The study also involved degradability measurements of emerging perfluorinated surfactants substitutes. The stability of the substitutes of perfluorinated surfactants was tested by employing advanced oxidation processes, followed by conventional tests, among them an automated method based on the manometric respirometry test and standardized fix bed bioreactor [FBBR] on perfluorobutane sulfonate (PFBS), a fluoroethylene polymer, fluorosurfactant (Zonyl), two fluoraliphaticesters (NOVEC ™ FC4430 and NOVEC ™ FC4432) and 10-(trifluoromethoxy) decane-sulfonate. Most of these emmerging surfactants are well-established in the market and have been used in several applications as alternatives to PFOS and PFOA based surfactants. The results of this study can be used as pioneer information for further studies on the sources, behaviour and fate of PFOA and PFOS and other related compounds in both abiotic and biota compartments of Lake Victoria and other lakes. Further an overview in degradation of emerging perfluorinated compounds substitutes is presented. Contribution in method development especially for acid group based fluorosurfactants is presented. The data obtained in this study can particularly be considered when formulating policies and management measures for preservation and sustainability of Lake Victoria resources.

An evaluation of the Cypress Creek watershed for inorganic chemical load as it flows into Lake Houston

Background. The Cypress Creek is one of the main tributaries of Lake Houston, which provides drinking water to 21.4 million customers. Furthermore, the watershed is being utilized for contact and non-contact recreation, such as canoeing, swimming, hiking trail, and picnics. Water along the creek is impacted by numerous wastewater outfalls from both point and non-point sources. As the creek flows into Lake Houston, it carries both organic and inorganic contaminants that may affect the drinking water quality of this important water source reservoir. Objective. This study was carried out to evaluate the inorganic chemical load of the water in Cypress Creek along its entire length, from the headwaters in Waller County and up to the drainage into Lake Houston. The purpose was to determine whether there are hazardous concentrations of metals in the water and what would be the likely sources. Method. Samples were collected at 29 sites along the creek and analyzed for 29 metals, 17 of which were on the Environmental Protection Agency priority pollution list. Public access sites primarily at bridges were used for sample collection. Samples were transported on ice to the University Of Texas School Of Public Health laboratory, spiked with 2 ml HNO3 kept overnight in the refrigerator, and the following day transported to the EPA laboratory for analysis. Analysis was done by EPA Method 200.7-ICP, Method 200.8ICP/MS and Method 245.1-CVAAS. Results. Metals were present above the detection limits at 65% of sites. Concentrations of aluminum, iron, sodium, potassium, magnesium, and calcium, were particularly high at all sites. Aluminum, sodium, and iron concentrations greatly exceeded the EPA secondary drinking water standards at all sites. ^ Conclusion. The recreational water along Cypress Creek is impacted by wastewater from both permitted and non-permitted outfalls, which deposit inorganic substances into the water. Although a number of inorganic contaminants were present in the water, toxic metals regulated by the EPA were mostly below the recommended limits. However, high concentrations of aluminum, sodium, and iron in the Cypress Creek bring forward the issue of unauthorized discharges of salt water from mining, as well as industrial and domestic wastewater.^

Oversight on the problems of small business : hearing before the Subcommittee on Small Business of the Committee on Banking, Housing and Urban Affairs, United States Senate, Ninety-fourth Congress, first session ... Salt Lake City, Utah, November 7, 1975.

Mode of access: Internet.