Indiana University-Purdue University Indianapolis (IUPUI) / The transport of excess nutrients, sediment, and other contaminants to surface waters has been shown to cause a number of environmental and human health concerns. An understanding of the export pathways that these contaminants follow to surrounding water bodies is crucial to the anticipation and management of peak concentration events. Several studies have demonstrated that the majority of annual contaminant loading in the Midwest occurs during periods of elevated discharge. However, many studies use a limited number of sampling points to determine concentration patterns, loadings, and fluxes which decreases accuracy. Through high-resolution storm sampling conducted in a 2945 km2 (1137 mi2) area of central Indiana’s Upper White River Watershed, this research has documented the complex concentration signals and fluxes associated with a suite of cations, nutrients, and contaminants and isolated their primary transport pathways. Additionally, by comparing the results of similar studies conducted on smaller areas within this watershed, differences in concentration patterns and fluxes, as they relate to drainage area, have also been documented. Similar to the results of previous studies, NO3- concentrations lacked a well-defined relationship relative to discharge and was attributed to primarily subsurface contribution. DOC was exported along a shallow, lateral subsurface pathway, TP and TSS via overland flow, and TKN through a combination of both. Near or in-channel scouring of sediment increased DOC, TKN, TP, and TSS concentrations during Storm 2. Atrazine export was attributed to a combination of overland and subsurface pathways. 2-MIB and geosmin derived from different sources and pathways despite being produced by similar organisms. 2-MIB concentration patterns were characterized by dilution of an in-stream source during Storm 1 and potential sediment export during Storm 2 while in-stream concentrations or a sediment source of geosmin was rapidly exhausted during Storm 1. Many of the concentration patterns were subject to an exaggerated averaging effect due to the mixing of several larger watersheds, especially during Storm 1. This research illustrates the need for high-frequency sampling to accurately quantify contaminant loads for total maximum daily load (TMDL) values, developing best management practices (BMPs), and confronting the challenges associated with modeling increasingly larger-scale watersheds.

Made available in DSpace on 2016-06-02T19:32:01Z (GMT). No. of bitstreams: 1 4263.pdf: 9365338 bytes, checksum: 030df2b1cc08e54985c90dbafbefaf8c (MD5) Previous issue date: 2011-12-22 / A comunidade de macrófitas aquáticas se constitui como importante componente em ecossistemas lênticos e lóticos, habitando áreas permanentemente alagadas ou sujeitas a inundações. Desta forma o presente estudo caracterizou as áreas alagadas e as possíveis diferenças nas características físicas e químicas dos sedimentos e da água circundante aos estandes das espécies de macrófitas Eichhornia crassipes, Salvinia auriculata e Mayaca fluviatilis ocorrentes no reservatório do Broa em distintos tributários. Estes vegetais possuem importante papel como fonte de matéria orgânica e dos nutrientes fósforo e nitrogênio contribuindo para uma maior estocagem dos mesmos. A qualidade das amostras de água circundante aos estandes foram influenciadas principalmente pela ação dos ventos ocorridas na amostragem do período seco (agosto de 2010), que contribuíram para o revolvimento da coluna d`água agindo diretamente sobre os estandes. A avaliação do estado trófico do reservatório verificou que os ambientes estudados apresentam diferenças nas concentrações de fósforo na água, onde foi possível identificar uma área alagada hiper-eutrófica próximo ao rio Itaqueri e oligo-mesotrófica nas áreas alagadas formadas pelos Ribeirão do Lobo e Córrego das Perdizes. Contatouse que os teores de fósforo e nitrogênio apresentam uma distribuição desigual entre as espécies e também entre as suas estruturas, sendo as raízes responsáveis pelo armazenamento de maiores concentrações destes nutrientes. The aquatic macrophyte communities constitutes an important component in lentic and lotic ecosystems, inhabiting areas permanently flooded or subject to flooding. Thus the present study characterized the wetlands and possible differences in physical and chemical characteristics of sediments and water to the surrounding stands of macrophytes Eichhornia crassipes, Salvinia auriculata and Mayaca fluviatilis occurring in Broa reservoir in different tributaries. These plants play an important role as a source of organic matter and nutrients phosphorus and nitrogen contributing to greater storage of same. The quality of water samples from the surrounding stands were mainly influenced by the wind occurred in the sample of the dry period (August 2010), which contributed to the turning of water column acting directly on the stands. Assessing the trophic state of the reservoir found that the studied environments having different concentrations of phosphorus in the water, where it was possible to identify a hyper-eutrophic wetland near the Itaqueri river and oligomesotrophic in Ribeirão do Lobo and Cóorego das Perdizes. It was noted that the levels of phosphorus and nitrogen have an unequal distribution among species and also between their structures, the roots being responsible for the storage of higher concentrations of these nutrients / A comunidade de macrófitas aquáticas se constitui como importante componente em ecossistemas lênticos e lóticos, habitando áreas permanentemente alagadas ou sujeitas a inundações. Desta forma o presente estudo caracterizou as áreas alagadas e as possíveis diferenças nas características físicas e químicas dos sedimentos e da água circundante aos estandes das espécies de macrófitas Eichhornia crassipes, Salvinia auriculata e Mayaca fluviatilis ocorrentes no reservatório do Broa em distintos tributários. Estes vegetais possuem importante papel como fonte de matéria orgânica e dos nutrientes fósforo e nitrogênio contribuindo para uma maior estocagem dos mesmos. A qualidade das amostras de água circundante aos estandes foram influenciadas principalmente pela ação dos ventos ocorridas na amostragem do período seco (agosto de 2010), que contribuíram para o revolvimento da coluna d`água agindo diretamente sobre os estandes. A avaliação do estado trófico do reservatório verificou que os ambientes estudados apresentam diferenças nas concentrações de fósforo na água, onde foi possível identificar uma área alagada hiper-eutrófica próximo ao rio Itaqueri e oligo-mesotrófica nas áreas alagadas formadas pelos Ribeirão do Lobo e Córrego das Perdizes. Contatouse que os teores de fósforo e nitrogênio apresentam uma distribuição desigual entre as espécies e também entre as suas estruturas, sendo as raízes responsáveis pelo armazenamento de maiores concentrações destes nutrientes.

As homeostatic organisms, rotifers have to use the mechanism to cope with nutrition unbalance in their food. The regulation of digestive enzyme activities as a possible physiological mechanism involved in maintaining of rotifer homeostasis was studied. This study further explored the effect of food quantity and quality on rotifer population growth rate and reproduction.