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Total suspended solids, discharge, conductivity, and nutrients in three watersheds of the Upper White River, INXu, Kejun January 2004 (has links)
Three watersheds of Upper White River were chosen for this study. Stream samples were tested for total suspended solids and conductivity. Fourteen percent of the total suspended solids samples were above 80 mg L-1 which can cause negative effects to aquatic life. Total suspended solids results were tested with a general linear model and in linear regressions with discharge and nutrients. Conductivity results were tested with a general linear model. Concentrations of the total suspended solids were significantly related to watershed, Julian date, the interaction of watershed and Julian date, and discharge. Increasing total suspended solids concentrations were significantly related to increasing concentrations of orthophosphate, nitrate, and ammonia. Conductivity levels were significantly related to watershed, location within watershed, and Julian date. Total suspended solids, discharge, and nutrient concentrations were high in the spring, but decreased in the following seasons. / Department of Natural Resources and Environmental Management
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Physical, chemical and biological factors affecting the survival of fingernail clams in pool 8, upper Mississippi RiverDePoy, Richard Mark January 1996 (has links)
1 examined the temporal and spatial distribution of total ammonia nitrogen (TAN) and un-ionized ammonia (NH,) in sediment pore water and compared the temporal and spatial patterns of TAN and NH, in overlying surface water with those in pore water, to determine if they were reaching concentrations known to be deleterious to fingernail clams. Pore water was obtained by core extraction and subsequent centrifugation. TAN and NI-I3 in pore water were measured from May through December 1994, at ninety two sites in pool 8, upper Mississippi River, to a depth of five centimeters below the sediment-water interface. TAN and NH3 in pore water were significantly different among sampling dates; with the greatest concentrations occurring in the summer months. Tan and N1-I3 in pore water was significantly greater in impounded open water and backwater side channel habitats and least in main channel border habitat. Tan and NH3 in surface water were significantly less than those in pore water from all of the habitats studied. Analysis of sediment substrate physical features, found that fingernail clam density and occupance were correlated to texture, with fingernail clams preferring silt loam and loam textures. Analysis of the data determined fingernail clams have a preference for particular water depths. It was found that a positive correlation exists between the occurrence and abundance of may flies and fingernail clams. Additionally, this study found a positive correlation between the density of dead fingernail clams (as per empty shells) and the abundance of live fingernail clams. Sites that contained a mean NI-I, concentration below 36 ug/L possessed the largest numbers of fingernail clams. When the mean un-ionized ammonia was above 36 ug/l, fingernail clam density declined precipitously-- 36 ug/L NH3 is the concentration demonstrated to inhibit growth of fingernail clams in laboratory studies. Mean concentrations of NH, in pore water at sites containing fingernail clams was 40 ug/L and ranged from 3 to 100 ug/L. At sites where fingernail clams were nonexistent, NH3 ranged from 3 to 375 ug/L with a mean of 57 ugfL. Mean un-ionized ammonia concentrations at sites containing fingernail clams were significantly different from and consistently lower than sites without fingernail clams. / Department of Natural Resources and Environmental Management
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Fish assemblage variation in the Wabash River, Indiana : covariation with hydrology and substratesPritchett, Jennifer M. 24 July 2010 (has links)
The local substrate composition of large rivers varies with local current velocity and high flow events. We evaluated effects of hydrology on local substrate variation for 28 Wabash River sites from 2005-08, and subsequent variation in fish assemblages using multivariate analyses. Sites were 500-m in length and fish were collected by boat electrofisher. Substrate collection methods were compared by way of habitat pole, developed by Ohio River Valley Sanitation Commission (ORSANCO), and substrate grabs. We characterized hydrologic variation with the Indicators of Hydrologic Alteration (IHA) software. We determined important driving variables of fish assemblages, substrates, and hydrology with Principle Components Analysis. Temporal effects of hydrology and substrate variation on taxonomic and functional fish assemblages were determined by repeated measures ANOVA. The analyses resulted in annual variation in fish assemblage structure, substrates and hydrologic variation. Significant relationships were found for fish assemblage structure, substrate variation, and hydrologic variation. . Our Mantel tests resulted in significant concordance among hydrology, local substrate variation, and fish assemblage structure variables in years 2005, 2006, and 2008, but not in 2007. These results demonstrated that Wabash River fish assemblages respond to substrate variation and substrate
variation is controlled largely by hydrology. A comparison of substrate quantification approaches demonstrated that the habitat pole and substrate grabs are both effective ways to describe fish assemblages but the costs of grabs outweigh the cost of the pole method. / Department of Biology
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Impact of land cover and antecedent moisture content on runoff discharge in the West Fork of the upper White River, IndianaAl-Mefleh, Naji K. January 2003 (has links)
There is no abstract available for this dissertation. / Department of Natural Resources and Environmental Management
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Massive ice in coarse-grained sediments, Western Canadian ArcticDe Pascale, Gregory P. January 2005 (has links)
Destruction of ecosystems and infrastructure can be caused by melting of massive ice within permafrost. To predict potential melting caused by natural and human disturbance, we need to know the nature and origin of massive ice deposits. The purpose of this research was to evaluate the nature of massive ice in coarse-grained sediments that accepted theories suggest should not occur. / Degradation of ice-rich granular resources is expensive and difficult to rehabilitate and can cause developmental thermokarst, overestimation of granular resources, disturbance of wildlife habitat and create conflicts with traditional land uses. / To locate massive ice we used a resistivity geophysical technique and to characterize the ice we used geochemical, petrographic and stratigraphic techniques. The resistivity technique detected bodies of massive ice and ice-rich sediments and coarse-grained sediments at high resolutions and laboratory analysis reveal that the ice was of glacial origin. / These findings indicate that massive ice of glacial origin occurs in coarse-grained sediments in permafrost. The techniques used in this study could form the basis of a predictive model of massive ice occurrence.
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Influence of physico-chemical factors on the distribution and biomass of invasive mussels in the St. Lawrence RiverJones, Lisa A., 1976- January 2005 (has links)
Biological invasions threaten the stability and biodiversity of freshwater ecosystems worldwide. The impacts of an invading species often vary across systems, making their prediction difficult. When data from multiple invaded sites are available, statistical models can be developed to correlate an invader's distribution and abundance with local environmental variables; such models could then provide managers with useful tools to help prioritize efforts to control the invader. The introduction of the zebra mussel (Dreissena polymorpha) and quagga mussel (D. bugensis) to North America ranks among the most ecologically and economically disruptive aquatic invasions ever documented. While some attempts have been made to predict zebra mussel occurrence and abundance, none have been made for quagga mussels. Furthermore, few studies have been based on river systems, which possess the bulk of North American freshwater biodiversity. I related zebra and quagga mussel occurrence and biomass to physical habitat variables (calcium concentration, substrate size and depth) in the St. Lawrence River. I then developed predictive models of abundance for each species from combinations of these variables. Each variable explained a significant amount of variation in mussel biomass, but different combinations of variables were obtained for each species. Although these models do not account for all of the variation in abundance, they do provide a useful basis for predicting dreissenid distribution and abundance in other invaded river systems.
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Yellow perch consumption of invasive mussels in the St. Lawrence RiverHarper, Kathryn M. January 2007 (has links)
Biological invasions are a global phenomenon that can threaten native species and disrupt ecosystem processes. Exotic species also impact ecosystems in less conspicuous ways by provoking native species to alter their foraging behaviour. Subtle impacts such as diet shifts are frequent, and can have consequences for food web dynamics and the fitness of native predators. Diet shifts involving the consumption of exotic species require native predators to recognize, capture and handle novel prey. In this thesis, I document a diet shift in the St. Lawrence River involving a common native fish and Eurasian mussels that invaded the river in the early 1990s. I conducted diet analysis of yellow perch (Perca flavescens) at multiple sites in the upper St. Lawrence River and discovered that they consumed substantial quantities of zebra and quagga mussels (Dreissena spp.) in the Soulanges Canal, an artificial waterway west of Montreal. This was unexpected because perch lack adaptations for crushing molluscs. This foraging innovation was not observed at the same site in the early 1990s or at other sites at any time. Mussel shells were weaker at this site, probably because of exposure to calcium-poor water. This suggests that water chemistry mediates yellow perch predation on mussels. This study provides an example of diet shifts involving exotic prey and illustrates the influence of abiotic factors on species interactions.
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"Bora belonga white man" : missionaries and Aborigines at Lockhart River MissionThompson, David A. Unknown Date (has links)
No description available.
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"Bora belonga white man" : missionaries and Aborigines at Lockhart River MissionThompson, David A. Unknown Date (has links)
No description available.
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Seasonal Variations in Colloidal Chromophoric Dissolved Organic Matter (CDOM) in the Damariscotta River Estuary, MaineFloge, Sheri Ann January 2005 (has links) (PDF)
No description available.
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