Fecal pollution of surface water is a significant environmental health issue. Indicator organisms are used to monitor microbial water quality, but often their presence does not coincide with the presence of pathogens. Bacterial source tracking is a term describing methods to determine the origin of fecal pollution based on bacterial traits. The objective of this research is to evaluate the use of 2 bacterial source tracking techniques, antibiotic resistance analysis (ARA) and ribotyping, to determine the sources of bacteria isolated from Sinking Creek. Based on the results of this study, ARA and ribotyping are not useful techniques for identifying sources of fecal pollution in Sinking Creek. ARA classification rates were low, and ribotype pattern generation success was 37%. The results of this study bring into question the reliability and reproducibility of these 2 source tracking methods for routine use in small watersheds.

The expansion of Interstate 26 from Erwin, TN to the North Carolina border was a project that potentially adversely impacted South Indian Creek because of the steep landscapes and potential for erosion. Several studies have shown the short-term, negative effects of road construction on the water quality of nearby water bodies. Non-point source pollution is the major source of water pollution in the United States. The primary objective of this research is to evaluate the long-term effects of the construction of Interstate 26 on South Indian Creek to see if there has been any ecological recovery. The Environmental Health Sciences Laboratory of East Tennessee State University was contracted by the Tennessee Department of Transportation to collect data from before construction (1991-1992), during construction (1993-1994), and postconstruction (1995-1996). Comparison of microbial enzyme activities and other parameters to present-day (2012-2013) water quality conditions indicate that South Indian Creek has not fully recovered from the effects of the construction of the interstate.

Imidacloprid is a neonicotinoid pesticide used to protect against biting and sucking insects. Land managers rely on its systemic properties, however long-term studies investigating imidacloprid effects on ecosystem function are limited. This study investigated imidacloprid applications to Tsuga caroliniana and Tsuga canadensis over time and compared concentrations to measures of ecosystem function including soil respiration, microbial function, and invertebrate density. Results indicate that imidacloprid is persistent (p0.5). Microbial function and invertebrate density were not significantly different between control and treatment locations nor did imidacloprid concentrations correlate with ecosystem functional indicator activity (p>0.05). It is evident that imidacloprid does not affect ecosystem function over time, however care should be taken when applying it in sensitive locations where endemic, threatened, and endangered organisms reside.

Currently, there is very little research available on nonpoint source pollution from rural watersheds. Government regulatory agencies are desperate for information regarding the causes of nonpoint source pollution, which includes the relationship between suspended soil particles and dispersion. Since soil dispersion is dependent on clay mineralogy, knowing the clay mineralogy of the soil in an area can help predict sediment loads entering the surrounding surface waters. This information is necessary to protect the resource value of our rivers, lakes, and estuaries, as well as to protect recreational activities such as fishing or hunting; but most importantly, this information is necessary to ensure the safety of our drinking water supply. Clay mineralogy and its influence on dispersion, as well as dispersion and its relation to water quality are the focus of this study. Soil mineralogy affects water quality in several ways: soil mineralogy determines the dispersivity of the clay portion of the soil and dispersive clays are likely to end up as suspended sediment in surface waters; weathering reactions contribute elements to water as dissolved load, and the sorption properties of clay minerals contribute to soils' ability to filter and carry pollutants. Through the use of X-ray diffraction, dispersivity, atomic absorption spectrometry, cation exchange capacity, and petrographic microscopy, this study shows that the clay mineral fraction of a soil determines the dispersivity, and that dispersed clay minerals contribute excess nutrients and metals as nonpoint source pollutants to surface waters.

Sleeper populations are established populations of a non-native species whose population growth is limited by one or more abiotic or biotic conditions, such as climate change. While the northeastern US is predicted to be a hotspot for future invasions, identifying potential sleeper populations before they become invasive can inform proactive, climate-smart invasive species management. I focused on 169 introduced species that are established in one or more northeastern states. I used the Environmental Impact Classification for Alien Taxa (EICAT) framework to systematically identify and review the peer-reviewed literature for these candidate species to quantify their negative ecological and socioeconomic impacts. I identified 49 plants with ‘major’ impacts linked to the decline of multiple native species or loss of community diversity. Using high negative ecological impact, habitat suitability, and climate suitability as selection criteria, I highlight 37 species as high priority for management in the North Atlantic –Appalachian Region.

Salar de Atacama (SdA) located in Northern Chile is home to one of the planet’s largest salar systems and lithium resources. Managing groundwater resources in salars is not obvious due to the lack of scientific understanding on the connectivity between the freshwater and brine systems. Using heat as a tracer in SdA provides a cost-effective method to further investigate groundwater flow in salars. This study employs 372 temperature-depth profiles from 90 boreholes between 2013-18 to understand the distinct thermal zones and flow between them in SdA. Three thermal zones exist within the southern margin of SdA’s thermal regime, at higher elevations alluvial fans containing freshwater have a temperature range between 23-28 °C. Down-gradient 2.5 km into the salar transition zone, characterized by freshwater lagoons and newly formed carbonates, the temperature range decreases to 12-17 °C. The transition zone, adjacent to the mature halite crust which hosts a lithium bearing brine and ranges in temperature from 18-22 °C. A 2D numerical groundwater and heat flow model was created to test three hydrologic scenarios to determine how the currently observed thermal regime exists and what the role of groundwater flow is between the different thermal zones. Results demonstrate that a focused flow concept matches current thermal observations with warm inflowing water discharging into the transition zone, cooling due to evaporation, reinfiltrating and preferentially flowing near the surface and discharging again at lagoons near the halite nucleus. Initial focused flow models had the halite nucleus and transition zone hydraulically connected, but results displayed advective flow between the two zones and the halite nucleus carried too much heat from current observations. Indicating the halite nucleus and transition zone has minimal connection, otherwise advective flow would result in thermal equilibrium and a lack of distinct zones as observed. Proper interpretation of temperature-depth profiles along with 2D models place critical constraints on the connectivity between the brine and freshwater systems, providing insight into salar surface energy budgets and a more comprehensive understanding of groundwater flow in the southern margin of SdA. This work gives a new perspective on the groundwater system in SdA while also contributing a novel case study to using heat as a tracer in salar systems.

<p>Coates Paradise is a 250 ha coastal marsh, located at the western most point of Lake Ontario, adjoining Hamilton Harbour. Currently the marsh is severely degraded. Only 15% of the marsh remains vegetated, while the rest exists as an open water turbid bay. Stresses affecting the marsh include a very high carp population, excessive nutrient and sediment input, and water level regulation. Both Coates Paradise and Hamilton Harbour are the targets of an extensive remediation plan, known as the Hamilton Harbour Remedial Action Plan (HHRAP 1991 ).</p> <p>Coastal marshes are recognized for their importance as reproductive areas for the fish community. Considering the importance of marshes to fish, there is a surprising lack of information available. There have been very few comprehensive studies of whole fish communities and their use of marshes, and even fewer which address reproductive utilization. Herdendorf et. al. (1986) listed fish community structure and utilization of marshes for spawning, nursery and feeding areas as the top priorities of coastal wetland research.</p> <p>This study examines the fish community of Coates Paradise for the purpose of providing detailed information on the fish community in association with the HHRAP, as well as examining fish community use of the marsh with respect to reproductive utilization.</p> <p>The study included both temporal and spatial coverage of the marsh fish community. In an attempt to capture whole fish community data for Coates Paradise, fish community surveys were done monthly during the ice-free portion of the season. Surveys were initiated in the summer of 1994, followed by 3 full seasons between 1995 and 1997. Further to this, Coates Paradise was subdivided into 3 habitat types including off-shore, near-shore, and lower river. These habitats were further subdivided into sub-habitats, based on habitat variables that included wind fetch, nutrient enrichment, and degree of vegetation. A total of 8 sub-habitat types were included. Within each sub-habitat type four 50 m transects were located. The transects were surveyed by electrofishing.</p> <p>A total of 47,512 fish covering 47 species were captured in the study. Annual species diversity averaged 38 species, while monthly richness followed a seasonal trend with a maximum of 34 species occurring in July. Most species of fish were found to exist only in the near-shore habitat. Also the near-shore habitat had substantially more fish (Exposed sub-habitat -187 I transect) than the off-shore habitat (Bay sub-habitat -8 I transect).</p> <p>All species demonstrated migration into and out of the marsh in association with spawning periods and spawning habitat guilds. Most species of non YOY fish had highest densities at corresponding spawning times and in correlation to spawning habitat guilds. Habitat preferences of YOY species also generally reflected a species spawning habitat guild. Total non YOY populations were also generally at a peak during spawning periods. The non YOY of most species showed a distinct migration out of the marsh following spawning periods. Samples taken two months prior to a species spawning periods had almost no fish of the species occurring in the marsh, while samples taken two months following peak spawning periods resulted in almost no larger fish of a species being found in the marsh.</p> <p>The dominant fish species of the marsh was adult carp. In the electrofishing data, adult carp represented 90% of the biomass, but only 10% of the total catch. Only six other species had substantial adult population, while most other species are represent by less than 15 individuals in the data set. These six species included, brown bullhead, white sucker, gizzard shad, white perch, spottail shiner and pumpkinseed, and are reflective of the state of the harbour (the adult habitat).</p> <p>The most abundant species in the marsh include YOY of gizzard shad, white perch and spottail shiners, reflecting the marsh's role as reproductive habitat. Maximum numbers of fish occurred in late August, with as many as 800 fish being captured in a single transect. At this time the fish community consisted almost entirely of YOY fish.</p> / Master of Science (MSc)

Storm damages to forested environments pose significant challenges to landowners, land managers, and conservationists alike. Damage scope and scale assessments can be difficult, costly, and time consuming with conventional pedestrian survey techniques. Consumer grade sUAS technology offers an efficient, cost-effective way to accurately assess storm damage in small to moderate sized survey areas (less than 10 km²). Data were collected over a 0.195 km² area of damaged timber within the Kisatchie National Forest in Central Louisiana using a DJI Mavic 2 Pro drone. Collected imagery was processed into an orthomosaic using Agisoft Metashape Professional with a resulting ground sampling distance of 2.58 cm per pixel. Combined X and Y ground distance accuracy r was calculated as 1.39230 meters and a combined horizontal error was calculated as 0.810455526 meters. From the generated orthomosaic, the total storm damage area was estimated as 2.68 Ha, or 6.63 ac based on digitized polygon area calculations.

Trace element sediment pollution due to coal power plants have been reported in many countries. In this study, pond sediment samples collected from locations around a coal fired power plant in Ackerman, MS, were evaluated for their trace element concentration and pollution status. The samples were collected at two depths to study changes in element accumulation over time. The samples were digested and the elements, As, Cd, Cr, Cu, Pb, Hg, and Zn were analyzed using ICP-MS. Results were then compared to known background concentrations as well as sediment quality guidelines and pollution thresholds. The sample locations downwind of the facility had the highest average trace element concentrations, indicating that wind is a primary driver in trace element transportation. With the potential for bioaccumulation and prevalent agricultural activity in the surrounding area, it could eventually affect humans in a negative manner and result in adverse health outcomes for nearby residents.

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Anthropological influences are threatening the state of many savanna ecosystems in most rural landscapes around the world. Effective monitoring and management of these landscapes requires up to date maps and data on the state of the environment. Degradation data over a range of scales is often not readily available due to a lack of financial resources, time and technical capabilities. The aim of this research was to use a medium resolution multispectral SPOT 5 image from 2010 and Landsat 8 images from 2014 to map habitat intactness in the Bushbuckridge and Kruger National Park (KNP) region. The images were pre-processed and segmented into meaningful image objects using an object based image analysis (OBIA) approach. Five image derivatives namely: brightness, compactness, NIR standard deviation, area and the normalised difference vegetation index (NDVI) were evaluated for their capability to model habitat intactness. A habitat intactness index was generated by combining the five derivatives and rescaling them to a data range of 0 to 10, with 0 representing completely transformed areas, 10 being undisturbed natural vegetation. Field data were collected in October 2014 using a field assessment form consisting of 10 questions related to ecosystem state, in order to facilitate comparisons with the remote sensing habitat intactness index. Both satellite data sets yielded low overall accuracies below 30%. The results were improved by applying a correction factor to the reference data. The results significantly improved with SPOT 5 producing the highest overall accuracy of 62.6%. The Landsat 8 image for May 2014 achieved an improved accuracy of 60.2%. The SPOT 5 results showed to be a better predictor of habitat intactness as it assigned natural vegetation with better accuracy, while Landsat 8 correctly assigned mostly degraded areas. These findings suggest that the method was not easily transferable between the different satellite sensors in this savanna landscape, with a high occurrence of forest plantations and rural settlements too. These areas caused high omission errors in the reference data, resulting in the moderate overall accuracies obtained. It is recommended that these sites be clipped out of the analysis in order to obtain acceptable accuracies for non-transformed areas. The study nevertheless demonstrated that the habitat intactness index maps derived can be a useful data source for mapping general patterns of degradation especially on a regional scale. Therefore, the methods tested in this study can be integrated in habitat mapping projects for effective conservation planning. / AFRIKAANSE OPSOMMING: Antropologiese invloede bedreig die toestand van savanna-ekostelsels in die meeste landelike landskappe regoor die wêreld. Doeltreffende monitering en bestuur van hierdie landskappe vereis op datum kaarte en inligting oor die toestand van die omgewing. Agteruitgangsdata van verskillende skale is dikwels nie geredelik beskikbaar nie weens 'n gebrek aan finansiële hulpbronne, tyd en tegniese vermoëns. Die doel van hierdie navorsing was om ‘n hoë resolusie multispektrale SPOT 5 beeld van 2010 en Landsat 8 beelde van 2014 te gebruik om die habitatongeskondenheid in die Bushbuckridge en Kruger Nasionale Park (KNP) streek te karteer. Die beelde is voorverwerk en gesegmenteer om sinvolle beeldvoorwerpe te skep deur die gebruik van ‘n voorwerp gebaseerde beeldanalise (OBIA) benadering. Vyf beeldafgeleides naamlik: helderheid, kompaktheid, NIR standaardafwyking, area en die genormaliseerde verskil plantegroei-indeks (NDVI) is geëvalueer vir hul vermoë om habitat ongeskondenheid te modelleer. ‘n Habitatongeskondenheidsindeks is gegenereer deur die kombinasie van die vyf afgeleides wat herskaal is na 'n datareeks van 0 tot 10, met 0 om totaal getransformeerde gebiede te verteenwoordig en 10 om ongestoorde natuurlike plantegroei voor te stel. Velddata is versamel in Oktober 2014 met gebruik van 'n veldassesseringsvorm, bestaande uit 10 vrae wat verband hou met die toestand van die ekostelsel, om vergelykings met die afstandswaarneming habitatongeskondenheidsindeks te fasiliteer. Beide satellietdatastelle het lae algehele akkuraatheid onder 30% opgelewer. Die resultate is deur die toepassing van 'n regstellingsfaktor tot die verwysing data verbeter. Die resultate het aansienlik verbeter met SPOT 5 wat die hoogste algehele akkuraatheid van 62.6% gelewer het. Die Landsat 8 beeld vir Mei 2014 bereik 'n verbeterde akkuraatheid van 60.2%. Die SPOT 5 resultate het geblyk om ‘n beter voorspeller van habitatongeskondenheid te wees as gevolg van ‘n beter akkuraatheid vir natuurlike plantegroei, terwyl Landsat meestal gedegradeerde gebiede kon voorspel. Hierdie bevindinge dui daarop dat die metode nie maklik oordraagbaar was tussen die verskillende satelliet sensors in hierdie savanna landskap nie, veral as gevolg van ‘n hoë voorkoms van bosbouplantasies en landelike nedersettings. Hierdie gebiede veroorsaak hoë weglatingsfoute in die verwysing data, wat lei tot gematigde algehele akkuraatheid. Dit word aanbeveel dat hierdie areas gemasker word tydens die ontleding om aanvaarbare akkuraatheid te verkry vir nie-getransformeerde gebiede. Nogtans het die studie getoon dat die afgeleide habitatongeskondenheidsindekskaarte ‘n nuttige bron van data kan wees vir die kartering van algemene patrone van agteruitgang, veral op 'n plaaslike skaal. Daarom kan die getoetsde metodes in die studie in habitatkarteringsprojekte vir doeltreffende bewaring beplanning geïntegreer word. Stellenbosch University https://scholar.sun.ac.za