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To assess the impacts of non-point source pollution on Ontarios wetlands I examined the landuse in the watershed, the water and sediment quality, and the aquatic vegetation in 22 wetlands. I characterized the primary contaminants that enter marshes in Ontario and relate their concentrations to the relative amounts and types of land use in their watershed. I measured levels of nutrients, suspended particulates and trace organics in water and sediment. Species richness and structural diversity of the vegetative community was used as an indicator of wetland health. I included a comparison of two techniques, immunoassays and gas-chromatography (GC) to measure trace organics (PAHs and metolachlor; Chapter 1). Comparison of results from both techniques indicated that immunoassays overestimated analyte concentration by approximately a third. I utilized the immunoassay results, along with selected water quality variables, to characterize contaminants entering these wetlands (Chapter 2). Watersheds containing greater than 95% agriculture contributed the highest suspended particulate, compared with those dominated by urban or forested land. Using multivariate statistics I identified important water and sediment variables that structured these wetlands to be: total phosphorus (TP), ammonia nitrogen (TAN), suspended solids (TSS), specific conductance (COND), sediment phosphorus CTPsed) and inorganic material (lnorgsed) in the sediment. Of these TP, COND and Inorgsed were negatively related to the submergent plant community, while TPsed was positively related. There was no relationship between water quality and the floating or emergent plants but the structural diversity of the plant community was negatively affected by poor water quality. The negative impact of developed land in the watershed on the health of the aquatic plant communities underscores the need to maintain natural areas to trap nutrients and sediments in runoff. / Thesis / Master of Science (MS)

This study investigates post-Glacial development of Cors Gyfelog and Tre'r Gof - lowland mires in north west Wales - and the vegetational history of the region over the same period. Using existing hydroseral theories, possible future successions are predicted, their desirablility from conservation viewpoints, and whether management might be considered necessary. Peat stratigraphy records vegetational changes at the two sites, supported by pollen analysis, which also reveals regional developments. Additionally, correlations are attempted between variations in peat chemistry and mineral content, and mire vegetational changes shown by the other techniques. Results from Cors Gyfelog indicate central parts of the mire were of early post-Glacial lacustrine origin, but terrestrialisation followed quickly. The wetland area expanded during the Atlantic period. Pollen and biostratigraphy indicate fluctuations between poor-fen and alder carr until the sub-Atlantic, when there was reedswamp and incipient valley bog, before general succession to sedge fen. Latterly, probably following minor drainage attempts, conditions have become drier, and large areas are now dominated by Molinia or Salix. Tre'r Gof history spans the post-Glacial. Until c.4000 B.P., conditions were lacustrine, with calcareous waters deriving from shelly Irish Sea till. Surrounding wet meadow succeeded to carr. With terrestrialisation, the mire became rich fen. Southern parts of the mire have recently been affected by drainage, leaving drier grassland areas and small patches of carr, although with some very wet patches. Whilst research on British mires suggests that eventual domination by Sphagnum mosses is normal, this does not appear to be happening here. Drainage attempts, however, could raise surface vegetation above the water table, away from nutrient-rich waters, and allow ombrotrophic Sphagnum growth. Alternatively, carr may spread and dominate, particularly at Cors Gyfelog. It is suggested that neither would be desirable, so frequent monitoring should be conducted, unwanted carr removed, and water

Delta islands make up the majority of coastal delta area. However, the groundwater hydrology of young, prograding delta systems and its relationship to surrounding surface water dynamics are poorly understood. Deltas in coastal environments are assumed to function as chemical “buffers”, filtering nutrient-rich terrestrial runoff through the island structures and surface water ecosystems as it travels to the sea, but the magnitude of this effect cannot be accurately quantified without understanding the physical relationships between the surface water and groundwater. This study developed the first conceptual model of the hydrology of prograding delta island groundwater systems. The study was based on field data collected at Pintail Island, a 2 km2 island within the Wax Lake Delta in Louisiana. Hydraulic properties and processes were quantified at multiple depths at locations spanning the island elevation gradient. Groundwater and surface water levels were monitored. A weather station recorded precipitation, air, and wind conditions. The groundwater within Pintail Island was both spatially and temporally dynamic throughout the study period of Sept/9/2013 to Feb/4/2014. The aquifer within the distal limbs of the island responded as a connected, saturated unconfined aquifer. The portions of Pintail Island within the older, proximal, higher elevation apex were found to be a two-layer system with fine sediments and organic matter overlying sandy deposits. The aquifer within this section of the island responded differently during times of elevated surface water (storm events) and times of normal surface water (calm periods) and differently from the distal-island unconfined system. The fine, shallow (roughly 0-60cm depth) sediments capping this older, higher portion of the island appeared to inhibit vertical flow between the surface and subsurface, creating semi-confined conditions within the sands in the deeper island subsurface. High water levels led to overpressurization of the apical aquifer, which was maintained between storms due to the low hydraulic gradient and the low permeability of the porous medium. During inundating storm events, groundwater potentials mimicked surrounding surface water levels. This conceptual model of a prograding coastal delta island now provides a foundation for further, hydrologically-realistic study of delta ecology and nutrient exchange. / text

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archives@tulane.edu / The influence of environment on microbial community structure is of increasing interest, especially in coastal habitats where climate change is rapidly altering the landscape. In this dissertation, I characterize the microbial communities associated with a key wetland species, the baldcypress tree (Taxodium distichum), and examine the relationship between environment, geographic distance, and microbial community composition. In a culture-based study of T. distichum leaf and root endophytes, I found that both salinity and flooding contributed to bacterial and fungal endophytic community composition. Additionally, I report that diversity and endophyte isolation frequency were higher in roots than in leaves, with leaf bacteria being almost negligible. Using 16S Illumina profiling, I found that geographic distance correlated with rhizosphere but not root endosphere bacterial communities and that mean water level, mean salinity, and the volume of woody debris were correlated with both endosphere and rhizosphere bacterial communities of T. distichum. Finally, using salt challenge assays, I isolated five strains of extreme halotolerant endophytes and eleven strains of moderately halotolerant endophytes— a necessary first step towards using endophytes for restoration, or towards understanding the functions of some of these organisms in situ. This dissertation demonstrates a connection between environmental variables, plant symbionts, and a key restoration species and may help in predicting future outcomes of sea level rise for endophytes communities in baldcypress and other wetland plants. / 1 / Elizabeth Kimbrough

<p>Abstract</p><p>Centro Universitaire UNIVATES is located in the town Lajeado that is situated in the most southerly state, Rio Grande Do Sul, in Brazil. The university has 5000 students, teachers and others staff. UNIVATES is not satisfied with their present wastewater situation and wants to improve it by eliminate the smell caused by the wastewater. They would also like to remove the oil that the storm water brings into the wetland. The high amount of particles in the storm water gives rise to a lot of sediments that eventually will fill up the wetland, and something has to be done about this, if the wetland should continue to be in use. Another aspect to consider is the wish of some people at UNIVATES, for the wetland to be a beautiful and recreational place. All these factors had to be considered, which led to the main question: How can the use of the wetland for wastewater treatment be combined with the request for the wetland to be a beautiful place with the wildlife preserved? </p><p>During the course Wetland Technology that we took before our departure to Brazil, we got introduced to the situation at UNIVATES by Professor André Jasper and Odorico Konrad who visited the course several times. They pointed out that the main issue is the smell from the wastewater and later during the field study at UNIVATES, more information were obtained through discussions, meetings and conversations with the people involved. Several visual inspections were carried out by walking around the wetland. We could determine where and how the inlets and outlets to the wetland were and when it was clear which inlets that brought wastewater and which that brought storm water, the water flow of the wastewater was estimated. Water samples from the wetland were collected at five different sites and analyses of pH, BOD, COD, N-Tot, phosphorus and metals were done by the accredited laboratory at UNIVATES. To test some of our theories, we did a smaller practical experiment that got the name Superficial Filtration Bed. </p><p>The results from the water samples showed the highest BOD, COD, N-Tot and Phosphorus levels in the samples from site 2 and 4 and this reveals that it is wastewater. This was also confirmed by the smell that we felt at these sites during the visual inspections. The results also showed that there is no wastewater coming from site 1, 3 and 5. </p><p>Our final proposal is to create a multifunctional wetland with the purpose to take care of both storm water and wastewater and at the same time work as a research and recreational area. The wetland, which would be divided into two parts, will constitute of all the fundamental functions; storm water buffering, sedimentation basin and biological oil separation and treatment. There will also be research sites and hybrid system for wastewater treatment. The hybrid system will consist of two steps where the first is aerobic and the second both aerobic and anaerobic. The first step is a Superficial Filtration Bed (SFB) and the second a FWS wetland. </p><p>The conclusion of this thesis is that more detailed research is needed to be able to dimension the specific functions correctly. With some further investigations the proposal presented is possible to carry through and our feeling when we left UNIVATES was that the people responsible really liked our ideas. They made it clear that they want to make a change and improve the situation and with the help they have gotten from us, they are a few steps closer to solving the problem.</p>

<p>One of the environmental problems today in seas, lakes and streams is eutrophication. This is often caused by nutrients such as phosphorus (P) and nitrogen (N) that leak from agricultural areas. A measure to partly prevent the nutrient discharge is to construct or restore wetlands.</p><p>In order to control the efficiency of nutrient reduction of existing wetlands in the county, the administrative board in Västra Götaland wants to find different criterias for reference wetlands. These reference wetlands should represent other wetlands and be used in future evaluations of reduction of nutrients and design of constructed wetlands.</p><p> </p><p>According to the administrative board in Västra Götaland the reference wetlands should have a catchment area of about 50 hectare consisting of at least 70 % arable land, to represent wetlands created to remove nutrients. The surface area should exceed 0,5 hectare and the inlet-nitrogen concentration should be around 5 mg N-1.</p><p>This report investigates nitrogen and phosphorus retention in two wetlands, Härstad and Åmot in the county of Västra Götaland, and if they fulfill the criteria of being a reference wetlands. In addition to this, a tracer study was performed in one of these wetlands with the purpose to study the hydraulic efficency.</p><p> </p><p>Neither the wetland in Åmot or Härstad achieves the guidelines of about 5 mg N l-1 in the incoming water. Therefore, they can be seen as inappropriate as reference wetlands according to their nitrogen retention. The wetland of Härstad, however, has significantly better N retention than the wetland of Åmot. Results from the report shows that N retention in the wetland of Härstad was relatively high not only due a higher N load, but also due to that N was largely in the form of NO3- facilitating efficient transformation of NO3- to N2 by denitrification bacteria. Nitrogen removal was much lower in the wetland in Åmot due to that N in incoming water was not in the form of NO3- and could therefore not be efficiently transformed to N2 by denitrification.</p><p>Incoming total phosphorus to the Härstad and Åmot wetlands exceeded 100 µg P l-1, which means "extremely high" tot-P concentrations according to environmental quality criteria from the Swedish Environment Protection Agency. Phosphorus load per wetland area was slightly higher in the wetland in Åmot than in the Härstad wetland. In spite of this, P retention per wetland area as well as relative P retention was clearly higher in the Härstad wetland. This can be explained by that P in incoming water to the Härstad wetland was to a larger degree than in the Åmot wetland bound to particles, facilitating P retention through sedimentation.</p><p>According to the tracer study, the Härstad wetland has a hydraulic efficency (λ) of about 0,13 which means it has a low hydraulic efficiency. The effective volume ratio (e) in Härstad was calculated to 18 % which means that the water has an inadequate spreading in the wetland, which is not good for the nutrient elimination in this wetland.</p><p>This study illustrates the difficulties in finding representative reference wetlands due to potential differences between wetlands in nutrient concentrations in incoming water, the degree that incoming P is bound to particles, the degree that incoming N is in the form of NO3-, and hydraulic efficiency.</p>