Florida is surrounded by water, and its many internal lakes and rivers have long been recognized for their excellent fishing and boating. This notoriety draws land developers to the lake shores to establish residential and commercial infrastructure. This land development brings with it flood plain alteration, water level stabilization, and increased nutrients which cause adverse impacts to our lakes. In response, the United States Environmental Protection Agency (EPA) passed the Federal Clean Water Act (CWA) in 1972 which set the framework for the water quality standards for the entire United States. As a result of the CWA many point sources were eliminated, but in the process it became apparent that nonpoint source loads represented even more of a threat. To further study the physical and chemical characteristics of urban runoff the Nationwide Urban Runoff Program (NURP) was established in 1978. This research lead to a series of management options, named Best Management Practices (BMPs) which proposed various structural and non-structural methods to reduce nutrient loads. But the research and data collection on the effectiveness of these systems to remove nutrients is in its infancy. The main objective of this study was to generate accurate and effective water quality and water quantity data that future stormwater management decisions can be based upon. More specific, this study established automatic monitoring sites throughout the City of Kissimmee, Florida to determine the pollutant loadings into the tributaries of Lake Tohopekaliga. These monitoring sites are located such that inflows from outside the city limits can be isolated and external pollutant loads quantified. Also, additional internal monitoring sites were established to determine the pollutant loads of internal sections of the city. Data from these internal monitoring sites will also be used to determine the variable pollutant removal efficiencies and hydraulic fluctuations of natural, irregular riverine systems. The secondary objective of this study was to perform a pilot study using the discrete grab samples in tandem with the continuous hydraulic and hydrologic data from the monitoring stations. An existing lake within the project limits was chosen for the pilot study area. Monitoring stations are located at the influent and effluent sections of the lake which provided data on the hydraulic and hydrologic parameters. The pilot study determined the nutrient loads to and from the lake and checked for any seasonal variations in pollutant loading or removal efficiencies. For the purpose of this pilot study, only total nitrogen and total phosphorous were examined for two monitoring sites. The nutrient removal efficiency was performed using both the event mean concentration method and the summation of loads method to check for seasonal variation. There were no storm event concentrations available for used in this analysis, however, there were 25 discrete grab samples collected on a bi-monthly basis over a twelve month period. This data was used with corresponding five-minute rainfall and flow data from both the inflow and outflow points. The results of this study did not reveal any seasonal variation in the nutrient concentrations either flowing into or out from the lake. Although there were some relatively lower values in late spring, the concentration levels of total nitrogen did not seem to vary significantly from its mean value of 0.90 mg/l throughout the year. The concentration levels of total phosphorus did range from 0.02 mg/l to 0.48 mg/l, but not in relation to either season or flow volume fluctuations. The lake showed no net removals of total nitrogen and was actually found to be releasing total phosphorus to the downstream receiving waters. The findings of this study are limited due to the fact that the period of pilot study was only for twelve months and there were no rainfall events used in the analysis. Rainfall events are typically high sources of nutrient loads to a lake. The lower efficiencies were probably due to missing the actual higher nutrient load concentrations during the rainfall event. However, even considering the lack of event data, the nutrient removal efficiency for the pond was still low. This analysis did serve well as a basis for performing future analysis once additional data, including rainfall events, has been collected.

<p dir="ltr">Nutrients are essential to support fish production in aquatic systems but are detrimental in excess. To that end, the relationship between nutrient loading and fish biomass is hypothesized to be unimodal. In the mid-20^th century, numerous aquatic systems in North America and Europe were receiving excessive nutrients and were considered heavily degraded as a result. Since then, nutrient abatement programs have resulted in increased fish biomass in many systems throughout the two continents. However, few systems have complete records of fish biomass and nutrient loading to offer support for both sides of the unimodal fishery production curve. In Saginaw Bay, Lake Huron, total phosphorus estimates are available back to when nutrient abatement programs were first implemented in the system in the 1970s. In addition, a long-term fall bottom trawling dataset from an annual monitoring survey conducted by the Michigan Department of Natural Resources has indexed fish biomass and composition since 1970. In Chapter 2, we utilize these datasets to analyze trends in system-wide fish biomass as well as fish community trends since 1970 in response to continued nutrient abatement. We found increasing fish biomass from 1970 until the early 2000s concurrent with total phosphorus declines. However, more recently, we documented declines in system-wide fish biomass with reduced nutrient loads. We found planktivorous and benthivorous fish species displayed similar initial increases in biomass followed by more recent declines in biomass. However, we determined current total phosphorus loading was still sufficient to support piscivore biomass near peak levels.</p><p dir="ltr">While nutrients in Saginaw Bay are lower than at times in the past, the system is still highly productive. One consequence of productive systems is increased susceptibility to hypoxia, or low dissolved oxygen that can result from organic matter decomposition. Past studies have documented hypoxic conditions in Saginaw Bay in the summer and over-winter period. However, past studies have been limited in scale and have not estimated the extent or duration of hypoxia throughout the Saginaw Bay system. With climate change expected to increase the occurrence of hypoxia throughout the Laurentian Great Lakes, knowledge of dissolved oxygen dynamics in the system is becoming progressively more important. In Chapter 3, we used an array of high frequency data loggers deployed throughout inner Saginaw Bay over two summer and over-winter periods to document dissolved oxygen conditions. We also analyzed a time series dataset of bottom oxygen and environmental parameter measurements to determine the conditions that contribute to low dissolved oxygen in the bay. Further, through stable isotope analysis we investigated whether hypoxic conditions had an effect on the carbon and nitrogen (δ¹³C and δ¹⁵N) isotopic signatures of chironomid larvae, an important basal prey item in Saginaw Bay. We found instances of seasonal hypolimnetic hypoxia in the summers of 2021 and 2022 but normoxic conditions throughout the over-winter periods following each summer. We also determined bottom water and wind speed to be the most reliable predictors of low dissolved oxygen since 2011, indicating the temporary stratification that can occur during warm, calm summer periods likely precedes the development of hypoxic conditions in Saginaw Bay. Chironomid δ¹³C and δ¹⁵N values were highly variable, but some individuals displayed very low values, indicative of hypoxia exposure.</p>

Atmospheric deposition is a marginally understood source of nutrient loadings to waterbodies. Atmospheric deposition occurs via wet (rain, snow) and dry (gaseous and particulate transport) pathways. Bulk atmospheric deposition is defined as the total deposition from both wet and dry pathways. Utah Lake is a shallow eutrophic freshwater lake located in central Utah, USA. Recent studies have shown atmospheric deposition to be a significant contributor to the nutrient budget of Utah Lake. This study presents the analysis using three different methods of six years' worth of wet atmospheric deposition samples from nine locations around the lake, though these samples do include some contribution from dry deposition. We present and compare nutrient loads and nutrient loading rates for total phosphorus, total in-organic nitrogen, and ortho-phosphorus. We conclude that wet atmospheric deposition contributed between 309 to 529 tons of total phosphorus, 1,166 to 2,078 tons of total nitrogen, and 106 to 201 tons of ortho-phosphorus to the lake during the study period. We extracted loading rates for the calendar year (in tons per year) and winter/summer month (in tons per month) from the data from each of the three methods of analysis. We show that wet atmospheric deposition is a significant pathway in which nutrients are transported to Utah Lake.

Most coastal ecosystems are dominated by marine macrophytes that deliver a range of ecologically and economically important services such as carbon and nitrogen cycling and storage, and habitat provision to a range of associated species. The relative contribution of these services among different vegetated habitats, however, and their alteration due to anthropogenic stressors is little known. In this thesis, I first examined the within and between ecosystem structure and services of eelgrass (Zostera marina) and rockweed (Ascophyllum nodosum) beds in Atlantic Canada. Both habitats significantly enhanced the overall abundance and diversity of associated species, whereas differences in the spe-cies assemblages were attributed to differences in canopy structure within and between habitats. Changes in the canopy structure of the foundation species will affect associated food webs and ecosystem services. Next, I used large-scale field surveys to examine the effects of eutrophication on the structure and services of eelgrass beds. As eutrophication increased, plant dominance shifted from eelgrass to macroalgae and phytoplankton at a regional scale. The faunal community showed increases in filter feeders, detritivores and some herbivores, while sensitive species declined. These faunal changes can be linked to enhanced food availability and predation refuge offered by increased phytoplankton and opportunistic macroalgae. However, the loss of eelgrass and sensitive species highlight the negative consequences of eutrophication on eelgrass ecosystems and the services they provide. I also reviewed the global carbon and nitrogen storage and habitat services of mangroves, salt marshes, seagrass meadows and macroalgal beds. Despite only occupying 0.7% of the ocean area, together these ecosystems make up 12% of the oceanic carbon stock thereby playing an important role in global carbon and nitrogen storage. Moreover, these macrophyte habitats enhanced species richness and abundance of associated fauna and juvenile fishes. Overall, my findings indicate that each macrophyte habitat has its strengths yet all are essential in providing the full range of ecosystem services. Increasing human impacts along the coasts, however, are threatening macrophyte ecosystems worldwide, and their further decline will impair the provision of important services and human well-being. Lastly, I discuss the implications of my work for management and conservation.

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The Gulf of Bothnia consists of two sub-basins in the northern Baltic Sea: the Bothnian Sea (salinity 4-5‰) and Bothnian Bay (salinity 2-3‰). Changing nutrient concentrations and signs of eutrophication has recently been observed in the Gulf of Bothnia. Many rivers enter this sea area, and potentially river inflows constitute a source of nutrient pollution via waste-water emissions. The aim of this study was to elucidate effects of waste-water emissions in four rivers in northern Sweden, Luleå, Skellefteå, Umeå and Söderhamn. My approach was to compare nutrient concentrations at upstream and downstream sampling stations related to the position of waste-water treatment plants. Temporal data from 2006 to 2021 were used and statistically analyzed using non-parametric tests to establish spatial and temporal patterns for nutrient discharged to the coast. The results showed that there are statistically differences in dissolved inorganic phosphorus (DIP) in the form of phosphate (PO4), ammonia (NH4) and total nitrogen (TotN) between the upstream and downstream of Luleå and Umeå wastewater treatment plants. No statistically significant differences were observed in the upstream and downstream data for Söderhamn and Skellefteå. This suggest that better management and mitigation of nutrient loading from wastewater treatment plants that serve higher populations is paramount to achieve the zero-eutrophication goal in the Gulf of Bothnia.

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Excessive nutrient loading of natural and artificial lakes has led, in some systems, to plethoric algal and aquatic macrophyte growth which can result in aesthetic degradation and undesirable tastes and odors. It would be advantageous to have some indication of the potential trophic status of a reservoir before it is filled. An objective of this study was to assess the water quality and nutrient loading potential of the tributaries entering Ray Roberts Lake, a large reservoir located in north central Texas. Samples from a maximum of thirteen sites were collected on the Elm Fork, Trinity River, Isle duBois Creek, and five additional tributaries. Data were also collected during six storms, from atmospheric deposition collectors, and from soil-water microcosms. The relationship between watershed landuse and mean water nutrient concentrations was evaluated. Significant differences will exist between the two major arms of Ray Roberts Lake: Elm Fork, Trinity River and Isle duBois Creek. While the majority of the annual phosphorus and nitrogen load entering both tributaries is coming from overland flow, the proportion is higher in Isle duBois Creek. Point sources in the Elm Fork contribute a larger percentage of the bioavailable phosphorus, which is significantly greater than in Isle duBois Creek. The water quality of Isle duBois Creek, especially nitrogen, is affected to a greater degree by the landuses in its watershed. Predictive regression models made accurate estimations of stream nutrient concentrations in Isle duBois Creek. The entire reservoir, upon reaching equilibrium conditions, will be classified as a eutrophic lake. The Trinity arm, with a higher phosphorus load, will display a higher trophic status. The Isle duBois arm has a lower phosphorus load which will give it a lower trophic status. The long hydraulic residence time of the two arms of the reservoir will remove nutrients upstream of the main body, thus contributing to overall better water quality in the main body of the reservoir.

Governance and participatory democracy theory suggest that strong policy can stem from the inclusion of all societal voices in discussion of options, and that the public must have a strong base of information in order to participate fully in democracy. The news media can be an important vehicle for these voices and a central source of information. However, academic literature has recorded that “elite” sources, such as government, dominate news coverage to the disadvantage of “non-elite” sources, such as civil society groups and citizens, a situation that results in imbalanced information in the news. This thesis examines patterns of civil society inclusion in Winnipeg Free Press coverage of Lake Winnipeg water quality, and discusses the implications of findings for good governance. Three methods of inquiry are used: 1) a literature review, 2) a quantitative content analysis of newspaper articles published in the Winnipeg Free Press from August 1991 through December 2008, and 3) interviews with civil society members with an interest in Lake Winnipeg water quality. Content analysis findings indicate that civil society sources generally received less coverage than “elite” sources, were used less frequently, were given lower prominence within articles, had fewer chances to “define” coverage and were less often used in “hard” news compared to opinion sections. Interview findings challenge the dominant view within media literature that journalists are fully responsible for “elite” source dominance due to journalist bias in source selection, the “beat system” of journalism that focuses on governmental institutions, decisions made by editors and corporate or political preferences of news entities. While journalism practices are undoubtedly a factor, this study finds that there are also shortcomings within civil society organizations and the framework within which they operate that limit their engagement with the media. Four key factors are identified. Registered charities are often hesitant to speak with the media due to real and perceived legal restraints on their communications activities under Canada’s Income Tax Act. Many organizations are apprehensive about voicing concerns in the media for fear of losing funding. Few organizations have communications staff, or even staff members trained in media outreach, resulting in a passive approach to communications. And few organizations have the capacity to deal with media requests for information within journalism deadlines. In addition, the interview data indicate that those organizations actively pursuing media coverage are focusing attention on smaller newspapers, alternative media and self-published pieces, which suggests that the mainstream news media are perhaps of less importance to such organizations than in the past. Alternatively, it is possible that organizations are finding access to the mainstream media effectively cut off. Finally, recommendations are made to civil society organizations on how they can increase their prominence in the news and conquer their reluctance to deal with the media, and to the media on how to improve attention to civil society voices. For the latter, ideas are drawn from public journalism, a journalism movement which emphasizes citizens as sources.