The novel application of combination, or two stage, photochemical and microbial degradation systems for removal of resin acids from natural river water and single stage photolysis for degradation of naphthenic acids in natural river water was investigated. The organic compounds included in this project comprise naphthenic acid model compounds and mixtures as well as four resin acids. Naphthenic acids are crude oil-derived and accumulate to significant concentrations (>100 mg/L) in tailings pond water at oil sands extraction facilities. Resin acids are pulp and paper mill-derived compounds that tend to persist at low levels in receiving waters. For each compound group, analytical methods utilizing liquid chromatography negative ion electrospray ionization mass spectrometry (LC/ESI/MS) were developed. The main hurdle to developing analytical methods for the naphthenic acids and resin acids are related to their polarity, complexity, and lack of available standards for the various individual components. As well, co-extractives, such as humic and fulvic acids, tend to interfere with the detection of naphthenic acids in aquatic samples (Headley et al., 2002a). Resin acid mixtures are not as complex as the naphthenic acids, although each group of hydrocarbon acids may include several isomeric compounds. The application of photochemical degradation prior to biodegradation was proven to be effective here for rapid degradation of the resin acids. In general, the resin acid precursors were more susceptible to the photolysis than were the naphthenic acids. Through thermal maturation and increased complexity, the naphthenic acids seemingly become more resistant to degradation, as evidenced by their commercial use as anti-microbial agents and the observed resistance to photolysis noted in this research. The results of this research may be significant for the design of staged treatment for reduced microbial shock loading and increased bioavailability (defined here as the ability of microbial organisms to degrade the target contaminants) in both bioremediation systems and receiving waters. Specifically, four selected pulp and paper mill-associated resin acids were exposed to several ultraviolet/visible (UV/vis) spectrum radiation sources in water collected from the River Saale in Germany. Background resin acid concentrations were observed in water collected in 2001 and 2002 from various locations along the well-forested River Saale and a manuscript detailing these results published. Analyses of water samples collected in the pulp and paper milling region of the river (in the state of Thuringia) indicated that resin acids persist through biodegradation treatment systems and for several hundred kilometres downstream. All four resin acids were degraded by facile photochemical and microbial degradation with pseudo-first-order kinetics. Half-life values were in the ranges of 18 to 200 minutes for photolysis applications, 8 to 40 hours for biodegradation applications and 3 to 25 hours for two-stage photochemical-microbial degradation processes, in which photolysis was limited to three hours. From these results, it was shown conclusively that photolysis pre-treatment is a viable and efficient method for reducing both resin acid concentrations and the associated acute toxicity. The naphthenic acids investigated in this study were not effectively degraded via UV/vis radiation, including UV-A/UV-B radiation between 300-400 nm, near-monochromatic UV254-radiation, full spectrum artificial solar radiation and natural sunlight. The photochemical degradation potential of three model naphthenic acid compounds and three naphthenic acid mixtures (one extract from the Athabasca Oil Sands and two commercial mixtures) were examined in Athabasca River water. Photolysis at UV254 was the most successful degradation source in all instances, although most naphthenic acids were not significantly degraded by any of the radiation sources. Therefore, it was determined that photolysis is not likely to contribute significantly to environmental degradation and attenuation in the aquatic ecosystem. The results observed from the various naphthenic acids photodegradation processes, coupled with their low affinity for adsorption to soils, reveal that naphthenic acids are likely to persist in the water column. However, UV/vis radiation is capable of significantly changing the composition of mixtures in the aquatic ecosystem, but not reducing overall naphthenic acid concentrations. This may not be a beneficial as there is the potential for increased toxicity toward the lower molecular weight naphthenic acids.

Pharmaceutical drugs are used extensively by humans and domestic animals. The detection of compounds such as non-steroidal anti-inflammatory drugs (NSAIDs) in effluents of sewage treatment plants and surface waters has raised concerns about whether these drugs have the potential to impact aquatic organisms. However, little is known about either the mechanism of action of NSAIDs or their impact on aquatic organisms. A key indicator of animal stress performance is the elevation in plasma cortisol levels, the primary circulating corticosteroid in teleosts, and the associated metabolic changes in response to stressor exposure. The secretion of cortisol is under the control of the hypothalamus-pituitary-interrenal (HPI) axis with the terminal step involving the activation of interrenal steroidogenesis by adrenocorticotropic hormone (ACTH) from the pituitary gland. Cortisol, predominantly via glucocorticoid receptor (GR) activation, is involved in a wide array of animal functions, including growth and metabolism, osmo- and iono-regulation, stress and immune function and reproduction, all of which play a role in regaining homeostasis after stressor insult. The overall objective of this thesis was to investigate the role of NSAIDs in impacting the evolutionarily-conserved adaptive stress response in a model teleost fish, the rainbow trout (Oncorhynchus mykiss). Specifically, the impact of NSAIDs on stress coping mechanisms was investigated by examining: i) interrenal steroid biosynthetic capacity and cortisol production, ii) target tissue GR function, iii) cellular heat shock protein response, iv) tissue-specific metabolic response to stressors, and iv) ionoregulatory performance in seawater. The experimental approach involved a series of whole animal in vivo and in vitro studies, using rainbow trout interrenal cell preparations, with two NSAIDs, salicylate and ibuprofen, commonly detected in our surface waters. Fish were subjected to stressors of varying intensity and duration, including handling disturbance, heat shock and salinity exposures, to identify targets impacted by NSAIDs in fish. NSAIDs did not affect resting plasma cortisol levels but disrupted the acute ACTH-stimulated corticosteroidogenesis in vitro and stressor-induced plasma cortisol response in vivo. The mode of action of NSAIDs in disrupting cortisol production involves inhibition of the key rate-limiting step, the steroidogenic acute regulatory protein (StAR), in steroidogenesis. Also, tissue (brain, liver and gill) GR protein content is a target for endocrine disruption by NSAIDs leading to abnormal negative feedback regulation of plasma cortisol levels and reduced target tissue responsiveness to cortisol after stressor exposure. The drugs also clearly affected the cellular stress response in rainbow trout by perturbing the expression of heat shock protein 70 (hsp70), a highly conserved stress coping mechanism. This impaired heat shock response with NSAIDs corresponded with an altered tissue metabolic capacity suggesting disturbances in biochemical adjustments to stressor. Specifically, the dynamics of glucose, the primary fuel to cope with the enhanced tissue metabolic demand, was disrupted in a drug-specific manner in rainbow trout. Exposure to NSAIDs also disrupted the ionoregulatory mechanisms critical for seawater acclimation in rainbow trout. The targets for ionoregulatory disturbance in seawater by NSAIDs include the major ion transporter gill Na+/K+-ATPase as well as gill GR, a key signaling protein for Na+/K+-ATPase upregulation in fish. Altogether, NSAIDs disrupt the adaptive endocrine and metabolic stress coping mechanisms in rainbow trout. The targets for endocrine disruption by NSAIDs include multiple sites along the HPI axis as well as target tissue response to cortisol action in fish. Specifically, the mode of action of NSAIDs involves disruption of StAR and GR, two key proteins critical for cortisol production and target tissue responsiveness to this steroid, respectively. While the work presented here identified the mechanism(s) of action of NSAIDs, the environmental relevance of this finding, specifically the impact of concentrations of NSAIDs present in our waterways on fish stress performance, remains to be explored.

Pharmaceutical drugs are used extensively by humans and domestic animals. The detection of compounds such as non-steroidal anti-inflammatory drugs (NSAIDs) in effluents of sewage treatment plants and surface waters has raised concerns about whether these drugs have the potential to impact aquatic organisms. However, little is known about either the mechanism of action of NSAIDs or their impact on aquatic organisms. A key indicator of animal stress performance is the elevation in plasma cortisol levels, the primary circulating corticosteroid in teleosts, and the associated metabolic changes in response to stressor exposure. The secretion of cortisol is under the control of the hypothalamus-pituitary-interrenal (HPI) axis with the terminal step involving the activation of interrenal steroidogenesis by adrenocorticotropic hormone (ACTH) from the pituitary gland. Cortisol, predominantly via glucocorticoid receptor (GR) activation, is involved in a wide array of animal functions, including growth and metabolism, osmo- and iono-regulation, stress and immune function and reproduction, all of which play a role in regaining homeostasis after stressor insult. The overall objective of this thesis was to investigate the role of NSAIDs in impacting the evolutionarily-conserved adaptive stress response in a model teleost fish, the rainbow trout (Oncorhynchus mykiss). Specifically, the impact of NSAIDs on stress coping mechanisms was investigated by examining: i) interrenal steroid biosynthetic capacity and cortisol production, ii) target tissue GR function, iii) cellular heat shock protein response, iv) tissue-specific metabolic response to stressors, and iv) ionoregulatory performance in seawater. The experimental approach involved a series of whole animal in vivo and in vitro studies, using rainbow trout interrenal cell preparations, with two NSAIDs, salicylate and ibuprofen, commonly detected in our surface waters. Fish were subjected to stressors of varying intensity and duration, including handling disturbance, heat shock and salinity exposures, to identify targets impacted by NSAIDs in fish. NSAIDs did not affect resting plasma cortisol levels but disrupted the acute ACTH-stimulated corticosteroidogenesis in vitro and stressor-induced plasma cortisol response in vivo. The mode of action of NSAIDs in disrupting cortisol production involves inhibition of the key rate-limiting step, the steroidogenic acute regulatory protein (StAR), in steroidogenesis. Also, tissue (brain, liver and gill) GR protein content is a target for endocrine disruption by NSAIDs leading to abnormal negative feedback regulation of plasma cortisol levels and reduced target tissue responsiveness to cortisol after stressor exposure. The drugs also clearly affected the cellular stress response in rainbow trout by perturbing the expression of heat shock protein 70 (hsp70), a highly conserved stress coping mechanism. This impaired heat shock response with NSAIDs corresponded with an altered tissue metabolic capacity suggesting disturbances in biochemical adjustments to stressor. Specifically, the dynamics of glucose, the primary fuel to cope with the enhanced tissue metabolic demand, was disrupted in a drug-specific manner in rainbow trout. Exposure to NSAIDs also disrupted the ionoregulatory mechanisms critical for seawater acclimation in rainbow trout. The targets for ionoregulatory disturbance in seawater by NSAIDs include the major ion transporter gill Na+/K+-ATPase as well as gill GR, a key signaling protein for Na+/K+-ATPase upregulation in fish. Altogether, NSAIDs disrupt the adaptive endocrine and metabolic stress coping mechanisms in rainbow trout. The targets for endocrine disruption by NSAIDs include multiple sites along the HPI axis as well as target tissue response to cortisol action in fish. Specifically, the mode of action of NSAIDs involves disruption of StAR and GR, two key proteins critical for cortisol production and target tissue responsiveness to this steroid, respectively. While the work presented here identified the mechanism(s) of action of NSAIDs, the environmental relevance of this finding, specifically the impact of concentrations of NSAIDs present in our waterways on fish stress performance, remains to be explored.

Invasive organisms are one of the major threats to the ecological integrity of aquatic systems in the 21st century. Among the most notorious and important aquatic invasive organisms are the dreissenid mussels, Dreissena polymorpha and D. rostriformis bugensis, which having originated in the Ponto-Caspian region are now common in many parts of Europe and North America. Dreissenids have large impacts on many aspects of lentic ecosystem functioning, the sum of which is thought to lead to the translocation of biological production from the pelagic to the littoral zones of lakes. In this thesis I explore the effects of dreissenids on the nearshore zones of large lakes, investigate the mechanisms by which dreissenids couple the pelagic and nearshore zones of lakes and attempt to elucidate the factors affecting the strength of the dreissenid-mediated connection between the pelagic and littoral zones. The effects of invasive organisms on an aquatic ecosystem will depend, in part, on the distribution and biomass of the invasive organisms in the system. In chapter 2 I present the results of a lake-wide survey of the distribution of invasive dreissenid mussels in Lake Simcoe, Ontario and discuss some of the factors that shape their distribution pattern in the lake. Dreissenid biomass averaged 27.2 (±24.3 SD) g shell-free dry mass (SFDM)/m2 in the main basin of Lake Simcoe and 12.4 (±16.9 SD) g SFDM/m2 in macrophyte-dominated Cook’s Bay. I argue that water movement is an important determinant of dreissenid distribution, both through catastrophic disturbance in shallow water and through non-catastrophic effects on substrate distribution and possibly food supply rates. In areas of dense macrophyte growth, mussel abundance was shown to be associated with that of preferred macrophyte taxa, in particular with that of Ceratophyllum demersum. I used the results of my survey and the relationships between environmental variables and dreissenid biomass to estimate the total biomass of dreissenids in Lake Simcoe: 12,000 tonnes SFDM. Most of the dreissenid biomass in Lake Simcoe was concentrated in the nearshore zone, where dreissenids would have maximal impacts on littoral biological production. One of the effects of the dreissenid invasion into the Laurentian Great Lakes appears to be a resurgence in the abundance of the nuisance alga Cladophora glomerata which experienced a marked decline following phosphorus abatement in the late 1970s and early 1980s. A subsidy of bioavailable phosphorus excreted by dreissenid mussels could be an important mechanism facilitating the growth of C. glomerata. In chapter 3, I describe a survey of dreissenid distribution and abundance followed by in situ experiments designed to measure dreissenid phosphorus excretion rates. Average dreissenid mussel abundance in our study area was 3674 (±2233 SD) individuals/m2, with an average biomass of 52.2 (±29.0 SD) g of shell free dry mass/m2. The mussels excreted bioavailable soluble reactive phosphorus (SRP) at an average rate of 7.0 μg SRP/g shell free dry mass/hour, contributing about 11 tonnes of SRP to the study area over the C. glomerata growing season. Dreissenids appear to be an important source of recycled bioavailable phosphorus to the littoral zone, potentially supplying more soluble reactive phosphorus to the study area than local watercourses and waste water treatment plants, and more phosphorus than is required to sustain local C. glomerata growth. Dreissenid establishment in many systems coincides with increases in the abundance and diversity of littoral benthic invertebrates and with changes to community composition of the benthos. Currently, there is a lack of long-term studies of the impact of dreissenid mussels on hard-substrate inhabiting littoral benthos. In chapter 4 I compare the littoral benthos of Lake Simcoe, Ontario just prior, and 14 years following the establishment of dreissenids in the lake. Densities of non-dreissenid invertebrates on hard substrata increased by nearly 50 times, from an average of 367.9 (±460.8 SD) individuals/m2 in 1993 to an average of 16,706.4 (±10,204.5 SD) individuals/m2 in 2008. The taxonomic diversity of the benthos increased significantly. The distribution of benthic organisms also changed; the numerical abundance of benthos has become more even across depths and sites, as has community composition. I suggest that in addition to increasing resource availability to benthic organisms dreissenids have also caused a homogenization of the littoral habitat by increasing the evenness of the distribution of food and habitat resources. The changes in the littoral benthic community in Lake Simcoe likely have wide-ranging implications to higher trophic levels and the cycling of energy in the lake. In addition to impacting nutrient cycling and the benthic invertebrate communities of littoral zones, dreissenid mussels can have large effects on food webs and energy cycling. In chapter 5 I used stable isotope analysis of pre- and post-dreissenid components of the nearshore food web of Lake Simcoe, Ontario to determine how dreissenids affected food sources and energy flow in the littoral zone of Lake Simcoe. Results suggest that the post-dreissenid food web relies about equally on two energy sources: dreissenid biodeposits (redirected pelagic primary production) and littoral benthic primary producers. Although the relative importance of pelagic and benthic primary production to benthic organisms has not changed much following dreissenid establishment, the absolute importance of both increased considerably in the post-dreissenid littoral zone: the large increase in invertebrate biomass that followed dreissenid establishment means that the amount of both pelagic and benthic primary production needed to sustain post-dreissenid organisms had to increase considerably. The results of this chapter suggest that dreissenids increase the availability to food to littoral organisms by redirecting pelagic primary production to the benthos and by stimulating littoral benthic primary production. The impacts of dreissenids on littoral benthic organisms probably have large effects on littoral and pelagic fish communities of lakes. Dreissenid mussels translocate biological production to the benthos by stimulating benthic primary production through nutrient excretion and increases in water clarity, by increasing habitat availability for benthic organisms and by biodepositing pelagic material that becomes available to benthic organisms and the fish that feed on them. I argue that hydrodynamic factors are important in controlling the strength of the dreissenid-mediated pelagic-littoral connection in lakes. Because hydrodynamics relate to lake size, a relationship between lake size and the ability of dreissenids to translocate production the littoral zone can be postulated, where dreissenid effects are maximal in intermediate-sized lakes.

Nuisance aquatic vegetation (mainly Hydrilla Verticillata ) has become problematic in Lake Conroe, TX. Consequently, triploid grass carp (Ctenopharynogodon idella) were stocked at densities sufficient to completely denude the reservoir of all vegetation (invasive and native plants) within one year. As a result, an assessment was designed to investigate the changes (before and after carp stocking) in the plant assemblage among sampling stations, changes in water quality parameters, length frequency and condition changes of Centrachid species, largemouth diet changes, and changes in the fish assemblages among randomly selected sampling stations between early fall 2007, when grass carp were stocked, and one year later in early fall of 2008. The areas for sampling were based upon aquatic vegetation surveys by Texas Parks and Wildlife during 2007 and 2008, thirteen sampling stations were randomly selected using ArcGIS software and the percentage of water surface covered by vegetation was recorded at each station. Within each station, fish were collected by electrofishing the entire station for five minutes; water samples were also collected. Largemouth bass diet did significantly change for mature (<200 mm-TL) bass as indicated by a chi-square test. Largemouth bass from the samples were shown to consume less sunfish and more shad by the second (post-carp) sample. This is consistent with expected results due to the removal of vegetation consequently eliminating small sunfish habitat. In similar fashion, significant length-frequency changes were seen in the second year as there were fewer smaller (juvenile) Centrachid species found in the sampling sites. Contrary to the Centrachids, length-frequency of gizzard shad significantly decreased in size by the second sampling year. Based upon the aquatic vegetation surveys within the sampling sites of 2007 and 2008, there was an almost complete elimination of all aquatic plants following carp introduction. This result was consistent with what was expected from the carp introductions. Changes in water quality parameters (phosphorous, nitrate, nitrites, orthophosphate, chlorophyll (a)), were generally inconclusive, with the exception of nitrate which significantly increased by the second year. The water quality parameters along with other measured habitat parameters were used in the multivariate analysis.

PAHs are hydrophobic organic compounds, which have received considerable attention because of their high bioaccumulation, toxicity, carcinogenicity, and mutagenicity. Because of their hydrophobic characteristics, PAHs intent to adsorb on particles, most of PAHs contained in wastewaters are treated biologically, especially in activated sludge systems. But due to the low construction cost and high efficiency, macrophyte-based treatment systems received increasing attention lately. In this work, batch experiments were conducted to study the adsorption behaviors between the aquatic plant (Najas graminea Del.) and PAHs aqueous solutions, including acenaphthene (Acp), fluorene (Flu), phenanthrene (Phe) and pyrene (Pyr). The interactions between different PAHs and if the plant conditions affected the adsorption were also discussed. The kinetic studies showed that the more hydrophobic the PAHs are, the faster the equilibriums achieve, The kinetic constants were found to correlate with Kow. Linear adsorption isotherms were observed in all the adsorption experiments. The adsorption equilibrium constants (K) increase with the Kow indicates that the hydrophobicity of the PAHs dominates the adsorption behaviors. The existence of small mount of Pyr could lower the adsorption of Phe on the plant, while Flu couldn¡¦t. Because the hydrophobicity of Flu is too weak to compete with Phe, so the competition was not observed. The plant after dry process had even better performances in both kinetic and adsorption experiments, which provide more flexibility when put this technology into practice.

This study was designed to integrate a mailing list-based survey with an internetbased presentation/response in order to take into account the trend toward selfadministration that is evident in everyday interactions with automated services that have taken the place of personal interactions. A random sample of 2,999 was taken from applicants for Triploid Grass Carp Permits from the Texas Parks and Wildlife Department. A forty-nine question survey was constructed containing five sections: general pond characteristics, physical pond characteristics, aquatic vegetation, fish and other wildlife, and management goals. The primary emphasis of this study was to determine what specific problems Texas pond owners faced, how widely these problems occurred, and where pond owners got the information they used to deal with pond management problems. A secondary emphasis of the project was to examine the potential presented by the Internet for use in this type of information gathering and distribution for Texas Cooperative Extension. An overall response rate of 21.3% (excluding non-deliverables and unusable submitted surveys) was obtained. Summary statistics for each question were calculated and then compared in order to gain a clearer picture of the pond management practices employed by Texas pond owners. These results indicated some initial discrepancies between pond owners?? management practices and current management recommendations, most dramatically where aquatic vegetation was concerned. The internet-based survey methodology worked effectively to lower the cost of distribution and the workload of data entry when compared to the mail survey. These benefits outweighed the disadvantages caused by survey error with the new methodology.

Thesis (M.S.) in Teaching--University of Maine, 2009. / Includes vita. Includes bibliographical references (leaves 108-117).

Thesis (Ph. D.)--Oregon State University, 2002. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.

Thesis (Ph. D.)--York University, 2000. / Typescript. Includes bibliographical references. Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pNQ56267.