Since the UK industrial revolution, coal combustion, ore smelting and other industrial activities have resulted in a marked increase in emissions of potentially toxic elements (PTEs) such as antimony (Sb), lead (Pb), arsenic (As), copper (Cu) and zinc (Zn), along with polycyclic aromatic hydrocarbons (PAHs), to the atmosphere. Although stricter environmental regulation and improved technology has led to a notable decline for some contaminant emissions in recent decades, this has not been observed for all elements, e.g. Sb, where only a modest reduction in emissions have been recorded. Once emitted, Sb along with Pb, As, Cu, Zn and PAHs may persist in the environment for considerable periods of time after their release; although their chemical associations may change, elements are not broken down over time and organic contaminants may break down slowly. Above all, PTEs and PAHs are detrimental to human and environmental health, with chemical forms of Sb, Pb, As and PAHs categorised as carcinogenic. Understanding their behaviour and fate in the environment is therefore an important step towards evaluating their likely impact on both ecosystem and human health. Consequently, this study focuses on the release, behaviour and fate of contaminants from current and past anthropogenic sources in the urban and rural environment, with a specific interest in Sb and PAHs, where emissions originate from similar anthropogenic sources, with Pb, As, Cu and Zn also included for comparison purposes. Current and past industrial activity was identified as the dominant source of PTEs and PAHs to the urban environment, with emissions from vehicle, coal combustion and metal smelting identified as main contributors to total contaminant concentrations. Using road dust collected from Edinburgh at five high- and low-traffic roads at a distance of 10 and 50 m from the closest road junction, concentrations of Sb, Pb, Cu, Zn, PAHs and Pb isotope ratios were determined, with road dust undergoing further characterisation using chemical (sequential extraction) and spectroscopic (X-ray diffraction, SEM-EDX) techniques. No consistent trend for the element concentrations released from vehicles braking at 10 and 50 m from the closest road junction was observed. Mean concentrations for Sb, Cu and Zn were 5.3 ± 2.8 mg kg-1, 91.4 ± 48 mg kg-1 and 237 ± 144 mg kg-1, respectively, and were similar to road dust sampled from five high- and five low-traffic locations in Glasgow (Sb 4.5 ± 2.1 mg kg-1; Cu 117 ± 71.9 mg kg-1; Zn: 283 ± 146 mg kg-1). This was in contrast to mean concentrations for Pb and Σ16PAHs obtained from Glasgow (Pb 250 ± 283 mg kg-1, Σ16PAH 7.7 ± 4.3 mg kg-1) where values were approximately double and two-thirds greater than those found in Edinburgh (Pb 135 ± 129 mg kg-1, Σ16PAH 4.7 ± 2.9 mg kg-1), respectively. Lead isotopic analysis of Glasgow road dust (206Pb/207Pb range of 1.140-1.174) showed a strong influence of past emissions from coal combustion and metal smelting, and was in agreement with Glasgow's industrial history. For Edinburgh, the isotopic signature was considerably lower (206Pb/207Pb range of 1.116-1.151), and was influenced moreso by emissions of Australian sourced Pb in leaded fuel. Isotopic signatures in Edinburgh were lowest at easterly locations within 5 km of Edinburgh airport (206Pb/207Pb ~ 1.12), and corresponded with past vehicle emissions from leaded petrol use, and to a lesser degree, emissions from avgas, which was consistent with the mean annual wind direction for Edinburgh. The mobility of elements from the road dust to the aqueous phase were assessed by sequential extraction, and by using road surface water samples which showed mobility decreased in the order of Zn > Cu > Pb > Sb. Road dust characterised by XRD and SEM-EDX had a high proportion of quartz present (~55%), whilst the presence of less abundant minerals such as calcite were found to increase Pb mobility through ease of dissolution into the aqueous phase. For the rural environment, the behaviour and fate of elemental pollution originating from two former mining sites, an Sb mine at Glendinning, SW Scotland, and a Pb mine at Tyndrum in central Scotland was examined. Under specific environmental conditions, Sb was found to be both mobile and immobile in the environment. The chemical weathering of stibnite found in spoil heaps at Glendinning Sb mine demonstrated that ~3% of total Sb can be mobilised during the chemical weathering process, while hydrous Fe oxides and organic matter in the surrounding soil favoured its retention. The retention of Sb, along with Pb, was similarly observed in Loch Tay sediment downstream of Tyndrum Pb mine, where upon deposition, Sb and Pb remained immobile in sediment and allowed the construction of deposition chronologies for two sediment cores to be established. Excellent agreement between the sediment core deposition chronologies was observed, with both chronologies identifying atmospheric deposition as the primary source of Sb to Loch Tay sediment, whilst the dominant source of Pb was from Tyndrum Pb mine ~25 km upstream of Loch Tay. Relative to Sb and Pb, As had the greatest mobility, with its geochemical behaviour and partial retention by the solid phase influenced by the presence of Fe. This was evident in the surrounding soil at Glendinning Sb mine, where As was associated with hydrous Fe oxides present in the solid phase, while at Loch Tay, the redox cycling of Fe resulted in the post-depositional mobility of As in sediment. The use of ombrotrophic peat bogs for this study provided an effective means to assess atmospheric deposition of contaminants over past centuries; they continually accumulate and receive all their nutrients and contaminants exclusively by deposition from the atmosphere. The deposition archives of Sb and Pb from two Scottish peat cores sampled from Great Moss, Cairngorms Mountains, and, Auchencorth Moss, Midlothian, were used to construct chronologies for historic and contemporary emissions, particularly in relation to current and historic anthropogenic activities observed in urban and rural environments. At Great Moss, the deposition of Sb and Pb during the 19th century increased by a factor of 10 and 4, respectively, as a result of the industrial revolution and emissions from the combustion of coal and metal smelting. The trend continued into the 20th century where Sb and Pb deposition peaked ~1950, followed by a decline towards the early 21st century by a factor of 5 and 11, respectively. Over this period of time, the contribution from coal combustion and metal smelting towards total anthropogenic emissions was on the decline, while emissions from the combustion of leaded fuel increased until the ~1980s. Although deposition chronologies before 1970 for Sb and Pb at Auchencorth Moss were generally in agreement with those from Great Moss, several differences were observed after 1970, or more specifically, in the top ~10 cm of the peat core. This was a result of sub-surface perturbations for Ti, Sb, Pb and 210Pb concentrations, and indicated once deposited, elements were susceptible to post-depositional mobility brought about from a change in environmental conditions. The thicker acrotelm layer present at Auchencorth Moss, and the vertical movement of the peat water-table within this layer, resulted in a change in redox conditions and led to the redox cycling of Mn and Fe, which in turn, influenced vertical concentrations of Ti, Sb, Pb and 210Pb. While Sb and Pb are usually found immobile in peat systems, the post-deposition mobility of Sb and Pb at Auchencorth Moss was comparable to a peat core sampled from Flanders Moss, and indicated that under specific environmental conditions, both elements can become mobile in ombrotrophic peat bogs. It is worth bearing in mind however, that these results are the exception, and in all other cases ombrotrophic peat bogs remain a reliable archival material to use.

Anthropogenic noise is increasingly widespread as human development continues. Noise can negatively affect humans and wildlife, but the most deleterious effects are incurred by species that rely on vocal communication for mating, territory defence, and other vital functions. Songbirds are particularly susceptible, often experiencing declines in richness and abundance in noise-affected areas. Yet, some species remain abundant in noisy environments. High frequency vocalizations, or the ability to shift to higher frequencies, is one adaptation that may allow birds to communicate above low frequency anthropogenic noise. However, the mechanisms underlying frequency shifting, and the relationship between vocal frequency and abundance, are still not fully understood. I examined whether black-capped chickadees produce songs at higher frequencies in noisy areas, and whether these differences could be due to altered vegetative structure rather than noise. I also examined whether chickadees could plastically change song frequencies as noise increased. Finally, I surveyed abundance and recorded vocalizations from several songbird species to evaluate whether plasticity in song frequency, or mean song frequency, could predict how abundance and urban prevalence would be affected by anthropogenic noise. I found that black-capped chickadees shifted to higher song frequencies in noise-affected areas, and that vegetative differences did not account for these changes. Further, chickadees at roadside locations plastically increased their song frequencies as noise levels increased. Vocal plasticity, however, was not related to abundance in my multi-species comparison. Instead, noise-related changes in abundance were predicted by a species minimum song frequency. Nevertheless, minimum song frequency did not necessarily predict whether a species would be widespread in urban areas. In addition to frequency parameters, urban species may avoid overlap with noise through spatial and temporal mechanisms, but those that lack any mechanisms to communicate within anthropogenic noise may experience declines. Thus, reducing anthropogenic noise may increase the quality of urban habitats for birds. / Ecology

No description available.

Thesis (Ph. D.)--Washington State University, August 2006. / Includes bibliographical references (p. 64). Also available online.

Thesis (M.S.)--Michigan State University. Dept. of Geological Sciences, 2006. / Title from PDF t.p. (viewed on Nov. 20, 2008) Includes bibliographical references (p. 76-80). Also issued in print.

Thesis (M.S.)--University of Massachusetts Amherst, 2009. / Includes bibliographical references (p. 83-87).

Thesis (Ph. D. ), Memorial University of Newfoundland, 1999. / Bibliography: p. 194-217.

Freshwater resources are threatened by the presence and increase of harmful algal blooms (HABs) all over the world. The HABs are sometimes a direct result of anthropogenic pollution entering water bodies, such as partially treated nutrient-rich effluents and the leaching of fertilisers and animal wastes. Microcystis species are the dominant cyanobacteria (algae) that proliferate in these eutrophic waters. The impact of HABs on aquatic ecosystems and water resources, as well as their human health implications are well documented. Countermeasures have been proposed and implemented to manage HABs with varying levels of success. These control measures include the use of flocculants, mechanical removal of hyperscums and chemical algicides. The use of flocculants such as PhoslockTM is effective in reducing the phosphates in a water body thus depriving nutrients that are available to cyanobacteria. The mechanical option entails the manual removal of hyperscums thus reducing the numbers of cyanobacteria cells that may be the inoculum of the next bloom. The major disadvantage of these two measures is cost. Copper algicides have been used successfully to control HABs in raw water supplies intended for potable purposes. The major disadvantages are copper toxicity and release of microcystins from lysed cyanobacteria cells. Algicides accumulate in the sediments at concentration that are toxic to other aquatic organisms and may also cause long-term damage to the lake ecology. In some studies, microcystins have been implicated in the deaths of patients undergoing haemodialysis. Therefore there is an increasing need to reduce the use of chemicals for environmental and safety reasons. Thus, the development of environmentally friendly; safe non-chemical control measures such as biological control is of great importance to the management of HABs. Some papers, describe bacteria, which were isolated from eutrophic waters, such as Sphingomonas species with abilities to degrade microcystins and Saprospira albida with abilities to degrade Microcystis cells. Further research is required to evaluate whether these bacteria are antagonistic towards cyanobacteria. Ideally, a combination of strategies should be introduced; that is, combine predatory bacteria that directly lyse the cyanobacteria with microcystin degrading bacteria that then ‘mop up’ the released microcystins. The major objective of this study was to isolate organisms that have a similar antagonistic properties; determine their mechanism of action and then develop a model to account for the interaction between the predator and prey as the basis for the development of a biological control agent. During the screening for lytic organisms from eutrophic waters of Hartbeespoort dam, seven bacterial isolates were obtained. Based on electron microscope observation, two of the isolates were found aggregated around unhealthy Microcystis cells. These were identified as Pseudomonas stutzeri strain designated B2 and <i.Bacillus mycoides strain designated B16. Based on efficiency and efficacy experiments B. mycoides B16 was a more effective antagonist than P. stutzeri B2. Furthermore the <i.B. mycoides B16: Microcystis critical ratio was found to be 1:1 in 12 days. Thus altering the predator-prey ratio by increasing the predator bacteria numbers reduced the Microcystis lysis time to six days. The B. mycoides B16 managed to reduce the population of alive Microcystis cells by 85% under turbulent conditions and 97% under static conditions in six days. The increase in predator bacteria numbers coincided with a decrease in growth of Microcystis. The study on the interactions of Microcystis aeruginosa and Bacillus mycoides B16 indicated a series of morphological and ultrastructural changes within the cyanobacteria cell leading to its death. These are summarised in a conceptual model that was developed. The predatory bacteria, B. mycoides B16 attached onto the Microcystis cell through the use of fimbriae and or exopolymers. During this attachment the bacteria released extracellular substances that dissolved the Microcystis cell membrane and interfered with the photosynthesis process. The presence of numerous bacterial cells that aggregated around Microcystis cell provided a ‘shade’ that reduced the amount of light (hv) that reached the Microcystis cell. In response to these adverse conditions, the Microcystis cell did the following: It expanded its thylakoid system, the light harvesting system, to capture as much light as possible to enable it to carry out photosynthesis and it accumulated storage granules such as phosphate bodies, glycogen and cyanophycin and swollen cells. Other researchers have also reported the swelling phenomenon prior to cell lysis but did not account for what might be the cause. During the course of the lysis process the Microcystis cell underwent a transition stage that involved changes from alive (with an intact membrane) to membrane compromised (selective permeability), to death (no membrane) and eventual cell debris. Due to the depleted Microcystis cells, the B. mycoides B16 (non-motile, non-spore former) formed chains, i.e., exhibited rhizoidal growth in search of new Microcystis cells to attack. In conclusion, the present evidence in this study suggests that B. mycoides B16 is an ectoparasite (close contact is essential) in its lysis of Microcystis aeruginosa under laboratory conditions. These findings that B. mycoides B16 is a predatory bacterium towards Microcystis aeruginosa need to be further evaluated under field conditions in mesocosm experiments (secluded areas in a lake) to determine the possibility of using this organism as a biological control agent. The study on the interactions of Microcystis aeruginosa and Bacillus mycoides B16 indicated a series of morphological and ultrastructural changes within the cyanobacteria cell leading to its death. These are summarised in a conceptual model that was developed. The predatory bacteria, B. mycoides B16 attached onto the Microcystis cell through the use of fimbriae and or exopolymers. During this attachment the bacteria released extracellular substances that dissolved the Microcystis cell membrane and interfered with the photosynthesis process. The presence of numerous bacterial cells that aggregated around Microcystis cell provided a ‘shade’ that reduced the amount of light (hv) that reached the Microcystis cell. In response to these adverse conditions, the Microcystis cell did the following: It expanded its thylakoid system, the light harvesting system, to capture as much light as possible to enable it to carry out photosynthesis and it accumulated storage granules such as phosphate bodies, glycogen and cyanophycin and swollen cells. Other researchers have also reported the swelling phenomenon prior to cell lysis but did not account for what might be the cause. During the course of the lysis process the Microcystis cell underwent a transition stage that involved changes from alive (with an intact membrane) to membrane compromised (selective permeability), to death (no membrane) and eventual cell debris. Due to the depleted Microcystis cells, the B. mycoides B16 (non-motile, non-spore former) formed chains, i.e., exhibited rhizoidal growth in search of new Microcystis cells to attack. In conclusion, the present evidence in this study suggests that B. mycoides B16 is an ectoparasite (close contact is essential) in its lysis of Microcystis aeruginosa under laboratory conditions. These findings that B. mycoides B16 is a predatory bacterium towards Microcystis aeruginosa need to be further evaluated under field conditions in mesocosm experiments (secluded areas in a lake) to determine the possibility of using this organism as a biological control agent. The study on the interactions of Microcystis aeruginosa and Bacillus mycoides B16 indicated a series of morphological and ultrastructural changes within the cyanobacteria cell leading to its death. These are summarised in a conceptual model that was developed. The predatory bacteria, B. mycoides B16 attached onto the Microcystis cell through the use of fimbriae and or exopolymers. During this attachment the bacteria released extracellular substances that dissolved the Microcystis cell membrane and interfered with the photosynthesis process. The presence of numerous bacterial cells that aggregated around Microcystis cell provided a ‘shade’ that reduced the amount of light (hv) that reached the Microcystis cell. In response to these adverse conditions, the Microcystis cell did the following: It expanded its thylakoid system, the light harvesting system, to capture as much light as possible to enable it to carry out photosynthesis and it accumulated storage granules such as phosphate bodies, glycogen and cyanophycin and swollen cells. Other researchers have also reported the swelling phenomenon prior to cell lysis but did not account for what might be the cause. During the course of the lysis process the Microcystis cell underwent a transition stage that involved changes from alive (with an intact membrane) to membrane compromised (selective permeability), to death (no membrane) and eventual cell debris. Due to the depleted Microcystis cells, the B. mycoides B16 (non-motile, non-spore former) formed chains, i.e., exhibited rhizoidal growth in search of new Microcystis cells to attack. In conclusion, the present evidence in this study suggests that B. mycoides B16 is an ectoparasite (close contact is essential) in its lysis of Microcystis aeruginosa under laboratory conditions. These findings that B. mycoides B16 is a predatory bacterium towards Microcystis aeruginosa need to be further evaluated under field conditions in mesocosm experiments (secluded areas in a lake) to determine the possibility of using this organism as a biological control agent. / Thesis (PhD (Water Resource Management))--University of Pretoria, 2008. / Microbiology and Plant Pathology / PhD / Unrestricted

Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv and Cons Biol) / African penguin (Spheniscus demersus) mainland colonies are a popular tourist attraction in the Western Cape of South Africa. The African penguin population is in decline and the species is listed as endangered on the International Union for the Conservation of Nature (IUCN) Red List. This thesis aimed to investigate the impact of ecotourism upon African penguin colonies by comparing two colonies of differing levels of tourist visitation in the Western Cape in 2017. The high visitation colony is a mainland colony where ecotourism activities take place (Stony Point), and the low visitation colony is an island colony where ecotourism does not occur (Robben Island). As well as inter-colony comparisons, nests at the high visitation colony within areas of differing exposure levels were also compared.

Boat noise has been shown to distract and cause harm to many marine organisms. Most of the study effort has been focused on fish & marine mammals, even though invertebrates represent 99% of all living organisms, both terrestrial and aquatic. The small amount of studies conducted on invertebrates have demonstrated a clear negative correlation between anthropogenic noise pollution and invertebrate well-being. The small giant clam Tridacna maxima and the spider conch Lambis lambis are two invertebrate species which play key roles in coral reef ecosystems, and are little studied for the effects of noise disturbance. If their behaviour is significantly affected by boat noise, this could cause a knock on effect on the rest of the reef ecosystem. T. maxima functions as prey to many fish species, contributing up to 9% of the reef’s calcium carbonate budget, as well as playing a role in nutrient cycling. L. lambis is essential prey for molluscivore snails and certain elasmobranchs, and through its herbivorous feeding, helps to keep filamentous algae levels low. Moreover, coral reefs are reliant on the biological sound primarily created by invertebrates, such as snapping shrimp, to attract larvae from the pelagic environment for settlement. During experiments conducted in February 2020 in the Red Sea, Daily Diary Monitoring (DDMT) smart tags were used to measure the reactions of T. maxima and L. lambis respectively during underwater playback of boat noise compared with ambient reef sound. It was found that both T. maxima and L. lambis exhibited behavioral changes during the boat noise treatment. The implications of this study is that individuals of L. lambis and T. maxima may spend energy averting the invisible "threat" of boat noise, rather than feeding and/or photosynthesizing, in the case of T. maxima. If this hinders the acquisition of food/production, the whole reef ecosystem may be compromised in a knock-on effect from these producers and primary consumers. As boat noise is prevalent on inshore Red Sea reefs, shown by a 24-hour acoustic analysis of a patch reef sound pressure levels (SPL), invertebrates might be affected on a large scale in the Red Sea.