The intertidal sea grass populations of the Moray Firth are a valuable food source for migrating and overwintering wildfowl, but the survival of the sea grasses is threatened by continuing industrial development and human disturbance. The current distribution and standing crops of the two Zostera species in Nigg Bay have been determined and information has been obtained on their taxonomy and biology. For example, the Z. angustifolia population is maintained primarily by seed whereas Z. noltii is maintained by vegetative reproduction. Knowledge of such differences is useful for predicting the responses of Zostera to possible physical and chemical disturbances. Oil spillages and cleaning-up operations present a major threat to the sea grasses. Field and laboratory trials were carried out using Forties crude oil; two types of ship's oil; the dispersants BP 1100X and BP 1100WD; mixtures of the oils and the dispersants; and BP 'Oil Marshal'. Field results showed that one month after treatment with the oils, dispersants and mixtures, the cover of Z. angustifolia and Z. noltii was largely unaffected. 'Oil Marshal' however, is not suitable for protection of these shores because direct contact with the chemical proved to be very damaging, with the cover of Z. amgustifolia being reduced by as much as 90% on drying surfaces. Fortunately, most of Nigg Bay remains water-logged at low tide, which helps to reduce the penetration of pollutants into the substrate. Laboratory trials with oils, dispersants and mixtures demonstrated that, for all treatments, the water-soluble components by themselves depressed net photosynthesis in Z. angustifolia, and that the mixtures had a worse effect than either the oils or the dispersants. Therefore, if oil is deposited high up the shore, dispersants should not be applied to the oil because of the potentially harmful effects on Zostera of the water-soluble products draining down through the water-logged flats.

No description available.

1. The idea of pollution is elucidated, historically and currently; pollutants are classified analytically; the estimation of social costs and benefits from abatement are discussed. Static micro-models of pollution involving pollution as a joint output, as a factor of production and as an input to recycling activity are developed, and comparative static analysis on each is performed. A brief consideration of the effects of exogenous technological change is made. Pollution considered as a dynamic phenomenon using a time-dependent pollution stock and decay rate independent of the stock level. A novel social damage function with positive damage at a positive pollution threshold is postulated, and the Planning Authority's optimal control problem of maximising production benefits net of pollution costs is solved for the various possible trajectories pf pollution tax and pollution stock. It is shown that society will not always prefer a decreasing quantity of pollution over time especially if it starts in the pre-threshold range of the stock. In this context it may be considered optimal to let transversality determine the final pollution stock thereby implying a zero final shadow price. 2. Various linear economic models (Leontief, Stone input-output and Activity Analysis) are expounded and developed where necessary, and their theoretical underpinnings criticised on purely economic criteria. The adaptation of these models to the study of economic-environmental interactions, specifically air pollution, is examined. Several recent developments in this area are expounded and criticised and some alternative models and techniques evolved. (Activity Analysis models are developed, the concepts of commodity and industry ecology in the Stone system are analysed, and a short-run technique for shadow pricing of ecologic commodities in the absence of data on abatement is evolved). 3. Leontief-Stone economic-environmental Input-Output is applied to a 90-sector, 12-pollutant model of the UK in an excercise in the methodology of pollution control. Data on pollutants initially derived from American sources is subjected to various statistical adjustment procedures based on knowledge of control efficiencies applicable to the UK. Ecologic Impact Tables for 90 economic commodities with respect to the pollutants are calculated, and for a subset the rankings of commodities for each pollutant are tested for correlation.

The sandstone aquifer underlying the Four Ashes industrial site near Wolverhampton, UK, is contaminated with high concentrations of organic pollutants, in particular phenol, cresols and xylenols. Although in the past the geochemistry of the site has been studied extensively, relatively little is known about the in situ microbial communities despite their potential for bioremediation. The aim of this thesis was to investigate the effect of groundwater pollution on the diversity of planktonic and attached microbial communities and to make comparisons between the two. This aim was investigated by sampling planktonic microbial communities at different positions within the fringes of the plume and the planktonic and attached communities at one plume depth (30 metres below ground level in borehole 59). Denaturing Gradient Gel Electrophoresis (DGGE) analysis of peR amplified 16S ribosomal RNA (rRNA) gene fragments indicated that diversity of planktonic microbial communities varied with depth across the steep geochemical gradient of the plume whilst under the same geochemical conditions the planktonic and attached microbial commu~ities differed markedly. The latter result was investigated further by 16S rRNA gene cloning and sequencing. Phylogenetic analysis of the two clone libraries demonstrated that there was limited overlap between the two communities and that the planktonic community was less diverse than the attached community. The 'groundwater' clone library was dominated by four bacterial phylogenetic groups (ex-, (3-Proteobacteria, Firmicutes and Bacteroidetes) whilst the 'sand' clone library was characterised by the presence of a-, {3-, "fProteobacteria, Bacteroidetes as well as a large number of clones (29%) that could not be classified or belonged to minor bacterial phyla. Thirteen percent of the groundwater and 5% of the sand clones had 100% 16S rRNA gene sequence identity to a phenol degrading Azoarcus strain, while 14.7% of the sand clones were closely related (98% sequence identity or more) to members of the Acidovorax genus that have been isolated or detected in phenol contaminated environments. In addition to the in situ studies, laboratory microcosms were inoculated with mixtures of bacteria isolated from the Four Ashes site (with known functional characteristics regarding their abilities to degrade or tolerate phenol and to attach to sand) in order to investigate the influence of different phenol concentrations or changes in phenol concentration on microbial community composition of both planktonic and attached communities. These studies revealed that the relative abundance of microbial isolates within the microcosms altered in response to phenol suggesting that complex metabolic and cell-cell interactions may influence microbial community composition.

The increased growth of wildlife tourism in Kenya over the last few decades has placed increasing demand and attention for the development and subsequent delivery of sustainable tourism. Today ecotourism ventures are perceived by many as a solution to the negative impacts of "traditional" wildlife tourism and thus a way to achieve ecologicalsustainability within the industry. To date however, there has been no attempt to qualifyand quantify any possible wildlife impacts of ecotourism - the basis of this research, usingthe Mara Ecosystem as a case study. Using WildKnowledge© software, this research recorded biotic and abiotic data from wildlife tourism developments of various sizes and assessed their anthropogenic impacts upon key ungulate species in the ecosystem over a three year period. The findings of this aspect of the research indicate that the effects of the tourism industry on wildlife are highly species specific. In particular Buffalo were most affected by differences in tourism seasonal variability (X2=5.040, df=l, p=O.025), distance to developments (X2=23.341, df=l, p=O.OOO) and group size (X2=7.998, df=1, p=O.005) between the different lodge types. In contrast, waterbuck and eland displayed similar patterns of disturbance irrespective of lodge type or tourism seasonal variability. Using historical species count data spanning a twenty year period, kernel density maps were constructed to demonstrate spatial changes in ungulate density and distribution patterns in relation to tourism growth. The resulting density maps revealed that while the national reserve offered a measure of security to wildlife, many ungulate species still heavily utilised their historical dispersal areas in the community lands. Interestingly, despite the tourism related land use changes demonstrated in the Mara's landscape, some species e.g. eland, displayed an increase in range size - to 4s0.5km2 in 2010 from 399.Skm2 in 2005 following the creation of wildlife conservancies in the surrounding ranches. Constructing site suitability models, the research explored how GIS modelling techniques can be employed to identify suitable locations for tourist accommodation, without compromising the ecological integrity of the wildlife areas where these facilities will be located. Employing two different bed occupancy models (conservancy model; 350 acres/bed and a current model; ; 174 acres/bed, derived from existing facilities), the Mara Ecosystem's ability to accommodate further tourism growth at low ecological cost was demonstrated. Application of the highest suitability criteria to select potential development sites revealed two suitable locations. A further 54 locations were identified as suitable for ecocamps and ecolodges on application of the second highest site selection suitability criteria. Importantly, the models employed clearly demonstrate that the majority of future ecotourism facilities be located outside the National Reserve in the group ranches if they are to have limited wildlife impact, as over-utilisation of any single sections of the ecosystem will lead to resource depletion and localized species loss. The results presented highlight the need for a more integrative approach to ecotourism provision. The utility of GIS based models to project the impacts of human disturbances on wildlife populations under different tourism scenarios is reinforced by this research. These suitability models are easily modified and can therefore be used under different planning scenarios in other wildlife areas in Kenya and the region. It is therefore hoped, that the results from this study will influence policy direction for tourism planning in wildlife areas for the Mara and other ecosystems, and be used to complement the country's tourism and wildlife bills which are about to be passed into law. This research concludes that although ecotourism plays an important role in environmental conservation, its ecological impacts on wildlife in receiving environments can be significant and should be a primary consideration in deciding upon the efficacy of individual proposals.

No description available.

Following the application of pesticides during normal agricultural practice these compounds can degrade to form transformation products. When assessing the risks posed by pesticides it is important to include any additional risks posed by these compounds. Current guidance within the EU suggests that data requirements for transformation products during the risk assessment do not necessarily need to be addressed with experimental studies but alternative techniques can be explored and used. Therefore the aim of this research was to investigate and develop pragmatic approaches for assessing the fate and effects of transformation products in the absence of experimentally determined data. Approaches designed to provide information on the physico-chemical properties, environmental parameters, ecotoxicology and toxicology of pesticide transformation products are explored and evaluated, and recommendations made on how to obtain the most appropriate estimates of these factors. Hydrophobicity, dissociation constant, soil sorption, daphnid aquatic ecotoxicology and rat oral lethality can all be estimated with confidence. Moreover, approaches were developed to I) indicate whether a transformation product may exhibit pesticidal activity and subsequently estimate its acute aquatic ecotoxicity in the absence of experimental data, 2) combine well known techniques and experimental data to obtain estimates of transformation product mutagenicity with limited risk of obtaining false negatives and 3) prioritise transformation products of most concern to drinking water supplies and its consumers. Overall, recommendations are made throughout this thesis on appropriate approaches and methods for generating estimates of transformation product properties, ecotoxicity and toxicity for use in risk assessment and prioritisation frameworks.

The residual lead contamination of human and livestock populations was studied in two villages set in the Southern Uplands of Scotland, where the environment is heavily contaminated through former mining activity. Possible routes of lead exposure involving domestic water, house dust, airborne dust, hands, food preparation, surfaces, garden soils and home grown vegetable consumption were investigated. There was a general increase in lead in the environment in the contaminated villages and blood lead levels were between 45 and 70 per cent higher than the control village. The major determinants of blood lead in both areas were sought through correlation and multiple regression analysis. Lead in drinking water had the largest influence in explaining blood lead variability (11%), although levels were low and within EEC guidelines; hand lead accounted for 6%, airborne dust lead 3% and kitchen surface and house dust lead less than 1% of variation in blood lead. A parallel study was made of lead contamination of grazing lambs. The need for further restoration work is indicated to support the educational programme instituted in an attempt to reduce the lead contamination which has persisted since closure of the mines in the 1930s.

The corrosion of iron is a very old and complex phenomenon. Its employment for the treatment of wastewater began in the earliest around ten years ago, with few earlier exceptions. Most researchers have considered its application to groundwater remediation, and its use a a permeable reactive barrier material is well established. The aim of this research is to measure parameters that govern zero-valent iron treatment of wastewater with the treatment of industrial influents prior to discharge to municipal sewage treatment works particularly in mind.

Anthropogenic C02 release is leading to a wide range of oceanic environmental changes that may influence the survivability of marine organisms in the future. Environmental change varies regionally, and Southern Ocean calcifying organisms are considered to be particularly at risk from change, due to low pre-existing pH conditions and rapidly increasing temperatures. UVic model data from the Southern Ocean is used to assess environmental change in the region, and shows the importance of considering the variability as well as the magnitude of change. Since pre-industrialisation, the four Southern Ocean locations analysed showed a modern pH range entirely outside the historic range. The southern west Antarctic Peninsula region is considered the most vulnerable due to historic environmental stability, increased variability in the modern, and the widest gap between historic and modern carbonate chemistry variability envelops. The geochemistry and crystal structure of eight species of Antarctic bivalves were investigated, and four of these species were used to assess organism response to environmental change since pre-industrialisation from the western Antarctic Peninsula to South Georgia. Bivalve response varied between and within species: Lissarca miliaris showed a decrease in shell robustness over time; Lissarca notorcadensis showed one instance of no change and another of increased robustness; and Limatula pygmaealLimatula ovalis showed no change. There was no correlation between sites identified as vulnerable in the UVic model, and bivalve response. Mytilus californianus, a temperate bivalve species, from Tatoosh Island on the NW Pacific coastline of the USA, were similarly tested as pH has declined in the region four times faster than the global average. Bivalve shells showed a change in biomineralisation, resulting in increased robustness from the historic to the modern. The variability in response illustrates that some species have sufficient plasticity to be unaffected by environmental change, some may struggle to survive in future oceans and others have the capacity to adapt on short timescales.