The thesis consists of three chapters of self-contained studies. In Chapter 1, I examine the decision of individuals to secure the provision of an environmental service under a Psychological Games framework. Since environmental services are considered public goods, there is an ongoing depletion of natural resources. While standard economic theory predicts the introduction of a PES is supposed to correct the associated externality by establishing a market which offers a monetary compensation to owners of vital natural resources as a recognition of their effort in providing the environmental services, this chapter argues such intervention might backfire: a motivation crowding-out arises if individuals believe others reciprocate friendly behaviour solely to receive the monetary compensation, ultimately decreasing total environmental protection. Even if environmental protection does take place, the motivation of individuals to secure the provision of the environmental service becomes commodified by the PES. Finally, awarding the PES only to a subset of individuals will also have negative effects on environmental protection, since those not receiving the PES will not want to do for free something that others are being paid to do. Environmental policy implications of this economic instrument are further discussed. In Chapter 2, a sample of the World Values Survey dataset is analyzed to show there are substantial behavioural differences between immigrants and native-born regarding pro-environmental action. In particular, while neither native-born nor immigrants are more willing to sacrifice money to save the environment, immigrants actually engage more on activities like choosing products that are better for the environment, recycling, and reducing water consumption. The engagement in proenvironmental behaviour of immigrants is region-specific and depends on their source region. Moreover, such relatively higher actual engagement in environmentally friendly behaviours can be explained by their high socio-economic status and their high education level, i.e. “selective immigration”. When the behaviour of immigrants by their length of residence in the host country is analyzed, no differences in proenvironmental attitudes or pro-environmental behaviour are found, a result which suggests they do not develop a “sense of belongingness” to the host country. Finally, in line with the standard finding in the literature of acculturation in environmental behaviour, this chapter finds that immigrants conform through time to some of the proenvironmental actions of native-born. In Chapter 3, I investigate the indirect effects on norm activation produced by monetary environmental policy instruments which introduce a situational cue that fosters a change of identity among individuals with potential negative consequences on their pro-environmental behaviour. For that purpose, a two-period identity selection model based on self-verification theory is developed. In each period there are two types of selves an individual can adopt: selfish and pro-environmental. The process of identity selection is driven by the desire of individuals to be consistent across the two periods in order to avoid social disapproval due to self-change. Results show that the monetary environmental policy introduces an asymmetry in the identity selection process that produces a failure of norm activation: while selfish agents preserve their selfish identity after the policy is implemented, pro-environmental agents might change their identity despite they experience social disapproval due to a reduction in the cognitive benefits of keeping such identity produced by the monetary component of the policy. Implications for environmental policy design are discussed.

Weathering releases lithogenic elements to soil and stream waters that support life in catchment ecosystems. Seasonal and inter-annual variations in hydrologic conditions change subsurface flowpaths, modifying the influence of weathering on stream waters. This study, over two climatically variable years, determined seasonal and inter-annual changes in solute sources to streams using a multi-tracer approach including major cations, strontium isotopes, germanium (Ge)/silica ratios, carbon species, and trace metals. Stream water cations display constant concentrations although discharge response was highly variable, suggesting that there is a consistent subsurface water supply. However, Sr isotope ratios, and concentrations of Ge, Fe, Al, and dissolved organic carbon, which originate from shallow soil waters, increase with the hydrograph during a wet winter snowmelt. This indicates that during a year with a thick snowpack, stream waters contain components of both shallow soilwater and groundwater during snowmelt, whereas during all other times groundwater contributes predominantly to the stream.

This project investigated the traditional treatment of chromium by oxidation-reduction reaction using Fe (II) and Mn (II). It was found that FE (II) was a potential remediation to stabilise chromium and reduce Cr (VI) to Cr (III), but Mn (II) oxidised Cr (III) to Cr (VI) mobilising it to the leachate. The characteristic of chromium leaching from soil was studied and showed there was fast release followed by a slow release. After a dry period the initial leachate had a high chromium concentration, this points out that the leaching of chromium is a long-term process. Those aspects of fast and slow release and the high chromium concentration at the initial pulse have been a concern for designing a system of fixed bed, low cost material such as (charcoal, coir, peat and wood bark) for adsorbing chromium from the leachate. The adsorption – desorption properties were studied, as both are of equal concern, and the Langmuir equation was applied for the various sorbent materials. Charcoal had a high percentage of Cr (VI) adsorbed, but on the other hand also had a high percentage of Cr (VI) desorbed. When applied to the column leach charcoal could not adsorb Cr (VI) properly. Wood bark had the lowest percentage of chromium released to the solution; therefore it was selected for further studies. The wood bark was studied with different contact times by both batch and flow through systems. The results showed that more chromium was adsorbed with longer contact time. The system using 2500g of wood bard completely retained chromium from a solution of about 100 litres of 30 mg Cr/l with a flow rate of 60 ml/h. The experimental results can be applied to larger scale systems; however, the system needs further development.

Shellfish processing results in the disposal of large quantities of waste to landfill sites. This project sought to deal with the issue of the processing of marine crustacean waste, specifically that of the prawn, Nephrops norvegicus. The exoskeleton of Nephrops norvegicus contains chitin, β-(1→4)-N-acetyl-D-glucosamine. In this study shell waste was demineralised, via lactic acid fermentation, using a commercial silage inoculant. The product contained 11.2% (w/w) ash, 31.1% (w/w) protein and 53.5% (w/w) chitin. Addition of the proteolytic enzyme, bromelain and a nitrogen source to the fermentation system led to deproteinisation and further demineralisation of the shell. The final product contained 4.2% (w/w) ash, 5.3% (w/w) protein and 79.6% (w/w) chitin. Chitin is relatively inert but can be converted to its more reactive derivative, chitosan, by deacetylation. Chitosan, prepared from bioprocessed shell waste, was investigated as a potential coating for urinary catheters. Attempts are currently being made to prevent blockage of these biomedical devices due to mineral ions, via the use of different manufacturing materials. Shell waste that had been demineralised using lactic acid fermentation was deacetylated using 50% (w/v) NaOH at 90oC. Membranes were prepared from the resultant chitosan. After immersion in a bath containing artificial urine, adherence of calcium and magnesium ions to the membranes was measured and compared with adherence of the same ions to polyurethane membranes. Adherence of calcium to the chitosan membranes was not higher than adherence to the polyurethane control membranes. Adherence of magnesium ions was significantly less than to the polyurethane control. The chitosan was hence shown to have potential for use as a coating for urinary catheters.

The appropriate management of visitors to nature reserves is an important conservation concern. In this thesis I briefly review the current literature describing the effects of disturbance on wildlife, concentrating mainly on birds (Chapter 1). Recent literature has provided worrying critiques of the practical and theoretical bases upon which management practice is based. Here, I address a number of questions that seek to clarify the impacts of human disturbance on birds. I started by asking whether behavioural measures of disturbance are accurate indices of the negative effects of disturbance. Through an experimental test of a theoretical model, I showed that animals that respond most to disturbance may in fact be those individuals that face the lowest cost associated with such disturbance (Chapter 2). Turnstones Arenaria interpres provided with extra food over three days showed stronger behavioural responses to a standardised disturbance stimulus than those without extra food. Behavioural measures are therefore not always a good index of disturbance effects. Consequently, the conclusions of some of the studies reviewed in Chapter 1 must be considered doubtful. Although some large declines in breeding success of some species are caused by human disturbance, such effects are obvious, simple to remedy and appear to be rather rare. If human disturbance is a general concern it is therefore necessary to assess whether human disturbance has impacts on species that are not obviously sensitive. To investigate this, I modelled the impact of human disturbance on the nesting success of kittiwakes Rissa tridactyla and guillemots Uria aalge (Chapter 3). By directly measuring a range of nest site parameters as well as those parameters involving human disturbance, I was able to improve the power of the analysis to detect disturbance effects over those of previous, less detailed, studies.

Chapter two investigates the adsorption of chlorpropham on six different absorbents including three soil types; the adsorption-desorption of chlorpropham from soil including the development of an analytical method suitable for the analysis of chlorpropham residues in drinking water. The analytical method involved preconcentration of chlorpropham residues on a solid sorbent (C18) followed by elution with a suitable solvent to achieve an environmentally safe and sensitive method for the detection and quantification of chlorpropham. Octaedecyl silylbonded silica cartridges (C18) proved to be very efficient for the determination of chlorpropham residues with a high recovery and reproducibility of 97%. The adsorption study of chlorpropham was carried out on six different adsorbents including three soil types in an effort to find out their efficacy for the purification of chlorpropham polluted water. The studies were carried out using three types of soils - Downholland (peat), Midelney (clay), and Dreghorn (sand) - and charcoal, bark, wheat straw, at three different temperatures and concentrations. The results showed generally, that charcoal had the greater adsorption efficacy followed by tree bark, wheat straw, Downholland (peat), Midelney (clay), and Dreghorn (sand) soil under all investigated temperatures and concentrations. The desorption study was carried out to determine the extent of reversibility of the adsorption process for all the adsorbents under the same conditions of temperatures and concentrations. The results of the assessment indicated that desorption, in general, was more at higher temperature for all the studied adsorbents. However, for charcoal, adsorption was irreversible except at zero time at higher concentrations. For Downholland (peat), Midelney (clay) and tree bark, there was zero desorption at lower concentration levels.

This thesis addressed a central theme in evolutionary biology, namely understanding the process of adaptive radiation, using the three-spined stickleback, which has become a model system in this context. In particular, the work concentrated on sticklebacks from several unique populations in the Outer Hebrides that have lost the body armour after which this species was named, lacking dorsal spines, pelvic girdle and spines and lateral plates. A first specific aim was to examine an existing hypothesis about the selective force responsible for armour loss in these populations, namely that it is an adaptive response to low calcium levels. This is in contrast to the selective force favouring armour loss in North American populations, where predation by piscivorous fish is thought to favour armour development and predation by invertebrates to favour armour loss. This was studied by relating variability in protective body armour to calcium concentration at 10 sites with calcium concentrations ranging from 1.2mgCA2+/L to 50.5mgCa2+/L and spread over a wide geographical range. The results confirmed previous studies, providing partial support for the low-calcium hypothesis for Hebridean populations. Thus armour reduction is only found in sticklebacks from low-calcium sites, although not all fish from such sites are unarmoured. Piscine, avian and invertebrate predators were present at all sites, ruling out the predation regime hypothesis. A second aim was to relate variability in risk-taking to variable armour expression, both within and between populations of stickleback. 180 wild-caught fish from 7 sites across Scotland (but mainly concentrated in the Hebrides) were screened for risk-taking behaviour using a well-established testing protocol (quantifying rates of exploration of and movement in a novel and potentially dangerous environment) that is broadly predictive of some aspects of the sticklebacks’ response to a predator. No significant relationship was found between individual risk-taking score and the extent of body armour, either across populations or among individuals within populations. The risk-taking test (chosen because it is simple and easily controlled) only reflects one aspect of anti-predator behaviour and may have been too focused to identity subtle and individual differences in risk-taking.

A series of terraces flanking the Lower Orange River in the study area were deposited after ca. 90% of the incision had occurred, thus only the late stage incision/depositional history of this margin is able to be addressed here. Two principal suites of river terraces are distinguished by their palaeo-courses, bedrock strath levels, overall geometry and clast assemblages: an older, higher lying Proto suite and a younger Meso suite. The Proto suite represents a long, post-Eocene, through the Oligocene into the Early Miocene, phase of incision, followed by a prolonged period of aggradation where up to 90 m of fluvial, diamondiferous deposits accumulated during the Early-Middle Miocene. The Meso suite of deposits represents shorter phrases of incision and aggradation in the Pilo-Pleistocene. The Proto and Meso deposits were built in response to both base level rise and increased supply of material from tributaries draining the Great Escarpment locally, with clast assemblage and downstream fining data indicating the latter to be the more important variable. River incision into bedrock is a topic of great interest to fluvial geomorphologists, although most data are derived from active tectonic settings. The incision of a large river into a plateau surface is relatively rare, the best known example being the Colorado River in the young (6 Ma) Grand Canyon. The Orange River in the study area represents a long-lived example of this setting, with the present day dissected topography having evolved from more confined canyon-like walls following the early incision of the Orange River in the Early Tertiary. Although a long-lived incision, the modern channel is not graded in the study area, and is actively incising. The world-wide dataset of incision rates in modern rivers indicates that the Orange River could have completed its entire incision within less than a million years. The continued downcutting of this river so long after the initial incision event is indicative of the roles of intermittent, ongoing epeirogenesis and/or eustatic influences (both of which cannot be proven at this stage), tributary input from the plateau rim (Great Escarpment) or merely the long tag time involved in landscape adjustment following incision into a plateau surface.

Study of a former industrial land, which was contaminated with chromium, was the major research topic of this study. A survey study of the land was made to evaluate the pH, electrical conductivity ;and percentage of organic matter of soils, available nutrients, total nutrients, available and total chromium and total other heavy metals in the soils. The survey also includes the total nutrients, total chromium and some other heavy metals in the plants and root mat. Soils throughout the site had high total chromium concentrations, high pHs and low plant available nitrogen and low vegetation yields. However, chromium was not detected in the plants. The effects of fertilizer additions were evaluated in two pot experiment studies of these soils using ryegrass as a test crop. The first pot experiment was carried out to look at the response of the soil samples to different combinations of N, P and K fertilizers to determine which fertilizer is limiting the plant growth. The response was measured by dry matter production. Nitrogen was shown to be the limiting factor for growth of the grass in these soils. Alleviating the limiting factor resulted in a yield increase. Since the trend of this increase can not be fully applied to all types of soils and spoils due to differences in nature of the material a second pot experiment was carried out to look at the response of the vegetation to addition of the different rates of nitrogen fertilizer. The results showed that the application of 100 /50 /50 of N/P/K kg/ha fertilizer could obtain the maximum yield for the site except for a soil sample from the base of the east side (sample 4) which did not respond to more than 50 of N kg/ha. Since the changes in the yields from these experiments were not affected by soil extractable chromium in the two experiments the possibility of the direct effect of chromium on plant growth was discounted. The occurrence of the nitrogen turnover and possible toxicity effects of chromium on these processes was assessed during a number of incubation studies. First of all the nitrogen supply power of the soils was evaluated using an incubation test for the nitrogen mineralization rate of the soils from this site. This experiment was done under aerobic conditions. An attempt was also made to look at possible volatization of ammonia due to the pH of these soils.

The effectiveness of using amendments in metal stabilization was determined, and their potential for remediation of contaminated soil was evaluated. A combined approach of evaluating soil and plant metal availability as well as microbial respiration was used as an indication of effectiveness of metal immobilization. This was done by sorption studies, incubation experiments in contaminated media, and greenhouse pot experiments. Batch sorption studies were conducted to evaluate the ability of bone meal, composts, peat, coir and wood bark to sorb Pb, Cu and Zn. Single sorption carried out over a metal concentration range of 0.1 mmol 1-1 using 0.001M and 0.1M Ca(NO3)2 as background electrolytes showed very high sorption of Pb, Cu and Zn by the amendments, but high background salt led to a reduction in the amount of metal sorbed by all amendments. Of the amendments tested, coir, compost and wood bark were most effective. Sorption was evaluated by applying the Langmuir equation, and maximum sorption values were calculated for all amendments. Theoretical maximum sorption of Pb was 87 mg g-1 (0.42 mmol g-1) by coir and green waste compost; Cu was 30 mg g-1 (0.47 mmol g-1) by green waste and general compost, while maximum Zn sorption was 14 mg g-1 (0.21 mmol g-1) in composts, closely followed by 13 mg g-1 (0.19 mmol g-1) in coir. Sorption mixed metal solutions of Pb, Cu and Zn was evaluated in a background salt of 0.001M Ca(NO3)2 only, either at equimolar concentrations of 0.1 mmol 1-1, equimolar concentrations of 1 mmol 1-1, or combinations of metals at either concentration. Metal sorption was reduced in the presence of other metals when compared with sorption in single metal solution. Pb sorption in equimolar solution of 0.1 mmol 1-1 was approximately 50% of that in single solution, Cu was 35%, while Zn was 40% if wood bark was not considered (wood bark sorption of Zn in low equimolar metal was not different from that in single Zn solution). The effect of metals on microbial respiration was evaluated in metal spiked amendments over a ten week period using metal solutions of Pb, Cu and Zn as contaminants. Pb, Cu and Zn toxicity led to an inhibition in CO2 evolved in all amendments, as addition of any amount of Pb, Cu or Zn led to a decrease I amount of CO2 evolved when compared with the non-contaminated amendments. The effect of increasing metal toxicity on CO2 evolution was reflected best in coir, where inhibition increased with an increase I metal concentration. In other contaminated amendments however, the inhibition was highly pronounced once there was metal contamination regardless of the metal concentration.