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With the Scottish Government's commitment to sourcing 100% of the national electricity demand from renewable sources by 2020, within the global framework of climate change mitigation, the potential of the marine environment around the Highlands and Islands Region of Scotland to add to Scotland's renewables portfolio has led to the expansion of the wave and tidal industries in recent years. Nevertheless, to date, there has been limited research conducted on the social systems around marine renewable energy development, excluding offshore wind. In answer to this deficit, this study explores a well-established concept within the academic arenas of business, health, and rural development, among others, of agents for change (AFCs), within the context of the rapidly emerging wave energy sector. Two case studies, Lewis in the Outer Hebrides, and Orkney, were chosen based on their localities and the interest that they have garnered from wave energy developers due to their high energy marine environments. A grounded approach was taken to data collection and a social power analysis was conducted in order to find AFCs working within or closely with the wave energy industry that were not part of structured or hierarchical organisations. One emergent theme was that there was a noteworthy barrier to wave energy development in the case studies and to the work that the agents for change were doing in the form of a complex dynamic between financial investments in the sector, national grid, national energy policy, and the technology itself. The agents for change were found to act as catalysts for the wave energy industry through their perseverance and visionary approach to development. The motivations of the AFCs is discussed and the shifting roles that they took as a project progresses is described and compared to other change process models, namely Lewin (1958) and Kotter (1995).

Carbon Capture and Storage is a nascent technology developed with the intention of collecting carbon dioxide emissions from the flue gasses of point source producers, such as power stations or cement works. The carbon dioxide is then stored in underground geological reservoirs so that it does not reach the atmosphere, reducing the rate at which greenhouse gasses accumulate and influence climate change. However, as with all nascent technologies, the benefits of these developments and concepts must be weighed against the risks of serious and long-term environmental impact should an accidental release occur. The aim of this thesis is to study the potential for environmental damage caused by a release of carbon dioxide into the marine environment from a sub-seabed carbon dioxide reservoir generated through carbon capture and storage development. The quantification of the rate of change caused by such an accidental release of carbon dioxide will be studied, as will the rate at which natural conditions are re-established upon cessation of the release.

Sourcing energy from renewable sources is currently a key theme in modern society. Consequently, the pace of development of these emerging technologies is likely to increase in the near future, particularly in marine renewables. However, the environmental and ecological impact of many of these new developments in the marine environment is largely unknown. My thesis has focused on one unknown area of interaction; the potential effect of tidal-stream devices on marine mammals. Collision risk is often cited as a key concern. Therefore, my premise was - for marine mammals to avoid a collision with a marine renewable device (assuming they are on a collision course) they must first detect the device. It is well understood that marine mammals use sound and hearing as their primary sense for communication, foraging, navigation and predator avoidance, so it is highly likely that the primary cue for device detection will be acoustic. However, it is not known how operational marine renewable devices might modify the acoustic landscape in these areas, or whether they will be audible to marine mammals in time to alert them to the presence of devices. It has been suggested that the high level of natural and anthropogenic background noise in tidal-stream areas may mask (drown out) the signal of the tidal devices. The acoustic characteristics of underwater noise in shallow coastal waters are currently not well known. My thesis adds data to this knowledge gap by measuring and mapping underwater noise levels in tidal-stream areas.

The Nordic Seas region marks a transitional zone between the temperate North Atlantic Ocean and the polar Arctic Ocean. The influence of contrasting fluxes of organic matter on benthic community structure and function within the deep waters of the region were investigated. Samples of the macrofaunal community were collated throughout the region employing a standardised method. In the summer of 2002, during the RRS James Clark Ross 75 cruise, replicated samples were obtained with the SMBA multiple corer and the USNEL boxcorer from four stations located at similar sampling depths along a latitudinal transect at the Norwegian Sea continental margin. Additional replicated samples were obtained with a megacorer at six stations located along two bathymetric transects across the Norwegian Sea continental margin in the summer of 2005 during the RRS James Clark Ross 127 cruise. Contrasting fluxes of organic matter influenced benthic community structure, functional ecology and bioturbation potential. Species known to adopt the feeding strategy of the sub-surface storage of organic matter occurred in areas characterised by a seasonal input of organic matter. Species richness and diversity was highest at the Svalbard Margin, located within the marginal ice zone. Bathymetric patterns of macrofaunal biomass were comparable with previously reported global patterns. However, bathymetric patterns of macrofaunal abundance were higher than global patterns. The previously reported rapid subduction of organic matter by the sipunculan Nephasoma sp. and associated deep burrow networks on the Voring Plateau was linked to the species Nephasoma lilljeborgi. It is proposed that N. lilljeborgi is an ecosystem engineer.

The Arctic region is a seemingly pristine, remote environment, yet in the past few decades there has been increasing evidence that it is greatly impacted by anthropogenic metal contamination. The heavy metals are attributed to adverse effects on the health of biota and indigenous populations, due to their toxicity and bioaccumulative tendencies within the environment. There are three main metal contaminants of major concern, lead (Pb). mercury (Hg) and cadmium (Cd). They have all been reported as ubiquitous anthropogenic pollutants with elevated concentrations identified throughout the Arctic's sedimentary environment. The aim of this research was to investigate further heavy metal contamination, specifically within the sediments of the Svalbard region, and the Barents Sea area, within the Arctic. Ten sediment cores were taken for analysis from three main fieldwork excursions. The cores were taken from three different environments; lacustrine, fjordic and marine. A comparison between these core sites allowed the identification of the major transport pathways within this region and the relative importance of atmospheric and oceanic transport. Three cores were taken from the inner Kongsfjorden area, four cores from the Barents Sea, with three further cores taken from the Vøring Plateau and the area south of Svalbard. Each core was analysed to ascertain metal concentrations and to reconstruct the temporal contaminant history of the area. The source of the contaminant can be determined through the use of stable isotope analysis. The isotopic ratio provides a 'signature': ultimately reflecting the source of the Pb, and this tool can also be used to verify the transport pathways of the anthropogenic Pb contamination. The 206Pb/207Pb isotopic ratio of western sources of anthropogenic Pb has a value of approximately 1.14, with Eastern Europe and Eurasian sources represented by a higher value of 1.18. Two cores taken from the Barents Sea (BASICC 1 and BASICC 40), along with cores taken from a freshwater lake (ICOS1), an anoxic lagoon (ICNL1), and the Vøring plateau (VP2a), show a clear increase in Pb concentration in modern sediments, corresponding with a decrease in the 206Pb/207Pb isotope ratio. This pattern signifies a change in the source of the Pb over time, associated with anthropogenic contamination: the results providing evidence of the long range distribution of contaminant Pb following the industrial revolution and the utilisation of alkyl Pb in petrol. Lake Ossian (ICOS1), a site situated close to Ny Ålesund provides unequivocal evidence for the atmospheric transport of Pb. The excess 206Pb/207Pb ratio was calculated as 1.165, indicative of an Eastern European emission source. The most compelling story, however, emerges from the contaminant archives contained in the marine sediment cores within the Barents Sea area, and from the Vøring Plateau. These sediment cores provide vital evidence that contaminant Pb is transported by oceanic currents to the Arctic environment. There is only one other study that has concentrated on the specific oceanic transport of Pb. This thesis further supports the hypothesis that the Atlantic water current is a prominent pathway for the transportation of Pb to the Eurasian Arctic Basin, with the Pb being scavenged to the underlying sediments en-route. From the area around Kongsfjorden, north-west Svalbard, four sediments cores were taken along a longitudinal transect, from freshwater to the marine environment, and analysed for Hg. None of the four sediment cores displayed evidence of significant anthropogenic contamination. Sediment from Brandallaguna (ICNL1) showed a small increase in Hg concentration towards the surface of the core. Diagenetic processes, however, cannot be disregarded, with Hg forming HgS in anoxic conditions. It is evident in the literature and from this study that further research is required to improve the understanding of the complex Hg biogeochemical cycle. For the contaminant Cd, there has been unequivocal evidence from snow and ice records, indicating an increase in Cd flux from the mid 18th century to the mid 19th century, associated with anthropogenic influence. None of the cores within this study show this temporal change in flux. Elevated concentrations of Cd, however, have been shown in the deep parts of two of the cores taken from the Barents Sea (BASICC 40 and BASICC 43), the Cd being precipitated as authigenic CdS in anoxic sediment. This research supports the hypothesis that the dissolution and remobilisation of Cd can make sediments a poor record of Cd temporal history.

Salmon farming is a major industry in many Scottish sea lochs. Although the impact of salmon farming and pathways of several farm wastes have been studied extensively, there has been little research into the fate of metals originating from fish farms. This thesis investigates the influence of salmon farming on sediment biogeochemical conditions, with particular reference to the cycling, interactions, and effects of metals in farm sediments of Scottish sea lochs. Scottish sea lochs are fjordic systems, and have a defined set of physical processes occurring within them that depend on topographical characteristics of the sea loch and the influence of external forces. The most common definition of a fjord, also know as a sea loch, is “a deep, high-latitude estuary which has been (or is presently being) excavated or modified by landbased ice” (Syvitski et al. 1987). The established opinion of their origin is that fluvial action along fault lines allowed subsequent glaciers to follow this path of least resistance, leading to major excavation (Skei et al. 2003). Fjords are found in all northern and southern regions of the earth that were once ice-covered, but this review will focus on the sea loch (fjordic) systems of western Scotland.