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This study is an examination of the late-Quaternary palaeoenvironments of the Eastbourne area, The principal techniques employed are pollen, Foraminifera, Ostracoda, Mollusca and sediment particle size analyses. The lithostratigraphic investigation, using hand auger and a commercial drilling rig, revealed extensive unconsolidated sediments down to a maximum depth of 33m. which consist of gravels, sand, silt and clay with restricted peat development. The history of the vegetation has been traced back to the Lateglacial when, it is argued, an unusually thermophilous community which included Alfids prospered. The early Flandrian vegetation was dominated by Corylus and Pinus the latter genus being replaced by members of the 'Mixed-Oak Forest' before 8,770 plus or minus 50 B.P. Prior to this date, Juniperus expanded. The nature of the mid-Flandrian vegetation is unclear due to the presence of secondary pollen. However, this secondary pollen has been used to provide information on the nature of sedimentation on Willingdon Levels. In addition, a model of pollen transfer in estuarine sediments is proposed. Poor pollen preservation has allowed an examination of pollen deterioration and its possible use for palaeoenvironmental reconstruction to be attempted. The late-Flandrian vegetation reveals the impact of both anthropogenic factors and coastal changes. The pattern of Flandrian coastal/sea-level change has been reconstructed through an examination of transgressive and regressive contacts and overlaps and their associated biostratigraphies. In addition to two contacts, three phases of positive dominant tendency and two phases of negative dominant tendency of relative sea-level movement are recognised. It is argued that the coastal sediments at Eastbourne are probably the result of the growth and over-running of depositional features superimposed upon the main Flandrian rise in sea-level, rather than reflecting eustatic oscillations. The pattern of sedimentation and the vegetation successions are placed within a regional context, and then combined to produce a model of landscape evolution for the late-Quaternary at Eastbourne.

Parrotfish are a diverse and ubiquitous group found on coral reefs worldwide. They are categorised into three main feeding modes; the browsers, scrapers and excavators, which together perform a number of important functional roles on coral reefs. Scraper and excavator parrotfish are common on most Indo-Pacific coral reefs where their roles in bioerosion, sediment production, grazing pressure and sediment reworking have been shown to influence benthic community composition, reef growth potential and sediment supply to reef habitats and reef associated sedimentary landforms. However, despite the widely known importance of parrotfish on coral reefs, our understanding of how their roles in carbonate cycling vary among species and among whole parrotfish communities in different reef habitats remains limited. This thesis produces original contributions to knowledge in the areas of species specific bioerosion estimates for the central Indian Ocean, bottom-up controls of habitat type on parrotfish assemblages and how variations in parrotfish assemblages translate to contributions to carbonate cycling processes among different reef habitats. The study was carried out across eight habitats on an atoll-edge reef platform in the central Maldives, where it was found that parrotfish community composition was driven by reef structural complexity and substrate type. Parrotfish occurred in six of the eight habitats, comprising ~44% of the platform area. Among these habitats, overall grazing pressure, bioerosion rates, sediment reworking and sediment production varied markedly. These processes were also found to have different spatial patterns over the reef platform, showing that they are not necessarily tightly coupled. In addition, reef habitats can vary in their importance for both sediment supply, and the relative importance of reworked sediment. Parrotfish produced a wide range of sediment size fractions, from < 32 to 2000 μm and produced predominantly coral sands (>80%) between 125 and 1000 μm in diameter. This is comparable to the grain types found on local reef islands, and it is likely that the most significant supply of this material is from habitats on the atoll-edge side of the platform (which make up ~20% of the total platform area). Quantifying parrotfish functional roles and understanding the drivers behind these processes is important for informing future empirical and modelling studies, particularly as coral reefs undergo a time of dramatic environmental change.

Climate change is one of the greatest threats to marine environments globally. Fisheries are being increasingly affected, with impacts not only to fish stocks but also the fishers who rely on marine resources for their livelihoods. This thesis uses an interdisciplinary, mixed methods approach to examine climate change impacts on fisheries within the under-studied, yet rapidly warming, south-west region of the UK. The thesis begins with a comprehensive review of the literature regarding climate change impacts on UK fisheries, the vulnerability of these fishery systems to future climate change and how climate change is perceived among fishers. In Chapter 2 a methodology is developed to standardise abundance data across multiple scientific fisheries survey datasets in order to facilitate future projections to be generated for the south-west UK region. Chapter 3 presents future projections of abundances and distributions for eight key commercial fish species under future warming scenarios until the end of the century. Results suggest that increasing temperatures and limitations of bathymetry are key drivers of species responses. Certain cold-water species including Atlantic cod (Gadus morhua L.) and anglerfish (Lophius piscatorius L.) will experience declines, while warm-water species such as red mullet (Mullus surmuletus L.) and John dory (Zeus faber L.) are expected to expand across the region. The uncertainty associated with future projections is explored through the use of 11 separate climate-ensembles. Chapter 4 uses information gained through interviews with fishers from a UK fishing port—Brixham—to explore how climate change is perceived and the factors influencing these perceptions. Findings suggest that while fishers generally felt that climate change posed a low risk to the future of their businesses and fisheries in the region, three groups emerged that showed differences in the extent to which they perceived climate change as a risk. A number of key factors were important in influencing these three groups. Chapter 5 develops further insight into fishers’ perceptions by exploring how fishers anticipate climate change to affect the physical environment, fishery resources, and their own practices in the future. Many fishers felt they would not need to alter their fishing practices in the future, with various reasons cited including personal preferences and perceived constraints to their adaptation. Fishers’ ability to adapt was further explored and three main groups were identified who differed according to a number of core dimensions of their adaptive capacity. Through adopting an interdisciplinary approach, the research in this thesis presents a number of new findings that have important implications for fisheries management and climate adaptation policies.

Understanding the impact of warming on organisms, communities and ecosystems is a central problem in ecology. Although species responses to warming are well documented, our ability to scale up to predict community and ecosystem properties is limited. Improving understanding of the mechanisms that link patterns and processes over multiple levels of organisation and across spatial and temporal scales promises to enhance our ability to predict whether the biosphere will exacerbate, or mitigate, climate warming. In this thesis, I combine ideas from metabolic theory with a variety of experimental approaches to further our understanding of how warming will impact photosynthesis and respiration across scales. Firstly, I show how phytoplankton can rapidly evolve increased thermal tolerance by downregulating rates of respiration more than photosynthesis. This increased carbon-use efficiency meant that evolved populations allocated more fixed carbon to growth. I then explore how constraints on individual physiology and community size structure influence phytoplankton community metabolism. Using metabolic theory, I link community primary production and respiration to the size- and temperature- dependence of individual physiology and the distribution of abundance and body size. Finally, I show that selection on photosynthetic traits within and across taxa dampens the effects of temperature on ecosystem-level gross primary production in a set of geothermal streams. Across the thermal-gradient, autotrophs from cold streams had higher photosynthetic rates than autotrophs from warm streams. At the ecosystem-level, the temperature-dependence of gross primary productivity was similar to that of organism-level photosynthesis. However, this was due to covariance between biomass and stream temperature; after accounting for the effects of biomass, gross primary productivity was independent of temperature. Collectively, this work emphasises the importance of ecological, evolutionary and physiological mechanisms that shape how metabolism responds to warming over multiple levels of organisation. Incorporating both the direct and indirect effects of warming on metabolism into predictions of the biosphere to climate futures should be considered a priority.