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This thesis seeks to develop an integrated shoreline management plan (ISMP) to address problems of "ad hoc" defences, shoreline retreat and the impacts of rising sea-level on Ghana's coast. Coastal management strategies in Ghana, past and existing, have largely focused upon provision of hard protection at specific "high risk" locations. There has been little commitment to the concepts of integration of management interventions with wider natural processes and long-term sustainability. In most cases, such 'ad hoc' management interventions classically tend to stabilise the shoreline at the protected section and aggravate the situation elsewhere along the shoreline (knock-on effects). Such problems 3 occurred previously on many other developed coastlines and have consequently resulted in development and application of more holistic and potentially sustainable shoreline management methods in recent decades.

Geochemical analyses of Holocene coastal sediments from eastern England were made to better understand the cycling of organic carbon and nutrients in the coastal zone in the past, present and future. Sediments and peat were deposited in freshwater marshes, saltmarshes and intertidal mud- and sand-flat environments that were much more extensive during the Holocene than they are at present. The reduction in these areas, largely through human activities, has decreased the potential annual accumulation and storage of organic carbon, nitrogen and phosphorus associated with sediments. While the carbon and nitrogen contents of modem intertidal environments are similar to Holocene intertidal areas, phosphorus is enriched in modem sediments by up to a factor of two. Budgets of nitrogen and phosphorus cycling in Fenland, eastern England, suggest that the Holocene estuaries in this area were sinks of nutrients from the North Sea despite nitrogen isotopic evidence suggesting that nitrogen buried in freshwater marshes was predominantly terrestrially derived. The present-day estuaries are sources of nutrients to the North Sea as riverine loads and atmospheric deposition are much higher than during the Holocene and sedimentation is also greatly reduced. The southern North Sea is probably autotrophic, in contrast to the coastal zone global average which is heterotrophic. The major differences between these two areas are: 1) the global coastal zone receives much greater loads of riverine particulate matter than the southern North Sea, and 2) sedimentation in the global coastal zone occurs in large river deltas which are absent from the relatively small European estuaries, thus much of the sediment supplied to the North Sea is exported to the shelf edge. Approximately 4x 109 t C, 0.3 x 109 tN and 0.1 x 109 tP are currently stored in fine-grained Holocene sediments in the southern North Sea coastal zone.

Chalk forms many hundreds of kilometers of European coastal cliffs particularly in the UK, France and Denmark. This thesis is an outcome of the PROTECT (PRediction Of The Erosion of Cliffed Terrains) Project, a European 56' Framework funded programme undertaken by the University of Brighton, BGS (British Geological Survey), BRGM (Bureau de Recherche Geologiques et Miniirres) and GEUS (Geological Survey of Denmark and Greenland) to study coastal chalk cliff instability in the UK, France and Denmark. Chalk coastal cliffs of north-west Europe are continually subjected to changes in stress caused by internal and external factors. This leads to fresh geological properties, features and materials becoming an active part of the cliff instability regime. The methods, types, volumes and mechanisms of collapses have been investigated, characterised and found to be dependent on the chalk formation, rock mass properties cliff face orientation and cliff height. This knowledge has been used to investigate the possibility of providing better ways of predicting when, where and how cliff instability will occur. To better understand the mechanisms involved in cliff instability and help predict imminent failure research sites were selected in England, France and Denmark in areas where geological investigation was possible and the experimental methods of instrumentation could be undertaken and analysed to provide the most useful data. The research programme set out to investigate: (i) the temporal aspects of movements in the cliffs leading to collapse (ii) the failure mechanisms. This required integrating the detailed engineering geology with the results from the geophysical techniques and the rock mechanics testing (iii) An additional part of the investigation was interpreting the evolution of the landscapes and how this contributes to cliff instability. The principal factors identified here as contributing to cliff collapse are: (i) the influence of the fracture network (ii) the material properties (iii) different types of failure (iv) long term relaxation of fractures in the top 20-25m of the chalk causing this section to be more predisposed to weathering and instability, than the lower part of the cliff (v) the range of chalk strengths and a salt water weakening effect identified. The results indicate that each of the techniques studied (geological/geotechnical fieldwork, geophysical investigation, site instrumentation, topographical survey, cliff stability analysis, laboratory testing and numerical modelling) is suited to a particular type of geology, but not to all the geological situations investigated, and best result and interpretation are obtained when all the data available is combined in a holistic model. Hence, the detailed engineering geology is an essential prerequisite to the interpretation of results and the application of the techniques. Geological study through out north-west Europe indicates the transferability of these results to any chalk section so long as the detailed geology is understood. The research has proved capable of predicting a cliff collapse prior to the event occurring.

The geomorphology of tropical island beaches has received little attention in literature compared to their temperate equivalents. This is particularly true of studies of the spatial and temporal variability of carbonate beaches. The British Virgin Islands (BVI), a small archipelago located in the north-eastern Caribbean contains numerous beaches in a wide variety of settings within a small geographical area. Over 100 beaches across 60+ high volcanic and reef islands were selected for study. Through the analysis of benthic habitat maps, aerial photographs, sedimentary characteristics, and ground-truthing, beach distribution and form are interpreted in terms of their geologic, oceanographic and ecologic setting. The Atlantic-facing beaches exhibit modally high energy waves which drive carbonate-rich sediment onshore from extensive reef systems and a carbonate bank. In contrast, Caribbean-facing beaches, primarily those of coral rubble, are dominated by modally low energy waves punctuated by very high energy events (i.e. hurricanes) and contain a lower proportion of fine-grained carbonate sands. While some of these high energy events have significant short-term impact, many beaches exhibit long-term stability. There has, however, been a general narrowing of beaches over the past 50 years which is tentatively attributed to sand mining in the past. In contrast to the high volcanic islands, Anegada is an emergent reef island comprising a lithified Pleistocene reef core and a sequence of Holocene deposits (beach ridges, lagoons, and mangroves). The form and distribution of the island's contemporary sedimentary environment reveal four distinctive coastlines. Three of these coastlines have shown relative stability over the past 149 years while one coastline has morphologically adjusted to surrounding environmental conditions by rotating in a counter clockwise motion. All the beaches are subject to a variety of human impacts and require a formal coastal management response, however, this has not yet been realised. Despite an existing statutory framework for beach management, environmental degradation from uncontrolled coastal development and space-use conflicts caused by unmanaged mass tourism continues. A current case study reveals the management plan requires implementation via a co-management regime between the local beach community and stakeholders with support from the local government. A simple framework is presented that provides thirteen environmental, socio-cultural, economic and governance goals which define the context in which the management plan operates. This framework ensures not only a clear understanding of what constitutes sustainable beach management, but also sustainable development specifically within the BVI.

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This investigation focuses on the prediction of sediment transport and beach evolution in coarse-grained beaches. This includes observed morphological changes on both gravel and mixed beaches from experimental investigations at the Large Wave Flume (GWK) in Hanover. Germany. The recorded measurements show that the majority of morphology change took place adjacent to the zone of wave-breaking, close to the shoreline in both cases. Based on these observations, the discussions are carried out with psirticular regard to the observed tendency for onshore transport axid profile steepening in the swash zone. The aim is to identify the cross-shore hydrodynamics and sediment transport mechanisms involved, to advance understanding of this type of beach and to improve our qucintitative capabilities for predicting shoreline and morphological changes in this zone. With this in mind, this thesis includes a discussion of the physical processes related to swash hydrodynamics and sediment transport. It also introduces the description of the mathematical framework used to study wave hydrodynamics in the swash zone. Emphasis is given to the Boussinesq equations which have been found to be a suitable approach. For these equations an evaluation of the two available shoreline boundary conditions is carried out and it is shown that the moving shoreline accurately reproduces the velocity field in the swash zone. The profile evolution investigation is carried out evaluating the transport rates from a bed-load sediment transport formulation coupled with velocities calculated from a set of Boussinesq equations (Lynett et al 2002). Then the equation for conservation of sediment is solved to estimate the morphological changes as proposed by (Rakha et al 1997). It is shown that such an approach is useful to investigate the processes that control this evolution. A discussion on the influence of bottom friction on the predicted profiles is presented. Numerical results in both beaches show that the use of a higher friction factor f during uprush improves the simulations of morphological changes. However, the variation of friction by itself was not able to reproduce the measured profiles. A plausible reason to explain this is that further mechanisms other than friction play an important role in the overall response of coarsegrained beaches. For both beaches it is established that, if the efficiency factor (C) in the sediment transport equation and bottom friction are kept the same in the uprush and backwash, accurate representation of profile evolution is not possible. Indeed, the features of the predicted profiles are reversed. When the C parsimeter is set larger during the uprush than during the backwash, the predicted profiles are closer to the observations. Differences between the predicted profiles from setting non-identical C-values and friction factors for the swash phase, are believed to be linked to both the infiltration effects on the flow above the beachface, the bore collapse picking up sediment from the bed, and the accelerated flow in the uprush. The discussion is made with reference to main physical processes acting over the beachface for both the mixed and gravel beach.

Positive interactions are increasingly recognised to be important as community structure processes. Bertness and Callaway's model predicts positive interactions to be important under high consumer pressure or high environmental stress. Associational defences between organisms, when palatable algae take advantage of living with less palatable ones, will be the dominant structuring forces under high consumer pressure and low physical stress. Habitat ameliorations become more important under harsh physical conditions and low consumer pressure. This model was tested at Wembury Bay, Devon, Southwest England, using rockpools and emergent rock habitats distributed over the vertical height of the shore to generate gradients of environmental stress. Relationships between rockpool physico-chemical parameters and assemblage composition were investigated across the shore. Highest rockpool communities on the shore experienced the harshest environmental stress. Consumer pressure measured in rockpools was twice that recorded on emergent rock owing to high tide limpet movements from the surroundings into the pool rather than herbivore densities. Over these gradients, experimental plots were maintained at natural and reduced grazer density to control consumer pressure. Species interactions during succession were examined. Experimental plots distributed at three shore heights (high, mid, low) were scraped in both habitats to initiate succession and were then sampled regularly over a 2 year period. Species susceptibility to grazing drove different trajectories of succession under high and low consumer pressure suggesting that palatability influences species interactions. Physical stress affected species recruitment and development of the successional sequence in both habitats and over the intertidal gradient. Selective removal of early ephemeral and later perennial colonising algal species provided some evidence of positive interactions under both elevated levels of physical stress and high consumer pressure. These results are discussed in the context of the Bertness and Callaway model with which they are consistent and other models of succession.