An ecological perspective on the deployment and design of low-crested and other hard coastal defence structures

Coastal areas play a crucial role in the economical, social and political development of most countries; they support diverse and productive coastal ecosystems that provide valuable goods and services. Globally flooding and coastal erosion represent serious threats along many coastlines, and will become more serious as a consequence of human-induced changes and accelerated sea-level rise. Over the past century, hard coastal defence structures have become ubiquitous features of coastal landscapes as a response to these threats. The proliferation of defence works can affect over half of the shoreline in some regions and results in dramatic changes to the coastal environment. Surprisingly little attention has been paid to the ecological consequences of coastal defence. Results from the DELOS (Environmental Design of Low Crested Coastal Defence Structures, EVK3-CT-2000-00041) project indicate that the construction of coastal defence structures will affect coastal ecosystems. The consequences can be seen on a local scale, as disruption of surrounding soft-bottom environments and introduction of new artificial hard-bottom habitats, with consequent changes to the native assemblages of the areas. Proliferation of coastal defence structures can also have critical impacts on regional species diversity, removing isolating barriers, favouring the spread of non-native species and increasing habitat heterogeneity. Knowledge of the environmental context in which coastal defence structures are placed is fundamental to an effective management of these structures as, while there are some general consequences of such construction, many effects are site specific. Advice is provided to meet specific management goals, which include mitigating specific impacts on the environment, such as minimising changes to surrounding sediments, spread of exotic species or growth of nuisance species, and/or enhancing specific natural resources, for example enhancing fish recruitment or promoting diverse assemblages for eco-tourism. The DELOS project points out that the downstream effects of defence structures on coastal processes and regional-scale impacts on biodiversity necessitate planning and management at a regional (large coastline) scale. To effectively understand and manage coastal defences, environmental management goals must be clearly stated and incorporated into the planning, construction, and monitoring stages.     

Lessons learned from Eastern Africa: the development of policy on ICZM at national and regional levels

Coastal zones of Eastern Africa are endowed with a diversity of life forms and resources which support large populations of coastal communities. The economies of the countries in the region are dependent on these resources in the form of fisheries and coastal forest products, tourism, shipways and coastal facilities such as ports, industries and urban centers.Population growth, especially in coastal urban centers is increasing the demand for coastal and marine resources. In addition, poverty, lack of awareness and inadequate management have resulted in over exploitation of coastal and marine resources, habitat destruction including shoreline erosion as well as marine pollution. The rate of resource depletion and environmental degradation is on the increase. There is an urgent need for instituting management measure that will reverse the current trend.The governments in the region have accepted and are committed to the implementation of Integrated coastal management (ICZM) as an effective mechanism for addressing and resolving the multiplicity of issues experienced in coastal areas through sectoral coordination and collaborative approaches. However, the process has just begun and there are a number of ICZM initiatives in progress at local, national and regional levels. This paper presents the issues of the coastal zone and reviews some of the progress made to date in the implementation of ICZM.     

Public perception of managed realignment: Brancaster West Marsh,North Norfolk,UK

In an attempt to provide more sustainable and environmentally acceptable coastal defence options, engineers and policy-makers alike are increasingly turning to ‘softer’ approaches such as managed realignment. However, gaining public acceptance of managed realignment schemes can be challenging given that the local communities often view managed realignment as ‘giving in’ to the sea (Coastal defences: processes, problems and solutions. UK, Routledge, 2001). By studying public perceptions, engineers, planners and policy-makers will have a better understanding of the public's reactions, concerns and issues of managed realignment, which not only fills the existing research gap but also promotes public awareness and knowledge alongside the consultation process. This paper reviews findings from a pilot study conducted at a public exhibition and meeting in Brancaster, North Norfolk. Questionnaire surveys were used to collect the data and address three main research objectives (1) to gain an insight into the locals’ perceptions of flooding in Brancaster; (2) to assess their awareness of the managed realignment scheme; and (3) identify the main issues that they considered to be important. The results demonstrated that many variables influence public perceptions of managed realignment, including personal experience, lack of information and media influence. The study concludes that while there is no formula to calculate which variables come into play, researching public perception towards managed realignment projects must be addressed by following a case-by-case approach.     

ICZM and coastal defence perception by beach users: Lessons from the Mediterranean coastal area

Member States of the European Union and the Mediterranean Regional Sea need to elaborate national strategies for coastal management according to ICZM principles and to undertake national stock-taking, which must consider major actors, laws and institutions influencing the management of their national coastal zone. However, different approaches to coastal management and defence and various degrees of development and implementation of national ICZM strategies can be found. The research presented in this article aims to analyze the different situations and to contribute to the further development of a common approach in terms of methodology to establish stakeholder and users participation in ICZM. An extensive survey was conducted in five pilot sites along the European Mediterranean coastal zone (Greece, Italy and France) show beach visitors’ perception of ICZM, coastal erosion and coastal defence systems, and beach visitors’ Willingness To Pay (WTP) for beach defence. The survey yielded important information for coastal and beach managers. Surprisingly, the level of awareness about generic Coastal Zone Management was found to be rather low in all regions except Riccione Southern beach, Emilia-Romagna Region. In the Languedoc-Roussillon Region, this is justified by the fact that most of the respondents were not local people or beach visitors (other than recreational day-visitors). As regards coastal erosion it appears significant that, despite the lack of awareness demonstrated overall by stakeholders in the Region of East Macedonia and Thrace, visitors respond very positively to definitions and show awareness of the erosion process in their coastal system. In conclusion, in order to raise public awareness about ICZM, erosion and coastal defence systems, it is suggested that education, training and public awareness should be promoted as well as identification of local needs for the implementation of specific demand-driven studies.     

Stakeholder priorities for multi-functional coastal defence developments and steps to effective implementation

To fulfil international conservation commitments, governments have begun to recognise the need for more proactive marine planning policies, advocating sensitive engineering design that can deliver secondary benefits above and beyond the primary purpose of developments. In response, there is growing scientific interest in novel multi-functional coastal defence structures with built-in secondary ecological and/or socio-economic benefits. To ensure research efforts are invested effectively, it is first necessary to determine what secondary benefits can potentially be built-in to engineered coastal defence structures, and further, which of these benefits would be most desirable. It is unlikely that secondary benefits are perceived in the same way across different stakeholder groups. Further, their order of priority when evaluating different options is unlikely to be consistent, since each option will present a suite of compromises and trade-offs. The aim of this study was to investigate stakeholder attitudes towards multi-functional coastal defence developments across different sector groups. A preliminary questionnaire indicated unanimous support for implementing multi-functional structures in place of traditional single-purpose ones. This preliminary survey informed the design of a Delphi-like study, which revealed a more nuanced and caveated level of support from a panel of experts and practitioners. The study also elicited a degree of consensus that the most desirable secondary benefits that could be built-in to developments would be ecological ones – prioritised over social, economic and technical benefits. This paper synthesises these findings, discusses the perceived barriers that remain, and proposes a stepwise approach to effective implementation of multi-functional coastal defence developments.     

The non-statutory approach to coastal defence in England and Wales: Coastal Defence Groups and Shoreline Management Plans

The paper examines the aims and objectives behind the development of the non-statutory shoreline management process in England and Wales. The roles played by Coastal Defence Groups and associated Shoreline Management Plans will be examined as well as their perceived benefits and shortcomings encountered by those in both policy and practice. The paper concludes that, although not panacea, there have and will continue to be significant improvements in the planning and management of coastal defence since the emergence of these groups and plans in England and Wales.     

How supportive are existing national legal regimes for multi-use marine spatial planning?—The South African case

Over the past six years international interest in multi-use marine spatial planning (MSP), as a practical process to launch integrated coastal management (ICM), exploded. This paper explores the extent to which existing national legal frameworks can support this process, focusing on the coastal marine environment. First the characteristics of an appropriate legal regime for multi-use MSP are explored by interrogating secondary data sourced from literature reviews and case studies. Key paradigms are distilled as a means of dissecting this complex process into a suite of characteristic determinants that disclose the underpinning environmental management approaches or principles. These criteria are then used to assess the compatibility of national legal regimes for multi-use MSP—in this instance the South African legal framework. Although multi-use MSP has not been explicitly adopted as a process within South Africa's broader ICM implementation, existing legislation does reveal support. The department responsible for the environment is viewed as the most appropriate agency to house the statutory mechanism for multi-use MSP at national and provincial levels, but delegating local multi-use MSP processes to local government agencies. The political will to deploy and dedicate duties and resources to effective implementation of multi-use MSP, however, remains critical. Finally, the approach adopted here is proposed as a means to assess the compatibility of other national legal regimes for multi-use MSP, although the suite of characteristic determinants may need to be reviewed from time to time, as new learning emerges from practice.     

Public perceptions and attitudes towards a forthcoming managed realignment scheme: Freiston Shore,Lincolnshire, UK

Managed realignment is viewed as a sustainable flood defence strategy by practitioners as it provides environmental and economic benefits in light of potential global climate change. However, in many cases social barriers are in existence, with public perception and attitudes towards this approach less than favourable, as there is always resistance in surrendering land to the sea. Freiston Shore managed realignment scheme is the second of three on-going studies that aim to detect the drivers surrounding public acceptance of managed realignment and confidence in the Environment Agency, the lead agency for managed realignment in the UK. This research presents the hypothesis that local residents will be more accepting of a fully established scheme (since it will have been in the public domain for longer), rather than at its inception or during its construction. Findings from the Freiston scheme showed that the majority of residents supported the managed realignment scheme at its current construction phase, although two main barriers were identified as suppressing public acceptance. These are public confidence in the Environment Agency and public understanding of coastal defence and managed realignment issues. This investigation recommends that local community engagement activities are effective means of addressing such deficiencies whilst providing the education necessary for understanding the requirements and limitations of managed realignment. However, such participation activities should be tailored for the needs of individual target audiences.     

Wave farm impact on the beach profile: A case study

If wave energy is to become a fully-fledged renewable, its environmental impacts must be fully understood. The objective of the present work is to examine the impact of a wave farm on the beach profile through a case study. The methodology is based on two coupled numerical models: a nearshore wave propagation model and a morphodynamic model, which are run in two scenarios, both with and without the wave farm. Wave data from a nearby coastal buoy are used to prescribe the boundary conditions. A positive effect on the wave climate, the cross-shore sediment transport and, consequently, the evolution of the beach profile itself due to the presence of the wave farm was found. The wave farm leads to a reduction in the erosion of the beach face. This work constitutes the first stage of the investigation of the effectiveness of a wave farm as a coastal defence measure, and the accuracy of the quantification of the erosion reduction will be enhanced in future research. In any case, the overarching picture that emerges is that wave farms, in addition to providing carbon-free energy, can be used as elements of a coastal defence scheme.     

Implementing Integrated Coastal Zone Management in a national policy vacuum: Local case studies from Ireland

Integrated Coastal Zone Management (ICZM) is widely advocated at all levels of governance as a means of delivering sustainable development in coastal areas. This paper explores the status and characteristics of various forms of ICZM at the local level given that it is at this level that most ICZM activity currently takes place. In this context, local level ICZM includes agency-led initiatives, local pilot projects and bottom-up approaches. Providing empirical evidence about the relative strengths and weaknesses of these various models for local delivery, this paper presents an overview, critique of and lessons learned from approaches in Ireland, where there is no over-arching national coastal management policy to provide any steer for management. The potential for local government involvement in these approaches is emphasised, particularly in bottom-up and local projects which foster strengthened management capacity within local government with limited resource implications. Whilst the paper highlights difficult jurisdictional issues in the Irish context, the potential for improved coastal management, through continued local government involvement in ICZM networks and local projects, as well as through the implementation of the European Integrated Maritime Policy and Marine Strategy Framework Directive, is outlined.     

厦门海岸带资源与管理战略

本文分析了厦门海岸带资源现状和管理中存在的问题。厦门海岸带管理素来以行为的基础,实施行业管理。这种管理机制已经难以解决海岸带过度开发、环境恶化、资源开发利用与保护之间的矛盾等日益严重的问题。新型的海岸带资源管理是一种较为全面的管理方法,致力于建立综合管理体制,其中考虑到各行业部门对海岸带及其资源可能造成影响的各种活动,同时综合考虑社会、经济、环境和生态等问题,从而平衡和优化经济发展、公共利用和环境     

Coastal risk adaptation: the potential role of accessible geospatial Big Data

Increasing numbers of people are living in and using coastal areas. Combined with the presence of pervasive coastal threats, such as flooding and erosion, this is having widespread impacts on coastal populations, infrastructure and ecosystems. For the right adaptive strategies to be adopted, and planning decisions to be made, rigorous evaluation of the available options is required. This evaluation hinges on the availability and use of suitable datasets. For knowledge to be derived from coastal datasets, such data needs to be combined and analysed in an effective manner. This paper reviews a wide range of literature relating to data-driven approaches to coastal risk evaluation, revealing how limitations have been imposed on many of these methods, due to restrictions in computing power and access to data. The rapidly emerging field of ‘Big Data’ can help overcome many of these hurdles. ‘Big Data’ involves powerful computer infrastructures, enabling storage, processing and real-time analysis of large volumes and varieties of data, in a fast and reliable manner. Through consideration of examples of how ‘Big Data’ technologies are being applied to fields related to coastal risk, it becomes apparent that geospatial Big Data solutions hold clear potential to improve the process of risk based decision making on the coast. ‘Big Data’ does not provide a stand-alone solution to the issues and gaps outlined in this paper, yet these technological methods hold the potential to optimise data-driven approaches, enabling robust risk profiles to be generated for coastal regions.     

A model-based approach to unravelling naval defence heritage: supply- and demand-side issues in Portsmouth's coastal zone

The paper explores the nebulous concept of heritage in order to highlight issues relevant to the revitalisation and management of historic naval waterfronts. A model separating supply and demand sides, and further subdividing each side into political, social and economic structures, is used as a framework for analysis. The whole is set within a perceptual filter, and interpretation is subsumed within social structure. The model is applied to heritage concepts at Portsmouth Dockyard and to the legacy of naval defence in the neighbouring coastal zone. From the review of all three structures it is shown that economic considerations are increasingly powerful on both the supply and demand sides, as sovereignity passes to customers who are less interested in authenticity and architectural quality than in securing value for money. Issues and implications arising from this trend, and relevant to naval heritage planning and management, are identified.     

Coastal management in Tanga, Tanzania: a decentralized community-based approach

This paper describes a new initiative in coastal management in northeastern Tanzania. The region is within the equatorial part of the Western Indian Ocean. The priority environmental issues being faced include declining fish catches, use of destructive fishing techniques, mangrove cutting and coastal erosion. There is a widespread perception among the users of the coastal resources that management of these issues is inadequate. This programme initiative is developing flexible, community-based approaches to identifying the problems and to take achievable actions. The programme provides training in a wide range of skills and appropriate technical methods for government officials, extension workers and villagers. A collaborative process is evolving that includes participatory appraisals, village environmental committees, facilitation by government extension workers, technical advise and supervision by district technical teams, and regional-wide workshops with key players. Village initiatives taken so far include new by-laws, gear inspection, reef zoning and closures. A number of village mariculture projects are being piloted.     

WTO fisheries subsidies negotiations: implications for fisheries access arrangements and sustainable management

The paper considers the WTO negotiations on fisheries subsidies and the implications that envisaged disciplines will have on coastal developing countries. This is considered in relation to fisheries access agreements in the Central and Western Pacific where several least developed but resource rich island states such as Kiribati and Tuvalu are highly exposed to the risks associated with new WTO fisheries subsidies disciplines that do not consider their particular vulnerabilities. The paper considers some of the issues that coastal developing countries should incorporate into their emerging negotiating positions at the WTO. State-to-Sate fisheries access agreements which are often highly subsidised but where fishing vessel owners pay the equivalent of lump sum tax are paradoxically, the least distortionary and damaging to the environment. Strategies for managing the possible new disciplines are considered.     

基于管治理念的区域海岸带综合管理模式探究

海岸带综合管理(Integrated Coastal Zone Management,即ICZM)是一种能够协调多方利益冲突,并以实现海岸带资源配置最优化和公共利益最大化为目标的管理方法。以区域海岸带综合管理模式为研究对象,在分析地方海岸带综合管理存在问题的基础上,通过对西方管治理念的引介,构建了一个强调协调和融合的区域海岸带综合管理新模式,并对该模式的组织构成、管理计划的制定、冲突的解决、计划的实施和反馈以及管理模式有效运作的保障机制作了系统的阐述,以期推动海岸带地区的可持续发展。     

Towards the evaluation of naval waterfront revitalisation: comparative experiences in Chatham,Plymouth and Portsmouth,UK

Waterfront revitalisation in naval ports involves economic restructuring, socio-political reorientation and the re-use of highly specialised facilities made redundant by far-reaching changes in national and international defence strategies. Not least because of the opportunities and challenges presented by naval heritage resources, these changes are comparable to, but significantly different from, those associated with commercial ports. This paper explores methodological approaches to the problem of evaluating strategies based on the waterfront in three major British naval ports. Critical analysis of outcomes and issues is employed to propose an evaluative framework for heritage-based revitalisation in naval cityports in a wider context.     

The Mediterranean: vulnerability to coastal implications of climate change

The Mediterranean is experiencing a number of immediate coastal problems which are triggering efforts to improve short-term coastal management. This paper shows that coastal management also needs to address long-term problems and, in particular, the likelihood of climate change. Regional scale studies suggest that the Mediterranean is particularly vulnerable to increased flooding by storm surges as sea levels rise—a 1-m rise in sea level would cause at least a six-fold increase in the number of people experiencing such flooding in a typical year, without considering population growth. Protection is quite feasible, however, this would place a greater burden on those Mediterranean countries in the south than those in the north. All coastal wetlands appear threatened. Case studies of coastal cities (Venice and Alexandria), deltas (Nile, Po, Rhone and Ebro), and islands (Cyprus) support the need to consider climate change in coastal planning. However, the critical issues vary from site to site and from setting to setting. In deltaic areas and low-lying coastal plains climate change, particularly sea-level rise, is already considered as an important issue, but elsewhere this is not the case. Therefore, there is a need for coastal management plans to explicitly address long-term issues, including climate change, and integrate this planning with short-term issues. This is entirely consistent with existing guidelines.¹ Given the large uncertainty concerning the future, planning for climate change will involve identifying and implementing low-cost proactive measures, such as appropriate land use planning or improved design standards incorporated within renewal cycles, as well as identifying sectors or activities which may be compromised by likely climate change. In the latter case, any necessary investment can be seen as a prudent ‘insurance policy’.     

Low-crested coastal defence structures as artificial habitats for marine life: Using ecological criteria in design

Coastal defence structures to protect sedimentary coastlines from erosion and flooding are increasingly common throughout Europe. They will become more widespread over the next 10–30 years in response to rising and stormier seas and accelerating economic development of the coastal zone. Building coastal defences results in the loss and fragmentation of sedimentary habitats and their replacement by artificial rocky habitats that become colonised by algae and marine animals. The engineering design and construction of these structures have received considerable attention. However, the ecological consequences of coastal defences have been less extensively investigated. Furthermore, due to their rapid proliferation, there is a growing need to understand the role of these man-made habitats in the coastal ecosystems in order to implement impact minimisation and/or mitigation measures.As part of the DELOS project, targeted studies were carried out throughout Europe to assess the ecological similarity of low-crested coastal defence structures (LCS) to natural rocky shores and to investigate the influence of LCS design features on the colonising marine epibiota. LCSs can be considered as a relatively poor surrogate of natural rocky shores. Epibiotic communities were qualitatively similar to those on natural rocky shores as both habitats are regulated by the same physical and biological factors. However, there were quantitative differences in the diversity and abundance of epibiota on artificial structures. Typically, epibiotic assemblages were less diverse than rocky shore communities. Also, LCSs offered less structurally complex habitats for colonisation and in some locations experienced higher disturbance than natural shores. We propose several criteria that can be integrated into the design and construction of LCSs to minimise ecological impacts and allow targeted management of diversity and natural living resources.     

Outside the law? Analyzing policy gaps in addressing fishers’ migration in East Africa

Coastal areas, and their small-scale fisheries, are important targets for both internal and transboundary migration partly because high mobility is an inherent feature of many artisanal fisheries livelihoods. As climatic changes are forecast to occur, environmental changes may trigger increased flows of migrant fishers. Policies that seek to promote development in ways that do not extensively degrade natural resources will thus have to deal with likely increases in flows of people across administrative boundaries. However, to date little attention has been directed at this issue and little is known about how policies related to coastal resources and development address these issues. This paper addresses this knowledge gap by analyzing policies and legal documents related to coastal resource management and development to examine the extent to which they recognize and integrate fishers' migration in their provisions. Migrant well-being and vulnerabilities are also addressed by examining the extent to which existing policies dealing with socio-economic development and environmental management address migrants and their needs. The analysis shows that policies related to governance of marine resources and coastal development lack an acknowledgment of fishers' migration issues and suggests that this signals an important gap in policy. The implications of this are discussed. The paper also highlights the fact that the invisibility of the issue in policy means that institutions developed to deal with coastal management at the community level may not have sufficient support from legal and policy documents, and may not be developed or equipped to handle the possible conflicts and difficult trade-offs that need to be addressed as a result of current and potentially increasing fishers’ mobility.