Total water levels (TWL) - the combination of wave-runup, tides, surges and in the future, sea-level rise - stand as a critical variable contributing to coastal inundation during storms. Quantifying the contribution of wave runup to extreme TWL is essential for accurate assessments of coastal inundation risk at wave-dominated coastlines. Despite decades of research, a fundamental challenge for coastal practitioners is selecting from numerous runup models, often constrained by the unavailable site-specific beach slope data. This study presents a novel dataset of TWL observations inferred from marine debris deposits surveyed immediately after storms in New South Wales, Australia. Using this dataset, this work assesses the accuracy of simplified TWL models integrating still water levels, local nearshore wave data, various runup formulae and different beach slope proxies derived from remote sensing technologies. Models utilising historical beach slopes from LiDAR outperformed the models using satellite-derived slopes. Findings suggest that runup formulae calibrated during small-to-moderate wave conditions can be extrapolated to extreme storms when applied to similar sites, emphasising the preference for site-specific formulae over one-model-fits-all approaches. Challenges and opportunities of modelling TWL for coastal inundation assessments are discussed, highlighting the need to incorporate beach slope uncertainties to fully assess inundation impacts as sea-levels rise.
Saltmarshes along the United States South Atlantic Coast, and globally, face critical threats from sea-level rise, edge erosion, ponding and historical human modifications, all of which are exacerbated by sediment deficits. Uncontaminated sediment stored in confined disposal facilities (CDFs) represents a significant and often overlooked resource for marsh restoration. As a result of management practices in the second half of the twentieth century, many unnaturally high earthen structures occur adjacent to drowning saltmarshes in the United States. In this perspective article, we explore the potential for mining CDFs to provide the sediment necessary to restore and sustain at-risk saltmarshes. Using publicly available data from the US South Atlantic coast, we estimate that reclaiming sediment from existing CDFs could offset sea-level rise impacts by 2100 for 13% of South Atlantic marshes. While the potential benefit is substantial, scientific, planning and implementation hurdles are presented. These pitfalls include potential issues with sediment characterization, limited guidance on chemical evaluation to reduce environmental risks, construction complications due to soft soils and legal and financial considerations. Despite these barriers, we conclude with a path forward for researchers and practitioners to address the hurdles through dedicated case studies, adaptive management principles and stakeholder engagement.
The winter storms of January and February 2026 caused severe coastal damage along southwest England, reviving memories of the destructive 2013/14 winter and exposing persistent weaknesses in UK coastal resilience policy. Using the Slapton Sands gravel barrier system, in Devon, as a case study, this article argues that repeated damage to the village of Torcross and the A379 road section that runs along the barrier illustrates a broader national cycle of escalating coastal risk despite decades of scientific understanding and strategic planning through Shoreline Management Plans (SMPs). Although none of the winter 2026 storms were individually extreme, their rapid succession, sequencing, and coincidence with spring tides caused substantial erosion, infrastructure collapse, and property damage, highlighting the cumulative threat of compound events. The case study exemplifies how defended coastlines and transport corridors can function as "single points of failure," where disruption produces cascading social and economic consequences. While SMPs acknowledge the eventual need for "Managed Realignment," implementation remains slow, politically contentious, and operationally vague, with policy often defaulting to short-term "Hold the Line" responses. This creates an adaptation deficit between national ambitions for resilience and practical action on the ground. We emphasise that transformational adaptation - including managed realignment, infrastructure relocation and community transition - requires coordinated national leadership, statutory support, a consistent approach and socially just frameworks that prioritise participation and fairness. Current local and national governance structures remain insufficient to meet the pace and scale of climate-driven coastal change. Torcross, like many vulnerable coastal communities, serves as an early warning of broader systemic failure: sea-level rise and intensifying coastal hazards will increasingly force the UK to confront difficult choices about protection, retreat and relocation.
Southeast Asia's coasts are among the world's most physically and ecologically sensitive environments, facing escalating threats from climate change, rising seas, extreme events and pervasive land subsidence. Understanding the magnitude, rate and trajectories of coastal transformation is critical for adaptation planning and hazard mitigation. This review synthesises current knowledge of coastal landform change across Southeast Asia (SEA), emphasising spatial and temporal variability driven by geological, climatic and anthropogenic boundary conditions. While globally sea levels are rising, tectonic deformation and vertical land motion dominate local trajectories, resulting in large spatial variability in relative sea-level rise (RSLR), offsetting SLR in uplifting areas and amplifying it in subsiding areas, where rates exceed 8 mm/yr, rivalling those of the Holocene marine transgression and surpassing global averages. The evolution of coastal landform types in response to boundary controls is examined. Paleo-reconstructions reveal that the Holocene transgression inundated ~2.3 million km2 of the Sunda Shelf, fundamentally resetting the land-sea interface of SEA countries. Sea-level fall from the mid-Holocene highstand drove extensive coastal deposition, generating >100,000 km2 of lowlands over the past 6,000 years, with progradation rates of 101-102 m/yr. These geologically young landscapes now face rapid, multidirectional change under contemporary forcing. Coastal change in SEA is complex, and rather than uniform erosion and inundation, the region exhibits a mosaic of responses, from stability to rapid progradation and island migration. Contemporary rates of change are comparable to those documented across the Holocene (102 m/yr), but are responding to a broader suite of drivers, including tectonic deformation, variable RSLR, extreme events and intense human activity. Attribution remains elusive, constrained by sparse spatial coverage, uneven representation of landform types and limited temporal resolution of data. Addressing these gaps requires comprehensive, site-specific studies of both geological and contemporary dynamics across all coastal typologies, supported by high-resolution monitoring and integrated modelling. Such efforts will provide the empirical foundation needed for informed coastal management and adaptation strategies in one of the world's most vulnerable regions.
The permanent closure of large marine areas is often regarded as an effective strategy for conserving marine biodiversity. However, implementing large permanent closures can be difficult in many small-scale fisheries systems, where communities depend heavily on marine resources for their livelihoods and food security, and where issues of equity and access must be carefully considered. Around the world, many coastal communities instead rely on temporary closures - areas that open and close over time - to balance ecological recovery with ongoing use. Despite their prevalence and potential, these dynamic approaches remain conceptually underdeveloped compared to permanent marine-protected areas. This article calls for a reevaluation of marine management's prevailing focus on space by bringing time to the forefront of analysis. We introduce a framework that distinguishes two key temporal dimensions - duration and cyclicity - to clarify how different temporal designs shape ecological, social and governance outcomes. Within this framework, cyclicity captures how closures and openings alternate over time, including the relative balance between periods of access and closure (i.e., the access ratio). Drawing on diverse examples where temporary management is implemented, this framework lays the groundwork for developing more formal theory and comparative evidence about how temporal strategies can align ecological recovery with livelihood dynamics in resource-dependent systems.
This perspective examines the application of transfer learning (TL) within deep learning (DL) frameworks for extreme water level (EWL) and spatiotemporal flood predictions. We discuss the main advantages of TL, such as enabling model transferability of pretrained DL models from/to diverse coastal-estuarine systems and reducing computational time compared to physics-based models. These advantages can accelerate the deployment of flood prediction models in data-limited locations. We also discuss challenges and limitations that hinder accurate pattern recognition and propagation of EWLs from gauge (observation) stations to surrounding locations within model domains. These limitations include dependence on similarity in data distributions, overfitting the training data and both lag and hysteresis effects in the timing of peak water levels and flood dynamics. Lastly, we explain several misconceptions and challenges in current DL approaches that hinder EWL and spatiotemporal flood prediction, including training models exclusively on extreme conditions, assessing accuracy solely through goodness-of-fit metrics, and connecting the model's knowledge of input data with physical explanations of flood processes without an adequate context. We argue that these challenges can be addressed by prioritizing storm-relevant patterns of the input data features as well as embedding spatial propagation of EWLs in DL frameworks to mimic coastal-estuarine hydrodynamic models. Ultimately, progress toward generalizable model transferability relies on the modeler's ability to incorporate physical understanding in DL architectures, alongside continued advances in physics-informed machine learning models via soft or hard constraint approaches. There remains substantial work to establish guidelines and/or formal procedures to develop robust, interpretable, and generalizable DL models for spatiotemporal flood prediction, thereby supporting effective flood management, mitigation, and emergency preparedness.
Barriers to ecosystem-based adaptation (EbA), which is part of the broader nature-based solutions (NbS) category, remain poorly understood and assessed. This article addresses this research gap, by proposing a structured analytical framework to understand barriers and applying it to 24 coastal EbA projects deployed in French tropical island territories. This framework considers four dimensions of barriers: categories, origins, impacts on the adaptation process, and temporalities. The findings highlight three main barriers relating to institutions, governance, politics, laws and regulations (35%); awareness, knowledge and technical resources (20%); and finance (15%). Most barriers are objective (80%), contextual (51.7%) and not adaptation specific (63.3%). Prevalent adaptation-specific barriers are the lack of or weakness of EbA-oriented policy and tools (59.5%) and lack of a future-oriented risk- and solution-based approach (27.0%). Most barriers (56.7%) affect two stages of the adaptation process (readiness and implementation) and were not overcome over the lifetime of the projects (53.3%). Thirteen solutions to barriers were implemented, with information, knowledge and awareness sharing or strengthening and increased coordination efforts being the most utilised and successful. This study highlights the benefits of including a barrier-oriented analysis in the evaluation of adaptation projects and proposes an operational and transferable framework to do so.
Urban coastal regions in the Great Lakes Basin are increasingly vulnerable to destructive flooding driven by climate impacts, outdated gray infrastructure systems, and a legacy of urban hydrological alteration and habitat fragmentation. While Nature-based Solutions (NbS) offer a path to adaptation, their implementation is often hindered by governance fragmentation, uneven regional resources, and a lack of integrated planning and design tools. This article discusses a transdisciplinary research through design framework that translates complex hydrological, ecological, and socio-spatial datasets into a suite of multimodal tools that serve as boundary objects for regional NbS planning in Southeast Michigan. The study's core contribution is a transferable and translational methodology that bridges the gap between technical and institutional protocols, the practices of organizations stewarding existing green stormwater infrastructure projects, and the disparate experiences of flooding across urbanized watersheds. Findings show that the act of designing these tools as translational devices - such as interactive and thematic cartographies, actor-network diagrams, and sets of NbS and multispecies habitat cards - evidences a mode of inquiry that allows diverse actors to move from reactive control paradigms toward a relational framework for addressing regional interdependencies.
Awards and invited keynotes are critical markers of scholarly achievement that shape visibility, career advancement and retention in academia. Yet extensive evidence across science, technology, engineering, mathematics and medicine shows that women remain underrepresented among recipients of these honors. To evaluate equity within the coastal geosciences and engineering (CGE) community, we compiled the gender distribution of 1,138 awards and invited keynotes granted by professional societies and conferences relevant to CGE over the past 50 years. We additionally reviewed publicly available nomination and selection procedures to assess transparency and inclusivity in award processes. Overall, 65% of honors were presented to men, and 35% were awarded to women and gender-diverse recipients. While men received more than 94% of awards before 2000, female representation among honorees increased to an average of 42% since 2020, outpacing the growth of women in the global scientific workforce and in tenure-track positions in the physical sciences and engineering in the United States. Disparities persist, however, across organizations and career stages: late-career awards and invited keynotes remain disproportionately male-dominated. Most organizations publicly share eligibility criteria, but few provide information on committee composition, evaluation rubrics or conflict-of-interest policies. Our findings show substantial progress toward gender equity in CGE recognition, yet highlight continued gaps in senior-level honors and the transparency of selection procedures. We provide community-focused recommendations such as clearer nomination policies, actions to reduce implicit bias, improved record-keeping and expanded mid-career awards to support equitable recognition across career stages and to ensure that honors reflect the evolving diversity of the CGE workforce.
Abstract Coastal areas that are characterized by coastal squeeze are highly vulnerable to the contemporary threats of climate change, sea level rise and biodiversity loss. Innovative coastal adaptation policies are necessary to accommodate these threats and have become salient issues on the agendas of mandated decision-makers on a global scale. This article provides a perspective on how historical–geomorphological knowledge can be integrated as an evidence base for coastal adaptation in such vulnerable zones when re-thinking and re-designing coastal adaptation policies. Our historical–geomorphological perspective proposes that we explicitly need to account for the geological, natural extent of human-modified and squeezed areas to fully understand their present-day developments. The geo-historical extent provides information on the long-term development of sedimentary structures and the functioning of coastal systems, and evaluates their effects on coastal protection, conservation and necessary adaptation. We use the Wadden Sea coastal zone as a case study to illustrate the necessity of the development of a geo-historical perspective and operationalize its integration into contemporary decision-making. The North European Wadden Sea is the largest continuous region of intertidal sand and mud flats in the world, and was recognized for its outstanding universal value by UNESCO in 2009. Nonetheless, it is an area that suffers intensely from coastal squeeze and has lost 70–80% of its coastal zone due to land reclamation and dike building. In short, our geo-historical perspective demands: (i) geo-historical risk assessment of coastal areas, (ii) geomorphological modelling that links the historical-induced risk to contemporary dynamics, (iii) assessment of ecological and societal values that are capable of estimating trade-offs between different coastal adaptation options in the contemporary system, (iv) evaluation of feasibility and legitimacy of potential coastal adaptation on the local scale of coastal inhabitants and (v) applying a transdisciplinary process that enables effective knowledge co-production between science and societal stakeholders.
Efforts on loss and damage assessments primarily focus on the macro-level assessments that often overlook micro-level heterogeneity. This paper adopts a bottom-up approach by measuring household-level L&Ds from cyclones. Estimates are derived for a representative household in Odisha, India, using two case studies: a super cyclone and a very severe cyclone., Data were collected through focus group discussions and household surveys, and were valued using the then prevailing market prices. The findings suggest that the annual L&Ds for a coastal household in Odisha amount to USD 193 from a super cyclone and USD 396 from severe cyclones, measured in 2014 prices and exchange rate (1 USD = INR 60.95). While the super cyclone caused extensive losses, a substantial portion of the damage was compensated through government support and international aid. In contrast, very severe cyclones are more frequent but receive limited external assistance, leaving households to cope largely on their own. L&D assessment across different occupational groups reveals significant disparities in aid distribution and insurance coverage. Given that the area is a core zone of cyclogenesis, localised resource mobilisation and expanded insurance coverage should be prioritised, along with a fairer aid distribution mechanism, to strengthen disaster management.
Coastal fisheries are central to Pacific Island nutrition, livelihoods and cultural identity, yet growing microplastic contamination threatens food security and public health. This study integrates fishers’ knowledge of locally important coastal fish species with empirical measurements of microplastic loads to identify priority taxa for monitoring across Fiji, Tonga, Tuvalu and Vanuatu. Interviews with 110 fishers documented commonly caught species, and the number of times each taxon was reported was calculated. Family-level catch data and mean microplastic loads were each standardised between 0 and 1 to generate Catch and Microplastic Scores, which were multiplied to create an Exposure Index reflecting both social relevance and contamination levels. Regionally, Lethrinidae and Scombridae had the highest Exposure Index values, while Acanthuridae, Lutjanidae, Scaridae and Serranidae emerged as country-specific priorities. Gendered fishing patterns revealed differences in catch, influencing potential exposure pathways and highlighting the need for gender-disaggregated data in future assessments. This approach of combining local knowledge with contamination studies offers a replicable, regionally-grounded method for identifying key indicator species for future microplastic monitoring. Species within the Lethrinidae family, particularly Lethrinus harak, stand out as regional priorities because of their importance to subsistence and artisanal fisheries, exposure to microplastics and consistent occurrence across the region.
Early warning systems for coastal erosion and flooding are currently primarily designed for local applications, offering high-resolution, site-specific predictions. Only a few early warning systems (EWS) are used at large regional or national scales. There is also a lack of standardised indicators and thresholds, which vary widely across systems and hinder cross-regional applicability. While current EWS perform well in binary hazard detection (Yes/No hazard; 80-95% accuracy), they struggle to accurately classify intermediate hazard levels. A lack of comprehensive field datasets has impeded rigorous validation for most systems, with many assessments relying on qualitative observations. Improving the reliability of the EWS requires improving their validation against field data obtained during storms and regular updating of the topobathymetric data to include the actual pre-storm morphology. Currently, most EWS rely on outdated or synthetic morphological inputs, which increases prediction uncertainty. The computational constraints of physics-based models may prevent warnings from being issued in time and have led to the adoption of surrogate approaches that depend on robust training datasets. Furthermore, most systems focus solely on hazard detection, paying limited attention to the risk to assets or populations. Future development must prioritise stakeholder engagement and the co-design of systems that incorporate both hazard and risk assessments, in order to improve their usefulness and facilitate decision-making by end users.
J.N. "Ding" Darling National Wildlife Refuge (DDNWR) is located on Sanibel Island along the southwestern coast of Florida, USA. There, eutrophication attributed to agricultural discharge along the Caloosahatchee River has affected the area's aquatic habitat. In anticipation of additional nutrient loading, we experimentally fertilized mangrove forests with nitrogen (+N; NH4) and phosphorus (+P; P2O5) for 3 years, and monitored soil and pneumatophore CO2 fluxes and tree sap flow from two mangrove species. Furthermore, we modeled individual tree and stand water use, from which we developed carbon (C) budgets for +N and + P vs. control simulations based on a novel application of water use efficiency conversion. Many of the measured response variables provided hints of subtle changes in response to +P rather than +N, which were enhanced when scaled. From this, we found that additional P loading is expected to reduce both gross and net primary productivity as well as CO2 uptake via net ecosystem exchange of C, likely pressing the system beyond metabolic capacity and leading to a 48-62% decrease in projected lateral C export. Greater eutrophication will likely compound vulnerabilities to sea-level rise submergence, especially where P concentrations are high and already reducing soil surface elevations.
The Chignecto Isthmus is the sole land connection between Nova Scotia and mainland Canada, supporting national trade, agriculture and transportation. Much of this low-lying corridor is protected by aging dikes that are increasingly vulnerable to compound flooding from tides, storm surges and sea-level rise. This study combines static flood modeling and GIS-based land use classification to evaluate the elevation-based flood exposure of infrastructure and agricultural land. A planar water surface modeling approach validated with differential GPS measurements was applied to a 1-m-resolution digital elevation model. Results indicate that water levels in the adjacent basin can reach within 1 m of the mean dike crest elevation during spring tides. Planar surface modeling scenarios demonstrate that relatively modest increases in water level beyond this threshold could result in inundation, affecting thousands of hectares of cropland and hundreds of hectares of developed land, along with critical transportation infrastructure. This exposure has the potential to disrupt agricultural productivity, rural livelihoods, groundwater quality and interprovincial supply chains across the isthmus. While simplified, this analysis highlights the diminishing safety margin afforded by existing dikes, underscores the need for more detailed scenario-based modeling and reinforces the importance of proactive adaptation planning to safeguard this nationally significant corridor.
Sea-level projections are highly anticipated outcomes of climate model simulations, relevant for coastal management worldwide. Ideally, any model simulation needs to be validated against observations, but this is impossible for the most recent sets of future climate model simulations, which start near to the present day (2020). Here, we compare satellite observations of regional sea-level change against projections from the Intergovernmental Panel on Climate Change Fifth Assessment Report for total sea-level change and its individual components over their overlapping period, from 2007-2022. We first test and compare three different methods to reduce the internal variability in the observations, which hampers the comparison with models, in particular for shorter time periods. While all three methods reduce the internal variability, we find the low-frequency component analysis (LFCA) removes most of the internal variability. We find that the regional projections are in good agreement with the LFCA-filtered observations, for 96% of ocean area within the 90% confidence interval. For the total sea level and sterodynamic component, the projections both under- and overestimate the observations, depending on the region. For mass-driven sea-level change, the regional projections tend to overestimate the observations. Our analysis gives confidence in sea-level projections for the instrumental era.
Coastal areas are vital hubs for diverse ecosystems and socio-economic activities, but they face significant threats from climate change, biodiversity loss and pollution. These challenges require urgent, cooperative actions and interdisciplinary approaches to develop sustainable solutions. However, interdisciplinarity requires blurring traditional academic disciplinary boundaries, and this can be a challenge. Increasingly, early-career researchers (ECRs) are undertaking interdisciplinary research while facing uncertainty about their career progression. In this research paper, we explore the challenges and opportunities faced by ECRs in the United Kingdom conducting Interdisciplinary Coastal Research (IDCR). We draw on findings from internal workshops, webinar discussions and an online survey, all conducted in 2024. The main barriers to IDCR are systemic in nature and include demanding workload, short-term contracts, ineffective supervisory and limited institutional support. Generally, ECRs felt positive about the benefits of interdisciplinarity to coastal research and their career development, but some ECRs expressed feelings of impostor syndrome. Enhanced flexibility in approaches, improved communication and open-mindedness are among the proposed solutions. This research highlights the mismatch between the ambition and the day-to-day reality of ECRs working in IDCR and provides recommendations for IDCR, which can both enhance the experience of ECRs and secure better outcomes for coastal areas.
Near-shore marine habitats are well-documented as diverse and productive social-ecological systems; their degradation and loss have led to growing interest in marine restoration. However, the literature offers limited consideration of the interactions between these projects and stakeholders and local communities. We present a case study showing how a stakeholder engagement strategy ultimately led to the co-production of a marine restoration project among scientists, stakeholders and local communities. Alongside biological recovery, we present the complex social, logistical and ecological lessons learned through this stakeholder engagement strategy. Principally, these relate to how the success of the project hinged on the point at which the project was co-developed with the input of local communities and strategic stakeholders, rather than in a disconnected, independent manner. This project demonstrates that for marine restoration to truly be successful, projects need to engage and work with local people from the outset, through open and early stakeholder engagement and particularly with the people possibly impacted by its presence. Projects need to be created not just for ecological design but also to be relevant and beneficial to a wide range of people. What we show here is that co-producing a project with communities and stakeholders can be complex but lead to long-term sustainability and support for the project, with strong ecological outcomes. To achieve this requires an open and flexible approach. Finally, this work showcases how the restoration of marine habitats can be achieved within a social-ecological system and lead to benefits for people and the planet.
