Coastal Protection Services Research Articles

Analysis Of Hybrid Solutions For Coastal Protection Combining Physical And Numerical Cfd Modeling

Historically, flooding and erosion challenges in coastal areas have been addressed through conventional gray/rigid structures such as breakwaters, dikes, and walls (Morris et al., 2017). As a consequence of the context of climate change, which is accompanied by a global biodiversity crisis and an increasing risk to coastal systems and communities, Nature-based Solutions (NbS) have emerged in recent years as an alternative to conventional engineering options. NbS can completely or partially mitigate coastal flooding and erosion problems while offering several additional co-benefits, such as carbon sequestration, improved water quality, habitat creation, and more (Sutton-Grier et al., 2015). Nevertheless, NbS may not be effective on their own in areas where there is insufficient available space for their development or in high-risk areas. In such cases, combining conventional engineering with nature-based solutions to obtain a so-called hybrid solution can represent an optimal approach, capable of providing the necessary risk reduction and realizing the benefits associated with natural solutions (Vuik et al., 2016). This makes hybrid solutions a highly attractive option that is currently gaining increasing interest. However, due to the limited number of real cases implemented, their relatively novel nature, and existing gaps in our knowledge about their hydrodynamic behavior, there is a pressing need to study hybrid solutions in greater detail. To this end, an experimental campaign is being conducted and is complemented by numerical CFD modeling, coupling IH2VOF and OpenFOAM models, to better understand the coastal protection services provided by the combined solution and to assess the suitability of the method of process superposition, commonly used to analyze the interaction between the flow and the hybrid solution. The main variables analyzed for this purpose are the evolution of wave height and wave run-up.

Mangrove tree strength estimated with field experiments

Mangrove forests protect coastal communities from wind and wave energy, including during extreme events such as cyclones and tsunamis. Under extreme conditions, energy absorption often exceeds mangrove tree strength, resulting in broken stems and uprooted trees. Such damage can restructure mangrove community composition and function for decades. Predicting the vulnerability of mangrove forests to damage from external forces is critical for understanding the likelihood of forest structural change during damaging events. Despite the importance of such predictions, we have little mechanistic understanding of mangrove tree strength. We measured mangrove strength across three root types (prop roots, pneumatophores, and buttress roots) using static pulling tests. We applied a non-destructive load to mangrove trees using a winch, and related the force applied to the bending induced in the tree. Mangroves were stronger than terrestrial trees, per unit tree size, and this scaled strength was similar across mangrove species of different root types. Un-scaled mangrove strength increased exponentially with tree size, towards a strength asymptote for the largest trees. Enhanced empirical knowledge of mangrove tree strength is critical to understand the coastal protection services provided by diverse mangrove forests, particularly in a future of global climate change and increased occurrence of extreme storms.

Using vulnerability assessment to characterize coastal protection benefits provided by estuarine habitats of a dynamic intracoastal waterway.

The existence of coastal ecosystems depends on their ability to gain sediment and keep pace with sea level rise. Similar to other coastal areas, Northeast Florida (United States) is experiencing rapid population growth, climate change, and shifting wetland communities. Rising seas and more severe storms, coupled with the intensification of human activities, can modify the biophysical environment, thereby increasing coastal exposure to storm-induced erosion and inundation. Using the Guana Tolomato Matanzas National Estuarine Research Reserve as a case study, we analyzed the distribution of coastal protection services-expressly, wave attenuation and sediment control-provided by estuarine habitats inside a dynamic Intracoastal waterway. We explored six coastal variables that contribute to coastal flooding and erosion-(a) relief, (b) geomorphology, (c) estuarine habitats, (d) wind exposure, (e) boat wake energy, and (f) storm surge potential-to assess physical exposure to coastal hazards. The highest levels of coastal exposure were found in the north and south sections of the Reserve (9% and 14%, respectively) compared to only 4% in the central, with exposure in the south driven by low wetland elevation, high surge potential, and shorelines composed of less stable sandy and muddy substrate. The most vulnerable areas of the central Reserve and main channel of the Intracoastal waterway were exposed to boat wakes from larger vessels frequently traveling at medium speeds (10-20 knots) and had shoreline segments oriented towards the prevailing winds (north-northeast). To guide management for the recently expanded Reserve into vulnerable areas near the City of Saint Augustine, we evaluated six sites of concern where the current distribution of estuarine habitats (mangroves, salt marshes, and oyster beds) likely play the greatest role in natural protection. Spatially explicit outputs also identified potential elevation maintenance strategies such as living shorelines, landform modification, and mangrove establishment for providing coastal risk-reduction and other ecosystem-service co-benefits. Salt marshes and mangroves in two sites of the central section (N-312 and S-312) were found to protect more than a one-quarter of their cross-shore length (27% and 73%, respectively) from transitioning to the highest exposure category. Proposed interventions for mangrove establishment and living shorelines could help maintain elevation in these sites of concern. This work sets the stage for additional research, education, and outreach about where mangroves, salt marshes, and oyster beds are most likely to reduce risk to wetland communities in the region.

Global protection from tropical cyclones by coastal ecosystems—past, present, and under climate change

Coastal ecosystems have the potential to contribute to disaster risk reduction and adaptation to climate change. While previous studies have estimated the value of current coastal ecosystems for reducing coastal risk, there have been relatively few studies that look at changes in ecosystem service provision, in the past and under climate change. We employ the probabilistic, event-based CLImate ADAptation platform (CLIMADA) to quantify the protection from tropical cyclones (TCs) provided by coastal ecosystems, modeling the number of beneficiaries in the past and under future climate change. We also investigate the potential of nature-based solutions (NbS), such as mangrove restoration. We find that currently, one in five (21%) of all people impacted annually by TCs in the global low-elevation coastal zone is within the protection distance of coastal ecosystems. Over the last 30 years, the share of protected people has decreased by approximately 2%, due to ecosystem loss. With climate change, the average annual number of people impacted will increase by 40%. Simultaneously, the proportion of people protected by coastal ecosystems with climate change decreases due to changes in TC distribution (−1%). The importance of current coastal protection, and the potential for increasing protection by NbS, varies widely between countries. While the number of people protected globally only increases slightly with mangrove restoration, the share of people protected in individual countries can increase by up to 39%. Our findings provide a basis for NbS planning and adaptation policy, by highlighting areas which will be crucial for coastal protection services in a world altered by climate change.

Kelp Aquaculture as a Nature-Based Solution for Coastal Protection: Wave Attenuation by Suspended Canopies

Suspended kelp canopies have the potential to provide a coastal protection service in addition to their primary function of generating a sustainable resource. In this study, the attenuation of incident waves by kelp suspended from the surface was quantified. We adapted an analytical 1D cross-shore wave attenuation model and tested the effect of (1) water depth, (2) vegetation density, and (3) longline density. The results show that as the percentage of vegetation in the water column increases, wave attenuation by the canopy also increases. However, this attenuation is affected by seasonal variations in kelp growth as well as harvesting strategies. Careful choice of the adopted harvesting strategy was found to be important to maintain optimal wave attenuation by kelp aquaculture farms throughout the year. Partial and targeted removal of the vegetation along longlines is preferred to harvesting all laterals on longlines. This study demonstrates that there is an opportunity for the emerging global kelp aquaculture industry to provide a coastal protection service in addition to resource production, which will help to affect how coastal protection is realized and scaled globally.

EXPERIMENTAL ANALYSIS OF HYBRID SOLUTIONS FOR COASTAL PROTECTION

Among the newest strategies are nature-based solutions based on coastal ecosystems (Spalding et al., 2014; Jongman 2018). Such solutions have several co-benefits, such as habitat creation, increased water quality or carbon sequestration. However, these solutions may not be effective on their own in high-risk areas or in areas where there is not enough space for their implementation. In these cases, the union of conventional engineering with these nature-based solutions, the so-called hybrid solutions, can represent an optimal solution that provides the necessary risk reduction while reporting the cobenefits associated with natural solutions (Sutton-Grier et al., 2015; Vuik et al., 2016). This makes hybrid solutions a highly attractive option in which there is a growing interest. However, their relatively novel character, the few real cases implemented and the need for a strong integration of knowledge linking different disciplines pose a series of gaps in knowledge. To this end, an experimental campaign is proposed to study different typologies of hybrid solutions. The interaction between the ecosystem and the hard structure is studied to better understand the coastal protection service provided by the joint solution. To compare the performance of the different hybrid solutions, wave run-up over the rigid structure is analyzed and it is compared to the run-up obtained for the traditional rigid solution.

Drivers of mangrove vulnerability and resilience to tropical cyclones in the North Atlantic Basin

The North Atlantic Basin (NAB) has seen an increase in the frequency and intensity of tropical cyclones since the 1980s, with record-breaking seasons in 2017 and 2020. However, little is known about how coastal ecosystems, particularly mangroves in the Gulf of Mexico and the Caribbean, respond to these new “climate normals” at regional and subregional scales. Wind speed, rainfall, pre-cyclone forest height, and hydro-geomorphology are known to influence mangrove damage and recovery following cyclones in the NAB. However, previous studies have focused on local-scale responses and individual cyclonic events. Here, we analyze 25 years (1996–2020) of mangrove vulnerability (damage after a cyclone) and 24 years (1996–2019) of short-term resilience (recovery after damage) for the NAB and subregions, using multi-annual, remote sensing-derived databases. We used machine learning to characterize the influence of 22 potential variables on mangrove responses, including human development and long-term climate trends. Our results document variability in the rates and drivers of mangrove vulnerability and resilience, highlighting hotspots of cyclone impacts, mangrove damage, and loss of resilience. Cyclone characteristics mainly drove vulnerability at the regional level. In contrast, resilience was driven by site-specific conditions, including long-term climate trends, pre-cyclone forest structure, soil organic carbon stock, and coastal development (i.e., proximity to human infrastructure). Coastal development is associated with both vulnerability and resilience at the subregional level. Further, we highlight that loss of resilience occurs mostly in areas experiencing long-term drought across the NAB. The impacts of increasing cyclone activity on mangroves and their coastal protection service must be framed in the context of compound climate change effects and continued coastal development. Our work offers descriptive and spatial information to support the restoration and adaptive management of NAB mangroves, which need adequate health, structure, and density to protect coasts and serve as Nature-based Solutions against climate change and extreme weather events.

Understanding ecosystem services for climate change resilience in coastal environments: a case study of low-canopy sub-tidal seagrass beds in Fiji

The Pacific Island Countries (PICs) are exposed to extreme wave conditions which are projected to be exacerbated by rising sea levels due to climate change, prompting the need for strategic planning of coastal communities and assets. Nature-based protection has been proposed as a sustainable solution to promote the resilience of coastal areas from physical impacts such as wave-induced erosion. In this study, we investigate the potential coastal protection service of shallow sub-tidal low-canopy seagrass beds, dominated by Halodule uninervis, on the rate of wave height and wave energy reduction on a barrier and fringing reefs. The data was collected using bottom-mounted pressure sensors to measure wave height and energy reduction as waves moved toward the shoreline across the seagrass beds. The results show that on average, the seagrass beds were able to reduce wave height by 30% and energy by 47% in both reef environments. These reduction rates are strongly influenced by water depth, seagrass characteristics and local reef conditions. Based on these results, seagrasses can strengthen the resilience of coastal shorelines to wave erosion, thus conserving healthy low-canopy seagrass habitats has measurable benefits for shoreline protection in Fiji and other PICs.

Effectiveness of community-based mangrove management for coastal protection: A case study from Central Java, Indonesia

Management and restoration of mangrove forests to protect coasts are promoted in many countries, including Indonesia. Indonesian mangrove forests are actively restored and managed by local communities for their ecosystem services, including coastal protection. Whether community-based mangrove management (CBMM) is effective is still debated. Our study analysed the effectiveness of different CBMM practices in four Central Javan communities by analysing the capacity of their mangrove forests to protect against coastal hazards. We used complementary interviews, field assessments and literature reviews to collect the necessary information.The overall CBMM performance and success significantly differed for each community's mangrove rehabilitation effort and the resulting coastal protection service. Of the four communities, Bedono performed best in terms of mangrove coverage, forest structure and restored coastal protection service. This is explained by multiple factors, such as application of long-term and integrated CBMM approaches, involving appropriate maintenance and additional measures to reduce wave energy. Our results can help governments, practitioners and communities to better understand the factors that contribute to CBMM's success and failure when restoring and managing mangrove forests and protecting coasts.

Environmental Policy and Regulatory Framework for Managing Mangroves as a Carbon Sink in Cuba

Carbon stored in mangroves is valuable for climate change mitigation. Managing the carbon stored in the mangrove requires an adequate legal framework and an environmental policy. In Cuba, there is little research on the capacity of mangroves to retain carbon and its articulation in environmental policy and management. In the present study, the following research question is raised: Is there a favorable context in the environmental policy to manage the mangrove as a carbon reservoir in Cuba? The aim of this research is to identify aspects of environmental policy, legal and administrative frameworks related to managing mangroves as a carbon sink in Cuba. The qualitative method of social research, the content analysis technique, and the modified Ibero-American Network for Integrated Coastal Management (IBERMAR) decalogue were used to compile, understand, and discuss the potential for effective management of mangroves for carbon storage. One hundred and twenty-one articles published in WOS and Scopus databases between 2019 and 2022, as well as books and material reviewed on the official websites, were checked. Present policy in Cuba manages mangroves for coastal protection and other ecosystem services but lacks a developed plan for considering the role of this marine forest system as a carbon sink. Managing mangroves as a carbon reservoir will require vigorous efforts to measure and monitor the system. It is necessary to build a robust national political agenda and strengthen institutional and regulatory capacities. This research provides a systematization of environmental policy as a baseline for the management of carbon reservoirs in mangroves in Cuba.

Climate change mitigation by coral reefs and seagrass beds at risk: How global change compromises coastal ecosystem services

Seagrass meadows provide valuable ecosystem services of coastal protection and chemical habitat formation that could help mitigate the impact of sea level rise and ocean acidification. However, the intensification of hydrodynamic forces caused by sea level rise, in addition to habitat degradation threaten the provision of these ecosystem services. With quantitative field measurements of the coastal protection and chemical habitat formation services of seagrass meadows, we statistically model the relationships between hydrodynamic forces, vegetation density and the provision of these ecosystem services. Utilising a high-resolution hydrodynamic model that simulates end of the century hydrodynamic conditions and three scenarios of coral reef degradation (i.e., keep up, remain or loss) we quantify how the environmental conditions within a tropical bay will change given changes to the provision of ecosystem services. Our study shows that increasing hydrodynamic forces lead to a seafloor made up of a larger grain size that is increasingly unstable and more vulnerable to erosion. The loss of a fringing reef leads to larger hydrodynamic forces entering the bay, however, the 0.87 m increase in depth due to sea-level rise reduces the bed shear stress in shallower areas, which limits the change in the ecosystem services provided by the current benthic seagrass meadow. Loss of seagrass constitutes the greatest change in a bay ecosystem, resulting in the sediment surface where seagrass existed becoming unstable and the median sediment grain size increasing by 5-7 %. The loss of seagrass also leads to the disappearance of the unique fluctuating chemical habitat, which leaves the surrounding community vulnerable to ocean acidification. A reduction or complete loss of these ecosystem services would impact the entire community assemblage while also leaving the surrounding coastline vulnerable to erosion, thus exacerbating negative effects brought about by climate change.

Changes in Mangrove Cover and Exposure to Coastal Hazards in Kenya

Mangroves are effective carbon sinks, support coastal fisheries and provide wood and non-wood resources to coastal communities. They are threatened by natural and human-induced stresses including over-exploitation, conversion pressures, pollution and climate change. Understanding changes in this important ecosystem is essential to inform the sustainable management of mangroves and assess the implications related to the loss of ecosystem services. This study used global remote sensing mangrove forest data to quantify changes in mangrove cover in Kenya between 2010 and 2016 and applied the InVEST coastal vulnerability model to assess the implications concerning the provision of natural coastal protection services in Kenya. The results indicate that the annual rates of mangrove cover loss in Kenya were 0.15% between 2010 and 2016. Currently, 16% of the Kenyan coastline is at higher levels of exposure to coastal hazards but this could increase to 41% if coastal ecosystems (mangroves, corals and seagrasses) are lost. The study further identified that higher rates of mangrove loss are observed in areas at higher risk of exposure in the southern and northern counties of Kwale and Lamu, where monitoring and management efforts should be prioritized.

The protective role of mangroves in safeguarding coastal populations through hazard risk reduction: A case study in northeast Brazil

Coastal and estuarine ecosystems such as mangroves provide coastal protection services, safeguarding coastal communities and economies. However, sea-level rise can affect mangroves' protective role by increasing exposure to coastal hazards and economic costs. To better understand the role of mangroves as coastal protective barriers against hazards and their importance for conservation planning in the face of sea-level rise, we first analyzed temporal changes in the coastal landscape by measuring the erosion/accretion rates on the shoreline. We assessed coastal exposure to hazards with the presence and absence of mangroves. Finally, we estimated the economic losses and costs from the long-term retreat in the shoreline and mangrove loss. This study was carried out along the western coast of the South Atlantic, in the northeast Brazilian region. Coastal exposure indices were estimated using the Integrated Valuation of Environmental Services and Tradeoffs (InVEST) software, and the multitemporal analysis of shoreline was developed using the Digital Shoreline Analysis System (DSAS) software. Finally, the economic losses produced by those shoreline changes and social costs were estimated by predicting economic losses in terms of private property and by calculating societal costs in mangrove restoration and rockfill building. The results show that nearly a third of the shoreline is experiencing erosion and the coast could lose an additional 118 ha by 2030. In terms of the value of property loss, this translates to US$38,800 and would increase to US$72,000 under the maximum erosion rate scenario. Based on our coastal vulnerability assessment, almost 50 km of the coastline (20%) would transition to intermediate-high exposure levels if the current distribution of mangroves were to be lost. It is expected to cost about US$145 million in rockfill works and US$21 million in forest restoration to mitigate the impacts from human activities and sea-level rise on mangroves ecosystem services. At the national level, a total loss of mangroves in Brazil could mean mangrove forest restoration costs of nearly US$4000 million. More robust conservation policies are needed to conserve mangrove forests and safeguard the ecosystem-service co-benefits they provide. The latter is essential in low- and middle-income nations where the economic and welfare losses from coastal hazards are more challenging due to dependence on nature for livelihoods and well-being.

The Impact of Eco-retrofitting on Coastal Resilience Enhancement – A Physical Modelling Study

Recent climate change studies highlight that the sea-level rise and increase in intensity and frequency of extreme climatic events and storm surges will result in catastrophic wave overtopping events from coastal defences. Retrofitting of the existing seawalls provides great potentials for enhancement of the climatic resilience in coastal region through overtopping attenuation. With increasing attention towards sustainable and low emission solutions for improving the resilience of critical infrastructures to natural hazards, providing coastal protection service is no longer the only concern of scientists, but the environmental impacts of such interventions also started to be considered. This paper presents a laboratory-scale investigation of ‘eco-retrofitting’ approaches including vertipools and reef breakwater for their impact on mitigating overtopping from seawall. The laboratory tests were conducted on a vertical seawall with 1(V):20(H) smooth foreshore. Each test was consisted of approximately 1000 pseudo-random waves based on JONSWAP spectrum. Both impulsive and non-impulsive wave conditions were tested. The plain vertical seawall was taken as the reference case, that exhibited an overall good agreement with empirical predictions, when compared to EurOtop. The analysis of data highlights the significance of the tested eco-interventions in mitigating wave overtopping volume, with approximately 70% reduction of mean the overtopping rate.

Adapting to heatwave-induced seagrass loss: Prioritizing management areas through environmental sensitivity mapping

Seagrass meadows support complex species assemblages and provide ecosystem services with a multitude of socio-economic benefits. However, they are sensitive to anthropogenic pressures such as coastal development, agricultural run-off, and overfishing. The increasing prevalence of marine heatwaves (MHWs) due to climate change poses an additional and growing threat. In this study, we apply the environmental sensitivity mapping approach MESA (Mapping Environmentally Sensitive Assets) to explore the potential consequences of MHWs on the ecosystem services that Posidonia oceanica provides to coastal communities. Under the intermediate climate change scenario Representative Concentration Pathway 4.5, Mediterranean marine heatwaves will be severe by 2050, and will very likely increase mortality of P. oceanica. However, the societal risk of seagrass loss is not evenly distributed across the Mediterranean. The spatial distribution of socio-economic implications of seagrass loss is highlighted through two case studies on seagrass-dependent fisheries and coastal hazards. Coastal communities in Tunisia and Libya show very high sensitivity to a loss of fisheries due to a combination of increasingly intense and frequent MHWs, coupled with high proportions of regional seagrass-dependent fisheries catch. The coastlines of Italy, Tunisia, and Cyprus are shown to potentially be highly sensitive to loss of seagrass due to high levels of coastal hazards, and seagrass meadows susceptible to MHW-induced degradation. These coastlines are likely to suffer from reduced coastal protection services provided by intact seagrass meadows. We demonstrate the implications of MHWs for ecosystem service provision to coastal communities in the Mediterranean and the need for policy instruments to help mitigate and adapt to its effect. We also highlight the potential for environmental sensitivity mapping to help support policymakers with rapid screening tools to prioritize resources more effectively to areas where in-depth local planning is needed.

Assessing the coastal protection services of natural mangrove forests and artificial rock revetments

Coastal flooding and erosion cause significant social and economic impacts, globally. There is a growing interest in using natural habitats such as mangroves to defend coastlines. The protective services of mangroves, however, have not been assessed in the same rigorous engineering and socio-economic terms as rock revetments, and therefore are often overlooked by coastal managers. We used field measurements, a social science survey and economic valuation to compare the coastal protection services of mangroves and rock revetments, at five locations across Victoria, Australia. The results showed, in sheltered locations, both mangroves and rock revetments attenuated waves, however, the wave attenuation (per metre) of rock revetments was greater than mangroves, at two of the five locations. Only a small proportion of the survey respondents had observed flooding or erosion in their suburb but most agreed that mangroves provide important coastal protection benefits. Coastal landowners visited areas with mangroves more often than the public but were less likely to worry about the links between climate change and coastal erosion and flooding, or to agree that the coast was well protected with existing artificial coastal infrastructure, than other respondents. There were much higher up-front costs associated with building rock revetments, than planting mangroves, but rock revetments required less land than mangroves. Mangroves covered a larger area and averted more damages than rock revetments. Coastal managers and policy makers will have more success in advocating for nature-based solutions for coastal protection, if they are implemented in locations where they are eco-engineering and socio-economically acceptable options for climate change adaptation.

Coastal Ecosystem Services Modeling in Latin America to Guide Conservation and Restoration Strategies: The Case of Mangroves in Guatemala and El Salvador

We modeled the coastal protection and blue carbon ecosystem services provided by the mangroves of the Paz River Basin (El Salvador and Guatemala) using InVEST Coastal Vulnerability and Coastal Blue Carbon Models, with the goal of supporting the Regional Coastal Biodiversity Project of the International Union for the Conservation of Nature, in determining potential priority mangrove areas for conservation and restoration. To quantify the relative coastal protection that mangroves provide, we combined maps of different aspects of vulnerability, including ecological, physical, and social data. We also estimated carbon stocks, net sequestration, and the economic value of carbon sequestration as a service in 2050 and 2100. We then developed a combined index of coastal protection and carbon sequestration services to highlight potential priority conservation and restoration areas for mangroves. We found that in Guatemala the coastal protection service was provided in greater quantity in the province of Moyuta, while in El Salvador this service was the highest in the provinces of San Francisco Menéndez, Jujutla and Acajutla, which also had the greatest total carbon stock. In the Paz River Basin, we estimate there are approximately 1,741 hectares of mangroves that provide the highest coastal protection and carbon sequestration services. Furthermore, we identified 318.9 hectares across both countries where mangroves could potentially be restored.

Coral Reef Geometry and Hydrodynamics in Beach Erosion Control in North Quintana Roo, Mexico

Coral reefs are increasingly recognized for their shoreline protection services. The hydrodynamic performance of this ecosystem is comparable to artificial low-crested structures often used in coastal protection, whose objective is to emulate the former. Coral reefs also provide other important environmental services (e.g., food production, habitat provision, maintenance of biodiversity and social and cultural services) and leave almost no ecological footprint when conservation and restoration actions are conducted to maintain their coastal protection service. However, studies have focused on their flood protection service, but few have evaluated the morphological effects of coral reefs through their ability to avoid or mitigate coastal erosion. In this paper, we investigate the relation between shoreline change, reefs’ geometry and hydrodynamic parameters to elucidate the physics related to how the Mesoamerican Reef in Mexico protects sandy coastlines from erosion. Using numerical wave propagation and historical shoreline change calculated from satellite imagery, a direct correlation was found between shoreline movement, the depths and widths of reef flats, changes in the wave energy flux, and the radiation stresses of breaking waves. The findings indicate that the most remarkable efficacy in preventing beach erosion is due to reefs with shallow crests, wide reef flats, a dissipative lagoon seabed, located at ∼300 m from the coastline. The results provide essential insights for reef restoration projects focused on erosion mitigation and designing artificial reefs in microtidal sandy beaches. Results are limited to wave-dominated coasts.

Assessment of coastal ecosystem services and its condition for policy management plan in East Nusa Tenggara, Indonesia

As a developing and archipelago country, Indonesia is expected to assess its coastal ecosystem services to unleash Indonesia’s coastal potential and to drive Indonesia’s economic development. With this line of reasoning, it is indeed to apply the concept of Ecosystem Services (ES) and its condition to measure how much natural potential we have in coastal ecosystems. However, there has been no comprehensive framework on how ES and its condition are holistically conducted. For that purpose, we pioneered integrated research to assess the spatial distribution of the ES (coastal protection and recreation) across districts of East Nusa Tenggara province and its condition toward habitat by applying integrated InVEST (Integrated Valuation of Ecosystem Services and Trade-offs) models. InVEST model would acknowledge the potential ES that is available in the coastal ecosystem and its condition. Additionally, we also suggest the form of coastal management policy in East Nusa Tenggara that needs to be applied based on the available ES data. Our result indicated that West Manggarai and Southwest Sumba have the highest and lowest ES for coastal protection and tourism services. The HRA models showed that the condition of the coastal ecosystem in West Manggarai is at moderate risk; however, most of the seagrass is at high risk. The results suggested that conservation areas in West Manggarai intensified the existing ES provided there, whereas it also brings pressures to habitat conditions. Therefore, there is indeed to achieve an ideal coastal management practice in East Nusa Tenggara. It is also needed to consider ecological, social and economic aspects and involve all government levels to establish synergistic and inclusive policies. Simultaneously, it is also notable in paying attention to each area’s carrying capacity that can affect ecological functions.

Fishers perceptions of ecosystem service change associated with climate‐disturbed coral reefs

Abstract Understanding ecosystem service change necessitates an understanding of the social and ecological dimensions of ecosystem services and how they contribute to the well‐being of different people. These empirical research gaps persist across the tropics and in coastal environments, posing a challenge for small island states that depend on ecosystem services associated with near‐shore ecosystems like coral reefs. Perception‐based approaches allow for a rapid appraisal of what constitutes ecosystem service change, providing insights into why these changes matter, and how experiences of change differ between individuals. To capture perceptions of change in four ecosystem services associated with coral reefs (habitat, fishery, coastal protection and recreation services), we conducted 41 semi‐structured interviews with coral reef fishers from Seychelles, where reef ecosystems have been severely impacted by climate disturbance. We gathered quantitative and qualitative data to understand (a) if and what changes in reef‐associated ecosystem services have been perceived; (b) if fishers’ characteristics are associated with differences in perceived changes and (c) which changes matter most in fishers’ lives. Using a three‐dimensional approach to well‐being, we sought to identify whether reasons behind the importance of change connect to fishers’ well‐being. There have been noticeable changes across all four ecosystem services investigated. Changes include social, ecological and behavioural dynamics. Every fisher perceived at least one ecosystem service change but fishers who dive/snorkel or work from larger boats perceived a higher number of ecosystem services to have changed. Education, age and participation in snorkelling/diving were associated with fishers who identified changing habitat services as most important, whereas fishers from families with fewer livelihood alternatives and from smaller islands identified changing fishery services as most important. Different aspects of the subjective, relational and material dimensions of well‐being were implicated in why changing services matter. Despite known ecological shifts in reef condition, this research is one of few studies to empirically show how changes across multiple ecosystem services are being perceived. These perceived changes are complex, engage both the social and ecological dimensions of services, and connect in multiple ways to how fishers feel about their lives, their relationships and material well‐being. A free Plain Language Summary can be found within the Supporting Information of this article.