Coastal Protection Structures Research Articles

Storm surge induced by 2019 Tropical Storm Pabuk and impact on the shoreline in Kuala Nerus Terengganu, east coast of Peninsular Malaysia

This study investigates the one-year shoreline impacts of 2019 Tropical Storm Pabuk and the morphological changes of beaches in the study area of Kuala Nerus in Malaysia mediated by the hydrodynamic conditions. The study used a numerical model that utilised the two-way coupling of the wave and hydrodynamic model of MIKE 21 to simulate the event. The impact of the event was determined by employing the Digital Shoreline Analysis System, along with regular in-situ measurements of beach profiles carried out monthly. The results show a significant retreat rate of −58 m/year at Tok Jembal, highlighting the significant erosive impact, particularly on the northwest side of the airport. Despite a storm surge height below the extreme thresholds (>1 m), the beach morphology and the presence of coastal protection structures exerted a significant modulating influence. Batu Rakit, which is characterised by a wide beach, exhibited increased wave run-up and erosion resulting from the combined effect of a tidal surge of 0.64 m and significant wave heights of more than 1.12 m. UMT and Teluk Ketapang, on the other hand, which are shielded by coastal structures and influenced by longshore currents, experienced beach accretion. The intensification of the recirculation current with the surge is postulated to have contributed to the pronounced erosion at Pengakalan Maras. Although the overall magnitude of the storm surge was not exceptional, this study emphasises the importance of studying the effects of storm surges on monsoonal coasts. The intricate interplay between waves and currents, elucidated by coupled hydrodynamic and wave modelling, is crucial for understanding the consequences of storms and for proactive coastal management strategies. This study emphasises the crucial role of detailed hydrodynamic modelling in developing effective erosion control measures, which is an ongoing challenge for coastal communities.

Sand dune restoration as sustainable natural architectural design for coastal protection along seasonal storm-prone beach

Monsoonal storms cause coastal erosion of worldwide sandy beaches, including coasts in Malaysia. Although hard engineering structures are effective in mitigating erosion, those constructions can create several environmental issues such as down-drift erosion. The Effective Sand Fence (also known as E-Fence) is considered one of the sustainable alternative structures to protect beach erosion. Therefore, the objective of the current study is to identify the effectiveness of E-Fence for dune restoration. In this study, we measured beach profile survey, grain size distribution, and wind speed. In addition, XBeach simulation was used to determine sediment accumulation under the E-Fence protection. Results of the beach profile survey (i.e., slope and dune volume) indicate dune restoration in protected areas of the E-Fence. Grain size distribution and wind speed suggest the decreasing of wind velocities from the swash zone to the backshore. Accordingly, the E-Fence acts as a barrier, and the reduction of energy leads to accumulate sediments by passing through gaps in the structure. The E-Fence is thus capable of sustaining against wave attack and can maintain stable coastal ecosystems. Consequently, this coastal protection structure assists in developing cheaper coastal erosion mitigation strategies in Malaysia and elsewhere.

Integrated Modeling of Coastal Processes Driven by an Advanced Mild Slope Wave Model

Numerical modeling of wave transformation, hydrodynamics, and morphodynamics in coastal regions holds paramount significance for combating coastal erosion by evaluating and optimizing various coastal protection structures. This study aims to present an integration of numerical models to accurately simulate the coastal processes with the presence of coastal and harbor structures. Specifically, integrated modeling employs an advanced mild slope model as the main driver, which is capable of describing all the wave transformation phenomena, including wave reflection. This model provides radiation stresses as inputs to a hydrodynamic model based on Reynolds-averaged Navier–Stokes equations to simulate nearshore currents. Ultimately, these models feed an additional model that can simulate longshore sediment transport and bed level changes. The models are validated against experimental measurements, including energy dissipation due to bottom friction and wave breaking; combined refraction, diffraction, and breaking over a submerged shoal; wave transformation and wave-generated currents over submerged breakwaters; and wave, currents, and sediment transport fields over a varying bathymetry. The models exhibit satisfactory performance in simulating all considered cases, establishing them as efficient and reliable integrated tools for engineering applications in real coastal areas. Moreover, leveraging the validated models, a numerical investigation is undertaken to assess the effects of wave reflection on a seawall on coastal processes for two ideal beach configurations—one with a steeper slope of 1:10 and another with a milder slope of 1:50. The numerical investigation reveals that the presence of reflected waves, particularly in milder bed slopes, significantly influences sediment transport, emphasizing the importance of employing a wave model that takes into account wave reflection as the primary driver for integrated modeling of coastal processes.

Impacts of anthropogenic structures in long- and short-term shoreline evolution of Santa Marta Bay (Colombian Caribbean)

Interaction of Anthropic interventions (rigid structures) with coasts is an essential aspect for understanding their geomorphic evolution and incorporating these data into adequate coastal management. This study analyses the short and long-term behavior (1985 to 2019) of shoreline at Santa Marta Bay (Caribbean - Colombia) and their relationship with coastal protection structures. The shoreline variations were analyzed through aerial photographs and satellite images using DSAS tools. The short-term assessment showed initial intense 1985–1991 erosion, with an average retreat speed rate of − 1.6 m·y− 1. It changed gradually since 2003, due to the construction of rigid structures and beach nourishment, decreasing shoreline retreat and even a progradation rate of 0.2 m·y− 1 was observed. The 2009–2019 period, despite recording a positive average value, exhibited a high percentage of erosion profiles. Therefore, in a decadal or long-term analysis (1985–2019), despite engineering works present positive results in the short term, new interventions are required. The coastal erosion is not uniform along the shoreline, because the area is a closed bay with small sediment inputs, the variations in erosion and accretion rates change with human intervention and the installation of new structures. Therefore, quantifying the scale and rate of shoreline changes and correlating them with anthropogenic structures is an essential step in assessing shoreline vulnerability.

Integrating mangrove growth and failure in coastal flood protection designs

Mangrove forests reduce wave attack along tropical and sub-tropical coastlines, decreasing the wave loads acting on coastal protection structures. Mangrove belts seaward of embankments can therefore lower their required height and decrease their slope protection thickness. Wave reduction by mangroves depends on tree frontal surface area and stability against storms, but both aspects are often oversimplified or neglected in coastal protection designs. Here we present a framework to evaluate how mangrove belts influence embankment designs, including mangrove growth over time and failure by overturning and trunk breakage. This methodology is applied to Sonneratia apetala mangroves seaward of embankments in Bangladesh, considering forest widths between 10 and 1000 m (cross-shore). For water depths of 5 m, wave reduction by mangrove forests narrower than 1 km mostly affects the slope protection and the bank erodibility, whereas the required embankment height is less influenced by mangroves. Sonneratia apetala trees experience a relative maximum in wave attenuation capacity at 10 years age, due to their large submerged canopy area. Once trees are more than 20 years old, their canopy is emergent, and most wave attenuation is caused by trunk and roots. Canopy emergence exposes mangroves to wind loads, which are much larger than wave loads, and can cause tree failure during cyclones. These results stress the importance of including tree surface area and stability models when predicting coastal protection by mangroves.

An experimental study on the evolution of beach profiles under different beach nourishment methods

Due to the influence of storm surges, hard coastal protection structures may exacerbate beach erosion, hence beach nourishment methods are considered in coastal protection and restoration efforts. An experiment is conducted in a wave flume to compare the advantages and disadvantages of three types of beach nourishment methods (berm nourishment, profile nourishment, and bar nourishment) under non-storm and storm wave conditions. The experiment analyzes wave height distribution, beach morphology changes, net sediment transport, shoreline recession, beach width increase, and beach volume changes. The findings indicate that the implementation of bar nourishment strategies facilitates the pre-breaking of storm waves, thereby mitigating the disruption caused by wave breaking on water flow dynamics. Moreover, the application of berm and profile nourishment methods proves to be highly effective in expanding the width of the beach and bolstering its stability. However, it is worth noting that bar nourishment exhibits limited efficacy in terms of restoring beach berms and mitigating coastal erosion within the same duration of wave action. The study presents two equations incorporating hydrodynamic parameters to predict the erosion or accretion status of beaches, and compares the predicted results with experimental data, thereby refining the criteria and making the formulas more applicable to beach nourishment projects. These findings provide valuable insights into the strengths and weaknesses of different beach nourishment methods, which will contribute to the implementation of nourishment projects.

Modelling Turbulent Flows near Coastal Structures Using Various Turbulence Models

Introduction. The reduction in beach width due to erosion is a significant issue that can either be mitigated or exacerbated by coastal protection structures. Modelling breaking waves near the coast and around coastal structures can be used to determine their impact on the dynamics of the coastal zone. The objective of this study is to model and analyze the dynamics of turbulent structures around a single breakwater, obtained using two turbulence modelling schemes: RANS and LES.Materials and Methods. Turbulence induced by breaking waves was investigated. The modelling was based on bathymetric measurements conducted along the Azov Sea coast and a three-dimensional wave hydrodynamics model supplemented with various turbulence calculation configurations.Results. Modelling results of wave processes generating turbulent flows in the presence of coastal protection structures using different turbulence models were obtained. Results obtained based on Reynolds-averaged Navier-Stokes (RANS) equations are compared with the results of Large Eddy Simulation (LES) approach with Smagorinsky dynamic subgrid-scale model (DSM).Discussion and Conclusions. The results showed that wave heights simulated by LES were higher than those simulated by RANS in the front and leeward regions of the coastal protection structure and were lower in its upper part. Thus, according to LES, a greater amount of wave energy was preserved after passing over the breakwater. Velocity vectors of the water medium showed the formation of a vortex when LES was used, whereas no evidence of such turbulent vortices was detected in the case of RANS, confirming the better performance of LES for turbulence modelling in the coastal zone. According to the presented results, LES is the preferred tool for generating turbulence under incoming wave conditions in engineering practices.

Effects of sea level rise and tidal flat growth on tidal dynamics and geometry of the Elbe estuary

Abstract. Future global mean sea level rise (SLR) will affect coastlines and estuaries in the North Sea and therefore also coastal protection structures, unique local ecosystems and important waterways. SLR will not only raise water levels but also influence tidal dynamics and morphodynamics, which is why the tidal flats of the Wadden Sea can grow to a certain extent with SLR. Investigations on the effects of climate-change-induced SLR and the related potential bathymetric changes inside of estuaries form an important basis for identifying vulnerabilities and developing appropriate adaptation strategies. To analyse the influence of potential SLR and tidal flat elevation scenarios on the tidal dynamics in the Elbe estuary, we used a highly resolved hydrodynamic numerical model of the German Bight. The analysis results show increasing tidal range in the Elbe estuary solely due to SLR. They also reveal strongly varying changes with different tidal flat growth scenarios: while tidal flat elevation up to the mouth of the estuary can cause tidal range to decrease relative to SLR alone, tidal flat elevation in the entire estuary can lead to an increase in tidal range relative to SLR alone. Further analyses show how the geometric parameters of the Elbe estuary are changing due to SLR and tidal flat elevation. We discuss how these changes in estuarine geometry can provide an explanation for the changes in tidal range.

Evolution of trends in Sri Lankan mangrove research and future prospects

The trend of sporadic surveys and qualitative descriptions of Sri Lankan mangrove flora in the first half of the 20th century has gradually changed to include quantitative studies on floristics, nevertheless, studies on quantification of fauna associated closely with mangrove ecosystems are scarce. Microbial diversity, especially in soil, and its ‘contribution to the detritus cycle are the least studied. The tendency to engage in short-term research at convenient sites affects the quality and relevance of research output with some redundancy, resulting in a marginal contribution to the knowledge base on mangrove ecology. Studying mangrove ecosystem functions/ services demands long-term collection of data that would have made them less attractive research ventures.  Research on trophic relationships, detritus and nutrient cycling, habitat and pollination functions too have had the same fate. The Indian Ocean tsunami in 2004 triggered a considerable interest in the coastal protection function of mangroves, as it was evident that mangroves and other coastal vegetation provided superior resistance to tsunami waves than hard engineering coastal protective structures. This has led to an unprecedented trend of mangrove afforestation for coastal defense, more than to research on planting techniques and maintenance to enhance the survival and growth of seedlings. This is still an under-researched aspect. Escalating recognition of blue carbon as a climate-smart solution and the development of market mechanisms for blue carbon trading have induced a considerable research interest in quantifying the mangrove blue carbon stocks, especially in the soil. Research on atmospheric carbon removal capacity/rates of mangrove plants/forests through photosynthesis however, lags behind for the reason that it requires data collection for a longer period that demands greater financial and labour investment. The urgency created by the current climate change crisis for effective solutions to reduce atmospheric greenhouse gases may provide a conducive environment for mangrove research.

Current extent and future opportunities for living shorelines in Australia

Living shorelines aim to enhance the resilience of coastlines to hazards while simultaneously delivering co-benefits such as carbon sequestration. Despite the potential ecological and socio-economic benefits of living shorelines over conventional engineered coastal protection structures, application is limited globally. Australia has a long and diverse coastline that provides prime opportunities for living shorelines using beaches and dunes, vegetation, and biogenic reefs, which may be either natural (‘soft’ approach) or with an engineered structural component (‘hybrid’ approach). Published scientific studies, however, have indicated limited use of living shorelines for coastal protection in Australia. In response, we combined a national survey and interviews of coastal practitioners and a grey and peer-reviewed literature search to (1) identify barriers to living shoreline implementation; and (2) create a database of living shoreline projects in Australia based on sources other than scientific literature. Projects included were those that had either a primary or secondary goal of protection of coastal assets from erosion and/or flooding. We identified 138 living shoreline projects in Australia through the means sampled starting in 1970; with the number of projects increasing through time particularly since 2000. Over half of the total projects (59 %) were considered to be successful according to their initial stated objective (i.e., reducing hazard risk) and 18 % of projects could not be assessed for their success based on the information available. Seventy percent of projects received formal or informal monitoring. Even in the absence of peer-reviewed support for living shoreline construction in Australia, we discovered local and regional increases in their use. This suggests that coastal practitioners are learning on-the-ground, however more generally it was stated that few examples of living shorelines are being made available, suggesting a barrier in information sharing among agencies at a broader scale. A database of living shoreline projects can increase knowledge among practitioners globally to develop best practice that informs technical guidelines for different approaches and helps focus attention on areas for further research.

An application of gabions for design of coastal protection structures in lakes

With large areas of water reservoirs and lakes, the wave runoff distance is also large, resulting in the high waves in the wind blow direction. These waves intensively disrupt the coast of the lake or water reservoir. Another intense factor of coastal erosion is ice. A lot of engineering measures for the coastal protection of reservoirs and especially for lakes are used: reinforced concrete slabs, blocks, jibs, cellular systems (geosynthetics), etc. An eroded coastline, reshaped by installing a coastal protection structure using gabion construction, is analysed in this research. Gabions are designed to protect banks and slopes from fast water flow (water speed over 5 m·s–1) and ice impacts. They are designed according to geotechnical principles, assessing stability according to the limit design situations specified in Eurocode 7 (EN 1997-1). The aim of this work is to illustrate the features of wave and ice loads and geotechnical design situations evaluated in the design of a coastal protection structure made of gabions.

Impacts of coastal protection measures along the coast of Kerala, India (through remote sensing techniques)

ABSTRACT The maritime state, Kerala, is located along the southwest coast of the Indian peninsula, which extends from Trivandrum district (8° 17´ 41.03´´ N, 77° 5´ 37.29´´ E) in the South to Kasaragod district (12° 45´ 20.76´´ N, 74° 51´ 58.92´´ E) in the North, exposed to the waves from the Arabian Sea. The shoreline is extremely dynamic due to the impact of waves, tides, currents, coastal orientation and other associated occasional coastal hazards. The annual climatic calendar for the Kerala coast can be broadly classified as South-West monsoon (June to September), North-East Monsoon (October to December), and Pre-monsoon or Non-Monsoon (January to May). Prior to the 2004 Indian Ocean tsunami, a standardised seawall section had been preferred for highly eroding coastal stretches. The coastal hazards in addition to the tsunami impact paved the way for considering several other structures for coastal protection, of which groyne fields have been predominantly implemented. As it is essential to quantify the performance assessment of these protection measures, an exercise using the DSAS (Digital Shoreline Analysis System) tool was carried out, the results of which are presented and discussed in this paper.

Investigation of the effects of small fishing ports on the shoreline: a case study of Samsun, Turkey

Shoreline change analysis is crucial for identifying coastal issues and understanding their underlying causes. This study focuses on investigating the coastal impacts of the Derekoy Fishing Port in Samsun, a city located on the Black Sea coast of Turkey. Temporal changes between 1984 and 2021 were analyzed using Landsat-5 TM/Landsat-8 OLI satellite images in conjunction with image processing and geographic information systems (GIS). Net shoreline movement (NSM), shoreline change envelope (SCE), end point rate (EPR), and linear regression rate (LRR) methods were used to investigate the changes in the shoreline. Polygon overlay analysis was utilized to determine the areas of erosion and accretion. The results indicate that prior to the port's construction, the coast remained relatively stable during the period of 1984–1995. However, sediment accretion occurred on the updrift side of the port, while erosion intensified on the downdrift side during the port's construction from 1995 to 2004. Despite the implementation of coastal protection structures to combat erosion, complete prevention was not achieved, and erosion shifted further eastward. Throughout 1984–2021, approximately 15.62 hectares of beaches were lost due to erosion, with a maximum value of -56.2 m recorded. The coastal erosion and the construction of coastal protection structures have disturbed coastal morphology and resulted in various environmental and socio-economic issues along the 19 Mayis and Atakum beaches. This study reveals the significant consequences of a small fishing port built without proper planning and adequate precautions, drawing attention to the problems.

Coastline Monitoring and Prediction Based on Long-Term Remote Sensing Data—A Case Study of the Eastern Coast of Laizhou Bay, China

Monitoring shoreline movements is essential for understanding the impact of anthropogenic activities and climate change on the coastal zone dynamics. The use of remote sensing allows for large-scale spatial and temporal studies to better comprehend current trends. This study used Landsat 5 (TM), Landsat 8 (OLI), and Sentinel-2 (MSI) remote sensing images, together with the Otsu algorithm, marching squares algorithm, and tidal correction algorithm, to extract and correct the coastline positions of the east coast of Laizhou Bay in China from 1984 to 2022. The results indicate that 89.63% of the extracted shoreline segments have an error less than 30 m compared to the manually drawn coastline. The total length of the coastline increased from 166.90 km to 364.20 km, throughout the observation period, with a length change intensity (LCI) of 3.11% due to the development of coastal protection and engineering structures for human activities. The anthropization led to a decrease in the natural coastline from 83.33% to 13.89% and a continuous increase in the diversity and human use of the coastline. In particular, the index of coastline diversity (ICTD) and the index of coastline utilization degree (ICUD) increased from 0.39 to 0.79, and from 153.30 to 390.37, respectively. Over 70% of the sandy beaches experienced erosional processes. The shoreline erosion calculated using the end point rate (EPR) and the linear regression rate (LRR) is 79.54% and 85.58%, respectively. The fractal dimension of the coastline shows an increasing trend and is positively correlated with human activities. Coastline changes are primarily attributed to interventions such as land reclamation, aquaculture development, and port construction resulting in the creation of 10,000.20 hectares of new coastal areas. Finally, the use of Kalman filtering for the first time made it possible to predict that approximately 84.58% of the sandy coastline will be eroded to varying degrees by 2032. The research results can provide valuable reference for the scientific planning and rational utilization of resources on the eastern coast of Laizhou Bay.

Comparison of the SIMAR-WANA, ERA-5, and Waverys Databases for Maritime Climate Estimations and the Implications of Coastal Protection Structures

Comparison of the SIMAR-WANA, ERA-5, and Waverys Databases for Maritime Climate Estimations and the Implications of Coastal Protection Structures

Feasibility Study of Sustainable Coastal Protection through the Integration of Bamboo Breakwater and Green Mussel Cultivation

One pressing issue posing a significant threat to the coastal ecosystem is abrasion. Therefore, it is imperative to implement an effective and stable coastal protection structure using readily available and cost-effective materials combined with green mussel cultivation to bolster economic benefits for the community. The methodology employed in this study encompasses the integration and analysis of secondary data and the collection of archival information. The findings indicate that the ecological conditions of the waters in Bedono Village, Sayung District at Demak Regency meet the necessary criteria for green mussel cultivation. Bamboo with a minimum length of 7.5 meters and a planting depth of 2 meters is utilized. Financially, this approach proves to be quite advantageous, yielding a Net Present Value (NPV) of Rp1,202,383 for the stake method of green mussel cultivation. The Net Benefit-Cost Ratio (Net B/C) for the stake method of green mussel cultivation is 1.20. Based on the NPV and Net B/C feasibility criteria, the stake method of green mussel cultivation is considered viable. This structural concept is evaluated as adhering to ecological principles across all its components.

Assessment of the solitary wave attenuation through pervious concrete breakwater

Breakwaters are coastal structures typically used to protect shorelines from coastal erosion by providing wave energy attenuation and reflecting amounts of wave currents. Traditional breakwaters made of impervious materials can have a significant environmental impact, disrupting the coastal ecosystem and altering natural wave patterns. In general, permeability has become an acquainted characteristic since it directly influences the interaction between the structure, the coastal zone behind it, and the lateral zone without structural protection, which makes pervious concrete a sustainable alternative to traditional concrete. In this study, pervious concrete is utilised as a permeable breakwater considering the influence of permeability introduced to deliver ecological friendliness defence for shorelines. A physical experiment was used to evaluate four models of structures that varied in porosity in order to study the physical properties and then analyse the performance of the pervious concrete breakwater over the solitary wave impact. Subsequently, the hydrodynamic scattering coefficient is analysed by considering changes in physical parameters. The results indicated that pervious concrete breakwater (PCB) could effectively work in the case of emergence due to the increased interaction between wave and structure. PCBs can effectively reduce wave reflection and increase wave transmission, with the magnitude of these effects increasing with porosity. The result indicated the potentiality of PCB to serve as a feasible alternative to traditional breakwaters for a prospective coastal protection structure by reducing the environmental impact as PCBs allow for the passage of water and other marine organisms, which can help maintain the health of coastal ecosystems. Finally, the structure of PCBs, which can be prefabricated, could reduce the complexity and time of installation, making them a cost-effective solution for coastal protection.

Retaining of dredging waste using geotextile tubes: analysis of the dewatering and undrained shear resistance of the sludge cake

The city of Rio Grande has its economy linked to coastal and port activities and has a port complex of high economic importance for the region. To maintain the depth of the port channels, periodic dredging operations are carried out, as occurred in the Port of Rio Grande between 2018 and 2020. Approximately 16 million m³ of sediments were removed from the channel and deposited in disposal zones. There has been an attempt to develop techniques that carry out the reuse and disposal of dredging waste more appropriately, seeking to minimize environmental impacts by avoiding inappropriate open-sea or onshore disposal. Within this context, this work aims to evaluate the potential of the retaining and dewatering process of dredging waste in geotextile tubs (linear geoforms, geobags e etc). This technique reduces the volume of dredged mud through desiccation and allows the geotextile tubs to be installed in sedimentation basins onshore or coastal protection structures. Thus, the present study evaluated the dewatering and filtration efficiency of these systems through tests of small bags. The advantages of adding flocculation polymer and the behavior of undrained shear strength over time of the retained cake were evaluated.

Unmanned aerial vehicles (UAVs) for coastal protection assessment: A study of detached breakwater and groins at Marawila Beach, Sri Lanka

Coastal protection plays a vital role in mitigating coastal hazards and erosion risks. However, the effectiveness of various global coastal protection structures is questionable due to the uncertainties they face. Many developing countries struggle to evaluate the long-term productivity and efficiency of these structures, primarily due to the lack of reliable and affordable monitoring methods. To address this problem, this study used an approach based on unmanned aerial vehicles (UAVs) for coastal monitoring to assess the effectiveness of coastal protection structures on Marawila Beach, Sri Lanka, where different structures have been implemented. The UAV imagery was analyzed using photogrammetric techniques as a pilot study to estimate shoreline changes, erosion rates, and sediment transport patterns. The results demonstrated that coastal protection structures significantly reduced erosion rates and sediment transport compared to unprotected areas. Among the structures, the detached breakwater proved to be the most effective in reducing erosion rates and sediment transport, while the groins showed moderate effectiveness. This study's findings significantly contribute to evaluating the effectiveness of coastal protection structures and highlight the value of UAV-based coastal monitoring as a cost-effective and efficient alternative to traditional methods.

Living on the Coast in Harmony with Natural Processes

The coastal zone is a fascinating place that comprises the interface between sea and land. This interface, which is both very dynamic and sensitive, has been affected by strong urban and industrial pressures, and an increase in both traffic and recreational uses, leading to the deterioration of natural habitats and the growing instability of residential areas. Added to this disruption is ongoing climate change, which will lead to rising sea levels and increased wave action. Another problem we are increasingly concerned about is ocean pollution, which has been one of the main causes of threats to deep-water coral reef areas. The main sources of pollution include oil spills and offshore oil drilling. The effects of pollution caused by oil spills can not only seriously affect the global environmental balance of our planet but can also, on a different scale, seriously affect the economy of countries whose main resources depend heavily on the sea. Wave energy has the potential to alleviate the world's dependence on depleting fossil energy resources. With regard to coastal protection, the development of ecological solutions to preserve ecosystems and address coastal processes as an alternative to traditional coastal protection structures (seawalls, groins and breakwaters) is becoming increasingly important. These structures, generally referred to as passive measures, are usually built to alter the effects of sea waves, currents and the movement of sand along the coastline, with the aim of protecting beaches, ports and harbors. The concerns outlined are critically addressed throughout this review article. All of them are highly relevant today and, as demonstrated throughout this article, are expected to grow even more and with much more pronounced consequences starting from the middle of the current century.