Coastal Stretch Research Articles

Multiple proxies to investigate the submarine groundwater discharge into the Arabian Sea, Southwest coast, India: integration of biogeochemical, geophysical, and remote sensing techniques.

Submarine Groundwater Discharge (SGD) constitutes a pivotal mechanism for the transference of freshwater, nutrients, and pollutants from terrestrial to marine environments, exerting a profound influence on coastal water quality and ecosystem dynamics. In this investigation, we executed an extensive field sampling campaign along the 650km coastal expanse of southwest India, employing a 10-km sampling interval, to discern and validate the probable zones of SGD. We have utilized a transect-based methodology for the systematic collection of groundwater, porewater, and seawater samples, employing a suite of proxies to scrutinize SGD). This multifaceted approach encompassed biogeochemical, geophysical, and remote sensing techniques. The in situ physio-chemical parameters, encompassing electrical conductivity (EC), total dissolved solids (TDS), pH, dissolved oxygen (DO), temperature, and salinity, facilitated the delineation of prospective SGD sites. Adjacent continuous probable SGD sites were amalgamated into nine potential SGD zones spanning the 650km coastal stretch. Comprehensive analyses of major ions and nutrients revealed maximum observed seawater concentrations of nitrate, phosphate, and silica at 22.11µM/L, 12.5µM/L, and 11.69µM/L, respectively, underscoring the SGD signatures and the subsequent transference of nutrients from terrestrial sources to the ocean via subsurface pathways. Furthermore, geophysical investigations employing Electrical Resistivity Tomography (ERT) at the nine potential SGD zones substantiated the groundwater signatures, elucidating subsurface lithology, delineating the aquifer system, and determining the extent of the saline-freshwater interface, including discharge depth. All ERT profiles were meticulously calibrated against available lithological data. Additionally, we executed a comprehensive evaluation of Landsat-8 satellite imagery within the thermal infrared spectral domain (10.6-11.19μm) to monitor variations in sea surface temperature (SST) and sea surface anomalies across three stratified thermal ranges (21-28°C, 25-33°C, and 11-23°C) encompassing the entire study area. The visual correlation observed between lower SST values and the identified SGD probable zones further substantiates supplementary validation. Ultimately, the verification of these nine prospective SGD zones was reinforced through a meticulous comparison with groundwater level data, which ranged from 0 to 41m above mean sea level (MSL). This extensive investigation represents the inaugural comprehensive identification and confirmation of SGD zones along the southwest coast of India, spanning a 650-km stretch, resulting in a more precise demarcation of the area into nine SGD probable zones where multiple proxies are mutually corroborative.

Analyzing and Modeling Shoreline Variability at the Barrier Spit of Chilika Lagoon

Shoreline change has emerged as an alarming threat to the coastline worldwide, impacting the natural environment and human development. Among India’s coastal lagoons, Chilika Lagoon bears international importance for its rich biological significance. However, growing coastal erosion along the Odisha coast poses a significant concern for the lagoon’s stability. The present study investigates shoreline change along the 80 km coastal stretch of Chilika Lagoon over a 46-year period (1975–2020) using the DSAS 5.0 model. The coastline was divided into four zones, each exhibiting distinct patterns of erosion and accretion. Overall, accretion dominated over erosion, with Zone 2 showing the least variability and Zone 3 experiencing the highest accretion rates, particularly after the artificial opening of the Sipakuda inlet in 2000. Zone 4, with high variability, demonstrated a lower rate of accretion. Shoreline predictions for the period 2013–2040, using the LITLINE model, revealed both erosional and depositional trends, with significant shoreline advancement to the south of Gabakunda inlet and recession to the north of Dhalabali inlet. Cyclonic storm landfall positions and inlet dynamics were identified as key contributors to shoreline change, especially in Zones 3 and 4. Future wave climate simulations suggest the lagoon is not at immediate risk from wave climate. The study highlights the vulnerability of the northern spit, with recommendations for strategic inlet management, mangrove restoration, and periodic dredging of inner channels to mitigate shoreline erosion. These measures align with the principles of SDGs 13, SDG 14, SDG 11, and SDG 15, supporting sustainable coastal management practices. This research underscores the importance of balancing ecological preservation with climate resilience in coastal management efforts.

Microplastic pollution from pellet spillage: Analysis of the Toconao ship accident along the Spanish and Portuguese coasts.

Microplastic pollution from pellet spillage: Analysis of the Toconao ship accident along the Spanish and Portuguese coasts.

Key environmental predictors as drivers of avifauna assemblages in Ghana’s coastal ecosystems

Avian assemblages are not only influenced by spatial factors but also by temporal variations in environmental conditions, creating dynamic patterns of bird presence in a given area. This study examined environmental elements affecting bird assemblages in Ghana's coastal ecosystems. We conducted point transect sampling along a 15-km coastal stretch, analyzing bird abundance, richness, and diversity in relation to microclimate and urbanization. Humidity and wind speed had a significant negative relationship with bird abundance as well as time of day (morning) having a negative relationship. Mean bird richness, diversity, were significantly higher in natural shoreline areas compared to urbanized ones. Bird abundance and seasonality were positive related where wet season was characterized by higher bird numbers which can be attributed to the favorability of the wet season in terms of food availability and habitat suitability. Indicator Species Analysis identified nineteen species significantly associated specific habitat characterization, with eleven species linked to lagoon adjacent shorelines. These results show the relationship between environmental factors and avian assemblages in coastal ecosystems, highlighting impacts of human disturbance and climate-related factors and the importance of pristine ecosystems in biodiversity conservation.

Occurrence and Distribution of Microplastics on the Beaches of Limón on the Southern Caribbean Coast of Costa Rica

This study aimed to characterize the temporal and spatial occurrence of microplastics on the beaches of the Caribbean coast of Limón, Costa Rica. The selected beaches comprise a stretch of 70 km, characterized by large environmental protection areas, agricultural and residential areas with low occupation density, urban areas, and port areas. Despite the great importance of the beaches for the country, studies related to solid waste pollution remain scarce on the Caribbean coast. The methodology consisted of conducting fieldwork in 2017 and 2019 to collect materials on five beaches and laboratory analyses for extraction using hypersaline solution and the quantification and characterization of microplastics based on type, size, and color. The results show that the beaches studied in the northwestern sector had the highest concentrations of microplastics, with emphasis on Cieneguita Beach and Airport Beach, with a predominance of pellets (56.7%) followed by fragments (21.8%). These beaches are inserted in a coastal stretch with a strong concentration of industrial, port, and airport activities. The lower occurrence of microplastics in the southeastern sector (Manzanillo and Gandoca) may be related to the greater number of preservation areas. With varying sizes, shapes, and colors, most microplastics had a worn appearance, which suggests reworking by coastal processes and subsequent deposition on the studied beaches. The impact of this type of pollution on the coast of Limón is notorious and shows the need for further research into the occurrence and distribution of microplastics on Caribbean beaches so that possible sources and damage to coastal ecosystems can be identified.

An integrated coastal exposure modelling approach to Foster mangrove-based disaster risk reduction (eco-DRR) in Tamil Nadu, India

This paper attempts to measure the role of the mangrove ecosystem in minimizing coastal exposure using the InVEST (V3.9.0) Coastal Vulnerability Assessment (CVA) model in Tamil Nadu, India. The result depicts that the exposure value of the Tamil Nadu coastal stretch varies from 1.71 to 4.78 on a five-point scale. More than half of the coastal segments in Tamil Nadu have high to very high exposure, whereas nearly 10 % of the coastal segments are recorded under very low exposure. The model demonstrated that having the existing mangrove patches in the Pichavaram and Muthpet regions significantly reduces the exposure value from 3.47 to 2.80 and 4.78 to 2.10, respectively. Further, the present study modelled the impact of future Sea Level Rise (SLR) on the mangrove ecosystems using a static inundation modelling approach under different Representative Concentration Pathways (RCPs). Results depict a significant loss of mangrove habitats from 9.55 % to 58.33 % and 20.88 % to 48.02 % for both the Pichavaram and Muthupet mangrove regions, respectively, by the end of this century (2100). Since the coastal hazards are expected to intensify, our results can benefit policymakers by highlighting the prioritized areas and location-specific interventions for fostering ecosystem-based disaster risk reduction (Eco-DRR) strategies.

Initial examination of marine microplastics along Jaffna Peninsula's coastal stretch in the Palk Strait, northern Sri Lanka.

Microplastics are pervasive pollutants in marine ecosystems worldwide and are increasingly recognized as a significant environmental threat. Sri Lanka, an island nation, is not exempt from this issue. While microplastic pollution has been extensively studied in the southern and western parts of Sri Lanka, limited data is available for the northern coastal regions. This first quantitative study aimed to assess the concentration of microplastics on three northern beaches: Mathagal, Point Pedro, and Charty Beach. This study reveals substantial microplastic contamination, with an average abundance of 11.06 ± 6.06 items/m2. The predominant size range of microplastics was 3 to 4 mm (32%). The most common shapes identified were fragments (58%), pellets (17%), and foam (10%), with the primary colours being white (42%), blue (26%), and green (21%). Polyethylene (53%) and polypropylene (18%) were the most prevalent polymers found. Among the beaches studied, Point Pedro had the highest pellet pollution index (PPI), although all three beaches were categorized as having a "very low" PPI level (0.0 < PPI ≤ 0.5). The study highlights the significant contribution of land-based sources to microplastic pollution on these beaches and emphasizes the urgent need for ongoing research and systematic monitoring of microplastic pollution in northern Sri Lanka.

A cluster of Pleistocene hominin ichnosites on South Africa’s Cape South Coast

Seven Pleistocene tracksites and two lithic sites, identified with varying degrees of confidence and attributed to Homo sapiens, have been identified in aeolianite deposits along a 1200 m coastal stretch at Brenton-on-Sea on South Africa’s Cape south coast. Some sites contain more than one track- or trace-bearing layer, and each site is from a geological different unit. The aeolianites adjacent to the ichnosites that have been dated span an age range from 113 ± 8 ka to 76 ± 5 ka. Globally, hominin tracks preserved in aeolianites are rare, as are tracks preserved in hyporelief, which are observed at several of the Brenton-on-Sea sites. Clusters of hominin tracksites older than 40 ka are also rare. The sites represent groups of hominins of different sizes traversing dune fields, sometimes jogging or using sticks, and provide details of their tool-making and diet. The ichnological record thus complements the extensive and globally significant archaeological record from the region. The likely presence of nearby accessible caves, and a shoreline that was not too distant, provide an explanation for the profusion of ichnosites and their registration over millennia.

Microplastic dynamics and risk projections in West African coastal areas: Developing a vulnerability index, adverse ecological pathways, and mitigation framework using remote-sensed oceanographic profiles

Microplastic dynamics and risk projections in West African coastal areas: Developing a vulnerability index, adverse ecological pathways, and mitigation framework using remote-sensed oceanographic profiles

Investigating Holocene relative sea-level changes and coastal dynamics in the mid-Tyrrhenian coast, Italy: An interdisciplinary study

Investigating Holocene relative sea-level changes and coastal dynamics in the mid-Tyrrhenian coast, Italy: An interdisciplinary study

An updated reconstruction of Campi Flegrei caldera (southern Italy) ground deformation history and its interaction with the human sphere since Roman time

An updated reconstruction of Campi Flegrei caldera (southern Italy) ground deformation history and its interaction with the human sphere since Roman time

Defining an exposure index along the Schleswig-Holstein Baltic Sea coast

Defining an exposure index along the Schleswig-Holstein Baltic Sea coast

Urban Landscape Management of Makassar City Based on Waterfront City Concept

Abstract Makassar City is one of the coastal cities in Indonesia with a 32 km long coastline. This extensive coastal stretch harbors numerous potential natural resources. Recognizing the coastal region’s potential, the government has been implementing the Waterfront City concept to develop and manage this area. Since 2003, the Makassar City government has actively undertaken revitalization and reclamation efforts in the coastal zone, aiming to establish various facilities including commercial areas, public parks, residential zones, and tourism infrastructure, all with the aim of achieving the status of a waterfront city. However, these ongoing development and reclamation activities are inevitably transforming the coastal landscape, bringing about both positive and negative changes. On the downside, there are adverse effects such as deteriorating water quality and diminishing mangrove areas. Conversely, there has been an increase in tourist arrivals, showcasing a positive aspect. This study aims to assess the suitability of land in the coastal areas and the visual appeal of Makassar City’s waterfront, providing recommendations for coastal landscape management. Based on the analysis of land suitability and the aesthetics of the coastal area of Makassar City, the urban areas generally possess land suitable for implementing the waterfront city concept, categorized into three zones: tourism, residential, and conservation, to optimize land functionality. Besides the quality of the beautiful coast has a fairly good value with a neat and clean conditions.

Rock-fall runout simulation using a QGIS plugin along north–west coast of Malta (Mediterranean Sea)

Coastal instability in the form of rock fall is widespread along the northern coasts of Malta and is strictly connected to structural controls, such as lithology and tectonics. The local geological and geomorphological setting combined with extreme weather events, whose spatial and temporal occurrence is enhanced by ongoing climate and land use change, determines rock-fall hazard along the north–west coast of Malta, a hotspot for Mediterranean tourism. The present research portrays the results of a pilot study aimed at analyzing rock-fall runout probability along this stretch of coast. Cliffs and downslope terrains were the object of detailed field surveys. This included the detection of persistent joints in the source areas and the identification of slope-forming materials like debris and boulders present along the downslope terrains. The outcomes of the field surveys and GIS-based processing of topographic information were used for identification of the input parameters for rock-fall runout simulation. The latter was performed using a QGIS based plugin (QPROTO) that allows to determine expected runout extents and assess the rock-fall susceptibility. The result is the characterization and mapping of rock-fall runout probability zones along six investigated sites. The outputs of the research and the replicability of the method can be of interest for authorities aiming at defining risk management actions and undertaking mitigation measures compliant with sustainable development of coastal areas.

Evolution of Coastal Environments under Inundation Scenarios Using an Oceanographic Model and Remote Sensing Data

A new methodology to map Italian coastal areas at risk of flooding is presented. This approach relies on detailed projections of the future sea level from a high-resolution, three-dimensional model of the Mediterranean Sea circulation, on the best available digital terrain model of the Italian coasts, and on the most advanced satellite-derived data of ground motion, provided by the European Ground Motion Service of Copernicus. To obtain a reliable understanding of coastal evolution, future sea level projections and estimates of the future vertical ground motion based on the currently available data were combined and spread over the digital terrain model, using a GIS-based approach specifically developed for this work. The coastal plains of Piombino-Follonica and Marina di Campo (Tuscany Region), Alghero-Fertilia (Sardinia), and Rome and Latina-Sabaudia (Lazio Region) were selected as test cases for the new approach. These coastal stretches are important for the ecosystems and the economic activities they host and are relatively stable areas from a geological point of view. Flood maps were constructed for these areas, for the reference periods 2010–2040, 2040–2070, and 2040–2099. Where possible, the new maps were compared with previous results, highlighting differences that are mainly due to the more refined and resolved sea-level projection and to the detailed Copernicus ground motion data. Coastal flooding was simulated by using the “bathtub” approach without considering the morphodynamic processes induced by waves and currents during the inundation process. The inundation zone was represented by the water level raised on a coastal DTM, selecting all vulnerable areas that were below the predicted new water level. Consequent risk was related to the exposed asset.

Temporal variability of sea surface temperature affects marine macrophytes range retractions as well as gradual warming

Record mean sea surface temperatures (SST) during the past decades and marine heatwaves have been identified as responsible for severe impacts on marine ecosystems, but the role of changes in the patterns of temporal variability under global warming has been much less studied. We compare descriptors of two time series of SST, encompassing extirpations (i.e. local extinctions) of six cold-temperate macroalgae species at their trailing range edge. We decompose the effects of gradual warming, extreme events and intrinsic variability (e.g. seasonality). We also relate the main factors determining macroalgae range shifts with their life cycles characteristics and thermal tolerance. We found extirpations of macroalgae were related to stretches of coast where autumn SST underwent warming, increased temperature seasonality, and decreased skewness over time. Regardless of the species, the persisting populations shared a common environmental domain, which was clearly differentiated from those experiencing local extinction. However, macroalgae species responded to temperature components in different ways, showing dissimilar resilience. Consideration of multiple thermal manifestations of climate change is needed to better understand local extinctions of habitat-forming species. Our study provides a framework for the incorporation of unused measures of environmental variability while analyzing the distributions of coastal species.

Geospatial technology based shoreline change analysis (1992–2022) and predictive forecast modeling for 2032 and 2042, utilizing DSAS, along the eastern coast of India

Geospatial technology based shoreline change analysis (1992–2022) and predictive forecast modeling for 2032 and 2042, utilizing DSAS, along the eastern coast of India

Factors Controlling the Formation and Evolution of a Beach Zone in Front of a Coastal Cliff: The Case of the East Coast of Evia Island in the Aegean Sea, Eastern Mediterranean

The present study examines the recent evolution of a cliff coast along the Aegean Sea, considering its geotectonic context, oceanographic factors, sediment dynamics, and human impact. Initially, the formation of this coastal stretch was influenced by neotectonic faults, oriented both semi-parallel and diagonally relative to the present coastline orientation (NE–SW). Subsequently, the delivery of terrestrial sediment from ephemeral rivers and cliff erosion, along with nearshore wave-induced hydrodynamics have played a secondary role in shaping its current configuration, which includes a beach zone along the base of the cliff. This secondary phase of coastal evolution occurred over the past 4–5 thousand years, coinciding with a period of slow sea level rise (approximately 1 mm/year). Evidence such as uplifted notches and beachrock formations extending to around 5 m water depth suggests intervals of relative sea level stability, interrupted by episodic tectonic events. Anthropogenic interventions, related to both changes in coastal sediment budget and coastal engineering projects, have caused beach erosion, particularly in its central and northern sectors.

Coastal flood susceptibility assessment along the Northern coast of Portugal

Coastal flood susceptibility assessment along the Northern coast of Portugal

First estimates of Common Sandpiper &lt;i&gt;Actitis hypoleucos&lt;/i&gt; and Ruddy Turnstone &lt;i&gt;Arenaria interpres&lt;/i&gt; wintering along the coast of Trapani (Sicily, Italy)

A census was carried out using the method of transects along stretches of coast of the Province of Trapani in order to estimate the wintering population of Common Sandpiper and Ruddy Turnstone. Although the International Waterbird Census (IWC) provides accurate estimation of wintering waders in Italy, the number of wintering individuals of Common Sandpiper Actitis hypoleucos and Ruddy Turnstone Arenaria interpres are strongly underestimated. The reason for this underestimation lies in the type of habitat they are used to populate along with the solitary life habits of the Common Sandpiper. To address this issue, we inspected 46.9 km of coastline where we recorded to 92 Ruddy Turnstones and 56 Common Sandpipers. For both species, the sites (coast) where bird-sightings occurred were marked with georeferenced data and classified as harbour area, sandy, rocky (including vermetid reefs) and posidonia banquettes. For each species, the IKA (Index of Abundance per Kilometer) was calculated, both global index and relative to each type of coast. As for the Common Sandpiper we observed 87 individuals, between transects and spot observations in the province of Trapani, which is the 22% of the whole wintering population estimated in Italy. Notably, even greater is the importance of our observations of the Ruddy Turnstone, which accounting for up to 154 individuals corresponds to the 71% of the whole Italian wintering population. Projection of these data to the entire Italian coast allows estimating a wintering population in Italy much larger than that reported so far, especially for the Common Sandpiper, which uses not only the sea cost but also inland wetlands and rivers as suitable wintering habitats for wintering.