Sandy Shores Research Articles

A brief review on Antibacterial activity of Citrullus Colocynthis

Due to contamination or the rapid microbial growth that happens naturally in fish, seafood is very poorly preserved. Fish storage facilities commonly employ artificial preservatives to guarantee quality and safety while prolonging shelf life. Natural preservatives originating from plants, animals, and microbes have been shown to have the ability to take the place of synthetic antimicrobials. The bitter fruit Citrullus colocynthis has been used as a natural preservative. It belongs to the family Cucurbitaceae. The wild melon species also known as colocynth produces cantaloupe-sized fruits with a bitter flavor and seeds that are high in protein and oil. It is a prolonged perennial that thrives in xerophilic environments on sandy shores. When young, fruits are plump and speckled with dark green; when ripe, they typically become yellow. Since ancient times, the fruit of colocynthis has been used medicinally. The current study intends to investigate antibacterial properties of C. colocynthis on gram-negative bacteria E.coli & gram positive bacteria S.aureus. Natural antimicrobials derived from plants, animals, and microbes have the potential to replace chemical antimicrobials. Utilizing UV spectrometery, the chemical characterization of extracts was accomplished. Nile tilapia fish species was used for this experiment to determine antibacterial potential of C. colocynthis.

Balancing recreation and flood safety for integrated coastal management: Understanding beach visitors' types of attitude and behaviour in sandy anthropogenic shores

In the Netherlands, with its coastal lowlands, coastal management is performed through sand nourishment and dune utilisation. While policy aims for multifunctionality, coastal management studies predominantly emphasise flood safety, neglecting the recreational function and its interplay with flood safety measures. This study aims to investigate beach visitors' views and behaviour at two reinforced sandy shores in the Netherlands, namely Sand Motor and Hondsbossche Dunes. As the magnitude of the sand-based reinforcements completely changed the original beach landscape, we refer to these as sandy anthropogenic shores (SAS). We conducted surveys to assess SAS visitors' profiles, attitudes (visit motivations, landscape attractiveness), and recreational behaviour (facility preferences, activities, visitation patterns, spatial distribution). We examined differences between SAS and non-SAS beach visitors and compared their perspectives with management expectations. In our analysis, we categorised visitors into three types: local, one-day, and overnight visitors. Our analysis identified three distinct visitor motivation clusters: socialising, relaxation while appreciating beach landscapes, and engaging in sports activities. Natural landscape quality and quietness were the top attractions for SAS visitors. Despite significant human intervention in the design and alteration of the SAS landscape, visitors still appreciate its natural dynamics and beauty. Our analysis indicates that users perceive the SAS as either natural or semi-natural beaches, as intended by their designers and managers. We also developed a conceptual framework of the SAS recreation model based on survey data, forming the foundation for a quantitative model of SAS socio-environmental dynamics in the next phase of our research. Moreover, considering the similarities between SAS and natural shores, we anticipate that our findings will have broad applicability well beyond the specific SAS we have studied.

Variation in Community Structure and Abundance of Fish in Simple Structured Shallow Sandy Habitats

ABSTRACTSandy beaches and their surf zones characterise many of the world's open coastlines. They are important breeding, nursery and feeding areas for many species of fish. Despite the commonness and importance of sandy beach surf zones, the dynamics, space occupancy and diversity patterns of residing fish is in many places poorly understood. The aim of this study was to (1) characterise the fish community structure in 11 simple structured sandy surf zones of the northern Baltic Sea and (2) relate variation in fish abundance and community structure to a set of chosen abiotic variables. Using beach seine, weekly or biweekly sampling was conducted at fixed sites at 10 occasions throughout a summer season. A total of 60,006 fish individuals belonging to 20 species were recorded. Changes in abundance and community structure were mainly driven by the variation of only five species reflecting species‐specific recruitment patterns and different spatial responses to abiotic variables. Dominating groups were Gasterosteidae, Ammodytidae and Gobiidae that together formed 86% of the total adult fish catches. Larval numbers were completely dominated by Gobiidae. Multivariate analyses indicated species‐specific responses to measured environmental variables, most important being a combination of wave exposure, beach slope, bottom roughness, and temperature. The present study shows that changes in fish abundance on simple structured sandy sublittoral beaches in the northern Baltic Sea are large over the course of a breeding season. It also reveals that variation in adult and juvenile fish are driven by a set of abiotic factors that influence on the fish assemblage structure through mainly species‐specific, rather than through generic responses. Unravelling the degree to which the sandy shore fish community vary in the northern Baltic Sea will help in managing coastal environments that are increasingly being threatened by many anthropogenic stressors.

Drivers of variability in surf zone habitat use by sandy beach fish: Unwitting citizen scientists reveal detailed spatiotemporal patterns

Surf zones of sandy beaches are among the most heavily impacted aquatic ecosystems, yet are of critical ecological importance for inshore fish and fisheries. Knowledge of the drivers of fish habitat use in surf zones is needed across broad scales to advise conservation and fisheries management, but sampling capabilities can be limited in spatio-temporal extent and resolution. The lesser weever Echiichthys vipera is a small, benthic, venomous fish that dominates surf zone fish assemblages in Northwest Europe and inflicts painful stings on beachgoers. This study capitalises on an extensive record of E. vipera sting incidents to characterise variations in surf zone habitat use in relation to key physical environmental factors. Sting incidents, standardised by water user numbers, are used as a proxy for E. vipera abundance across 77 beaches throughout Southwest England, with 2 h resolution, from April–November 2018. General Additive Models indicated a clear peak in E. vipera abundance at spring low tides, in the afternoons of summer months, under calmer wave conditions and at higher levels of solar irradiance. Although the order of significance differed, human water users were also driven by the same variables, compounding sting interactions over time. Key physical variables did not explain spatial variation in E. vipera abundance, although there was a weak relationship with sea surface temperature, and some evidence that reflective beaches are unsuitable. Physical factors explained more spatial variation in human water users, who gathered at more dissipative beaches with greater wave heights. This detailed study of an important surf zone fish reveals clear drivers of temporal variation in habitat use, yet infers wide suitability of beaches varying in the key physical drivers of sandy shore ecology.

Intertidal assemblages on groynes along sandy shores in Portugal: Exploring the effects of orientation and distance to rocky shore

Coastal erosion is becoming increasingly problematic as sea level rise and coastal areas become more urbanised. In response, more defence structures such as groynes are being built, which are crucial for counteracting sediment loss and coastline retreat. Despite worldwide use, comparatively little is known about the factors that determine the species composition on such structures. In this study, the composition and abundance of intertidal benthic species on groynes was investigated as a function of groyne orientation (North vs. South) and distance to natural rocky shores (5 km vs. 42 km). While orientation showed no effect on benthic assemblages, distance to rocky shores was identified as a key factor influencing the assemblage composition. Macroalgae were found in greater abundance further away from rocky shores, while snail and barnacle species were found in greater numbers closer to rocky shores.

Management of Coastline Variability in an Endangered Island Environment: The Case of Noirmoutier Island (France)

This article presents a diachronic study of evolution along the coastline of Noirmoutier Island in France, a sandy shore particularly susceptible to erosion and submersion risks, which are exacerbated by climate change due to two-thirds of its territory being below sea level. The study is based on an analysis of aerial images covering a period of 72 years, divided into five distinct periods: 1950–1974, 1974–1992, 1992–2000, 2000–2010, and 2010–2022. The methodology used combines two complementary approaches: the Digital Shoreline Analysis System (DSAS) for taking linear measurements of the erosion and accretion that have taken place along various shorelines, and the surface method to evaluate the amount of surface lost or gained between different shorelines while calculating the uncertainties associated with the obtained results. The overall trend observed between 1950 and 2022 indicates that the Noirmoutier coastline studied has gained surface area (81 hectares) at an average rate of +0.57 ± 0.06 m per year. The article then presents an application of the method developed by Durand and Heurtefeux in 2006 to estimate the future position of the shoreline. A map of the local area is also provided, identifying the areas susceptible to coastal erosion by 2052 and by 2122, in accordance with the provisions of the Climate and Resilience Law adopted in France on 22 August 2021. The results reveal that there are many sources of uncertainty in predicting the future evolution of the shoreline using this methodology. Therefore, it is crucial to consider these uncertainties when planning future coastal management actions and adopting appropriate adaptation methods to counteract unforeseen developments.

Correction: Harenda et al. Spatio-Temporal Morphodynamics of a Nourished Sandy Shore Based on LiDAR Measurements. Water 2024, 16, 1055

There was an error in the original publication [...]

HERMIT CRABS (CRUSTACEA: DECAPODA: ANOMURA) IN ADEN COASTS AT THE GULF OF ADEN WITH A NEW RECORD

The information on the hermit crab diversity on the northern shore of the Gulf of Aden is very limited and almost completely unknown. This study aims to record the hermit crab species in different habitats in Aden coasts at Gulf of Aden. The specimens were collected from 7 sites, by hand, and snorkelling up to 3 m depth, during the period time October 2020- October 2022. In this study, 10 hermit crab species were recorded belonging to 3 families (Coenobitidae, Diogenidae, Parapaguridae) belonging to 6 genera. One of these species represents the first records in the Gulf of Aden (Dardanus lagopodes (Forskål, 1775)). The dominant hermit crab on sandy shores was Coenobita scaevola (Forskål, 1775), while the dominant hermit crab in rocky shores was Clibanarius signatus Heller, 1861.

Inducing mussel beds, based on an aquaculture long-line system, as nature-based solutions: Effects on seabed dynamics and benthic communities

Nature-based solutions (NbS) offer a promising path to enhance climate-resilient shorelines. For instance, the creation of mussel beds in subtidal sandy shore systems provides a versatile strategy for coastal management, reinforcing coastal defense and fostering biodiversity, ultimately strengthening the resilience and well-being of coastal communities. This study analysed the changes in seabed dynamics and surrounding benthic communities as a result of the formation of mussel beds (Mytilus edulis) using an aquaculture longline system. Therefore, a comprehensive monitoring approach at two sites characterized by distinct hydrodynamic conditions was applied over a three-year period. To assess the effects, a before/after control/impact design (BACI) was employed. Seabed dynamics were evaluated by observing mussel bed persistence, erosion/deposition, and sediment composition. The influence on the benthic community included assessments of community structure and biodiversity. Finally, the impact of mussels, hydrodynamic conditions, and their interactions on seabed dynamics and benthic communities was examined using linear mixed models (LMMs). Factors such as mussel presence, Lanice conchilega abundance, shell cover, and sediment composition played a role in shaping the distinct characteristics observed between two different sites: a site that lies at a location that is more sheltered from hydrodynamic conditions, and a second site that is exposed to higher current and wave conditions. The sheltered site exhibited higher species density, richness, biomass, and diversity compared to the exposed site. In relation to the mussel bed development, mussel patches were found at both sites (with higher occurrence at the sheltered site) in the 2nd and 3rd years (mainly in summer towards early winter). The influence of mussels on sediment deposition was noticeable at the sheltered site, albeit lacking statistical significance, suggesting their potential role in erosion/deposition mechanisms. Also, a higher proportion of very fine sand was observed in the mussel bed compared to the bare sand. However, due to the absence of higher-density permanent mussel beds and irregular sedimentation/erosion patterns throughout the study period, no significant effect of the mussel beds on the community structure or diversity was found. In order to achieve a sustained and dense mussel bed and maximize the potential impact of mussels in combating climate change (e.g., shore protection and biodiversity enrichment), additional measures to increase coastal resilience against harsh hydrodynamic conditions may be necessary.

Light traps as an exploratory tool in light pollution studies: Assessment of vulnerable species and their migratory patterns

Artificial Light at Night (ALAN) is one of the most widespread stressors on coastal marine habitats. Despite their sparse use in light pollution studies, light traps are a useful methodology to explore which species are attracted by ALAN. For that purpose, we placed light traps during the day and at night in the shallow subtidal adjacent to three natural sandy shores. Additionally, to determine the origin of the catches, the sediment and the water column were also sampled in both periods by a Van Veen grab and a plankton net, respectively. Our results showed that light traps catches at night were dominated by migrant fauna, mostly amphipod crustaceans emerging from the sediment. Other species that perform diel vertical migrations, such as calanoid copepods, were also attracted. This approach may help to understand which taxa are more susceptible to ALAN in these shallow habitats.

The influence of spatial resolution on coastline detection by means of multisource remote sensing data

Identifying an instantaneous coastline through remote sensing data poses a challenge due to various factors, such as the intricate nature of the coast and the selection of the appropriate sensor with its inherent spatial resolution. Even so, accurate identification of the coastline through remote sensing data has immense potential to provide reliable and timely information about the coastal environment. The purpose of this study was to evaluate whether there are spatial differences when detecting a coastline by means of multiple remote sensors. We vectorized orthomosaics from UAV flights during high, mean, and low tides manually, creating three reference baselines. The cross-shore distances from the three vectors were compared to the coastline vectors extracted from a water index, using six different satellite data collected on the nearest possible date to that of the UAV flights, with MODIS Terra, Landsat 8, Sentinel-2, RapidEye, PlanetScope, and Google Earth. The results indicate that the cross-shore distance of the coastline vectors depended directly on the spatial resolution of the sensors. Concerning the mean tide, Google Earth provided the highest accuracy, with a marginal error of 6.7 m, while MODIS provided the largest difference with a margin of 449 m. Our results indicate that future satellite-derived coastline detection approaches should consider the relationship between tide amplitude and spatial resolution on sandy shores.

The complete mitochondrial genome of the sand bubbler crab Scopimera longidactyla Shen 1932 (Decapoda: Dotillidae) and its phylogenetic analysis

The sand bubbler crab, Scopimera longidactyla Shen, 1932 (Arthropoda: Malacostraca: Decapoda: Thoracotremata: Dotillidae), is commonly found along tropical and subtropical sandy shores of China, Korea, and Taiwan. Ecologically, it plays an important role in the productivity of sandy shores through their feeding and burrowing activities. In this study, the first complete mitochondrial genome (mitogenome) of S. longidactyla was analyzed using next-generation sequencer. Its mitogenome, circular in structure, spans 15,965 bp with a GC content of 29.97%, consisting of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, and one putative control region. Its mitogenome arrangement and composition are identical to its two congeners, S. globosa and S. intermedia. Phylogenetic analysis fully supports for the monophyly of the genus Scopimera and the sister relationship between S. longidactyla and S. globosa. The complete mitogenome of S. longidactyla and its phylogenetic implications will provide valuable insights for further studies in phylogenetic and evolutionary biology.

Spatio-Temporal Morphodynamics of a Nourished Sandy Shore Based on LiDAR Measurements

Coastal erosion is a pervasive global phenomenon, exemplified by the Hel Peninsula situated in the Gulf of Gdańsk, the southern Baltic Sea. The geological constitution of the Hel Peninsula, characterized by sandy and loosely consolidated material, predisposes its coastal zones to continual morphological changes. The peninsula’s limited width and elevation exacerbate shoreline erosion, particularly during periods of heightened storm activity. This study scrutinizes the effectiveness of coastal nourishment interventions, with a specific focus on segments influenced by the Władysławowo port and the Kuźnica vicinity, over several years. This specific section of the coast serves as a significant case study due to its role as a transit zone for sand transport along the whole peninsula. Protective measures, including shore nourishments and coastal groynes, aim to mitigate erosion impacts. Utilizing Airborne Laser Scanning (ALS) data spanning from 2008 to 2022, erosion dynamics were analyzed. The analysis reveals significant erosion patterns coinciding with the frequency and volume of nourishment material deposition, particularly evident in heavily nourished areas proximate to Władysławowo and Kuźnica. Despite persistent monitoring endeavors, persistent erosive trends pose imminent threats to Kuźnica’s infrastructure, necessitating further research into the efficacy of implemented coastal protection measures.

Spawn and development of the olivid gastropod Olivancillaria carcellesi from north Patagonia, Argentina

AbstractOlivancillaria carcellesi occurs in shallow sandy shores from north Patagonia, in intertidal and subtidal sandy bottoms. Females of O. carcellesi exhibited a remarkable specificity for spawning on the shells of living males and females, indiscriminately, of the buccinanopsid Buccinastrum deforme, measuring 26.9 ± 4.7 mm in shell length. The egg capsule was semispherical and attached to B. deforme shells by a small elliptical and wide base. The capsule was translucid when spawned, with a thick and semirigid wall and a hatching aperture of 1.8 ± 0.1 mm (n = 111) in diameter. Each egg capsule contained a single egg that measured 1367 ± 34 μm (n = 5) in diameter before cleavage. The embryo developed a small bilobed velum and an operculum, which were both lost before hatching as a crawling juvenile of 1762 ± 47 μm (n = 28) in shell length. As in other species in the genus, the eggs of O. carcellesi are among the largest in the caenogastropods with direct development. The time from oviposition to hatching is estimated to be approximately 6 months.

Application of Shore Sediments Accumulated in Navigation Channel for Restoration of Sandy Beaches around Pärnu City, SW Estonia, Baltic Sea

Sandy beaches high in recreation value make up 16% of the over 4000 km long shoreline of Estonia. The shore processes associated with climate change have remarkably accelerated over recent decades. Many sandy shores have suffered from strong erosion, including an excellent former beach at Valgeranna. The jetties, which were built in the 1860s to protect the navigation channel of Port Pärnu from clogging, have prevented natural sediment transport along the coast from south to north. At the same time, the sandy beach in Pärnu is expanding, and part of the sand accumulates with strong storms also in between the jetties, reducing the width of the shipping channel. The channel needs regular dredging, but, so far, the dredged sediment has been taken far away to the open sea and accumulated on the seabed. The current paper addresses the possibilities of using that sand for beach restoration in destructed and eroded areas. An overview of the applied methods and measurements during field studies is given. The results of modelling the processes of wave activity and sediment transport are discussed. The recycling of shore sediments is an important measure in sustainable coastal zone management. Different options and scenarios are analysed in order to find the most reasonable ways to bring sand back onto beaches and stabilize natural processes. Support from the state by working out respective laws and regulations would be motivating as well.

A global analysis of how human infrastructure squeezes sandy coasts

Coastal ecosystems provide vital services, but human disturbance causes massive losses. Remaining ecosystems are squeezed between rising seas and human infrastructure development. While shoreline retreat is intensively studied, coastal congestion through infrastructure remains unquantified. Here we analyse 235,469 transects worldwide to show that infrastructure occurs at a median distance of 392 meter from sandy shorelines. Moreover, we find that 33% of sandy shores harbour less than 100 m of infrastructure-free space, and that 23–30% of this space may be lost by 2100 due to rising sea levels. Further analyses show that population density and gross domestic product explain 35–39% of observed squeeze variation, emphasizing the intensifying pressure imposed as countries develop and populations grow. Encouragingly, we find that nature reserves relieve squeezing by 4–7 times. Yet, at present only 16% of world’s sandy shores have a protected status. We therefore advocate the incorporation of nature protection into spatial planning policies.

The evolution of Kariat Arekmane Coast (province of Nador-Morocco) diachronic study and evaluation of proposed solutions

The coastline of the Nador region, in particular at Kariat Arekmane, is undergoing rapid changes influenced by natural and human factors, including submersion and erosion. An analysis of the coastline in this area has been performed in order to better understand these changes. The study began with a granulometric analysis, followed by a diachronic analysis of the coastline using the DSAS method in a GIS-ARCGIS environment. The results reveal significant variations in the study area, alternating between accretion and erosion. On average, the annual erosion rate is 0.66 m/year, while the accretion rate is 0.21 m/year. The average coastal change at Kariat Arekmane is 1.102 m/year, divided into two sectors: the first, undergoing severe erosion, comprises sandy shores and cliff areas, while the second, the western beach, benefits from accretion due to protective rock structures. The main causes of these coastal changes are coastal infrastructures and hydrodynamic forces. To solve this problem, several solutions for preserving Arekmane's coastline are currently being proposed and evaluated. Appropriate coastal management is essential to protect this region and mitigate the adverse effects of coastal erosion.

Evolution of sandy shores under the combined impact of global climate change and anthropogenic activities in Shandong Peninsula, East China

Most sandy shores (SSs) are currently experiencing erosion to various degrees due to the combined impact of increasing climate change and human activities. In order to reveal the evolution of the SSs in the Shandong Peninsula (SP), shoreline and elevation changing data are obtained from 29 SSs and results show that most (27 of 29) of the SSs exhibited erosion. The length of the SSs has decreased by 241.4 km from 2010 to 2020, and the average shoreline recession rate was found to be 1.0 m/a and the downward erosion rate was in the range of 0.05 to 0.10 m/a. Climate change-induced sea level rise has a smaller effect on the erosion in the short term and the construction of massive coastal engineering structures has become a major cause of local coastal erosion. The coastal erosion rate caused by river damming and sand mining in the early years has abated and reduced seaward sediment transport induced by the expansion of the built-up area has become a new factor of coastal erosion. In the past decade, the 672 km2 net increase in land area mainly originated from human activities, has occupied the original space for hydrodynamic energy dissipation, which has severely disrupted the balance between sediment supply and the hydrodynamic environment and the system then rebalance itself by eroding unprotected SSs. Therefore, with the increase in hydrodynamic forces caused by climate change and the scarcity of sediment supply caused by human activities, continued erosion is expected to occur in the SSs.

Archaeology of Australia’s coastline: The role of geomorphology in the visibility and preservation of archaeological deposits on sandy shores, with a Gippsland case study

In Australia as elsewhere in the world, coastal archaeological sites are increasingly threatened by rising seas and changing storm patterns, along with encroaching human activities. Understanding the geomorphological context is key to understanding the positioning of archaeological deposits in or on coastal landforms, their vulnerability to erosion and their resilience and capacity for longer-term management and preservation. Here we review the dynamics of beach-barrier systems to contextualise the potential of archaeological deposits to survive erosional processes, especially those associated with current and anticipated impacts of climate change. In doing so, we outline a practical logic for zoning coastal landforms and processes by their proclivity to either erode or preserve archaeological deposits, to assist in the planning of management agendas. It is the sediment budgets and how they change in relation to variation in sea level that fundamentally determine the potential preservation of archaeological deposits in coastal beach-barrier environments. We advocate close transdisciplinary collaboration between archaeology, geomorphology and site managers (i.e. Traditional Owners and land-and-sea management agencies) to better understand the wider landscape dynamics of coastal archaeological sites and landscapes.

Aeolian Landforms in the White Sea Coast: a Review of Classification and Spatial Distribution

This research provides classification and analysis of the spatial distribution of the Holocene aeolian landforms within the White Sea Coast. We identified 5 types of secondary dunes based on the interpretation of detailed satellite images, topographic charts and analysis of literary sources: foredune plains and beach ridges plains, cliff-top dunes, blowouts and parabolic dunes, transgressive dunefields, sand sheets. The dunes were formed mainly from the Middle-Late Holocene. They gravitate towards sandy shores, where post-glacial uplift rates didn’t exceed ~3 mm/year during the Middle-Late Holocene. The coastal dunes were formed in connection with sediments, which entered the coastal zone with solid river flow and from selective erosion of glacial deposits. The rhythms of aeolian processes activation in different parts of the White Sea Coast were non-synchronous.