Search Results (329)

Mangrove prop root epifaunal communities support coastal biodiversity by providing habitat and refuge for associated sessile species and contributing to larval supply. Yet, regional surveys across latitudinal gradients in southeast Florida remain scarce. Understanding how these communities vary spatially and temporally is essential for forecasting biodiversity responses to environmental change. This study tested how macrobenthic assemblage composition and beta diversity on red mangrove prop roots vary from Key West to Melbourne, Florida. Presence-absence data from 32 sites in four zones were analyzed using beta diversity partitioning, indicator species analysis, and temporal turnover metrics. A strong biogeographic boundary near Palm Beach County delineated a species-rich southern pool, formed by the Florida Keys and Miami-Dade and characterized by tropical sponges. Of the 41 indicator species, 34 were associated with these two southern zones, while neither northern zone had exclusive indicators. Northern beta diversity was dominated by nested subsets of a larger species pool rather than species replacement. Over the three years, only Broward-Palm Beach gained species, while the other three zones lost species, though this was not statistically significant. These findings highlight the ecological significance of the potential biogeographic ecotones and provide a baseline study from which to gain insight into how climate-driven mangrove range expansion may impact coastal biodiversity and ecosystem resilience. Full article

Coastal litter accumulates along urban shorelines, yet the floating and stranded litter compartments of tourism-intensive coastal cities are rarely characterised side by side. We conducted monthly macro-litter surveys over one year (April 2023–March 2024) at two Dubrovnik sites less than 200 m apart, each representing a different litter compartment: Porat harbour, a semi-enclosed basin retaining floating litter, and Posat, an urban beach collecting stranded debris. Surveys followed the updated European MSFD marine litter monitoring guidance. In total, 1325 items were recorded at Porat and 1768 at Posat. The harbour was far more variable month to month (coefficient of variation 135% versus 77%), consistent with episodic basin retention. Artificial polymers dominated both compartments (84.9% at Porat; 79.2% at Posat), but the leading category differed: plastic fragments in the harbour and expanded polystyrene on the beach. Composition differed significantly between the two compartments (PERMANOVA, p = 0.038), though the separation was modest. Because each compartment requires a different sampling method, compartment and sampling method are fully confounded; absolute magnitudes are therefore reported separately and not compared. At Posat, where cleaning was suspended, the Clean Coast Index averaged 7.1 (moderate) but ranged from 1.5 to 21.9 between months, spanning all five cleanliness classes. These distinct signatures indicate that single-compartment monitoring may overlook urban coastal heterogeneity, and that mitigation requires compartment-specific measures. Full article

Beach nourishment has become one of the principal soft-engineering strategies for mitigating coastal erosion while preserving the recreational, environmental and protective functions of sandy beaches. During the last four decades, Spain has accumulated extensive experience in beach nourishment, with annual nourishment volumes approaching 10 million m³ under a wide range of coastal settings. Many of the best-documented engineering examples originate from the Gulf of Cadiz, although the lessons synthesized here are interpreted within the broader context of Spanish coastal practice. This structured narrative review combines publications retrieved from Web of Science and Google Scholar with Spanish technical reports, project records, and institutional sources. It focuses on borrow-area characterization, sediment compatibility, construction quality control, post-nourishment monitoring, and adaptive management. Rather than providing a chronological description of nourishment projects, this review examines how repeated project implementation, monitoring and maintenance have progressively reduced uncertainty and improved engineering practice. Long-term nourishment performance is controlled more by sediment compatibility, local morphodynamics, and construction quality than by the total sediment volume placed. It also demonstrates that systematic monitoring provides the feedback required to improve future project design, optimize maintenance strategies and support evidence-based coastal management. The principal contribution of four decades of Spanish beach nourishment has been the progressive development of an engineering framework in which quality control, long-term monitoring and accumulated field experience continuously refine project planning and management. Although derived from Spanish practice, the lessons synthesized are broadly applicable to nourishment programs facing increasing pressures from climate change, sediment scarcity and growing environmental constraints. Full article

Wave runup reduces the horizontal beach buffer. At Namho Beach, South Korea, orthorectified CCTV estimation of Remaining Beach Width (RBW) and Stockdon-derived RBW sensitivity to morphology timing were evaluated separately. Sixty 10 min CCTV observation periods along two transects were analyzed. CCTV-derived $P_2$ RBW is a horizontal lower-tail statistic, whereas Stockdon $R_{2\%}$ is a vertical exceedance elevation converted to horizontal RBW; thus Stockdon-derived RBW was treated as an empirical comparator. ADCP wave heights at 24 m depth were reverse-shoaled to deep-water equivalents. Inter-analyst reproducibility was high (120 paired trajectories; RMSE = 0.83 m; $r=0.994$). In the screened $Q_{95}$ cohort, association was moderate with an appreciable error at Transect 1 ($n=35$, $r=0.66$, RMSE = 5.55 m, NSE = 0.18) and weak at Transect 2 ($n=35$, $r=0.24$, RMSE = 4.53 m, NSE = −0.44). Survey-matched agreement was stronger ($n=25$ per transect; r = 0.89–0.90; RMSE = 2.62–3.53 m; NSE = 0.58–0.65). In the selected morphology-input sensitivity set, the absolute CCTV–Stockdon difference was descriptively 1.94 m smaller with the nearest morphology; contrasts were negative in 21 of 27 periods and four of five survey epochs. CCTV provided time-resolved RBW observations, but agreement was dataset- and transect-dependent. Full article

The number of alien species recorded in the Black Sea has increased over recent decades, raising concerns regarding their long-term ecological consequences. Among the taxa currently extending their distribution within the basin are the Pacific oyster, Magallana gigas, and the Chesapeake blue crab, Callinectes sapidus. This study presents new records of both species from the Romanian Black Sea coast obtained through citizen-reported observations. Five specimens of M. gigas collected from Constanța and Mangalia harbours were examined, together with one ovigerous female specimen of C. sapidus collected from Vadu Beach. In addition, two male C. sapidus records from Sinoe Lake were documented and validated based on photographic evidence. The finding of M. gigas in Mangalia Harbour extends the known distribution of the species along the Romanian coastline and suggests that the species is more widespread than previously documented. The occurrence of an ovigerous C. sapidus female confirms that reproduction is taking place in Romanian Black Sea waters. Morphometric measurements and reproductive traits were within the ranges reported from other Black Sea and Mediterranean populations. While none of these species can currently be regarded as invasive in Romanian coastal waters due to the absence of documented ecological impacts, the increasing frequency of records suggests that both warrant continued monitoring. The results further indicate that citizen-reported observations, when validated by specialists, can complement conventional surveys and provide valuable information on the occurrence and spread of conspicuous alien marine species, thereby supporting sustainable marine biodiversity monitoring and informed ecosystem management. Full article

Sicily is a Mediterranean island region whose economy is based especially on tourism, with tourists being attracted to its beaches. The whole coastline of the island, including its minor islands, is 1745 km. At the moment, considering the whole period analyzed by the Coastal Plan of Sicilian Region (2008–2024), about 115 km of the 683 km of the main island’s sandy coastline present erosion problems that affect 23% of its unprotected coastline (506 km). Some of these problems are threatening Sicily’s economic and important historical assets as well as its cultural heritage; 177 km of protected beaches, using hard structure, have lost their original beauty. In the last fifty years, about 2.5 km² of beaches were lost due to erosion, causing damages worth approximately 5 billion Euros. Current coastal management guidelines identify artificial beach nourishment as the most sustainable strategy for protecting the insular economy against the accelerating impacts of climate change. Successful nourishment, however, hinges on the availability of vast quantities of borrow material that must be granulometrically, compositionally, and chromatically compatible with native beach sediments. While subaerial quarries are being phased out due to their irreversible environmental degradation and logistical inefficiency, as well as local “ephemeral” sources (such as harbor dredging or over-alluvial deposits) providing insufficient volumes, the research has shifted toward Remote/Relict Marine Sediment Deposits (RMSDs). This study evaluates the strategic potential of RMSDs as a high-volume, low-impact resource for coastal defense. By integrating the geological, morphological, and sedimentological characteristics of the Sicilian continental shelf within a GIS framework, we have delineated potential dredging sectors. These areas are bounded by the −30 m isobath (the lower limit of Posidonia oceanica meadows) and the −200 m isobath, which represents the current operational limit of Jumbo Trailer Suction Hopper Dredgers (TSHDs). A multi-criteria constraint analysis was performed, categorizing environmental and infrastructural overlaps into fatal flaws (prohibitive) and non-prohibitive constraints. This subtractive spatial analysis reveals that approximately 6500 km² of the Sicilian shelf may be eligible for resource exploitation concessions, pending site-specific, high-resolution surveys. Full article

Barrier islands along Florida’s Atlantic coast are increasingly threatened by sea-level rise, intensified hurricanes, shoreline armoring, and rapid coastal development. This study examined how beach and dune configurations varied in relation to coastal elevation patterns, NDVI-based surface greenness, and stakeholder perceptions across the East Central Florida Atlantic coast. Light Detection and Ranging (LiDAR) elevation datasets (2016, 2022, 2024), National Agriculture Imagery Program (NAIP)-derived Normalized Difference Vegetation Index (NDVI) analyses (2015, 2019, 2023), and stakeholder survey data from two coastal resilience workshops conducted in Volusia County in November 2024 were assessed to evaluate geomorphic change, vegetation-greenness patterns, and public perceptions of shoreline management strategies. Results showed descriptive differences among shoreline-type groups. Seawall-backed sites experienced the greatest net elevation loss (−0.529 m averaged over two sites) and a small negative mean transect-level NDVI change (−0.034) between 2015 and 2023, while natural dune sites showed an overall elevation gain (0.255 m averaged over three sites), despite some site-level loss after the 2022 hurricanes, and no net mean transect-level NDVI change (0.000) over the same NDVI period. Because the LiDAR and NDVI datasets are not temporally matched, these patterns are interpreted as complementary rather than causal lines of evidence. Stakeholder survey responses demonstrated that most respondents recognized the importance of dunes and coastal vegetation for resilience, but also expressed concerns about effectiveness, long-term maintenance, and cost of natural or hybrid solutions. Overall, the findings suggest that natural and minimally armored shorelines may retain greater capacity for elevation and vegetation-greenness recovery than hardened coastal systems, while also emphasizing the need for adaptive, conservation-based coastal management strategies that account for both physical shoreline conditions and stakeholder concerns. Full article

Drone-based shark surveillance has been implemented as a non-lethal mitigation method to minimise the risk of human–shark interactions along beaches of New South Wales (NSW), Australia. However, real-time misidentification remains problematic, often triggering unnecessary countermeasures due to marine animals that pose little to no risk to humans. We investigated shark misidentification in drone surveys by comparing real-time identification with post-flight verification across 900 flights. Post-flight analyses revealed false-positive detection rates of 53%, 79%, and 100% for bull (Carcharhinus leucas), white (Carcharodon carcharias), and tiger (Galeocerdo cuvier) sharks, respectively, which collectively are the ‘target’ sharks of mitigation measures in NSW. Of the 269 flights in which sharks were identified in real time as target sharks, 62% were confirmed post-flight as other sharks (i.e., whaler species, grey nurse, leopard, or wobbegong), sharks that could not be identified (unknown sharks), or non-shark species (i.e., guitarfish). Conversely, 25% of flights with target sharks identified post-flight were recorded in real time as ‘other’ or ‘unknown’ sharks. Overall, real-time classification overestimated the presence of target sharks, with an apparent prevalence approximately twice the true prevalence. Countermeasure activations based on real-time classification of target sharks were accurate in only 36% of instances. Non-shark species (i.e., guitarfish or gamefish) also triggered 39 countermeasures, including 28 water evacuations. Integrating artificial intelligence or other advances (e.g., higher-resolution video on larger screens) may enhance the effectiveness of drone-based surveillance by assisting pilots with real-time shark detection and identification. Full article

Cutaneous Larva Migrans (CLM) is a neglected tropical disease (NTD) caused by zoonotic Ancylostomatidae larvae, mainly Ancylostoma braziliense and Ancylostoma caninum, which infect dogs and cats. Humans are accidental hosts, acquiring infection when L3 larvae in contaminated soil penetrate the skin, producing serpiginous, pruritic lesions. We report a 24-year-old female from Quito, Ecuador, who developed a pruritic lesion on her right foot nine days after walking barefoot on wet, potentially fecally contaminated sand at Atacames Beach. Initial self-treatment with benzyl benzoate and herbal washes, followed by misdiagnoses as scabies and plantar warts, delayed proper care. Lesions progressed over three weeks with intense pruritus and functional impairment. CLM was correctly diagnosed by a podiatric technician 26 days post-exposure. Oral albendazole (400 mg/day for 4 days) led to rapid symptomatic relief within three days, with complete resolution by day 50. A survey analyzed by the McNemar Test revealed difficulties in recognizing early-stage CLM, regardless of experience or region among participants. Prevention requires personal protection, environmental sanitation, and regular anthelmintic treatment of dogs and cats. This case underscores the clinical consequences of delayed or incorrect diagnosis and highlights the need for enhanced healthcare training and One Health measures to reduce zoonotic diseases in Ecuador. Full article

The intertidal beach profile provides a fundamental representation of beach morphology and serves as a key indicator of shoreline morphodynamics. To enable frequent and accurate mapping of intertidal beach profiles, this study proposes an automated reconstruction framework that integrates single-pixel image columns with a stacked bidirectional long short-term memory (Bi-LSTM) network. Time-exposure imagery, commonly referred to as Timex imagery, acquired from a shore-based video monitoring station at Xisha Bay, China, is used as the primary data source, while wave records obtained from a wave buoy are incorporated to assign elevations to the detected waterline breakpoints, thereby enabling automatic beach profile reconstruction. The stacked Bi-LSTM network is trained for land–sea segmentation and waterline breakpoint localization. achieving the best performance among the tested methods, with precision, recall, accuracy, and F1 score values of 0.951, 0.894, 0.978, and 0.903, respectively, and a mean breakpoint localization error of 2.23 pixels. Breakpoint elevations were then estimated using a local slope–wave setup attribution model. Validation against field-measured topographic data from four fixed profiles and three survey periods showed good agreement between the reconstructed and measured profiles, with a period-based root mean square error (RMSE) of 0.212 ± 0.080 m. When all validation points were combined, the reconstructed elevations showed strong agreement with the measured elevations, with a coefficient of determination (R²) of 0.988 and an overall RMSE of 0.24 m. The profile comparisons further showed that the reconstructed profiles generally captured the overall profile shape and cross-shore morphological pattern of the measured profiles, although reconstruction accuracy varied among the four fixed profiles. These differences demonstrate that camera viewing angle, field-of-view position, camera-to-profile distance, and image quality are important factors influencing video-derived beach profile reconstruction. These results indicate that the proposed method can directly reconstruct fixed intertidal beach profiles from shore-based Timex imagery without generating a digital elevation model of the entire intertidal zone. It provides a practical tool for high-frequency monitoring of intertidal profile morphology and supports the quantitative analysis of beach erosion–accretion dynamics. Full article

Tourism destinations increasingly serve both domestic and international visitors whose geographic behaviors may differ substantially, yet most analytical frameworks treat visitor distributions as spatially homogeneous. Few studies compare how domestic and international tourists cluster spatially within the same destination. Those differences matter enormously for destinations where visitor segments follow distinct geographic patterns. We analyzed 1547 bilingual TripAdvisor reviews from Chanthaburi Province, Thailand (2014–2023), combining Random Forest classification (83.26% accuracy for Thai, 96.45% for English) with Incremental Spatial Autocorrelation (ISA), Global Moran’s I, and Getis-Ord Gi* hotspot analysis. International visitors clustered more intensely overall (I = 0.253 vs. 0.213), but domestic visitors spread across all six tourism areas including agrotourism, while international visitors were concentrated in heritage, coastal recreation, and nature-temple zones with agrotourism absent. Both segments clustered strongly at cultural heritage sites and at beach destinations, contradicting the common assumption that coastal areas primarily serve international visitors, while agrotourism clustered exclusively among domestic visitors despite active policy promotion. These patterns reflect differential information access rather than attraction quality. The zone-level framework is transferable to secondary heritage destinations across Southeast Asia, where platform-based monitoring offers a practical alternative to large-scale visitor surveys. Full article

Effective management and conservation of sea turtles is often constrained by a lack of knowledge of at-sea distribution and abundance. While abundance estimates of nesting females are typically well-documented on nesting beaches, counting sea turtles at sea presents challenges due to their widespread distribution and cryptic habits. Given nesting beaches only document adult females, at-sea data are also more informative of greater population demographics. To estimate the abundance and density of green sea turtles (Chelonia mydas) in the Red Sea waters of Saudi Arabia we conducted strip transect aerial surveys in four survey zones that spanned ~66% of shallow water habitats (<200 m depth), within which we counted sea turtles, and also other species such as dugongs and other marine mammals, sharks, and rays. Corresponding abundance estimates were modelled to account for perception bias (whether a surveyor saw a turtle that was available) and detection bias (whether a turtle was available to be seen). Our results suggest an abundance of ~201,427 green sea turtles potentially present between the 200 m bathymetric contour and the Saudi Arabian shore. However, there was a statistically significant relationship between turtle location and proximity to coral reefs, with over 90% of turtles found within 3500 m of coral reef structures (whether coastal fringing reefs, barrier reefs or atolls), and therefore it would be inappropriate to use an estimate assuming equal distribution. Adjusting for this buffer area we estimated ~95,000 turtles (95% CI: 64,000–142,000) within the proximity of reef structures. These findings represent the first abundance estimates of green turtles in the Red Sea. Repeated over time, surveys such as these can identify changes in population structure, distribution and abundance, and inform conservation and management agencies. Full article

Beach nourishment, as one of the most widely and effectively used coastal management measures recently, inevitably changes the coastal environment. This study aims to assess how the coastal profile is transformed during repeated beach nourishments with coarser-than-native sand in the Palanga recreational zone, Lithuania, Baltic Sea, using field survey data from the last three decades. When the granulometric composition of the sand is artificially changed during nourishment, the beach adapts to environmental changes by adjusting its morphometric parameters. These changes can be perceived as an intensification of coastal erosion, and, at the same time, a failure of the project. However, the results of this study show that these changes are associated with the transformation of the beach towards a morphologically adjusted state under the new sediment characteristics. In the Palanga case, the coarser-than-native sand used for nourishment led to narrower and steeper beaches compared to the pre-nourishment beaches composed of finer sand, and these characteristics persisted five years after nourishment. Therefore, the wide and low-slope beaches created during beach nourishment could not maintain the formed morphometric features with the coarser sand. For this reason, when implementing a replenishment project, it is important to predict the cross-shore profile that will develop for a given grain-size composition and quantity of the nourishment sand. Full article

Oil Detection Canines (ODCs) have been proven to detect spilled oil in various environments, including targets and residual oil sequestered along shorelines. A limitation within the capability is that an ODC detects and responds to all types of stranded hydrocarbons, including any from historical spills or naturally occurring chronic oils, such as tarballs washed up from offshore seeps. In locations historically known for chronic tar deposits, the value of a K9-supported Shoreline Cleanup Assessment Technique (SCAT) survey is limited when large numbers of tar deposits are present, because the canine detects and responds to all of them. This thoroughness can slow down SCAT surveys, reduce efficiency by requiring investigation of each response, and fatigue the canines from the number of alerts. A project supported by the Texas General Land Office (TGLO) was designed to investigate the ability of a trained ODC to discriminate hydrocarbons on a beach that represent a newly spilled oil while ignoring other potential “background” oils. In 2021, Texas Tech University’s Canine Olfaction Lab conducted a laboratory-based study to investigate canines’ ability to respond to weathered oil samples. This research demonstrated that trained canines could effectively discriminate between weathered oils in a laboratory environment. This knowledge was used to design a field program to conduct monthly surveys with two teams: one involved deploying two canines trained on a sample representative of relatively unweathered spilled oils, handled by citizen-scientist volunteers, and the other involved an ODC trained on a range of oil types. The field survey results show that a Specific Oil Detection Canine (SODC) can discriminate between unweathered oil deposits and other background deposits typical of chronic oiling at the same location. Field surveys indicated that SODCs consistently responded exclusively to target oil samples and disregarded naturally occurring background hydrocarbons, while a generalist ODC responded to all hydrocarbon sources present. Full article

Microplastics (MPs) adsorb hazardous substances and are ingested by a wide range of organisms; therefore, indicators for managing their environmental concentrations are needed. Ideally, threshold values should be based on health impacts. However, the diversity of MPs and the complexity of their environmental behavior make it difficult to establish unified environmental concentration standards. In this study, we propose a threshold for the presence of MPs on sandy beaches based on “visual cleanliness,” derived from the amount of MPs that people find psychologically unacceptable. Three types of MPs were used: white polypropylene (PP), blue PP, and white polystyrene (PS; expanded polystyrene). The survey was conducted in Japan, and the number of valid responses was 245. For defining a narrow-range cleanliness threshold, volume concentration was more appropriate than mass concentration. White particles were expected to be less noticeable because they tended to blend with white shell fragments, which are ubiquitous on beaches. In contrast, blue particles were expected to be less acceptable owing to their rarity. However, we found no difference in unacceptability between white PP and blue PP. The threshold, defined as the volume concentration at which half of the respondents find MPs psychologically unacceptable, ranged from 1 to 2 cm³-MPs/m²-sand. Gender, age, travel time to the beach, and frequency of beach visits did not influence unacceptability. Strong concern about marine plastic pollution and experience in cleaning public spaces were associated with a tendency toward low tolerance for MP contamination on beaches. Full article