Youn, S. and Zarillo, G., 2022. Morphological analysis of barrier islands in the Nakdong River Estuary, South Korea. Journal of Coastal Research, 38(3), 475–490. Coconut Creek (Florida), ISSN 0749-0208.

The Nakdong Estuary system and the associated barrier island system near Busan, South Korea, consists of dynamic shorelines characterized by morphological transformations that result from natural disasters (typhoons and flooding), rising sea levels, and construction projects (the Nakdong Estuary Dam and the Busan Newport). This study aims to synthesize existing water level, wave, meteorological, and morphological data obtained from various institutions with the objective of identifying major factors that influence shoreline and area change over time. These objectives were met by analyzing the shoreline and area with direction analysis from center point (DACP) to consider the influence of river discharge and sea-level rise and to determine shoreline shifts in barrier island orientation over time. From DACP, it was determined that the Nakdong barrier islands rotated clockwise because of erosion and deposition. Offshore shorelines of barrier islands advanced by 0.1 to 2 km between 1972 and 2013. The area change rate between 1972 and 2013 was 20.85% from 100 to 180° because of the Maenggeummeori-do channel construction and discharge from the Nakdong Estuary Dam. Morphological changes and shifts in shoreline positions were caused by alteration of flow patterns because of construction of the Nakdong Estuary Dam and sea-level rise in the Nakdong Estuary system based on the timeline of the shoreline and area change rates. This study exemplifies the need for a preconstruction development plan in a study area to ensure that the results of a project are environmentally sound with respect to the potential impacts of project construction and sea-level rise.

Finkl, C.W. and Makowski, C., 2022. Detailed interpretation of satellite images of coastal belts on the Coral Coast of Viti Levu, Republic of Fiji, South Pacific, using the BCCS (Biophysical Cross-shore Classification System). Journal of Coastal Research, 38(3), 491–511. Coconut Creek (Florida), ISSN 0749-0208.

Lying on the southwest Fijian coast of Viti Levu, the Coral Coast is noted for its fringing coral reefs that extend for an overall alongshore length of about 80 km (from Momi to Suva), with the study area being a 32-km-long subset in the Sigatoka region. The fringing reefs, extending offshore for an average maximum distance of about 650 m, are broken into contiguous segments by deep-water cross-shore channels composing discrete coastal belts. When the fringing reef segments are combined with other onshore (terrestrial) eco-geomorphological units, they make up nine distinct coastal belts in the study area comprised by 35 domains. The cross-shore classification of the Coral Coast examples was based on application of the BCCS (Biophysical Cross-shore Classification System), which required interpretation of satellite images to comprehend cross-shore catenary (linked) sequences that had alongshore extent. Imagery from 2010 to 2017 was accessed to obtain the best possible views of each reef segment and adjacent mountain hinterland. Due to spatial limitations, capabilities of the Google Earth Pro platform were accessed to acquire sufficient interpretive details for compilation of cross-shore transectal archetypes and subarchetypes from the reef front to coastal mountain slopes. Typical cross-shore classificatory sequences consisted of Coral Reef (Cr), Flat (F), Beach (Be), and Mountain (M) archetypes that formed tetrasequent Cr-F-Be-M catenas. Although a limited number of small Delta (De) archetypes overrode back-reef flat margins, their frequency of occurrence was not a domainal characteristic. The occurrence of Developed (Dv) archetypes were more or less ubiquitous onshore, whereas alongshore bedrock outcrops of the Rock (R) archetype were rare. Because the scale of natural and anthropogenic features along the coast demanded a detailed (hectometric) coastal classification, the BCCS was applied on an experimental basis to ascertain its applicability as an exemplar for similar studies in insular settings elsewhere.

Windom, H.L. and Palmer, J.D., 2022. Changing river discharge and suspended sediment transport to the Georgia Bight: Implications to saltmarsh sustainability. Journal of Coastal Research, 38(3), 512–522. Coconut Creek (Florida), ISSN 0749-0208.

Suspended sediment delivered in river discharge to the Georgia Bight (the coastal-shelf area of the SE U.S. Atlantic coasts of Georgia and South Carolina) provides a continuous supply of fine grain sediments to support coastal saltmarshes. Archived data on discharge and suspended sediment loads for Piedmont and Coastal Plain rivers collected over eight to nine decades were used to estimate the present rate of sediment discharge to the Bight to be about 1 × 10⁶ metric tons annually. The data used in this assessment are for the period after major reservoir/dam construction and other streamflow diversions occurring during the 1950s–1970s, which had a major effect on sediment yields of SE Atlantic watersheds. The estimated annual sediment delivery is about two-thirds of that needed to maintain vertical saltmarsh stability as sea level rises at the present regional rate of 3.3 mm/y. The observed 2% per decade decreasing trend in river discharge to the Bight, related to rapid population and temperature rise since ca. 1960, and the continual depletion of sediment stored in river floodplains below dams, suggests that the fine sediment supply to the coast will continue to decline.

Goforth, K.M. and Carthy, R.R., 2022. Tidally-driven gas exchanges in beaches: Implications for sea turtle nest success. Journal of Coastal Research, 38(3), 523–537. Coconut Creek (Florida), ISSN 0749-0208.

The success of individual sea turtle nests is influenced by nest location on the beach and the resulting incubation environment. Several abiotic factors affect nest incubation, and thus nest success, but tides and gas exchange are two of the most important. The effects of tides on nest success have been well documented in regard to overwash and inundation events. However, the possible effect of tidally-driven gas exchange has received little attention. The incursion and retreat of the saltwater wedge may cause substantial movement of gases through the beach during the tidal cycle. This study quantifies the differences in tidally-driven gas exchange among beach types and shoreline elevation levels. Carbon dioxide (CO₂) efflux was used as a means of measuring gas movement through the beach to examine tidal effects across different beach zones and among different beach types. CO₂ efflux was measured throughout the tidal cycle at three distinct beaches (accreting, eroding, and nourished) at Cape San Blas, Florida. There was a general pattern of CO₂ efflux rising and falling throughout the tidal cycle on each beach and a difference in the CO₂ efflux observed among beaches and beach zones. Efflux patterns at the nourished and eroding beaches were similar, but the nourished beach exhibited a decreased and dampened CO₂ efflux pattern throughout the course of the tidal cycle. Analyses of the hatchling turtle emergence success data from 2011 to 2014 for the three beaches found that emergence success differed among the three beaches. The highest emergence success was on the nourished beach, which exhibited a relatively consistent efflux pattern. These results suggest that tidally-driven gas exchange may have implications on nest incubation and survival and are a consideration in beach restoration management and best practices for coastline conservation.

Zhan, Y.; Aarninkhof, S.G.J.; Wang, Z., and Zhou, Y., 2022. Monitoring the monthly expansion pattern of pioneer vegetation in tidal flats using a terrestrial laser scanner. Journal of Coastal Research, 38(3), 538–547. Coconut Creek (Florida), ISSN 0749-0208.

Research on the expansion pattern of pioneer vegetation in tidal flats is important, because this pattern affects the development of both topography and ecology. This study aimed to determine the monthly expansion patterns of seedlings and tussocks by using terrestrial laser scanning (TLS). Overall change process research and spatial analyses of both seedling recruitment and tussock development were carried out in this work. The results show that the overall change in pioneer vegetation reflected an expansion toward the shoreline in the first year and then a northward colonization in the second year. Moreover, positive feedback effects were observed between vegetation colonization and sedimentation accretion. Colonization accelerated the depositional process at the study site. Moreover, sedimentation accretion in the northern subarea, which is located close to the seawall, promoted the colonization of vegetation in this region. A strong spatial relationship was observed between seedling recruitment and tussock development. Tussocks tended to force seedlings to expand outward by squeezing the established space of the seedlings. Moreover, seedlings were densely concentrated within a certain distance from tussocks. The distances between seedlings and tussocks tended to shorten annually as the entire vegetation area underwent the expansion process. The average distance between seedlings was found to be concentrated from 10 to 20 m. The monthly vegetation expansion process was studied on small and medium scales in this work, revealing the advantages of TLS technology in rapidly acquiring data with high resolution and high precision.

Song, M.-J.; Kim, B.-H., and Cho, Y.-S., 2022. Estimation of maximum tsunami heights using probabilistic modeling: Bayesian inference and Bayesian neural networks. Journal of Coastal Research, 38(3), 548–556. Coconut Creek (Florida), ISSN 0749-0208.

Although tsunamis may occur relatively infrequently, they can cause substantial loss of life and property damage. Most studies on tsunamis have focused on developing numerical models to describe ocean propagation and the associated run-up process because laboratory experiments are expensive. Probabilistic techniques have been used in various scientific and engineering fields with reasonable results. In this study, numerical simulations were performed for historical and virtual tsunami events to explore maximum tsunami heights. Bayesian inference and Bayesian neural networks were then employed to predict the maximum tsunami height. These results can be used to develop hazard maps for unexpected tsunami events.

Savasta, D.; Nucera, A.; Barbaro, G., and Foti, G., 2022. A new geographic transfer method of wave data. Journal of Coastal Research, 38(3), 557–566. Coconut Creek (Florida), ISSN 0749-0208.

The availability of quality, site-specific wave data is necessary for an accurate understanding of wave climate. Direct and indirect wave data often have insufficient spatial resolution to ensure the requirement for geographic representativeness of data. The proposed wave data transfer method, in two versions, transfers an entire time series of wave data from a point with data to a neighboring point. The method is based on the empirical relationships of the Shore Protection Manual method and involves estimating appropriate statistical parameters from wind data characterizing the area comprising the two points. The method has been tested and compared with De Girolamo and Contini's transfer method in three applications in the Mediterranean Sea, showing significantly better results in two applications and similar results in a third application. It is believed that the lower reliability of the new transfer method in one of the three applications results from the considerable distance, 112 km, between the data point and the transfer point. Transfer methods are more accurate in cases of modest distances between the two points, which is the classic application of the transfer method in engineering practice.

Akiner, M.E. and Lačnjevac, C., 2022. Managing saltwater intrusion and agricultural practices along the Boğaçay River, Turkey: Effects from excavation and land source pollution. Journal of Coastal Research, 38(3), 567–577. Coconut Creek (Florida), ISSN 0749-0208.

The Boğaçay is a river situated in the Konyaaltı district of Antalya. In 2017, Antalya Metropolitan Municipality implemented a large project in which the river bed was excavated to 1.5 m below sea level. The aquifer is vital for meeting the drinking water needs of the city of Antalya. The goal of this research is to discover the applications that may be made to combat seawater intrusion and nutrient contamination, both of which were brought to the forefront by the Boğaçay Project. In this work, modeling was used to estimate the extent to which agricultural best management practices (BMPs) will be efficient in reducing pollutant load. In BMP modeling with the soil and water assessment tool (SWAT), a decrease of 39%, 38%, and 38% is anticipated in the 5-day biochemical oxygen demand (BOD₅), total phosphorus, and total Kjeldahl nitrogen loads, respectively. Sediment accumulated in the channel, and sediment transport occurred on the beach due to coastal erosion. Coastal erosion of up to 25 m was observed from the project's beginning to the present. Substantial land base pollution because of the diffused sources was found. Saltwater intrusion in the Boğaçay River estuary functions as a catalyst in the production of poor odor and appearance, as well as the rapid expansion of algae. The municipality is attempting to remedy this problem by periodic harvesting, which is an overly expensive and ineffective option. Instead, the elevation of the riverbed should be restored to preproject levels to prevent additional environmental and geographic damages.

Jwa, M.-S.; Kim, S.-C., and Hong, C.-Y., 2022. The effects of breeding environment and food type on the survival and growth of red sea cucumber (Apostichopus japonicus) larvae. Journal of Coastal Research, 38(3), 578–584. Coconut Creek (Florida), ISSN 0749-0208.

This study aimed to investigate the effects of water temperature, salinity, and food type on the survival and growth of red sea cucumber (Apostichopus japonicus) larvae, over 14 days. Early Auricularia larvae (average length 475 ± 10.3 µm) were exposed to four different water temperatures (18, 22, 26, and 30 °C), four different salinities (25, 30, 35, and 40 psu), and four food types (Chaetoceros calcitrans, Pavlova lutheri, Isochrysis galbana, Rhodotorula+effective microorganisms (EM)). Subsequently, the survival rate, larval developmental stage (early Auricularia–Doliolaria), and the required time (days) to arrive at each stage were observed. The experiment was conducted at a private sea cucumber aquaculture farm in Jeju Special Self-Governing Province, and the results were statistically analyzed using SPSS version 22 (SPSS Inc., USA). This research team evaluated the average significance difference between groups, which was determined in p < 0.05, by applying a Duncan test due to variance heteroscedasticity. The results indicate the following optimum rearing conditions of red sea cucumber larvae: water temperature of 22 °C, salinity of 30–31 psu, with Rhodotorula+EM as food. The findings of this study could facilitate increasing seed production of the red sea cucumber A. japonicus.

Campbell-Martínez, G.E.; Thetford, M., and Miller, D., 2022. Germination response of three florida panhandle coastal dune plants to salinity. Journal of Coastal Research, 38(3), 585–591. Coconut Creek (Florida), ISSN 0749-0208.

Coastal dunes and their ecosystem services are threatened by human pressures warranting active restoration. Understanding dune plant germination responses to salinity is important when considering plant species and direct seeding locations for coastal dune restoration projects. The germination response of three Florida panhandle native coastal dune plant species to various salinity concentrations (0%, 0.25%, 0.50%, 0.75%, and 1% weight per volume) were tested. Species included were coastalplain honeycombhead (Balduina angustifolia (Pursh)B.L.Rob.), coastalsand frostweed (Crocanthemum arenicola (Chapm.)Barnhart), and squareflower (Paronychia erecta (Chapm.)Shinners). Seeds were germinated within germination boxes, placed in growth chambers under species-specific temperatures with a daily 12-hour photoperiod, and monitored weekly for 4 weeks. Germination responses to salinity were species-specific. Coastalplain honeycombhead had intermediate salt tolerance (highest germination at 0%–0.50% salinity), coastalsand frostweed was the least salt tolerant (highest germination at 0%–0.25% salinity), and squareflower was the most salt tolerant species in respect to germination (high germination across all salinities). Germination was delayed for all species at the highest salinity concentrations (0.75%–1%). However, for all three species, at least one-third of all seeds (>39%) at all salinity concentrations germinated by week 4. Results suggest germination for seeds of these species is possible in saline conditions documented within coastal areas before and after hurricane overwash. Future dune restoration studies for these species should test direct seeding of these plants under field conditions.

Yang, J.; Wang, J.; Dong, L., and Fan, P., 2022. Axial deformation behavior of precompressed coral sand under repeated impacts. Journal of Coastal Research, 38(3), 592–602. Coconut Creek (Florida), ISSN 0749-0208.

To investigate the subsidence behavior of backfill foundation under the disturbance of repeated landing of planes, a series of one-dimensional tests under repeated impacts were conducted on precompressed crushed coral sand with a variety of grading and relative densities. For each sample, the impacts (amplitude 600 kPa, frequency 5 Hz) were loaded three times in cluster form (lasting 6 s, one hour apart), while the static stress (200 kPa) was maintained continuously for 4 h. The axial deformations of the samples were recorded, and a comparative study was conducted by referencing the results of silica sand samples under the same conditions and coral sand samples under static loadings. The test results indicate that compared with silica sand, coral sand has a much larger total deformation, which is mainly influenced by the relative density, gradation, and order of impacts. By analyzing the results, it can be concluded that the deformation of coral sand has a greater plastic component and decreases faster than that of silica sand under repeated disturbances, and the total deformation and proportion of irreversible deformation decrease with increasing relative density. The influence of initial grading on the particle breakage index is more significant than the relative density. Improving the grading of coral sand can reduce the total deformation and minimize the proportion of unrecoverable deformation.

Visconti, G.; Scopelliti, G.; Caldareri, F.; Agate, M.; Cambera, I.; Sulli, A., and Arculeo, M., 2022. Hatching success of Caretta caretta on a Mediterranean volcanic beach: Impacts from environmental parameters and substrate composition. Journal of Coastal Research, 38(3), 603–612. Coconut Creek (Florida), ISSN 0749-0208.

New data on the potential impact of environmental parameters and the mineralogical nature of the substrate on the hatching success of the loggerhead sea turtle Caretta caretta on a volcanic beach on Linosa Island in the central Mediterranean Sea are reported. During 2 years of investigation (2018–19), five nests were observed. The temperature and moisture of the nests were determined along with the grain size and mineralogical nature of the substrate. The temperature values of the nests recorded at depths of 5 and 35 cm showed an average temperature incubation of 32.2°C ± 1.4°C and 32.8°C ± 1.6°C, respectively, with peaks close to 37°C. The sedimentological analysis carried out on two cores revealed the prevalence of large sandy particle and sediment moisture of about 35% in the deeper layers. A total of 214 laid eggs were recorded in 2018 with only 44 emerged turtles, whereas 45 turtles emerged from 199 laid eggs in 2019. Both years showed a low hatching success (25%–30%) and a high frequency of anomalies (>60%), which were present in individuals as nonmodal scutes or bifid limbs. Results suggest that environmental parameters such as temperature, sand moisture, and the geological nature of the substrate seem to play an important role in the reproductive success of this species. Some aspects for improving the nesting site and egg development conditions are also discussed.

Sun, P.; Pan, L.; Liu, W.; Zhou, J., and Zhao, T., 2022. Wake characteristic analysis of a marine propeller under different loading conditions in coastal environments. Journal of Coastal Research, 38(3), 613–623. Coconut Creek (Florida), ISSN 0749-0208.

The propeller wake field is closely related to the cavitation and noise performance of the propeller. The propeller wake fields under light and heavy loading conditions were numerically studied based on the delayed detached eddy simulation method. The characteristics of propeller wake dynamics under different loading conditions were analyzed to reveal the flow physics during the propeller wake evolution. The results showed that the pitch of the helicoidal vortex behind the propeller is large and the wake is relatively stable under light loading conditions with a high advance coefficient. In the heavy loading condition with a low advance coefficient, the pitch of the helicoidal vortex is smaller; the vortex system tends to be unstable and break down earlier. The downstream alternate strong- and weak-tip vortices indicate that the tip vortex evolution is accompanied by a dissipation process, which plays an important role in the interaction between adjacent tip vortices and the inception of propeller wake instability. The present work can provide a reference for the design and optimization of propellers used by ships sailing in coastal environments and zones farther out to sea.

Salaün, J.; Pioch, S., and Dauvin, J.-C., 2022. Socio-ecological analysis to assess the success of artificial reef projects. Journal of Coastal Research, 38(3), 624–638. Coconut Creek (Florida), ISSN 0749-0208.

Artificial reefs (ARs) have been deployed for different purposes: to protect marine areas, to increase production in artisanal fisheries, to restore degraded ecological functionality, and to offset the negative impact of development projects. The assessment of ARs is currently based preferentially on physical, chemical, and biological data, whereas the links between these ecological initiatives and social data are rarely taken into account. In this study, ARs were investigated using the actor–network theory (ANT), a holistic approach developed in the social sciences that considers that nonhuman as well as human actors play a role in systems and networks. The findings show that the socio-ecological objectives of ARs are deeply dependent on the interests of the stakeholders active in each phase of the project: project identification, planning, implementation, monitoring, and management. Their position and interests strongly influence how the project is performed, and the objectives of the ARs also evolve in line with the type of stakeholders involved. Based on the interest of each stakeholder, this ANT analysis reveals that French ARs, called production ARs, also have ecological and social support objectives, including reducing conflict between fishermen or increasing natural marine resources diversity and biomass. The translation process steps provide a framework to understand the interest of each stakeholder involved in the AR network and how management actions are deployed to reach their key objectives. This approach could be used as a first step in the assessment process to define clear objectives. It would provide managers a more integrated approach to assess the success of current and future marine environmental management tools.

Hu, Z.-H.; Zheng, Y.-X., and Hu, J.-J., 2022. Vietnam's maritime shipping ports: Using data-driven model analysis to determine connectivity and networking. Journal of Coastal Research, 38(3), 639–653. Coconut Creek (Florida), ISSN 0749-0208.

Vietnam is a typical coastal country bordering China, Laos, and Cambodia that possesses numerous seaborne transport facilities along the coast and two main river deltas (the Mekong River Delta and Red River Delta). Vietnam's ports and shipping flows were incorporated into a maritime network model. Vietnam's coast is on the Pacific Ocean, so the clustering method is a good way to formulate and investigate the maritime network. On the land side facing Laos and bordering China and Cambodia, Vietnam's maritime network can provide gateways for Laos, Thailand, Cambodia, and even China. Based on a big-data port and shipping system, this study focuses on the interaction between Vietnam's inland and coastal networks and the impact of throughflow as a sea gateway for Laos to connect the world. This analysis includes network connectivity, port positions and evolution, maritime port clusters, and regional deltas using clustering methods. The relationship between the maritime networks and the economic zones of Vietnam and its neighbors was also included in the current study. In summary, Vietnam can coordinate and optimize its seaside and landside networks to contribute to its trade and globally extend its maritime network to serve itself and its region.

Basack, S.; Loganathan, M.K.; Goswami, G., and Khabbaz, H., 2022. Saltwater intrusion into coastal aquifers and associated risk management: Critical review and research directives. Journal of Coastal Research, 38(3), 654–672. Coconut Creek (Florida), ISSN 0749-0208.

Coastal regions mainly rely on sources of local fresh groundwater for domestic, irrigational, and industrial usages, which are vulnerable to high-risk of getting intruded by saltwater. Excessive pumping of fresh groundwater initiates advances of saltwater-freshwater interface inward due to hydraulic equilibrium and continuity. This introduces saline water intrusion into coastal aquifers. This is also caused by natural hazards like sea-level rise and storm-surge. The saltwater intrusion in coastal aquifers contaminates the freshwater storage, thereby emerging as a major environmental issue. To incorporate adequate coastal groundwater control and management techniques that are effective and conveniently implementable, understanding the phenomenon of saline water intrusion and the risk assessment is of utmost importance. Several scientific contributions including theoretical (analytical and numerical) solutions, experimental (laboratory and field) results, design recommendations, and risk analysis are available, indicating remarkable advances in the research area. The authors have attempted to summarize the significant contributions over the last few decades in each of these study aspects through extensive literature survey and critical analysis of the existing knowledge. It is observed that risk prevention and control methodologies such as qanat-well structure, shallow and deep wells might not be effective in many coastal areas as the complex intrusion process is yet to be understood clearly. Moreover, the high intensity coastal hazards that often occur due to climate change continue to make aquifers more vulnerable, adversely affecting the coastal groundwater management. The paper presents a critical overview of existing studies on saline water intrusion into coastal aquifers and associated risks and management techniques. Furthermore, adequate research directives with recommendations for future development are also provided.

Wang, H.; Yin, Z.; Luan, Y.; Wang, Y., and Liu, D., 2022. Hydrodynamic characteristics of idealized flexible vegetation under regular waves: Experimental investigations and analysis. Journal of Coastal Research, 38(3), 673–680. Coconut Creek (Florida), ISSN 0749-0208.

Salt marshes protect coastal communities from erosion and damage by damping incoming waves. A series of physical experiments were conducted to investigate the wave attenuation characteristics of idealized flexible vegetation, and the parameters of submergence, stem density, wave height, and wave length were considered. It was observed that the wave transmission coefficient decreased and the wave damping factor increased with increasing submergence ratio, relative wave height, and relative stem density and decreasing relative wave length. Moreover, the wave transmission coefficient decreased with increasing Ursell number. In addition, with an increase in the submergence ratio, relative wave height, Reynolds number, Keulegan-Carpenter number, and Ursell number, the bulk drag coefficient decreased. The bulk drag coefficient was more strongly related to the Ursell number than the other parameters. A simple equation for the wave transmission coefficient was constructed using the dimensional analysis method, the least squares method, and randomly selected experimental data, and it was effectively validated based on the other experimental data.