Vickery, C.G.; Wang, P., and Cheng, J., 2022. Natural and anthropogenic factors controlling circulation at the terminus of a seagrass-covered estuary, Fort DeSoto Bay, West-Central Florida. Journal of Coastal Research, 38(4), 681–698. Coconut Creek (Florida), ISSN 0749-0208.

Causeway construction and channel dredging are common engineering activities in shallow estuaries and can significantly alter natural circulation patterns. Bridges are often installed on causeways to improve circulation. This study examines the influence of dredged channels, causeways, and bridges on circulation patterns within a shallow estuary with dense seagrass beds using a calibrated and verified numerical model. For the case of Fort DeSoto Bay in west-central Florida, the causeways disrupted the natural east-west flow and reduced current velocities within the seagrass beds in the southern terminus portion of the estuary by up to 76%. The tidal bridges increased velocity in the stagnant areas by up to 226%. Up to 26% of the tidal prism in the lower half of the bay passes through the bridges during a spring flood-tidal cycle. Thus, the bridges significantly improved tidal flushing between the estuarine cells divided by causeways. The unvegetated dredged channels serve as efficient conduits that facilitate penetration of tidal currents into the southern and terminus of the bay, leading to significantly higher current velocity in the channels and corresponding reduced velocity over the adjacent seagrass beds. The channels allow for improved tidal flushing within the otherwise stagnant southern terminus of the bay and therefore can be designed for the purpose of improving circulation.

Bazgirkhoob, H.; Linhoss, A., and Armandei, M., 2022. A numerical tool for dissolved oxygen simulation in the western Mississippi Sound. Journal of Coastal Research, 38(4), 699–711. Coconut Creek (Florida), ISSN 0749-0208.

Dissolved oxygen is an indicator of aquatic health. Hydrodynamic–water quality models facilitate the understanding of flow dynamics and dissolved oxygen in estuarine systems. In this study, dissolved oxygen concentration, seasonality, and vertical stratification were studied in the western Mississippi Sound, Northern Gulf of Mexico. Visual Environmental Fluid Dynamic Code and the water quality model CE-QUAL-ICM were linked together to develop a three-dimensional hydrodynamic and water quality model of the western Mississippi Sound. The model was verified and validated for nutrients and chlorophyl a. Then, the modeled results for dissolved oxygen were compared to measured data. Mean observed dissolved oxygen ranged between 6.29 and 8.48 mg/L in the top and bottom layers at each site. The root mean squared error between measured and modeled dissolved oxygen ranged between 1.30 and 2.87 mg/L. Results indicate that the model was able to capture measured seasonal trends and vertical stratification. The model simulated more realistic results in shallower areas compared to deeper areas. Overall, the model simulated slightly higher dissolved oxygen than what was measured, although 27% of the stations showed no statistical difference between the modeled and measured dissolved oxygen. These results are useful for interpreting the value of this model for future ecological studies. The model can be used as a tool to provide better understanding of the dissolved oxygen dynamics due to multiple scenarios such as hurricanes and storms.

Balstrøm, T. and Kirby, J., 2022. A GIS-based screening workflow for coastal storm surge impact assessments and mitigation action consideration. Journal of Coastal Research, 38(4), 712–724. Coconut Creek (Florida), ISSN 0749-0208.

A GIS-based screening workflow is presented, providing first overviews of storm surge–induced inundation impacts along coastlines and where to consider mitigative action. The modeling is based on analysis of a hydro-conditioned digital terrain model (DTM) in Esri's ArcGIS Pro environment targeting undergraduate students, professional municipality planners, federal agencies, and more. Unlike existing commercial inundation modeling software, this application works in a simplified timeless setting on steady-state surge levels. This is accomplished only at the cost of not predicting when a specific targeted location is inundated. In return, fast computations are obtained. First, it is demonstrated how the DTM is turned into a hydro-conditioned terrain model, DHyMSea, protecting surges from entering land where sluices, high-water flaps, etc., are present. Second, the inundation screening is initiated for a user-defined number of sea levels. The outputs are individual raster layers for each level showing inundation extents and depths. Also, outputs are produced for each modeled level to back trace where the inundation came from. Third, a combined raster shows the minimum surge level to inundate any cell in the DHyMSea. Fourth, when considered where to raise protecting dikes, they can be digitized and have their elevation values stamped onto the DHyMSea. Finally, the inundation scenarios can be re-executed to evaluate the mitigation impact; if necessary, the dikes' locations and elevation properties can be reconsidered, and the workflow re-executed once more. The workflow has proven successful in first assessments of inundation threats where sea levels are expected to rise significantly over the coming decades. Additionally, the workflow has proven successful in quality assessments of a DTM. To demonstrate the workflow's capabilities, storm surge consequences for the greater Copenhagen region's coastline in Denmark are discussed for inundation scenarios ranging from 1.0 m to 3.9 m above sea level in steps of 0.1 m.

Schiariti, J.P. and Salmon, M., 2022. Impact of Sargassum accumulations on loggerhead (Caretta caretta) hatchling recruitment in SE Florida, U.S.A. Journal of Coastal Research, 38(4), 725–734. Coconut Creek (Florida), ISSN 0749-0208.

Hatchling loggerhead turtles emerge from subsurface nests on oceanic beaches at night, then crawl toward and enter the sea. Recently, increases in a floating algae (Sargassum spp.) have been reported in the mid-Atlantic and Caribbean, resulting in large accumulation on Florida's beaches. The purpose of this study was to determine if, during the 2020 nesting season, these accumulations acted as a barrier that prevented the hatchlings from crawling to the sea. Seasonal changes in Sargassum density were recorded to determine when, and under what circumstances, hatchlings could cross the accumulated wrack. There was a significant overlap between when Sargassum accumulations peaked and when the turtles emerged, with the result that during the 2020 nesting season the number of hatchlings that entered the ocean was reduced by an estimated 22%. These results suggest that algal accumulations represent a significant threat that could potentially impede the recovery of loggerhead populations that currently are either threatened or endangered, worldwide.

Helm, C.W.; Carr, A.S.; Cawthra, H.C.; De Vynck, J.C.; Dixon, M.; Stear, W.; Stuart, C.; Stuart, M., and Venter, J.A., 2022. Possible Pleistocene pinniped ichnofossils on South Africa's Cape south coast. Journal of Coastal Research, 38(4), 735–749. Coconut Creek (Florida), ISSN 0749-0208.

Exposed surfaces of cemented foreshore deposits and aeolianites on the Cape south coast of South Africa have been demonstrated to contain numerous Pleistocene vertebrate tracksites. Two ichnosites have recently been identified that appear to demonstrate traces made by seals. These would be the first seal trace fossils thus far described in the global fossil record. The sites are situated 560 m apart in the Goukamma Nature Reserve. One site exhibits apparent flipper traces and a furrow, and the other site exhibits impressions consistent with moulds of juvenile seals. In conjunction with new luminescence dating of the associated sediments, these findings suggest a seal presence on Cape south coast beaches ∼75,000 years ago in the mild glacial period of Marine Isotope Stage 5a.

Cheng, J. and Wang, P., 2022. Factors controlling storm-induced morphology changes at an erosional hot spot on a nourished beach, Sand Key barrier island, west-central Florida. Journal of Coastal Research, 38(4), 750–765. Coconut Creek (Florida), ISSN 0749-0208.

Beach nourishment has become the dominant sandy shore protection method over the past 40 years. The performance of nourished beaches and therefore the design of renourishment projects are significantly controlled by the presence of erosional hot spots and storm impacts. Based on 5.5-year bimonthly beach profile surveys, along a nourished beach spanning an erosional hot spot, this study examines the hydrodynamic conditions of extratropical (winter) and tropical (summer) storms that cause significant morphology changes. The sand volume loss above the short-term closure depth averaged along the 1.8-km stretch erosional hot spot was 178 m³/m over the 5.5 years after the nourishment. A large portion of this volume loss was caused by several extratropical storms and Hurricane Irma in 2017, when the high, northerly approaching waves were associated with a depressed water level. The northerly approaching waves induced a large longshore sediment transport gradient along the generally north-south trending coast due to wave refraction over a nearby ebb tidal delta. The energetic Hurricane Irma induced a large negative surge and also transported sediment seaward beyond the short-term closure depth. On the other hand, during the passages of typical tropical storms, the southerly approaching waves superimposed on elevated water levels caused substantial beach volume loss above the mean sea level. The eroded sediment deposited on the nearshore sandbar, resulting in conserved sand volume above the short-term closure depth. Understanding the different beach response to extratropical and tropical storms would benefit beach management, especially under the circumstance of increasing storm activities due to climate change.

Gurung, D.P.; Chen, N.; Waguespack, Y.; Ishaque, A.B., and Chigbu, P., 2022. Assessment of the spatial and temporal variabilities of phosphorus sorption index of the sediments in the Maryland Coastal Bays. Journal of Coastal Research, 38(4), 766–775. Coconut Creek (Florida), ISSN 0749-0208.

Coastal bays are valuable ecosystems that can act as a sink of phosphorus (P), so it is essential to understand P sorption in sediments to investigate the dynamics of P in the coastal bays. The objectives of this study were to examine spatial and temporal variability of P sorption index (PSI) of the sediments of Maryland Coastal Bays (MCBs) and to identify factors that affect adsorption of P in sediments. Sediment samples were collected at 13 sites from 2012 to 2014 and PSI of dried sediments was measured. The PSI was comparatively higher in sediments at sites with finer particles than at sites where sediments comprised coarser particles. Water column dissolved reactive phosphorus (DRP) was significantly lower in 2013 than in 2012 throughout the MCBs. No clear pattern in spatial variation of average water column DRP occurred at each site. A positive relationship between PSI and percentage contribution of clay/silt to the sediment was observed, indicating that sediment grain size is a major factor influencing P sorption in the MCBs. Negative relationships between PSI and salinity were observed, suggesting that salinity is an important factor determining P sorption by sediment particles. There was, however, no clear influence of DRP, pH, and temperature in water column and L.Adsorp-P fraction in sediments on PSI in sediment in MCBs.

Zhang, J. and Larson, M., 2022. A numerical model to simulate beach and dune evolution. Journal of Coastal Research, 38(4), 776–784. Coconut Creek (Florida), ISSN 0749-0208.

A numerical model to simulate cross-shore (CS) beach and dune evolution induced by storms was developed in this study. The model development was partly based on previous CS modeling work in which modules describing the response of the beach profile in the offshore, surf, and swash zone were described in detail, but where the dune module is lacking. The dune module, adopting wave impact theory, was integrated into the previous model to complete a new numerical model. To calibrate and validate the new model, high-quality data on hydrodynamics and dune profile response from both laboratory and field data were used. The laboratory data included two experimental cases related to dune erosion from the SUPERTANK data collection project, whereas the field data consisted of two cases from Ocean City, Maryland and one case from Myrtle Beach, South Carolina. Overall, good agreement was obtained between calculations and measurements, illustrating that the model is reliable and robust in simulating beach and dune evolution. However, the poststorm beach recovery in the swash zone could not be well captured by this model. Thus, in subsequent model development, onshore transport and accretion in the nearshore will be emphasized to simulate long-term beach evolution.

Wu, X.; Xu, Z.; Xu, Z.; Hu, B.X.; Chang, Q., and Hu, Y., 2022. The influence of seasonal recharge and groundwater pumping on the seawater intrusion in a coastal karst aquifer. Journal of Coastal Research, 38(4), 785–794. Coconut Creek (Florida), ISSN 0749-0208.

Groundwater resources in the coastal karst aquifers are threatened by long-distance seawater intrusion. The severity of groundwater contamination can be affected by hydrologic and anthropogenic factors, including rainfall conditions and pumping situations. A better understanding of these factors' control on the seawater intrusion is critical for their vulnerability estimation and aquifer management. The aquifer salinization, pumping safety, and the vulnerability of inland springs were examined by a synthetic-modeling work in this study. Different pumping locations, pumping rates, the comparison of dynamic seasonal recharge (DSR), and steady-state recharge (SSR) were considered in this study. Several time-based metrics were developed to estimate the aquifer vulnerability and water quality. The results show that the distance of pumping location to the shoreline significantly impacts seawater intrusion. The near-shore pumping leads to lower aquifer contamination while higher salinity in pumped water, and the inland pumping causes more aquifer salinization with cleaner pumped water. In addition, aquifer, pumping water quality, and inland spring are more vulnerable to seawater intrusion under the DSR condition than SSR condition. The difference of aquifer salinization between DSR and SSR condition increases with pumping rate from 50 to 150 m³/day and then decreases from 150 to 200 m³/day, which shows a threshold pumping rate in comparing DSR and SSR conditions. The insights from this work provide essential suggestions for groundwater simulations and related management decisions.

Fenster, M.S.; Hughes, C.P., and Stutz, M.L., 2022. A survey of global mixed-energy and wave-dominated barrier island distribution and development. Journal of Coastal Research, 38(4), 795–806. Coconut Creek (Florida), ISSN 0749-0208.

This study quantifies the length, percentage, and type of development found on global mixed-energy and wave-dominated coastal plain and deltaic barrier islands. Google Earth photographic imagery from 2015–2017 was used to measure the lengths of individual islands, identify infrastructure types 300 m landward of the shoreline, and measure the alongshore extent of each island's land uses. The United States Geological Survey's land-use classification scheme enabled categorization and quantification of predominant structure types. The results from this study showed that, of the 1444 mixed-energy and wave-dominated barrier islands located within 53 countries around the world: (1) 832 (approximately 59%) of those barriers islands have some type of development; (2) approximately 16% of the total length of shorelines (approximately 1,793 km/11,249 km) are developed; (3) wave-dominated barriers (approximately 17%) are more developed than mixed-energy (approximately 14%) barriers; (4) coastal plain (approximately 21%) settings have double the development than deltaic settings; (5) the U.S. contains approximately 66% of all developed global barrier island shorelines and the highest percent development of mixed-energy (New Jersey approximately 67%) and wave-dominated (Florida approximately 62%) coastal plain barrier islands in the world; and (6) high-density, residential dwellings dominate development type and comprise an average 14% of the world's barrier island shorelines. Finally, development percentage and/or land use type do not appear to depend on or correlate with hydrodynamic or geologic setting and coastal processes and geology do not influence development type. Instead, site specific or regional factors most likely dictate the percentage and type of development.

Ascencio, J.A.; Jacobsen, N.G.; McFall, B.C.; Groeneweg, J.; Vuik, V., and Reniers, A.J.H.M., 2022. Evaluation of implicit and explicit wave dissipation models for submerged and emergent aquatic vegetation. Journal of Coastal Research, 38(4), 807–815. Coconut Creek (Florida), ISSN 0749-0208.

To address the important research question of whether implicit (bottom friction) or explicit (stem drag) dissipation models are most appropriate for the prediction of wave attenuation due to aquatic vegetation, the Simulating Waves Nearshore (SWAN) spectral wave model has been extended with an explicit frequency-dependent dissipation model for submerged and emergent vegetation. The new explicit model is compared to existing explicit and implicit dissipation models in SWAN, and the distinguishing features of each of the dissipation models are quantified. The present work verifies the implementation of the new and existing dissipation models, outlines their distinguishing features, and compares model predictions against experimental data. The emphasis is on the transformation of the spectral wave periods T_m0,1 and T_m–1,0 over a canopy. Model evaluation based on academic and laboratory cases allows for recommendations regarding applicability of the three dissipation models, where the new method has the broadest applicability, since it bridges the gap in applicability between the other two dissipation models. The implementation of Jacobsen, McFall, and van der A (2019; A frequency distributed dissipation model for canopies; Coastal Engineering, 150, 135–146) is publicly available in SWAN version 41.31B.

Chen, Q.; Lin, Y.; Zhang, Y.; Wang, C., and Cai, A., 2022. Evaluation framework for determining the developmental suitability and sustainability of uninhabited islands. Journal of Coastal Research, 38(4), 816–827. Coconut Creek (Florida), ISSN 0749-0208.

The sustainable development of an island ecosystem should be guided by accurately assessing its suitability for development. However, the possibility of sustainable development of a given uninhabited island has not yet been explored, and the corresponding development intensity remains unclear. In this study, an indicator evaluation framework was developed based on ecological and economic value to evaluate the developmental suitability of uninhabited islands. The ecological value of an island was determined based on the ecosystem conditions, environmental quality, natural and cultural heritage, and potential marine disasters. The economic value was calculated using spatial, biological, and tourism factors; energy and mineral resources; and local development conditions. Accordingly, the developmental suitability levels of islands were categorized into four levels on a 10-point score as high, moderate, low, and unsuitable depending on a mutually exclusive ecology–economy matrix. The application of this matrix in Xiamen Crocodile Island revealed a comprehensive ecological protection indicator score of 5.953 and a comprehensive economic feasibility indicator score of 6.346. The developmental suitability of this island was therefore moderate, and from the comparison of individual scores, eco-tourism should be regarded as the primary development mode. Each level of developmental suitability requires unique suitability strategies to ensure ecosystem preservation. For high suitability, the island resources could be reasonably utilized based on scientific demonstration; for moderate suitability, the carrying capacity of the island should be evaluated and an ecological compensation scheme should be established; for low suitability, the natural attributes and sustainability of the island should be maintained; for unsuitable level, external interference should be prevented to avoid ecosystem fragility. This framework is an effective tool for evaluating the sustainability of uninhabited island ecosystems. This study potentially facilitates the protection and development of Crocodile Island and assists in determining the developmental suitability of other uninhabited islands, besides fostering scientific decision-making.

Anderson, R.B.; Carter, O.T.; Pearce, K.G., and Capdevila, L.A., 2022. User perceptions of the Pleasure Point seawall in Santa Cruz county, California, U.S.A. Journal of Coastal Research, 38(4), 828–843. Coconut Creek (Florida), ISSN 0749-0208.

Communities up and down the California coast face the looming threat of rising seas, coastal erosion, and shoreline retreat. In this paper, the researchers use anthropological methods and a user survey to explore the social dimensions of the Pleasure Point seawall to assess some of the longer-term implications of coastal armoring in California and the U.S. more broadly. The users surveyed had an overall positive to neutral opinion of a coastal retention structure (in this case a seawall). About 35% had positive opinions of the seawall, 30% had neutral opinions, and 18% had negative opinions. While these results trend positive to neutral, they also reveal divided community opinions about and experiences with the seawall. The open-ended portions of the survey, combined with participant observation and follow-up interviews, add another qualitative dimension to this data. The participants in the survey and research expressed concerns about engineering and ecological issues, whether questions about how long the structure will last or observations/opinions about its impacts on local surf conditions, backwash, and loss of beach sand. Participants also expressed concerns about the social impacts of the seawall, including access issues, crowds, growing risks, problems with increasing numbers of inexperienced users, tourism growth, and fears about gentrification and local displacement. Combined, these insights illustrate how seawalls and other coastal armoring structures can and should be understood as engineered structures with critical social impacts that intersect with their physical, material, and environmental impacts.

Prado, M.F.V.; Dalinghaus, C.; Gomes da Silva, P.; Weschenfelder, J., and Klein, A.H.F., 2022. Estimating the different return periods of storm impact regimes on beach and foredune systems based in hindcast data: Applications to exposed and sheltered beaches of Santa Catarina Island, Brazil. Journal of Coastal Research, 38(4), 844–859. Coconut Creek (Florida), ISSN 0749-0208.

This paper presents an adapted methodology to estimate the different return periods of storm-induced impacts on beaches and foredune systems based on hindcast data, with examples of applications in areas exposed to and sheltered from the wave action. The methodology consists of using wave, tide, and surge reanalysis data to obtain large series of total water level, which are used to estimate the values related to different return periods (5,10, 25, and 50 years). Those levels are summed to the corresponding projection of sea level rise from the worst-case scenario projections. The final values are used to classify the beaches according to the coastal storm impact regime as (1) swash, (2) collision, (3) overwash, and (4) inundation. Finally, the limit between each regime is established based on the relation among dynamical and geomorphological parameters. The methodology was applied to the east (exposed beaches) and north (sheltered beaches) coasts of Santa Catarina Island (Florianópolis, Southern Brazil), a zone constantly submitted to extreme storm events and where large series of measured data are commonly missing. The results for Santa Catarina Island indicate that the storm impact regime in most of the exposed beaches is similar for different return periods (most of them classified as collision regime). Overwash regime is predominant on sheltered beaches. Sectors with an intense urban occupation are classified as under inundation regime for all return periods, while zones with well-developed foredune are classified as the collision regime. Some of those results could be qualitatively verified with observations from recent storm events, highlighting the value of this kind of methodology to estimate the impact of coastal storms in zones with an important lack of measurements.

Sauz-Sánchez, J.J.; López-Rocha, J.A.; Arceo-Carranza, D., and Poot-López, G.R., 2022. Spatial-temporal variations of discarded ichthyofauna from a small-scale shrimp fishery: Influence of ecological patterns in a Yucatan coastal lagoon. Journal of Coastal Research, 38(4), 860–869. Coconut Creek (Florida), ISSN 0749-0208.

Spatial-temporal variations of discarded catches associated with a shrimp-small scale fishery from the Celestun lagoon, Yucatan, Mexico, were analyzed throughout seasonal and spatial (inner, middle, and external estuarine zones) physicochemical gradients to observe the influence of ecological patterns on discarded ichthyofauna. Differences in abundance, biomass, composition, and physicochemical variables between seasons and among zones were tested using a two-way ANOVA and an analysis of dissimilarity, respectively. The best subset of environmental variables (BIOENV) function was used to observe the influence of physicochemical gradients on the discarded fish community. A total of 1611 individuals belonging to 36 species of discarded fish were identified, with mostly an abundance of juveniles occurring for the following species: Achirus lineatus, Archosargus probatocephalus, Cynoscion nebulosus, Eucinostomus gula, Floridichthys polyommus, Lagodon rhomboides, Lucania parva, Mayaheros urophthalmus, and Sphoeroides testudineus. Hence, the data shows a strong selection pressure on juvenile fish. Significant differences in abundance, species composition, and physicochemical variables were observed between seasons and zones. Results from the BIOENV indicated that temperature, salinity, and pH gradients, generated by underground freshwater discharges, influenced the spatial-temporal variations of discarded ichthyofauna from the Celestun lagoon. Furthermore, reproductive seasons, and capabilities to tolerate salinity concentrations also spatially structures a discarded fish community. The results showed the ecological complexity in which fish discards occur, in addition, suggesting measures to reduce discards by including ecological and social aspects to maintain the sustainability of this artisanal shrimp fishery.

Xu, H.; Rui, X.; Wang, Z.; Qiu, Z.; Cai, L.; Zhang, Z., and Zhao, M., 2022. The effects of physical properties on the compression modulus of coastal fully-weathered red sandstone: Consolidation compressibility and the settlement calculation of foundation. Journal of Coastal Research, 38(4), 870–884. Coconut Creek (Florida), ISSN 0749-0208.

The compressibility of rock and soil can be characterized by compression modulus, which is influenced by multiple physical properties, so it is difficult to be quickly and accurately measured on-site; thus, comprehensive exploration of their influence on the compression modulus is significant. In this paper, the physical properties of water content, fines content, and relative compaction, which can be easily measured on-site, were selected. Based on the orthogonal combination consolidation test, the variation of compression modulus of fully weathered red sandstone was investigated. Then, the relationship between compression modulus and the combination of physical properties was learned using the decision tree algorithm model for the first time, which can perform accurate and real-time prediction. The results showed that the cubic and quaternary polynomials can accurately represent the variation of compression modulus with a single physical property, and the model based on a 10-level decision tree algorithm can learn the coupling relationship between compression modulus and combination of physical properties to accurately calculate and predict the compression modulus. The algorithm model can be further applied to calculate the settlement of foundation in fully weathered red sandstone stratum with different water content during the precipitation process, which can effectively guide the engineering construction. This research provides a reference for the study of consolidation compressibility of fully weathered red sandstone and similar stratum, as well as the settlement calculation of foundation.