Boon, J.D. and Mitchell, M., 2015. Nonlinear change in sea level observed at North American tide stations.

The rate at which coastal sea level is expected to rise or fall is of considerable interest to coastal residents and managers who view changes on the time scale of a 30-year mortgage. Analysis of historical records at North American tide stations provides evidence of recent nonlinear sea-level change at this scale using relative mean sea-level (RMSL) observations. RMSL tracks local inundation risk directly without the need to correct an accepted worldwide geocentric measure—e.g., global mean sea-level rise—with locally estimated vertical rate adjustments. Published RMSL linear trends provide essential information but are routinely compared between tide stations with widely varying record lengths, thereby obfuscating nonlinear change (acceleration or deceleration) over a specific period of time. Here monthly averaged RMSL data from 45 U.S. tide stations and one Canadian tide station are analyzed from 1969 through 2014, extending a definitive period of acceleration previously noted along the U.S. NE Coast. Using a Bayesian approach to determine the joint probability of paired regression parameters for RMSL quadratic trends, probabilities for forward projections to the year 2050 based on these trends suggest continued sea-level rise will be aided by acceleration presently on the order of 0.1 to 0.2 mm/y² in the U.S. NE and Gulf Coast regions. Deceleration ranging from −0.1 to −0.4 mm/y² is likely to reinforce falling sea levels at specific locations on the U.S. West Coast in the near term.

Shaw, C.E. and Benson, L., 2015. Possible tsunami deposits on the Caribbean coast of the Yucatán peninsula.

The western Caribbean Basin is notable for its tectonic stability. It has experienced no historical earthquakes or the tsunami that sometimes accompany them. This paper describes a single, wedge-shaped, boulder-covered, coastal berm on the Yucatán coast of México that stretches unbroken for 50 km across a coastal segment characterized by rocky headlands that alternate with crescent beaches. The remainder of the 350 km of Yucatán coast consists mostly of mangrove that extends 1 to 30 km inland, often behind long, sandy beaches. On the headlands, the surface of the berm is densely paved with boulders—large boulders on its seaward face and smaller boulders and cobbles on its gently sloping inland surface. The top of the berm reaches an elevation >4 m, above the reach of all but the largest modern storm waves. Berm sediments on the headlands consist of two distinct layers of unbedded coarse sand with numerous randomly distributed boulders and cobbles in the lower layer and a crudely textured gravel and sand layer above. At first glance the two layers appear to be separated by 20 cm of white sand above a thin, discontinuous zone of dark, greyish sand that contains isolated balls and smears of black organic material, apparently derived from a soil, or possibly leaf litter. The berm and its associated boulders track the modern coastal morphology in precise detail as it follows the form of modern headlands, bays, and transcoastal channels, indicating that deposition took place after development of the present coast. The berm sediments record two or three large waves, depending on whether the wave that deposited the boulder pavement is regarded as part of the second wave or as a separate wave. Radiocarbon dating indicates that at least one wave struck the coast approximately 1500 years before present. Minimum wave run-up exceeds 4 m above present sea level, and inland inundation reached 400 m along bays and transcoastal channels. The position and elevation of the berm, its lack of well-developed internal bedding, the paving of the berm surface by thousands of boulders, and its 400-m extent inland along channels and bays are features commonly associated with tsunami. However, some recent studies conclude that all of the features listed also can be produced by mega-hurricanes. Placed in the context of our literature search of the recent history of hurricanes and tsunami in the Caribbean Basin, we conclude that the single berm on the Yucatán coast represents an anomalous event for this area and that the berm sediments bear a strong similarity to descriptions of sediments from some historical tsunami and are unlike sedimentary features associated with historical hurricanes.

Peterson, C.D.; Stock, E.; Meyer, J.; Kaijankoski, P., and Price, D.M., 2015. Origins of Quaternary coastal dune sheets in San Francisco and Monterey Bay, central California coast, U.S.A.: Reflecting contrasts in shelf depocenters and coastal neotectonics.

The San Francisco and Monterey Bay coastal dune sheets derive from similar origins in the central California coast but differ substantially in size (respectively, ~400 and ~900 km²) and age (respectively, <0.1 and >1.0 Ma). The San Francisco dune sheet is restricted to a short alongshore interval (<20 km) within a relatively straight coastline (150 km in length) that borders a broad shelf (~40 km in width). The Monterey Bay dune sheet is restricted to the Monterey Bay embayment (41 km alongshore length). The embayment includes a very narrow shelf (3–15 km in width), which is dissected by the Monterey Submarine Canyon. Generally low onshore topographic relief (<150 m elevation) likely enhanced inland transgression of Late Pleistocene dune fields in both the San Francisco and Monterey Bay areas. The locations of the dune sheets are directly related to sand accumulations in marine low-stand depocenters that supplied sand to the adjacent dune fields by eolian transport across the emerged inner shelves. The San Francisco shelf depocenter is apparently localized at a midshelf bight (−50 to −100 m elevation) that extends 25 km (east–west) offshore of a paleoriver mouth of a major river system, the Sacramento–San Joaquin River. The Monterey Bay shelf depocenter is bounded alongshore by major headlands and converging paleoshorelines (−30 to −90 m elevation) that effectively trapped littoral sand from small coastal drainages, primarily the Salinas River. High vertical rates of neotectonic deformation in the San Francisco dune sheet (0.4–1.0 mm y⁻¹) limited dune sheet longevity and deposit thickness (5–35 m). Low uplift rates (~0.1 mm y⁻¹) in the central Monterey Bay dune sheet permitted deposit accumulations of up to 250 m thickness. The differences in dune sheet extent, thickness, and age resulted from key differences in localized shelf accommodation space and coastal neotectonic vertical movements.

Slaymaker, D.H.; Peek, M.S.; Wresilo, J.; Zeltner, D.C., and Saleh, Y.F., 2015. Genetic structure of native and restored populations of American beachgrass (Ammophila breviligulata Fern.) along the New Jersey coast.

Ammophila breviligulata Fern. (American beachgrass) is planted extensively along the Atlantic coast of North America and in the Great Lakes region to stabilize damaged and constructed coastal dunes. Most A. breviligulata restorations are planted with a single cultivar for rapid dune stabilization. Restoration practice, however, is increasingly focused on maintaining native genetic diversity and restoring ecological services and function. We used intersimple sequence repeat (ISSR) markers to characterize the genetic structure of four native and four restored A. breviligulata populations along the coast of New Jersey on the northeastern Atlantic coast of the United States. Native populations had high levels of genotypic diversity for a clonal species, whereas restored populations on constructed dunes had low diversity or were monotypic. Commercial varieties used in dune restoration were not found in native populations. Native foredune populations were composed of many small- to medium-sized clones, while a rear-dune population was dominated by a single large clone. Genetic differentiation was low among native foredune populations. These results, discussed in the context of other clonal and coastal dune species, suggest that sexual recruitment plays an important role in determining the genetic structure of A. breviligulata populations, that gene flow has occurred among populations along the New Jersey coast, and that native New Jersey populations could provide genotypically diverse plant material for local restoration efforts.

Shi, B.; Wang, Y.P.; Yang, Y.; Li, M.; Li, P.; Ni, W., and Gao, J., 2015. Determination of critical shear stresses for erosion and deposition based on in situ measurements of currents and waves over an intertidal mudflat.

Accurate determination of the critical shear stress associated with the erosion and deposition of sediments is an important component of numerical models used to predict and quantify sediment behavior and transport across intertidal flats. In this study, water depth, wave parameters, near-bed turbulent velocity, suspended sediment concentration (SSC), and intratidal bed-level changes were measured to determine the erosion (τ_ce) and deposition (τ_cd) thresholds of sediments on an intertidal mudflat at Jiangsu, China. Based on integrated field measurements of bed-level changes and hydrodynamics, the bed shear stresses of currents (τ_c), waves (τ_w), and combined current-wave action (τ_cw) were calculated, and the critical shear stress required for erosion (τ_ce = 0.14 N/m²) and deposition (τ_cd = 0.08 N/m²) of these sediments was determined. Both values are in agreement with an estimate of τ_ce (0.13 N/m²) that was based on water content and τ_cd values calculated by previous works, indicating that the value of τ_ce estimated for these sediments is controlled primarily by the water content of the sediments. During field measurements, deposition occurred (τ_cw < τ_cd) when current action exceeded wave energy (τ_c > τ_w) during calm weather, whereas erosion occurred (τ_cw > τ_ce) when wave action increased dramatically during rough weather. Our field data showed that high current velocities lead to low τ_c, possibly because high SSC reduced the drag coefficient, which is variable during a tide, and further caused low τ_c under high current velocities. Additionally, bedforms characteristic of intertidal mudflat (e.g., gullies, small creeks, ripples, or saltmarsh) has a significant influence on the drag coefficient of the bed. These observations suggest that the bed level responds strongly to changing hydrodynamic conditions, and also that waves are of great importance to erosion. This study demonstrates that the in situ determination of the parameters that control erosion and deposition is a useful approach to obtaining values of τ_ce and τ_cd, which provide the basis for a mechanistic understanding of the morphological evolution and development of predictive sediment transport and erodibility models.

Yuan, R. and Zhu, J., 2015. The effects of dredging on tidal range and saltwater intrusion in the Pearl River estuary.

A dredging project in the Pearl River estuary would influence the topography, water dynamics, and mass transport process. The effects of dredging in the channel of the Pearl River estuary on tidal range and saltwater intrusion were studied using a hydrodynamic model (finite volume coastal ocean model) and historical water depth data. The measured data showed that the tidal range decreased and saltwater intrusion increased in the North River. The tidal range increased and saltwater intrusion decreased in the West River in recent decades from the 1980s. The simulations in this study showed that after dredging (1) the upstream flow split ratio in the river changed (i.e. more freshwater flowed through the Sanshui station), whereas less freshwater flowed through the Makou station; (2) the tidal range increased in the West River network and decreased in the downstream reaches of the North River network; and (3) the saltwater intrusion increased in the West River mouths and weakened in the North River mouths. These results agreed with the observed phenomenon. The change in the flow split ratio between the North River and the West River induced by dredging was the fundamental dynamic that caused changes in both the tidal range and saltwater intrusion in the Pearl River estuary.

Escobar, C.A.; Velásquez, L., and Posada, F., 2015. Marine currents in the Gulf of Urabá, Colombian Caribbean Sea.

A comprehensive study of the marine currents of the Gulf of Urabá is presented for temporal scales ranging from intertidal to seasonal. The analyses made were based on three-dimensional (3D) numerical modeling and extensive current observations. The hydrodynamic model based on the Delft3D platform included the influence of different forcings such as tide, waves, atmosphere, river discharges, and density gradients. Because field data concerning these variables are scarce for the study area, measuring campaigns, in combination with global models and databases, were used to overcome this condition. The evaluation of the model was attained by the use of unprecedented field data obtained in different climatic seasons through a mobile gauge station. This station registered instantaneous vertical profiles of flow along 1200 km with approximately 50-m spacing. This type of measurement was preferred instead of those obtained from stationary stations, because the spatial gradients of the currents were much greater than their temporal variations. The good agreement of the 3D mathematical model in the reproduction of the observed instantaneous currents supported its use in defining the marine currents in the gulf. A combined analysis of the model results and the measured currents revealed a complex circulation pattern comprising simultaneously typical estuarine circulation, one- to three-layer flows, and even inverse circulation. This flow complexity would hardly have been determined through common measurement methodologies based on stationary gauge stations.

Leadon, M., 2015. Beach slope and sediment-grain-size trends as a basis for input parameters for the SBEACH erosion model.

Results from Storm-induced BEAch CHange (SBEACH) model calibration studies have provided new techniques and support for selection of model input parameters and interpretation of model output results. Beach and dune erosion analyses using the SBEACH erosion model in St. Johns County, Florida, demonstrated sensitivity of simulated erosion to changes of two model input parameters: sediment grain size and maximum slope prior to avalanching (MSPA). The MSPA parameter corresponds with the seaward slope of the dune or beach-berm erosion escarpment at the landward limit of the storm-induced erosion. Model calibration work demonstrated trends of these two model input parameters and of the sediment-transport rate coefficient K in relation to changes in beach slope. Evaluation of beach-slope values computed from county-wide topographic survey data in relation to the available mean sediment-grain-size data has shown clear correlation between these two parameters. This analysis provided a method for estimating mean sediment-grain-size values needed for SBEACH model input throughout St. Johns County. Results of SBEACH calibration work performed throughout St. Johns County demonstrated trends in the K and MSPA model input parameters relative to mean sediment-grain-size variations. Results of SBEACH model calibration studies in Panama City Beach, Florida; Brevard County, Florida; and on barrier islands within the Barataria Basin along the Louisiana coast demonstrated consistency with these identified trends.

Ozturk, D.; Beyazit, I., and Kilic, F., 2015. Spatiotemporal analysis of shoreline changes of the Kizilirmak Delta.

The detection of shoreline changes in coastal countries is critical for successful management and planning. Determining shoreline changes and investigating reasons behind uncontrolled changes ensure that the necessary precautions can be taken. This study focuses on determining temporal changes that have occurred on the shoreline of the Kizilirmak Delta, which is one of the most crucial wetlands protected by the Ramsar Convention in Turkey. Landsat-5 thematic mapper (TM) satellite images from 1987, 1998, 2002, 2007, and 2011 were used to determine temporal changes. The approach, which integrates band-ratioing and histogram-thresholding methods, was applied using the second, fourth, and fifth bands of the Landsat TM images. The shoreline change envelope (SCE), end point rate (EPR), and linear regression rate (LRR) methods were used to determine the shoreline changes. The SCE method detected a landward migration that occurred on the delta, where its maximum migration was 655.6 m between 1987 and 2011. During the same period, the maximum coastal change rate was estimated to be −27.4 m/y using the EPR method and −29.7 m/y using the LRR method. The maximum amount of erosion occurred near the river mouth. The results indicated that the dams built on the Kizilirmak River and close to the delta significantly affected these changes and that the spurs, which were built to prevent coastal erosion and provide partial protection, cannot fully prevent erosion.

Chevalier; C.; Devenon, J.-L.; Rougier, G., and Blanchot, J., 2015. Hydrodynamics of the Toliara reef lagoon (Madagascar): Example of a lagoon influenced by waves and tides.

In meso-tidal lagoons, the coral reef barrier can be temporarily submerged at high tide and partially exposed at low tide, which causes highly specific lagoon dynamics. To understand those dynamics, three field-measurement campaigns were conducted in the Toliara Lagoon (Madagascar), where the tide and the waves increase that effect. The method combined measurements taken from fixed moorings and measurements from a small, moving, inflatable boat along the transects through the reef passages. A tidal analysis methodology adapted to this lagoon was used to reconstitute the currents through the passages and to determine the spatial and temporal current variability. Then, the lagoon water dynamics were studied. The tidal dynamics of the lagoon appear to depend significantly on flows through the passages, although they were also affected by water passing across the reef. Water entered the lagoon through the passages during the tidal flow and left it during the ebb. The tidal-prism flushing time (estimated using the tidal prism method) was 1 day during spring tide and 5 days during neap tide. At the same time, the average flow during a tidal cycle appears to be directly linked to the waves breaking over the reef. Indeed, the average cross-reef flow was inflowing and was mainly driven by the ocean swell. That inflow was balanced by an outflow through the passages. Hence, the average bulk flushing time was estimated at 13 days during the wet season and 4 days during the dry season.

Dans les lagons méso-tidaux, la barrière de corail peut être alternativement immergée à marée haute et quasiment émergée à marée basse ce qui entraîne une dynamique des masses d'eau tout à fait particulière. Pour comprendre cette dynamique, 3 campagnes de terrain ont été réalisée dans le lagon de Tuléar. L'approche expérimentale combine à la fois des mesures en mouillages et des mesures lors de transects réalisés à partir d'une petite embarcation. A partir de ces mesures et grâce à une méthode spécifique d'analyse de données, nous reconstituons les courants dans les passes et obtenons leur variabilité spatiale et temporelle. Nous étudions alors la dynamique du lagon. L'eau entre dans le lagon par les passes durant le flot et en sort durant le jusant. Cette dynamique est toutefois modulée par les courants au-dessus du récif barrière En effet, ces courants qui dépendent à la fois de la marée, mais aussi de la houle déferlant au-dessus du récif, peuvent engendrer des distorsions dans les ellipses de marée au voisinage du récif, générés une onde quart-diurne au sein du lagon. Enfin, alors que la dynamique tidale du lagon semble fortement dépendre du flux au niveau des passes, les flux moyennés sur un cycle de marée dépendent plus particulièrement du flux moyen au-dessus de la barrière et semblent directement lié à la houle déferlant le long du récif : le flux cross-récifal moyen est entrant et son intensité varie en fonction de la houle au large. Cet apport est compensé par un flux sortant au niveau des passes. Ainsi, le temps de résidence moyen est de 13 jours en saison humide et 4 jours en saison sèche.

Niencheski, L.F.H. and Windom, H.L., 2015. Chemistry of a surficial aquifer of a large coastal lagoon barrier and its relation to adjacent surface waters of Brazil.

The Holocene/Pleistocene barrier along the coast of southern Brazil, separating the Patos Lagoon (the largest in South America) from the South Atlantic Ocean, contains a surficial unconfined aquifer that connects to both water bodies. This has been the site of previous studies on surface-water chemistry and on the subterranean estuary (SE) and submarine groundwater discharge (SGD) along the barrier beach. In this paper we present the results of observations from monitoring wells placed in three transects across this barrier and make a preliminary assessment of spatial variations in chemistry of aquifer water, based on analyses of samples collected over a period of several years, and its relation to that of adjacent surface waters. In addition to general groundwater chemistry (DO, pH, Eh, and conductivity), dissolved nutrients (inorganic N, phosphate, and silicate) and trace metal (Ba, Cd, Co, Cu, Fe, Mo, Mn, Ni, U, V, and Zn) concentrations were also determined. From the results we conclude that the Patos Lagoon Barrier (PLB) aquifer serves as a reactive reservoir/filter of inputs from terrestrial runoff to the ocean. Processes occurring in the aquifer and at its interfaces with the ocean and lagoon influence nutrient composition and trace metal concentrations of adjacent surface waters and alter the land–sea flux of some dissolved trace metals.

Medina-Gómez, I.; Villalobos-Zapata, G.J., and Herrera-Silveira, J.A., 2015. Spatial and temporal hydrological variations in the inner estuaries of a large coastal lagoon of the southern Gulf of Mexico.

Coastal lagoons receive significant inputs from river basins, leading to inner estuaries or fluvial lagoon subsystems subject to the bidirectional flow of energy, organic matter, nutrients, and sometimes toxic materials between river mouths and lagoons. Such exchanges are highly dynamic and enhance lagoon productivity. Terminos Lagoon (TL) is a large coastal lagoon in the southern Gulf of Mexico that has two deep permanent inlets connecting the lagoon to the Gulf and strong riverine input. We evaluated the influence of river discharge on seasonal and spatial patterns of water quality in six fluvial lagoon subsystems in TL. Six bimonthly samplings were carried out from February to December 2001. Temperature, salinity, dissolved oxygen, dissolved inorganic nutrients (nitrate, nitrite, ammonium, soluble reactive phosphorus, and soluble reactive silica), and chlorophyll a were measured. There were large differences between the western and eastern river mouths due to differences in river discharge and the nature of their watersheds (e.g., land use, size). Furthermore, the influence that the dominant depositional environment and local habitats (i.e. submerged aquatic vegetation) developing adjacent to these estuarine lagoon subsystems may exert over the nutrient concentrations of the water column is discussed. These differences were more evident during the rainy season when river discharge was highest. It is suggested that the input of N rather than P could have the greatest impact on TL in the future.

Pan, Y.; Deng, J.-S.; Cai, J.; Wang, K.; Wu, C.; Li, J., and Li, J., 2015. Spatiotemporal dynamics of island land expansion response to intensive island development and reclamation.

Along with the numerous benefits of rapid reclamation and economic advancement in islands, the intensified conflict between island development and ecosystem sustainability should arouse concern worldwide. The islands in Zhejiang, China, have been an outstanding center of marine economic development but also among the areas most threatened by human activities in recent years. This study aimed to investigate the historical impacts of development and reclamation on the islands' land expansion and morphology change from the 1970s to 2013 and to identify the strongest signals of land transitions among the expanded areas. The results indicated that the islands dramatically expanded during 2000–13, with a threefold area increase compared to the first 30 years of the study period, and that the coastlines geometries became simpler with strong decreases in fractal dimension. More than 50% of the additional land was occupied by artificial structures that substantially altered the physical environment. These changes were mostly concentrated on the three island types: comprehensive, port and industry, and tourism. They are mainly the outcome of the spatial co-occurrence of port, logistics, and coastal industries or tourism establishments in response to government plans; moreover, the alteration of economic patterns presents as an aggravating force. Historically, the extensive islands' land expansion for coastal activities has brought about economic prosperity, but it has done so at the expense of environmental degradation, which highlighted the implications for guiding sustainable island development, particularly under the background of current economic booms in maritime China.

Medellín, G.; Mariño-Tapia, I., and Euán-Ávila, J., 2015. The influence of a seawall on postnourishment evolution in a sea-breeze-dominated microtidal beach.

The postnourishment beach evolution is evaluated on a sea-breeze-dominated microtidal beach in Yucatan (Mexico). The study area has experienced severe beach erosion due to both alongshore sediment-transport gradients during calm conditions and offshore sediment transport during extreme wave events. Therefore, a shoreline restoration program, including beach nourishment and the removal of groynes, was carried out in 2002. Bimonthly subaerial/intertidal beach profiles measured during 7 years (2002–09), in front of a seawall and at an adjacent beach (nonwalled), are employed to analyze the beach nourishment evolution. Empirical orthogonal function (EOF) analysis of the shoreline time series is performed using the data extracted from the 50 field surveys. The temporal evolution of the EOF analysis shows the following: (1) an abrupt increase in beach width due to nourishment at the study site at the beginning of 2003, (2) followed by a sustained increase (from 2004 to 2007) owing to the sediment advection from a massive beach fill performed up-drift of the study area, and (3) a decrease in beach width from 2007 until the end of the study period. Moreover, the mean profile-volume change is estimated separately for walled and nonwalled beach sections. The nonwalled profiles results are consistent with the temporal evolution described by the EOF analysis. On the other hand, walled beach profiles show a net volume loss from 2002 to 2007, remaining stable during the following 3 years. Consistent with previous studies, seasonal variability of sand volume was found to be greater in front of the seawall with respect to the nonwalled section. Nevertheless, the erosional/despositional rates in the two sections show opposite trends during mean (sea-breeze) wave conditions, being more important in the subaerial beach profiles. The latter implies that swash-zone sediment transport represents an important contribution to the total sediment budget in the study area; hence, seawalls can significantly modify coastal dynamics in sea-breeze-dominated environments.

Gandara-Martins, A.L.; Borzone, C.A.; Guilherme, P.D.B., and Vieira, J.V., 2015. Spatial effects of a washout on sandy beach macrofauna zonation and abundance.

Washouts have an important function in backshore zone drainage and remobilization of sediments for littoral transport. It is known that they can change beach morphology along its course, but their effects on the macrofauna community still represent a gap in knowledge of sandy beach ecology. Based on previous studies developed in larger systems, such as channels and estuaries, we aimed to assess how the macrofauna community responds to the presence of a permanent sandy beach washout. The study was carried out at an exposed sandy beach in southern Brazil, where six cross-cut transects 0, 3, 9, 27, 81, and 243 m in distance from the washout were defined. Biological and environmental samples were taken at nine levels along each transect. As expected, beach morphology and water table salinity were affected by the washout, resulting in changes in the macrofauna zonation pattern and community descriptors. The isopods Tholozodium rhombofrontalis and Excirolana armata were dominant at all levels close to the washout, where polychaetes, amphipods, and mollusks were almost absent. Macrofauna reached the typical zonation pattern for local, nearby beaches only at distant transects. A good correlation between biological and environmental variables was observed. These results indicate that washouts can modify the macrofauna community at a small spatial scale, and only species adapted to a high range of variation in salinity (euryhalines) with a high mobility can live in substantial numbers close to and within these freshwater streams.

Hereher, M.E., 2015. Assessment of South Sinai coastal vulnerability to climate change.

Coastal vulnerability assessment is important to help achieve the sustainable use of coastal resources and to incorporate coastal hazards into coastal planning and decision making for integrated management. This study applied the coastal vulnerability index (CVI) to delineate susceptibility of the South Sinai coastline to climate change. The following variables pertaining to inherent shoreline characteristics were used in the assessment of the CVI: coastal slope, coastal geomorphology, fauna/flora, and socioeconomic factors. GIS and remote sensing analysis were employed to extract intrinsic attributes of the coast in this study area. Results showed that about one half of the 635-km-long coastline is exposed to high and very high coastal vulnerability to climate change, and global warming could exacerbate biologic suffering in the region. The Gulf of Suez is likely to be more vulnerable than the Gulf of Aqaba. Most areas susceptible to climate change include gentle, unconsolidated, coral assemblages and inhabited coastal segments. Coastal zone managers should implement remediation plans for any anticipated ecosystem disruption episodes.

Lucrezi, S. and Saayman, M., 2015. Beachgoers' demands vs. Blue Flag aims in South Africa.

The Blue Flag is a beach award aimed to preserve features of the beach environment. While it is assumed that the Blue Flag attracts tourism, this depends on factors such as the socio-demographic background of beachgoers, their perception of beach attributes, and their knowledge and perception of the Blue Flag. This research used structural equation modeling (SEM) to investigate relationships between perceived beach attributes (beach selection criteria, deterrent factors of the beach, and beach quality rating) and beachgoers' knowledge and perception of the Blue Flag award on three Blue Flag and three non-Blue Flag beaches in South Africa. A single statistically significant relationship emerged between beach quality rating and evaluation (both positive and negative views, which are not necessarily mutually exclusive) of the Blue Flag award by beachgoers. The data highlight the importance of generating bottom-up information to assist potential, occasional, and running Blue Flag managers in South Africa, particularly in regard to proper education and promotion of the Blue Flag award.

Zhang, H.; Yang, H., and Jeng, D.-S., 2015. Contaminant transport in capped deformable partially saturated sediments.

Contaminated sediment tends to consolidate in response to the loading imposed by an overlying cap layer. The form of transient solute advection through sediments and caps is consequently changed. Therefore, the contaminant discharge into the overlying water is expected to increase and the effectiveness of the in situ capping system will be strongly affected. In this study, a one-dimensional sediment–cap model coupling consolidation and advection–dispersion equation was established. A simplified model was proposed through the sensitivity analysis, and then a parametric study was conducted. Numerical examples concluded that the absorption, degree of sediment saturation, cap thickness, and sediment depth significantly affect the contaminant discharge from the top of the cap. Therefore, these parameters should be considered carefully during cap design.

Jiang, C.; Yao, Y.; Deng, Y., and Deng, B., 2015. Numerical investigation of solitary wave interaction with a row of vertical slotted piles.

This study numerically investigated tsunami-like solitary waves propagating over a row of vertical, slotted, cylindrical piles. Existing studies using depth-integrated models, such as shallow-water equations, could not adequately resolve the wave dynamics over water depth. An alternative three-dimensional, numerical model, based on OpenFOAM^® software, was developed for this study. The Navier-Stokes equations for two-phase, incompressible flow, combined with methods of large eddy simulation (LES) for turbulence closure and volume of fluid (VOF) for tracking the free surface, were solved. Laboratory experiments were performed on the measurements of flow near the piles and the dynamic pressures on the pile surface. The model was then validated with the laboratory data as well as data in the literature, and good agreements were found for wave, flow, and dynamic pressure near the slotted piles. Finally, a set of numerical experiments was conducted to examine the evolutionary behaviors of wave run-up, vortex generation, and the vertical structure of dynamic pressure around the row of slotted piles and around a single pile. Total force between the row of slotted piles and a single pile was compared and discussed in the light of the Morison equation.

Lonard, R.I.; Judd, F.W., and Stalter, R., 2015. The biological flora of coastal dunes and wetlands: Solidago sempervirens L. and Solidago sempervirens L. subsp. mexicana (L.) Semple.

Solidago sempervirens L. and Solidago sempervirens L. subsp. mexicana (L.) Semple are New World humid continental, temperate, subtropical, and tropical maritime taxa. Both taxa are long-lived perennials that occur in wet mineral sands and clay soils. Reproduction is primarily vegetative in stable sites. However, achene/seed production is prolific, and seed viability is high in either stable or disturbed sites. Also known as seaside goldenrod, both taxa occur in conditions ranging from freshwater to salinity conditions of 40 parts per thousand. Seeds and seedlings do not tolerate excessive burial, but high levels of sand deposition are associated with plant vigor in mature clones. Optimal growth for both taxa occurs in habitats with increasing distance from the water table.

Wamsley, T.V.; Collier, Z.A.; Brodie, K.; Dunkin, L.M.; Raff, D., and Rosati, J.D., 2015. Guidance for developing coastal vulnerability metrics.

Appropriate coastal zone management and storm-damage risk reduction requires the assessment of vulnerability in natural and human environments. Confusion arises, however, as vulnerability is conceptualized in many different ways and is closely related to other concepts such as risk and resilience. This paper defines nomenclature, presents a conceptual definition of vulnerability, and lays out a proposed conceptual approach for identifying and defining meaningful metrics to ensure a complete assessment of coastal vulnerability. While the focus of this paper is developing metrics for assessing vulnerability to coastal storms, the approach is valid for a wide range of systems and hazards at multiple scales and can explicitly consider the impacts of climate change. The approach is demonstrated through application to a simply coupled human-environment system on the coast and explicitly considers natural and nature-based features.

Hartwell, S.I. and Fukuyama, A.K., 2015. The effects of sieve size on benthic community composition analysis.

Sediment samples were collected from the deep portion of Kachemak Bay, Alaska, for chemical analysis, toxicity testing, and infaunal community assessment as part of a larger Cook Inlet project. The benthos samples were sieved through nested 1.0- and 0.5-mm screens to allow a comparison of the relative efficacy of the two techniques. The community was highly diverse at all sampled locations (Shannon-Weiner Index > 3). Abundance was dominated by a relatively small number of species. A significantly higher number of individuals and species were retained on the 0.5-mm screen. Sieving the benthic organisms with a 1.0-mm sieve introduced biases in the data relative to the 0.5-mm screen, including calculations such as diversity and other parameters such as feeding guild distributions and benthic indices. Using a 0.5-mm mesh sieve did increase sample analysis costs and resulted in a larger number of individual organisms that were not identified to species.

Hale, R.; Jacques, R.O., and Tolhurst, T.J., 2015. Cryogenic defaunation of sediments in the field.

Ecological experiments designed to examine the effects of macrofaunal biodiversity may require the defaunation of intertidal sediments; however, many current techniques result in physical disruption of the sediments. A method of field-based cryogenic defaunation, which has advantages over existing methodologies, was developed to provide macrofaunal defaunation of intertidal cohesive sediment with minimum physical disruption. A sediment core transport apparatus and polystyrene freezing chamber allow the use of liquid nitrogen for effective freezing of a whole core of sediment in the field. Freezing the whole core intact minimises physical disturbance to the sediment and retains the topography of the sediment surface and sediment grain distribution with minimal effect on sediment properties and the microphytobenthos. This method is effective at removing up to 97% of infaunal macrofauna abundance from the sediment. Hediste diversicolor were found to be the most resistant species, with a 71% reduction in species abundance. Sediments defaunated in this way can be replaced in situ or removed to the laboratory for experimentation. This method of cryogenic defaunation would also be suitable for the defaunation of other marine or terrestrial sediments.