Arena, F. and Barbaro, G., 2013. The Natural Ocean Engineering Laboratory, NOEL, in Reggio Calabria, Italy: A commentary and announcement.

The Natural Ocean Engineering Laboratory (NOEL) of the Mediterranea University of Reggio Calabria, Italy, is the first ocean engineering laboratory working in the field. A peculiarity of the lab is that a local wind from NNW often generates sea states consisting of pure wind waves that represent a small scale model, in Froude similarity, of ocean storms. Significant wave height ranges between 0.20 m and 0.80 m, with peak periods between 2.0 s and 3.6 s. This local wind is very stable and sometimes stays steady from morning to evening. The tidal amplitude is very small (typically within 0.10 m). The physical structure was built after the successful experience of some initial small-scale field experiments directed by Professor Paolo Boccotti since 1989.

Stive, M.J.F.; de Schipper, M.A.; Luijendijk, A.P.; Aarninkhof, S.G.J.; van Gelder-Maas, C.; van Thiel de Vries, J.S.M.; de Vries, S.; Henriquez, M.; Marx, S., and Ranasinghe, R., 2013. A new alternative to saving our beaches from local sea-level rise: the sand engine.

A boldly innovative soft engineering intervention, comprising an unprecedented 21.5 Mm³ sand nourishment known as the Sand Engine, has recently been implemented in the Netherlands. The Sand Engine nourishment is a pilot project to test the efficacy of local mega-nourishments as a counter measure for the anticipated enhanced coastal recession in the 21st century. The proposed concept, a single mega-nourishment, is expected to be more efficient, economical, and environmentally friendly in the long term than traditional beach and shoreface nourishments presently being used to negate coastal recession. Preliminary numerical model results indicate that this local nourishment will result in the widening of the beach along a 10 to 20 km stretch of the coastline and a beach area gain of 200 ha over a 20-year period. First observations show indeed a redistribution of the sand feeding the adjacent coasts, roughly 40% toward the south and 60% toward the north. While the jury is still out on this globally unique intervention, if proven successful, it may well become a global generic solution for combating sea-level-rise driven coastal recession on open coasts.

Birch, G.F.; Apostolatos, C., and Taylor, S.E., 2013. A Remarkable Recovery in the Sydney Rock Oyster (Saccostrea glomerata) Population in a Highly Urbanised Estuary (Sydney Estuary, Australia).

Surveys of the Sydney rock oyster (Saccostrea glomerata) in the Sydney estuary (Australia) in 1995 and 2005 provided evidence of a significant and widespread increase in the abundance of this bivalve over this period. Oyster abundance and density increased predominately in the upper estuary where a 300% increase in water-line length coverage occurred over the 10-year period. The timing of increased abundance and co-incidence of high-shipping activity with areas of maximum oyster increase, suggest that partial banning of tributyltin in 1989 may have played a major role in the increase of S. glomerata in this estuary.

Klemas, V., 2013. Remote sensing of coastal wetland biomass: an overview.

Wetlands are highly productive and provide critical habitat to animals and plants. Coastal wetlands have been affected by human-created alterations and, more recently, by losses due to sea-level rise. To protect and restore tidal wetlands, scientists need to monitor the changes in the wetlands as the sea level continues to rise and the coastal population keeps expanding. Advances in sensor design and data-analysis techniques are making remote-sensing systems practical and cost effective for obtaining quantitative biophysical information, such as wetland extent, live aerial biomass, leaf area index, percentage of canopy closure, etc. This article reviews biomass mapping techniques and illustrates their use for wetland-change detection. The results show that analysis of satellite and aircraft data, combined with a small number of on-the-ground observations, allows researchers to map biomass and determine long-term changes in tidal marshes.

Skjong, M.; Naess, A., and Brandrud Næss, O.E., 2013. Statistics of extreme sea levels for locations along the Norwegian coast.

The focus of this article is the problem of estimating long return-period sea levels for locations along the Norwegian coast. For this purpose, a new method for estimating the extreme-value statistics associated with a recorded time series of data is applied. This method, briefly referred to as the Average Conditional Exceedance Rate or ACER method, is presented in some detail. The ACER method provides a statistical representation with error bounds of the actual extreme-value distribution given by the data and is applicable to nonstationary time series as well. The estimated return-level values obtained by the ACER method are compared with the corresponding values obtained by the annual maxima method, the peaks-over-threshold method, and the revised joint-probabilities method. Based on overall performance, the ACER method may be the preferred choice over the other three methods tested.

Torio, D.D. and Chmura, G.L., 2013. Assessing coastal squeeze of tidal wetlands.

As sea level rise accelerates and land development intensifies along coastlines, tidal wetlands will become increasingly threatened by coastal squeeze. Barriers that protect inland areas from rising sea level prevent or reduce tidal flows, and impermeable surfaces prevent wetland migration to the adjacent uplands. As vegetation succumbs to submergence by rising sea levels on the seaward edge of a wetland, those wetlands prevented from inland migration will decrease in area, if not disappear completely. Tools to identify locations where coastal squeeze is likely to occur are needed for coastal management. We have developed a “Coastal Squeeze Index” that can be used to assess the potential of coastal squeeze along the borders of a single wetland and to rank the threats faced by multiple wetlands. The index is based on surrounding topography and impervious surfaces derived from light detection and ranging and advanced spaceborne thermal emission and reflection radiometry imagery, respectively, and uses a fuzzy logic approach. We assume that coastal squeeze varies continuously over the coastal landscape and tested several fuzzy logic functions before assigning a continuous weight, from 0 to 1, corresponding to the influence of slope and impervious surfaces on coastal squeeze. We then combined the ranked variables to produce a map of coastal squeeze as a continuous index. Using this index, we compare the present and future threat of coastal squeeze to marshes in Wells and Portland, Maine, in the United States and Kouchibouguac National Park in New Brunswick, Canada.

Houston, J.R., and Dean, R.G. 2013. Effects of sea-level decadal variability on acceleration and trend difference.

Previous research has shown that sea-level acceleration determined from individual tide gauge records has remarkably large scatter as record lengths decrease due to decadal variations in sea level. We extend previous data sets to the present time and find even greater acceleration scatter. Using analytic solutions, sinusoidal oscillations with amplitudes and periods of typical decadal variations are shown to basically account for the relationship between record length and both acceleration and trend difference. Data show that decadal variations will obscure estimates of underlying accelerations if record lengths of individual gauges are not greater than at least 75 years. Although worldwide data are less affected by decadal variations than individual gauge data, decadal variations still significantly affect estimates of underlying accelerations, in particular for record lengths less than about 60 years. We give two examples of recent studies that use record lengths of about 30 to 60 years to determine acceleration or related trend difference. Previous authors dismissed the importance of decadal variations on their results and, as a result, reached invalid conclusions.

Aighewi, I.T.; Nosakhare, O.K., and Ishaque, A.B., 2013. Land use–land cover changes and sewage loading in the lower Eastern Shore watersheds and coastal bays of Maryland: Implications for surface water quality.

Changes in land use and cover influence surface water quality and thus are a potential threat to water systems and coastal ecosystem health. The objectives of this study were to evaluate the influence of historical land use–land cover (LULC) changes and point-source sewage discharge on surface water quality of some lower Eastern Shore watersheds of Maryland. LANDSAT data for 1986–2006 was acquired and classified using Anderson level-1 classification system in ENVI 4.5, whereas LULC changes were detected in Arc-GIS 9.2 environment. Historical water monitoring and climatic data were obtained from Maryland Department of Environment–Chesapeake Bay Program, and National Oceanic and Atmospheric Administration, respectively. Nutrient loading data from wastewater treatment plants were obtained from Maryland Department of Environment and data analyzed using regression analysis and principal component analysis (PCA). The result shows that total phosphorous levels in the surface waters decreased significantly (p < 0.05) during the 20-year study period. However, using PCA, we determined that the declining P trend was attributable to the decreasing agricultural land use rather than the sewage discharge from wastewater treatment plants. The increase in urban land use and the resultant runoff to the water bodies may explain the declining trends in dissolved oxygen levels observed during the period, with serious implications for eutrophication. An empirical model developed for P in surface waters (r²  =  0.90) showed that the combination of point and nonpoint sources and land use/cover change factors are good predictors. The incorporation of quantitative LULC data component as well as point-source nutrient loading into existing models is highly recommended for a more holistic assessment of land-use influence on water systems in general.

Dvarionienė, J.; Zobėlaitė-Noreikienė, G.; Kruopiene, J., and Stasiškienė, Z., 2013. Application of the life-cycle assessment method for pollution prevention in Klaipėda sea port, Lithuania.

Lithuania is one of the countries that have ratified the Marpol 73/78 Convention, which foresees the tools of reduction and prevention of sea pollution by bilge water and other substances. The Directive of the European Parliament and Council 2000/59/EB is addressed to the reduction of waste onboard ships and its wash overboard. Analysis of the ships entering Klaipėda sea port has estimated that oil waste constitutes about 74% of the whole collected waste amount. Engine bilge water is specific and hazardous to the environment because it is a liquid compound of water and oil products capable of making steady emulsions. It also acquires specific properties during various technological processes. Equipment, technological processes, specificity of the control related to combustibility and flammability, as well as conformity to the requirements of the International and European Union Rights, technological process management, and documents are needed for the management of this specific waste. For this reason, separation of this oily water from the common oil-polluted waste and analysis of these streams of waste treatment are of great importance to enhance the effectiveness of environmental protection during the management process of this oily waste. Applying a system approach to the oily waste in the port, we set up a waste management system algorithm based on the life cycle. The system of port waste management is a set of technological processes, each of them performing a certain function and requiring stock, electric energy, fuel, transport, heat, technological equipment, etc. Having made the environmental assessment, a suggestion was made to convert the waste resulting from the engine bilge water treatment into energy and to use it in a technological process when closing (finishing) the life cycle. In this paper, a life-cycle assessment (LCA) was performed to identify and quantify the environmental impacts caused by the ship-generated waste management, focusing on oily waters of the port of Klaipėda. LCA methodology was used to evaluate the environmental performance of ship-generated waste management of Klaipėda port, according to international standards.

Allahdadi, M.N.; Jose, F., and Patin, C., 2013. Seasonal hydrodynamics along the Louisiana coast: implications for hypoxia spreading.

Summer and fall inner-shelf flow characteristics, including the vertical current structure, obtained from three WAVCIS (WAVE-Current-surge Information System) stations off the Louisiana coast were analyzed to delineate the hydrodynamic conditions that contribute to the formation of seasonal hypoxia at each station location. Two of the WAVCIS data stations used for analysis are located west of the Mississippi bird-foot delta, whereas the third is located east of the delta. Relatively small vertical gradients in the horizontal velocity current (i.e., u and v velocity components) were observed during summer (2009) for both CSI-6 and CSI-9 stations, which are located well inside the hypoxia-prone zone west of the delta. In contrast, the summertime vertical gradient of horizontal current at CSI-16 (located east of the delta) was significantly higher than that of western stations. Significant differences in the vertical gradient of flow velocities along with contrast in water column density gradient during the summer culminated in a strong stratification, which is considered the main physical requirement for the formation of hypoxia. A computed criteria based on the Richardson number also pointed to higher potential for stratification at both stations west of the delta, whereas the water column east of the delta still remained subject to vertical mixing. Furthermore, summertime current fields at CSI-6 and CSI-9 were significantly less compared with CSI-16, suggesting less reoxygenation driven by advection from surrounding waters. These conditions may exacerbate hypoxia.

Muñoz Vallés, S.; Gallego Fernández, J.B., and Cambrollé, J. 2013. The biological flora of coastal dunes and wetlands: Retama monosperma (L.) Boiss.

Retama monosperma (L.) Boiss. (white bridal broom) is a legume shrub that establishes mainly on coastal sands and dunes in zones under a Mediterranean climate. The species is able to tolerate salt spray, high temperatures of substrate and air, and low levels of soil nutrients and humidity. It is important in middle stages of dune succession, functioning as a key species in structuring the plant community, and it can play an important role in geomorphology. Retama monosperma enriches soil with N and other nutrients, ameliorates the typical harsh environmental conditions in dunes for other plants, and provides refuge and food for wildlife and forage for livestock. Leaves fall rapidly after emergence, and gas exchange is carried out in photosynthetic stems (cladodes), thereby reducing salt-induced stress. Some compounds isolated from the species show potential in pharmacological applications. It has high fruit production and effective associated seed dispersers. Recently, it has been reported that R. monosperma displays invasive behaviour in coastal areas in different parts of the world, including within its natural range, showing potential to negatively affect singular and protected coastal dune flora. Here we present a summary of the biology of R. monosperma.

Retama monosperma (L.) Boiss. (Retama blanca, retama de olor) es un arbusto leguminoso que se establece principalmente en arenales y dunas costeras en zonas con clima mediterráneo. Está adaptada a las condiciones estresantes típicas de este medio, tales como la incidencia de espray salino, elevadas temperaturas del aire y el suelo y escasez de agua y nutrientes. La especie es importante en estadíos intermedios de sucesión en dunas costeras, donde funciona como especie clave en la estructura de la comunidad vegetal, y cumple un importante papel en la geomorfología dunar. Retama monosperma es capaz de enriquecer el suelo con N y otros nutrientes y atenuar las duras condiciones ambientales, facilitando la supervivencia de otras plantas bajo su dosel, así como proporciona refugio y alimento para cierta fauna silvestre y para el ganado doméstico. Pierde las hojas rápidamente tras la emergencia y la fotosíntesis se lleva a cabo en tallos fotosintéticos, lo que reduce el estrés inducido por la deposición de sal. Algunos compuestos aislados de sus tejidos muestran propiedades con aplicación farmacológica. Posee una elevada producción de frutos y dispersores efectivos asociados. Recientemente se ha puesto de manifiesto el comportamiento invasivo que muestra la especie en áreas costeras en diferentes partes del globo, incluyendo su área de distribución natural, afectando en ocasiones a especies singulares y protegidas de la flora dunar costera de forma negativa. En el presente trabajo presentamos un resumen de la biología de R. monosperma.

Turpie, K.R., 2013. Explaining the spectral red-edge features of inundated marsh vegetation.

In a previously published experiment, canopy reflectance spectrum was measured for three monospecific canopies as water level was artificially increased. As the water rose, spectral features appeared that could not be explained by the experimenters. To better understand their published results, a combination of a shallow-water reflectance model and a canopy reflectance model was used to simulate the spectral effects observed with increasing levels of inundation. Information from the Lee shallow water, in particular, helped explain the key spectral features observed during high water levels. However, the simulation results also suggested interesting implications regarding the nonlinear mixing of water and vegetation reflection spectra as found in marsh or other flooded canopies. As water level increases, the influence of leaf reflectance below the water's surface changes the characteristics of the background aquatic spectrum. In particular, the simulation yielded a 20-nm shift in the red-edge position as water rose from the bottom to the top of the canopy, which is very similar to the experimental results. This suggests that the interaction of water and chlorophyll absorption features and leaf reflectance near the red-edge of the vegetation spectrum can significantly the influence red-edge position of an inundated canopy. This, in turn, could affect the use of the red-edge position for indicating plant condition in remote-sensing applications of inundated vegetation.

Wang, J. and Liu, Y., 2013. Tourism-led land-use changes and their environmental effects in the southern coastal region of Hainan Island, China.

Tourism has been often considered as an effective way to promote economic growth for coastal areas in developing countries. As the most important tourist destination and the largest Special Economic Zone in China, Hainan chose tourism-led development and achieved rapid economic growth. This paper analyzes land-use changes driven by tourism-led development and their environmental effects during a period of time from 1991 to 2007 in Sanya City, southern coastal region of Hainan Island. High-resolution remote sensing and detailed socioeconomic data were used in the study. Based on a combination of remote sensing and geographic information systems methods, a matrix of land-use change was constructed to identify land-use changes between 1991 and 2007. The outcomes indicate that the changes from farmland to construction land and from forestland to orchard are the main transformation types. From 1991 to 2007, farmland and forestland decreased by 15% and 29% respectively; on the contrary, construction land and orchard increased by 242% and 258%. The transformation from farmland to construction land mainly occurred in plains along the coastline, while the changes from forestland to orchard mainly occurred in middle platform areas. Booming tourism not only led to the increased demand for tourism infrastructure and rapid urban expansion, but also boosted the demand for tropical fruit products quickly. However, rapid increases of tourism infrastructures occupied large fertile farmland, urban expansion caused construction land increase and farmland loss, and forest was converted to orchard, driven by the high speed of market demand of fruit products. Tourism-led development restructured the land-use pattern dramatically, which brought about landscape fragmentation, vegetation degeneration, and coastal erosion. Irrational tourism and land development have destroyed Sanya's tourism resources and dissipated its initial advantage to some extent, which will hinder the sustainable development of tourism. Finally, some suggestions are given to coordinate the tourism-led land development in coastal regions.

Andrade, C.A.; Thomas, Y.F.; Nicolae Lerma, A.; Durand, P., and Anselme, B., 2013. Coastal flooding hazard related to swell events in Cartagena de Indias, Colombia.

In the city of Cartagena de Indias, the urban areas of Bocagrande and Castillogrande were built over large sandbars and are extremely sensitive to the risk of coastal flooding during storm surges. However, the risk of flooding is not directly related to local meteorological conditions, but results essentially from hydrodynamic phenomena due to the arrival of heavy swell from far away. A statistical study based on hourly sea-level observations from 1950 to 2000 showed the existence of overflow levels of 0.29, 0.34, and 0.37 m corresponding to return periods of 10, 50, and 100 years. Numerical modeling of overflows was performed from a reanalysis of atmospheric pressure as well as wind and wave data sets produced by the National Oceanic and Atmospheric Administration. The models used were ADCIRC^® for the simulation of tides and wind setup, SWAN^® for the simulation of wave setup, and pCOULWAVE^® for wave run-up estimation. Coastal flooding that affected the city in January 2010 was validated using a HORUS^® video monitoring system. Simulations were conducted on expected extreme sea levels during the 21st century. Flooding simulations were performed using both a light detection and ranging high-resolution digital elevation model and a water propagation model based on a recursive algorithm. Results showed the extreme vulnerability of Bocagrande and Castillogrande areas facing the risk of submersion. They raise questions for future risks of flooding taking into account the rates of sea-level rise as well as the effects of wave erosion.

La ville de Carthagène des Indes est un pôle industriel et patrimonial important du littoral caribéen de la Colombie. Les quartiers de Bocagrande et Castillogrande édifiés sur un mince cordon littoral sont extrêmement sensibles à l'aléa submersion marine lors des épisodes de Mar de leva. Toutefois, le risque d'inondation n'est pas lié aux conditions météorologiques locales, mais résulte, pour l'essentiel, de phénomènes hydrodynamiques générés par l'arrivée de houles lointaines. L'étude statistique des chroniques horaires du marégraphe entre les années 1950 et 2000 montre l'existence de niveaux de surcote de 0.29, 0.34 et 0.37 m pour des occurrences de 10, 50 et 100 ans. La simulation numérique des surcotes a été conduite par réanalyse d'un certain nombre d'évènements majeurs grâce aux données de pression, vents et houles fournies par la NOAA et l'utilisation conjointe des modèles ADCIRC, pour la simulation de la marée et du set-up lié au vent, SWAN® pour la simulation du set-up lié aux vagues et pCOULWAVE pour le run-up. Les épisodes de submersion ayant affecté la ville en janvier 2010 ont été validés grâce aux caméras vidéo du système HORUS®. Des scenarii de submersion basés sur l'utilisation d'un modèle numérique de terrain haute résolution et d'un modèle de diffusion de crue ont permis de suivre la propagation des flux d'inondation pour les niveaux marins extrêmes attendus pour le 21ème siècle. Les résultats montrent l'extrême vulnérabilité de la ville face à l'aléa submersion. Ils posent la question du risque futur compte tenu des rythmes d'élévation du niveau marin et de l'impact érosif des vagues.

La ciudad de Cartagena de Indias es un polo industrial y patrimonial importante del litoral Caribe colombiano. Los barrios de Bocagrande y Castillogrande, construidos sobre un estrecho cordón litoral, son extremadamente sensibles al riesgo de sumersión durante los episodios de Mar de leva. Las inundaciones no son debidas a sobreniveles vinculados a condiciones meteorológicas locales, si no que resultan esencialmente de fenómenos hidrodinámicos generados por la llegada de olas distantes. El estudio estadístico de las cróni

da Silva Dias, F.J.; Valente Marins, R., and Parente Maia, L., 2013. Impact of drainage basin changes on suspended matter and particulate copper and zinc discharges to the ocean from the Jaguaribe River in the semiarid NE Brazilian coast.

This study aims to understand the fluvial contribution to the estuary and thence to the ocean and the behavior of the suspended particulate matter (SPM) and particulate Cu and Zn during spring tide cycles and during the dry and rainy seasons in 2005, 2006, and 2008, at the Jaguaribe River Estuary, NE Brazil. The distribution of metals concentrations in SPM during dry and rainy seasons suggests a lithogenic origin of aluminum (Al), iron (Fe), and copper (Cu), as a result of erosion and leaching of soils in the drainage basin due to anthropogenic drivers, such as urbanization, shrimp farming, and agriculture. Anthropogenic drivers also affect Zn flows associated with SPM during the dry season. The highest discharges of SPM and particulate metals occurred during rainy periods due higher freshwater volumes observed in the estuarine channel. The results strongly suggest that the high variability of discharges typical of semiarid drainage basins can be underestimated with the use of secondary data, showing the necessity of obtaining data in situ.

González-Leija, M.; Mariño-Tapia, I.; Silva, R.; Enriquez, C.; Mendoza, E.; Escalante-Mancera, E.; Ruíz-Rentería, F., and Uc-Sánchez, E., 2013. Morphodynamic evolution and sediment transport processes of Cancun Beach.

Large-scale construction of tourist infrastructure on beaches around the world is consistently linked to unwanted morphological changes that lead to coastal erosion. Dune destruction, alteration of sediment sources, and the rigidisation of the coastal system are known to be the main causes of erosive behaviour on many tourist beaches. To plan sound shoreline management strategies, detailed understanding of the sediment transport processes is necessary. The present contribution focuses on the main sediment transport processes that take place at Cancun, Mexico, a large (12 km) and highly developed tourist beach. High-resolution quarterly beach profile monitoring from September 2007 to June 2009 is used to calculate volumetric changes that are reasonably well explained by the spatial patterns of modelled sediment transport potential. This parameter was calculated using the wave propagation model WAPO of Universidad Nacional Autonoma de Mexico, which explicitly solves diffraction and reflection processes that are particularly important in systems with pronounced rocky headlands, such as the northern and southern ends of Cancun beach. Results show a dominance of northward longshore transport in most of the system, and an important transport divergence with consistent southward transport at the southern end. Cross-shore transport seems to dominate the middle-north section of the beach. This behaviour is consistent with recent advances in the understanding of wave circulation in embayed beaches. The method used here is considered a good approximation of sediment transport patterns when local (surf zone) morpho- and hydrodynamic data are absent or difficult to acquire.

Long, A.; Sun, L.; Shi, R.; Zhou, W., and Dang, A.,2013. Saltwater intrusion induced by a complete neap tide and its effect on nutrients variation in the estuary of Pearl River, China.

Temporal and spatial variations of water temperature, salinity, dissolved oxygen (DO), and dissolved inorganic nutrients (, , and ) were investigated over a complete neap tide in the estuary of Pearl River, China. Obvious saltwater intrusion was observed at the lower reaches of our survey section: surface water salinity varied from 2.00‰ to 17.80‰, and bottom water salinity varied from 5.59‰ to 22.13‰. The calculated stratification index indicated that the lower reaches had intense stratification during the present neap tide. Obvious dilution of and was observed in the course of saltwater intrusion. Due to intensive decomposition and desorption-releasing action, and concentration increased with increasing water salinity. Investigation results revealed that saltwater intrusion had a significant effect on nutrient structure and probably alleviated a phosphorus-limiting situation in the estuary ecosystem. All these changes were induced to some degree by tidal currents and their associated sediment-agitation process and had a profound effect on the estuary ecosystem.

Shearman, P.; Bryan, J., and Walsh, J.P., 2013. Trends in deltaic change over three decades in the Asia-Pacific region

Over the past decades, studies have shown considerable change in mangrove and deltaic systems around the world. Arguments for the controlling processes encompass natural and anthropogenic phenomena, including sea level rise, storms, sediment supply changes and enhanced subsidence. To evaluate whether similar gross trends are apparent across several larger systems, this research employed a consistent methodology to conduct region-wide change analyses of five major mangrove deltaic systems in the Asia-Pacific region that are reported to be under varying degrees of risk (“no risk,” Fly and Kikori-Purari; “in peril,” Ganges-Brahmaputra, Irrawaddy, Mekong). With the use of a full-scale semiautomated classification, the extent of mangroves was mapped and compared for two Landsat satellite image series at least 20 years apart. Overall, we found a net contraction in mangrove area of 76 km², or −0.28%, but trends in mangrove change varied across the five systems. We document net contractions in the Ganges-Brahmaputra, Fly, and Kikori-Purari and a net expansion in the Irrawaddy and Mekong. The biggest relative decline in mangrove area occurred in the Fly delta, which experienced a decline of 3.9% over 36 years. The largest relative increase of 2.7% over 20 years occurred in the Irrawaddy, whereas the Mekong was relatively stable with only a modest 0.14% decline over 20 years. System-wide patterns and rates of change were variable and complex. Generally, erosion is occurring at the mouths of rivers, where exposure to ocean processes (e.g. waves) is greatest, despite the large sediment supply by these great rivers (albeit reduced in some cases). The observed losses in the Ganges-Brahmaputra are not surprising considering the known anthropogenic effects, but given that similar change trends are occurring in the Fly and Kikori-Purari delta systems despite potentially increased sediment loading (e.g. from deforestation and mining) and without other anthropogenic effects (subsurface withdrawals or river rerouting), some of this morphological change might be attributed to an enhanced eustatic sea level rise. However, change in climate, marine processes (e.g. wave conditions), effective sea level rise (e.g. a local oceanographic or tectonically controlled response), or autogenic geomorphodynamics cannot be ruled out. Alarmingly, deltas that have the greatest and most intact mangrove systems (the Fly and Kikori-Purari systems) or those parts of deltas that are still forested, such as in the western Sundarbans, are being eroded the fastest of the studied systems. A more concerted effort to monitor large-scale delta changes is recommended.

Thorner, J.; Kumar, L., and Smith, S.D.A., 2013. Fine-scale three-dimensional habitat mapping as a biodiversity conservation tool for intertidal rocky reefs.

Habitat mapping is a useful tool for ecologists to analyze spatial data. Rocky shore ecosystems comprise a mosaic of habitat types and therefore require good technology to extract fine-scale spatial data on habitat extent and quality. Airborne topographic light detection and ranging data and 0.1-m resolution digital aerial photography were used to map and quantify distinct habitats that influence the distribution of biodiversity on rocky shores. The objectives of this study were to create and test the accuracy of a classification system for the rocky shore habitat, to develop remote sensing techniques useful for the conservation of intertidal rocky shores, and to create detailed digital terrain models for five headlands in the Solitary Island Marine Park, mid-north coast, New South Wales, Australia. The intertidal rocky shore habitats were classified according to tidal heights and substrate type. Ground-truthing of remote sensing data was carried out by visual surveys during low tide. Error assessments using precision analysis and classification accuracy tests confirmed the reliability of the technique with <5% error. The data generated from this research can be used as a platform for spatial analysis of this environment, including modelling changes in biodiversity under different climate change scenarios.

Peterson, C.D.; Gates, E.B.; Minor, R., and Baker, D.L., 2013. Accommodation space controls on the latest Pleistocene and Holocene (16–0 ka) sediment size and bypassing in the Lower Columbia River Valley: a large fluvial–tidal system in Oregon and Washington, USA.

In this study, we establish the roles that increasing basin accommodation space have on sediment size and bypassing in the transgressive fill (16–0 ka) in the submerged Lower Columbia River Valley (LCRV). The antecedent forearc valley (225 km in length, 4–8 km in width, and 60–115 m in axial valley depth) is characterized by high sediment supply rates (10–15 million t y⁻¹) but no delta at its mouth to the Pacific Ocean. Core sample sediment textures (N = 1600) are analyzed from 3000 m of borehole sections in 58 representative boreholes to characterize the ancestral valley fill: 57% sand, 17% muddy sand, 12% sandy mud, and 14% mud (total fill volume = 77 km³). Decreasing mud endmember texture from between 30 and 60% (early Holocene) to 18% (late Holocene) is directly related to (1) declining rates of increasing basin accommodation space and (2) increasing sediment bypassing through the LCRV. Both conditions result from decreasing rates of sea level rise (15.0–1.5 mm y⁻¹) in Holocene time. The overall coarsening of sediments, both upvalley and upsection, is controlled by declining rates of increasing basin accommodation space (5.66 million–0.57 million m³ y⁻¹) during middle to late Holocene time. Differences between middle and late Holocene sediment accumulation rates yield bedload bypassing rates of 5– 6 million m³ y⁻¹, under assumed conditions of constant sediment supply rates in middle to late Holocene time.

Jonkman, S.N.; Hillen, M.M.; Nicholls, R.J.; Kanning, W., and van Ledden, M., 2013. Costs of adapting coastal defences to sea-level rise—new estimates and their implications.

The cost of upgrading and raising coastal defences is an important consideration in societal response to sea-level rise. Currently available unit cost estimates have a limited empirical basis. This article presents new information on the unit costs of adapting coastal defences for three specific case studies in low-lying delta regions: The Netherlands, New Orleans, and Vietnam. Typical measures include dikes, flood walls, storm surge barriers, and nourishment. These unit cost estimates are significantly higher than earlier estimates that are still the main source of costs for global vulnerability assessments. Factors affecting these unit costs include local economic factors (material and labour costs), design choices related to the alignment of the system, and the types of measures for implementation of the system in an urban or rural environment. On the basis of an example for a Dutch sea dike, it is shown that the material quantities and associated costs are expected to rise linearly, in the case of depth-limited wave breaking, for the range of sea-level rise rates that are expected in the coming century. However, other factors, such as increasing costs for implementation of wider coastal defences in an urban environment and future changes in material and labour costs, could contribute to a nonlinear increase of the costs. Further collection and analysis of project information for coastal defence projects in other regions is recommended to strengthen the empirical basis of the cost estimates that are used for regional and global assessments.

Liu, Y.; Cheng, Y.; Li, H.X.; Liu, J.W.; Zhang, C.P.; Zhang, L.; Zheng, C.D., and Gao, J.H. 2013. Provenance Tracing of Indicative Minerals in Sediments of the Yalu River Estuary and its Adjacent Shallow Seas.

Vitreous tuff, sphene, andalusite, staurolite, and kyanite are minerals indicative of source and are found in the Yalu River estuary and its adjacent shallow seas. After analyzing the longitudinal variation of content and characteristic index of these indicative minerals (including mineral maturity, source zone index, stability coefficient, ATi index, and ZTR index) in 58 representative surface sediment samples and discussing their trace significance, results were obtained. Surface sediments in the Yalu River estuary and its adjacent shallow seas are found to belong to different provenances. Douliupu and its surroundings represent the southern boundary of the Yalu River's bed load transportation. Surface sediments in shallow seas have moved inward toward land. Sediments in the West-river-way reveal contact with the deposition from shallow seas, retaining characteristics of the main channel before construction of the Shuifeng reservoir, upstream in the Yalu River. While the deposits in the Middle-river-way are similar to the Aihe River, they showed a greater content of modern river deposits. Most sediments in the Liaodong shoals originate from the Yalu River; some originate from the shallow seas via storm surge. Modern river deposits are unable to reach easily the deposition zone near underwater tidal ridges in the shallow seas.

Payo, A. and Muñoz-Perez, J.J., 2013. Discussion of Ford, M.R.; Becker, J.M., and Merrifield, M.A., 2013. Reef flat wave processes and excavation pits: Observations and implications for Majuro Atoll, Marshall Islands.

Ford, Becker, and Merrifield observed reef flat wave conditions during two deployments over a 41 day period to investigate the impact of reef flat excavation pits on wave processes at Majuro Atoll. They noticed that the shoreline with the excavation pit received wave heights slightly less (∼8%) than those recorded at the nearby unmodified cross section. They suggested that this net decrease was the net product of a slight increase in sea and swell (SS) wave energy due to a bottom roughness reduction and a decrease in infragravity (IG) wave energy due to the disruption of the cross-shore quasi-standing modes caused by the excavation pit. We argue that, for this particular experiment, the coupling between the SS and IG energy waves may provide an alternative explanation of the observations, and we suggest that further investigations are needed. Although the coupling between SS and IG waves may be important for assessing the impact of excavation pits on IG-dominated shorelines, we show that these excavation pits in SS-dominated surf zones can lead to events such as the observed destruction of the Cadiz (SW Spain) seawall in 1792.