Oretga, L.; Celentano, E.; Finkl, C., and Defeo, O., 2013. Effects of climate variability on the morphodynamics of Uruguayan sandy beaches.

Effects of long-term trends in climatic variability on the morphodynamics of a reflective and a dissipative sandy beach in Uruguay (SW Atlantic Ocean) were analyzed. The Atlantic Multidecadal Oscillation (AMO) alternates between warm and cold cycles with a periodicity of roughly 70 years, with a shift toward a warm phase since 1995, resulting in an increase of sea surface temperature in the study area. Wind speed anomalies (WSA) also increased through time and were associated with an increasing speed of southerly winds, particularly after 1997. Beach morphodynamics showed no statistically significant trends in grain size, but long-term morphodynamic patterns differed between beaches: the dissipative beach showed an increase in swash and beach width, Dean's parameter, and the Beach Index (a measure of beach morphodynamic state). At the same time, the slope decreased, augmenting the beach's dissipative characteristics. The reflective beach showed an increase in slope and swash width through time, and a decrease in the Beach Index, indicating an intensification of reflective characteristics. Long-term morphodynamic changes were more evident in the dissipative beach and related to climate forcing (e.g. WSA). A higher resilience was observed in the reflective beach, even though an increasing frequency of storms is affecting both beaches. Accelerating erosion, rising sea levels, and expanding urban development in the Uruguayan coast could affect biodiversity and critical habitats. Multidisciplinary investigation programs and conservation strategies are needed to mitigate negative anthropogenic effects on these ecosystems.

Garboza Da Costa, K.; Cunha Monteiro, M.; Rabelo Bezerra, T.; Vallinoto, M.; Francisco Berrêdo, J.; Cajueiro Carneiro Pereira, L., and Marinho Da Costa, R., 2013. Tidal-induced changes in the zooplankton community of an Amazon estuary.

Because variations in the zooplankton community are common in macrotidal estuaries, the composition and density of these organisms in the estuary of the Paracauari River, an equatorial macrotidal system of the Amazon coastal zone, was studied during spring and neap tides to evaluate fluctuations related to variations in the physical and chemical characteristics of the water. Significant differences between tidal periods were recorded for salinity, pH, and dissolved oxygen. Phosphate concentrations were significantly higher in the spring tide. In all, 34 taxa were identified, with the Cirripedia dominating in both tides. Total density was highest in the spring tide (1871.6 ± 1248.4 individuals m⁻³), whereas chlorophyll a was lowest (10.46 ± 3.48 mg m⁻³). Diversity was also higher in the spring tide. Multivariate analyses indicated the formation of two distinct groups representing the spring and neap tides. The zooplankton comprised mainly estuarine and coastal species. Oithona oswaldocruzi, Paracalanus quasimodo, and Acartia tonsa were the most common, and their density was related directly to tidal oscillations.

Uma vez que as variações na comunidade zooplanctônica são comumente registradas em estuários de macromarés, a composição e a densidade destes organismos no estuário do rio Paracauari, um sistema equatorial de macromaré da zona costeira amazônica, foi estudada durante marés de sizígia e quadratura para avaliar as flutuações relacionadas aos parâmetros físicos e químicos da água. Diferenças significantes entre os períodos de maré foram registrados para salinidade, pH e oxigênio dissolvido. As concentrações de fosfato foram significativamente mais elevadas na maré de sizígia. No total, 34 táxons foram identificados, com Cirripedia dominando em ambas as marés. A densidade total foi maior na maré de sizígia (1871,6 ± 1248,4 ind m⁻³), enquanto que a clorofila-a foi menor (10,46 ± 3,48 mg m⁻³). A diversidade também foi maior na maré de sizígia. Análises multivariadas indicaram a formação de dois grupos distintos representando as marés de sizígia e quadratura. O zooplâncton foi constituído principalmente de espécies estuarinas e costeiras. Oithona oswaldocruzi, Paracalanus quasimodo e Acartia tonsa foram as espécies mais comuns, e suas densidades estiveram relacionadas diretamente com as oscilações da maré.

Raghavan, B.R. and Chauhan, O.S., 2013. Does SW monsoon influence total suspended matter flux into the Arabian Sea?

Seasonal enhancement in the flux of total suspended matter (TSM) has been attributed to climatology of the SW monsoon (SWM) in time-series trap experiments conducted in the Arabian Sea. To determine the influence of climate on TSM flux, synoptic variations in TSM have been obtained and evaluated during the SWM and the pre- and the postmonsoon seasons over the continental margin of the SE Arabian Sea during 2007. High TSM during the SWM (>82 mg l⁻¹) over the entire inner shelf was found. Contrary to the distribution over the inner shelf, there occurs uniformly low TSM (12–24 mg l⁻¹) over the entire outer shelf (water depth >30 m) year round. Therefore it is proposed that the higher fluvial flux during the SWM does not necessarily enhance the supply of TSM into the offshore regions of the SE Arabian Sea.

Makowski, C.; Finkl, C.W., and Rusenko, K., 2013. Suitability of recycled glass cullet as artificial dune fill along coastal environments.

Coastal dune systems are an integral component of maintaining a sustainable, well-performing beach. With the aid of dune-stabilizing vegetation, constructed foredunes provide a “natural” armorment behind the dry berm to help protect the backshore from storm surge and intense overwash. However, as the costs of beach nourishment continue to inflate, the urgency to construct or restabilize the foredune area of the beach is often overlooked. Furthermore, to compound the problem, suitable sand resources are becoming unobtainable because of regulatory restrictions, prompting engineers and coastal zone managers to use all available dredged sediments for berm and beach face replenishment. In order to provide an alternative method for dune construction, this study examined the suitability of recycled glass cullet as an artificial dune fill material. After construction of an artificial dune was completed, recycled (silica) glass cullet and natural beach sand were provided as growth mediums for dune-stabilizing vegetation. Immature transplants of sea oats (Uniola paniculata) and panic grass (Panicum amarum) were planted in the artificial dune and evaluated over a 1-year growing period. Suitability of the recycled glass cullet was determined through the overall performance of the salt-tolerant plants, which included fresh and dry weight measurements, new shoot development, and root and stalk length. It was determined that both species of dune-stabilizing vegetation planted in a recycled glass medium outperformed those specimens growing in the natural beach sediment controls. We postulate that the results may stem from a slight increase in the angularity of the recycled cullet vs. the natural sand grains. This minuscule planar difference in the surface area of the grains may contribute to more aggregated moisture content within a recycled glass cullet dune, allowing for optimal growing conditions for dune vegetation. By showing this positive suitability of recycled glass cullet as artificial dune fill, a new, innovative method for dune protection may now be considered.

Van Loon-Steensma, J.M. and Slim, P.A., 2013. The impact of erosion protection by stone dams on salt-marsh vegetation on two Wadden Sea barrier islands.

This paper describes and quantifies the effect of low stone dams on the extent and composition of salt-marsh habitats on two Dutch Wadden islands: Terschelling and Ameland. The stone dams were built to prevent erosion of the salt-marsh edge. Analyses of a series of aerial photographs taken between 1949 and 2010 show a strong reduction in retreat of the marsh edge on the island of Terschelling, from an average rate of 1.3 m per year before construction of the dam to 0.2 m per year after dam construction. Within 20 years of construction of the dam, sedimentation raised the mudflats between the dam and the former cliff, creating a broader foreshore and new marsh area with typical salt-marsh vegetation cover. The dam on the island of Ameland was built on the remnants of a previous low coastal defense. This reinforcement stopped cliff retreat and led to restoration of the eroded salt-marsh strip. Vegetation surveys along transects perpendicular to the coastline revealed that at both sites, typical pioneer salt-marsh vegetation had developed in the raised area between the erosion protection works and the former marsh edge. These habitats were not found in the reference transects without erosion protection. Based on these findings, we conclude that under favorable conditions for sedimentation, erosion protection by low stone dams may bring about a strong reduction in retreat of the salt-marsh edge while helping to restore an ecological attractive foreshore zone.

Papenmeier, S.; Schrottke, K.; Bartholomä, A. and Flemming, B.W., 2013. Sedimentological and rheological properties of the water–solid bed interface in the Weser and Ems estuaries, North Sea, Germany: Implications for fluid mud classification.

Fine, cohesive sediment suspensions are a common feature of estuarine environments. Generally, multilayer models are used to describe the vertical distribution of such sediments. Such conceptional models normally distinguish at least high suspended sediment concentrations (SSCs) as a topmost layer and a consolidated bed layer, often including an intermediate, fluid mud layer. Rheological, and in particular sedimentological properties are rarely included in these models. New data from two different estuaries provide new insights that can contribute toward the classification of near-bed cohesive sediments. The water–solid bed interfaces within the turbidity maximum zones of the Weser and Ems estuaries were sampled with 2–4-m-long cores. At 10-cm intervals, values of SSC, viscosity, particulate organic matter, mud ∶ sand ratio, temperature, salinity, and grain-size distributions were determined. By normalizing these parameters to SSC and performing a cluster analysis, sediment suspensions of <20 g/L SSC, fluid mud with up to 500 g/L SSC, and an underlying cohesive/consolidated bed can each clearly be distinguished. However, changes in flow behaviour and sedimentological characteristics represented by a shift in the cluster grouping support a subdivision of the fluid mud into a low-viscosity (I) (20–200 g/L SSC) and a high-viscosity (II) (200–500 g/L SSC) layer. Furthermore, by normalizing SSC measurements, site-specific differences were observed in the rheological behaviour of the fluid mud which might be caused by differences in grain-size composition. This suggests that the widely accepted 3-layer model of vertical SSC profiles should be extended by two layers of fluid mud identified in this study.

Dai, Z.-J.; Chu, A.; Li, W.-H.; Li, J.-F., and Wu, H.L., 2013. Has suspended sediment concentration near the mouth bar of the Yangtze (Changjiang) Estuary been declining in recent years?

There are considerable concerns about the decrease in suspended sediment discharge (SSD) into the large estuaries of the world as a result of extensive anthropogenic activities in their catchment areas. With the operation of Three Gorges Dam (TGD) in 2003, the riverine loads into the Yangtze (Changjiang) Estuary have been greatly changed with the sharp decrease of SSD and suspended sediment concentration (SSC). However, according to our analysis on the SSC in the surfacial water measured at different stations in the Yangtze Estuary, we conclude that the spatial characteristics of the annual mean SSC around the mouth bar area show no apparent change yet, even though the TGD was constructed with an ascending trend at the upper part of the estuary. The spring–neap periodicity of the daily mean SSC after the TGD was constructed remained the same as before. Moreover, the seasonal and annual mean SSC at the inner side of the mouth bar was relatively low due to the large reduction of upstream sediment supply after the operation of TGD began in 2003. But the seasonal and yearly mean SSC at the outer side of the mouth bar during 2007–2009 is comparable with those before the TGD operated, even though there is a decreasing trend of SSC into the Yangtze Estuary in corresponding years.

Santoro, P.; Fossati, M., and Piedra-Cueva, I., 2013. Characterization of circulation patterns in Montevideo Bay (Uruguay).

We studied the hydrodynamics of Montevideo Bay using a numerical approach. The RMA-10 model was implemented and calibrated in a vertical averaged mode for the Río de la Plata estuary to simulate the velocity field in Montevideo Bay. By conducting simultaneous analyses of the flow conditions at several control points situated in the bay, we identified the most frequent circulation patterns. We identified two circulation patterns that explain the water exchange between Montevideo Bay and the Río de la Plata. These patterns represented the flow conditions during 80% of the simulated period. In a more detailed analysis, six circulation patterns were identified in the interior of Montevideo Bay. These patterns occurred during 62% of the simulated period. We also studied the influence of the different forcings acting on water circulation in the bay: river flow from the tributaries, astronomical tidal waves and meteorological tides entering from the ocean, and local winds. The numerical model that we used helped us to understand the complex interaction between these factors and processes in the Río de la Plata and Montevideo Bay. Finally, we calculated the residual circulation fields for different scenarios with regard to forcing. The resulting characterization is very relevant to the environmental management of the bay and to engineering projects in Montevideo's harbor.

Depellegrin, D. and Blažauskas, N., 2013. Integrating ecosystem service values into oil spill impact assessment.

The catastrophic effects that oil spills have on coastal resources, the complex task of decision making during oil spill response, and the need for operational reasoning induce decision makers to seek science-based decisions. In light of these circumstances, spatially explicit, economic-impact assessment models can deliver an immediate assessment tool for preliminary oil-spill damage cost-quantification using a monetary unit as an indicator. The model presented in this study is based on an ecosystem-services assessment using economic evaluation methods such as travel cost, benefit transfer, and direct-market pricing. Ecosystem services were estimated for the 92-km-long Lithuanian coast using existing geographic information system (GIS) data sets. Outputs from the ecosystem-services assessment indicated that the total, annual economic value of biological and socioeconomic resources in the Lithuanian coastal zone (532 km²) amounts to more than €524 million/y (approximately US$690 million). Estimated values include marine biotopes, €307 million/y; recreational areas, €215 million/y; seabirds, €1.1 million/y; and commercial fisheries, €0.2 million/y. The estimation of monetary revenue from coastal resources was integrated with scenario-based cost estimation of damage supported by the Baltic Sea's three-dimensional particle-tracking model, Seatrack Web. Model testing was performed for 30 km of vulnerable Lithuanian coast with due consideration of its environmental, social, and economic importance to the SE Baltic Sea and its pertinent oil pollution risks. Results show that monetary losses of coastal resources depend highly on the oil type, impact area, meteorological conditions, and particularly the dispersion of the pollutant in the marine environment, by affecting target marine and socioeconomic resources. The damage cost-assessment tool is applicable in every coastal zone and pertinent to decision makers seeking preliminary cost estimates of damage and compensation for the damage caused by oil spills.

Shamkhali Chenar, S.; Karbassi, A.; Hajizadeh Zaker, N., and Ghazban, F., 2013. Electroflocculation of metals during estuarine mixing (Caspian Sea).

Estuaries as a geochemical reactor can change the chemical forms of trace metals during the mixing of fresh and salt water. The flocculation process has an important role in self purification of heavy metals during estuarine mixing. In the present study, flocculation of metals (Cd, Co, Ni, Cr, and Pb) during mixing of Shefaroud River water with Caspian Sea water has been investigated. Except for Cr and Co, the flocculation of other studied metals in the Shefaroud River is controlled by redox potential, pH, and dissolved oxygen. Rapid flocculation occurs in the earlier stages of mixing (salinity of 0.4 to 1.2‰). The final flocculation rates of the studied metals are in the following order: Co (92.6%) > Ni (73.4%) > Cr  =  Pb (66.6%) > Cd (62.2%). In addition, electroflocculation (EF) is investigated under different voltage conditions. The results reveal that EF increases flocculation rates of Ni and Pb, and decreases removal of Cr and Co. The maximum reduction of studied metals is found in lower salinity (>1.2‰). Even though increasing voltage is expected to exhibit a positive effect on reduction of metals, increasing electrical potential puts the Co, Ni, and Cr removal into reverse. This study reveals that salinity and electrical conductivity have a reverse effect on removal of studied metals during flocculation and EF processes. The general patterns of flocculation of metals during EF processes are in the following order: at electrical potential of 6 V: Ni (95.5%) > Pb (94.4%) > Cd (62%) > Co (57.7%) > Cr (22.2%); at electrical potential of 12 V: Pb (94.4%) > Ni (92.8%) > Cd (64.4%) > Co (35.5%) > Cr (0%).

Fontoura, J.A.S.; Almeida, L.E.; Calliari, L.J.; Cavalcanti, A.M.; Möller, O., Jr.; Romeu, M.A.R., and Christófaro, B.R., 2013. Coastal hydrodynamics and longshore transport of sand on Cassino Beach and on Mar Grosso Beach, southern Brazil.

The hydrodynamic and morphodynamic parameters of a region in southern Brazil were determined by collecting sediments with stream traps (bedload and suspended load) in the surfzone and capturing images, studying topography, and researching sedimentology with the help of a movie camera, a total station, and laboratory work. Data on deep-water waves were garnered with a CPTEC/INPE model. Field work was carried out in 50 field trips during a 1-year period; 42 out of 50 trips focused exclusively on hydrodynamic and morphodynamic data, whereas eight of the trips were also used for collecting sediments. In addition, data on wind direction and velocity and on the longshore currents were also collected. All data were obtained in normal atmospheric conditions. Field work was carried out in six cross-shore profiles along Cassino Beach and Mar Grosso Beach (three profiles on each side of the estuary of Patos Lagoon).

Yates, M.L.; Le Cozannet, G.; Garcin, M.; Salai, E., and Walker, P., 2013. Multidecadal atoll shoreline change on Manihi and Manuae, French Polynesia.

As interest in the impact of sea-level rise on atoll islands increases, this study contributes to the growing database of observations of shoreline changes on South Pacific Islands, where few observations are currently available. Historical aerial photographs and recent satellite images were used to evaluate multidecadal surface area and shoreline changes on two atolls in French Polynesia: Manihi and Manuae. During the 40- to 50-year study period, atoll island surface area primarily increased or remained stable on Manihi and decreased on Manuae. Distinct ocean and lagoon shoreline changes were observed in different geographical regions of each atoll. On Manihi, ocean shoreline accretion rates were larger on the NW rim than the SE rim. On Manuae, atoll islands on the NE rim were eroding on the lagoon side and accreting on the ocean side, whereas islands on the SE rim showed the opposite trend. Sea-level rise is often thought to cause atoll erosion, but in this study, lagoon and ocean shorelines both eroded and accreted over a period when sea-level rise rates were greater than the global mean. Surface area changes related directly to anthropogenic activities were identified on only two of the 47 atoll islands. After completing a classification of the incident wave field, it was hypothesized that waves have an important role in controlling the shoreline change variability. Additional field surveys and in situ observations are needed to validate this hypothesis and to understand better island response to changing forcing factors.

Une analyse de la mobilité du trait de côte au cours des cinquantaines dernières années a été réalisée sur deux atolls de Polynésie Franaise (Pacifique Sud): Manihi (Nord-ouest de l'archipel des Tuamotus) et Manuae (Est de l'archipel des îles de la Société). La mobilité de la limite de végétation permanente a été extraite de photographies aériennes anciennes de 1955 ou 1961 et d'images satellites à haute résolution acquises dans les années 2000. Cette analyse a nécessité le géoréférencement des photographies aériennes puis la digitalisation des limites successives de la végétation permanente. La ligne de végétation permanente a été utilisée comme marqueur des mouvements de basse fréquence du trait de côte (i.e., échelles de temps pluri-décennales). En effet, elle demeure aisément identifiable aussi bien sur les images anciennes que récentes tout en s'émancipant des variations à haute fréquence (marée, surcote etc.) et des difficultés de pointage de certains marqueurs sur les photographies anciennes. Les incertitudes liées au géoréférencement et à la digitalisation du trait de côte ont été évaluées et conduisent à ne considérer que des mouvements supérieurs à 5m sur la durée considérée. Dans de trés nombreux îlots (motu), des changements de plus grande ampleur sont observés et sont de fait sont considérés comme significatifs. Ils indiquent une tendance générale à l'érosion à Manuae et à l'accrétion à Manihi. Cependant, au sein d'un même atoll, nous observons une grande variabilité des évolutions des limites de végétation des motu : ainsi, la plupart des motu sont en accrétion côté lagon et côté océan à Manihi, toutefois, certains sont en érosion côté océan, côté lagon ou bien des deux côtés. Dans ces deux atolls peu anthropisés, les aménagements ne modifient la ligne de rivage que dans deux des 47 motu étudiés (quarante-et-un à Manihi, six à Manuae). Selon Becker et al. (2012), l'élévation du niveau marin, dans cette partie du Pacifique, a été supérieure à la moyenne globale depuis 60 ans. Des études antérieures suggèrent que l'élévation du niveau marin induit une érosion des îlots notamment sur leu

Bassler-Veit, B.; Barut, I.F.; Meric, E.; Avsar, N.; Nazik, A.; Kapan-Yeşilyurt, S., and Yildiz, A., 2013. Distribution of microflora, meiofauna, and macrofauna assemblages in the hypersaline environment of northeastern Aegean Sea coasts.

In this study, the morphology and taxonomy of microflora (charophytes and diatoms), meiofauna (benthic foraminifera and ostracoda), and macrofauna (mollusk) assemblages of the recent surface sediments from saltpans, hypersaline lagoons, and salt lakes of the Gulf of Saros (NW Turkey) were investigated. In total, 44 samples were collected from recent surface sediments in salt pans, hypersaline lagoons, and salt lakes of the Gulf of Saros (Enez Salt Lake, Isik Lake, Kuvalak Lake, Enez Gala Lake, Dalyan Lake, and Tasaltı Lake; Karagol, Vakif, and Erikli salt pans; and Uzungol Lagoon), Gallipoli Peninsula (salt pan), Biga Peninsula (Diremin and Azmak Lagoons and Dalyan Salt Lake), and Gokceada Island (salt lake). Surface sediments were collected, and some physical properties were measured, such as temperature, pH, and salt content. Grain size was determined and classified for each sample. In this study, foraminifera, ostracoda, and mollusca faunas in the normal marine environment were used as indicators and compared with the lagoonal environment, which has increased salt content during the summer months.

Berry, A.; Fahey, S., and Meyers, N., 2013. Changing of the guard: adaptation options that maintain ecologically resilient sandy beach ecosystems.

Sandy beach ecosystems adapt to sea-level rise by retreating landward. Retreat enables a sandy beach ecosystem to adapt while maintaining structure and function over various spatial and temporal scales. However, adaptation options, such as engineered barriers to shoreline retreat, reduce adaptive capacity and, therefore, ecological resilience to sea-level rise. Species richness and diversity becomes threatened when sandy beaches are squeezed between “fortifications” and increasing sea levels. Unidimensional management gives precedence to the protection of coastal investments at the expense of ecological resilience. This article provides a critical assessment of adaptation options to identify those capable of maintaining the ecological resilience of sandy beach ecosystems to sea-level rise. Hard- and soft-engineered options impede sand transport and storage systems and prevent retreat from advancing seas. In contrast, ecosystem conservation and setbacks enable coastal processes to continue and thereby maintain ecological resilience to sea-level rise. Managing sandy beach ecosystems from multidimensional perspectives allows coastal managers to better understand the consequences of implementing adaptation options. However, political, economic, and social necessity often dictates coastal managers employ unidimensional adaptation options to achieve quick results. This article proposes a four-dimensional lens through which sandy beach ecosystems can be viewed and managed. Longitudinal, transverse, vertical, and temporal dimensions characterise the function and structure of sandy beach ecosystems. A staged approach to adaptive management that takes a long-term view and considers a range of adaptation options tailored to achieve ecologically resilient sandy beach ecosystems is discussed.

Dusek, G. and Seim, H., 2013. A probabilistic rip current forecast model

A probabilistic rip current forecast model is created using a logistic regression formulation. Given input variables of nearshore significant wave height, vector mean wave direction, tidal elevation, and whether the forecast occurs in a 72-hour postwave event window, the probabilistic model predicts the likelihood of hazardous rip current occurrence. The model is trained using rip current observations made by lifeguards at Kill Devil Hills (KDH), North Carolina, in 2008–2009. Validation uses a hindcast at KDH over the summers of 2001–2007 and is compared with a hindcast of the National Weather Service (NWS) rip current model presently used at KDH. Using rip current rescues to indicate hazardous rip current occurrence, the probabilistic model has a Brier Score of 0.15 (0 is perfect prediction), compared with a minimum Brier Score of 0.45 for the NWS model, and represents a 67% or better improvement in prediction. Utilizing deepwater wave observations, instead of those collected nearshore, decreases model improvement by roughly half. The probabilistic model also outperforms the NWS model during high rescue instances, particularly on days with large tidal ranges. Functional improvements of the probabilistic model include the output of a true probabilistic forecast compared with a categorical forecast (low-medium-high) and the inclusion of only physically and statistically significant predictors.

Taboroši, D.; Jenson, J.W., and Mylroie, J.E., 2013. Field observations of coastal discharge from an uplifted carbonate island aquifer, northern Guam, Mariana Islands: a descriptive geomorphic and hydrogeologic perspective.

Understanding the hydrogeologic properties of carbonate island aquifers requires a conceptual framework within which specific and local properties, especially quantitative phenomena, can be placed and evaluated. In this paper, we present observations and hypotheses for such a qualitative conceptual model based on more than a decade of field studies in Guam. Fieldwork has shown that coastal groundwater discharge features can be usefully classified in terms of their geomorphic context and distinctive, readily observable characteristics: beach seeps and springs, reef seeps and springs, fracture springs, and cave springs. Seeps and springs on beaches and reefs are associated with matrix porosity and diffuse flow or are fed by fissures buried under sediment. Concentrated discharges from fractures and conduits are directly visible on rocky coasts, where springs emerge from dissolution-widened fractures and karst cavities. Although coastal zone conditions make it very difficult to accurately quantify the discharges from each type of feature, the fact that discharge is visibly distributed among these four categories suggests that aquifers of islands such as Guam—composed of uplifted geologically young limestones—can generally be expected to be triple-porosity aquifers, in which matrix, fracture, and conduit porosity each make a substantial contribution to discharge, and presumably to internal flow as well. This is in contrast to noncarbonate aquifers, from which coastal discharge is generally dominated by diffuse flow, and to continental karst aquifers in diagenetically mature limestones, in which flow and discharge are dominated by conduit flow. We propose a conceptual framework that relates these four geomorphic categories of coastal discharge to the evolution and reorganization of matrix, fracture, and conduit porosities in the aquifer, and offer a hypothesis for the general distribution of hydraulic conductivity on uplifted carbonate island aquifers, in particular the juxtaposition of high conductivity in the interior against lower conductivity in the periphery.

Pikelj, K., and Juračić, M., 2013. Eastern Adriatic coast (EAC): Geomorphology and coastal vulnerability of a karstic coast.

Coastal zones are one of the most rapidly changing environments on the global scale, mainly caused by anthropogenic activities (industry, urbanization, tourism, and food production). Coastal erosion is primarily a natural process, although human-induced coastal changes are becoming more and more present and are significant factors associated with the loss of beach capacity. The eastern Adriatic coast (EAC) is one of the most rapidly growing tourist markets within the Mediterranean, along which beaches still represent a leading component of the tourism resource. The objective of this paper is to provide an overview of natural geomorphologic features of the EAC as a starting point for further investigation and sustainable management of the coastal zone. The EAC is generally steep and rocky, mostly built up of karstified carbonates, and characterized, thus, by a variety of drowned karstic forms. Beaches in carbonates are mostly small, narrow, and scattered pocket gravel beaches. Coasts developed in the flysch and associated rocks are characterized by longer sandy and gravel beaches. The total beach length along the EAC presumably does not exceed 5%, and the small proportion of the beach length in relation to the rest of the EAC emphasizes their value in the tourist valorization, indicating the need for protection and sustainable management. Due to their geomorphologic diversities, fragmentation, different orientation, length, and sediment composition and budget, each beach should be studied separately and on a small scale. Detailed information on beach profiles, the nearshore geomorphology, and the beach processes needed to plan a sustainable coastal development is still mostly missing.

Klemas, V., 2013. Using remote sensing to select and monitor wetland restoration sites: an overview.

Coastal and estuarine wetlands represent highly productive and critical habitats for a wide variety of plants and animals and provide protection from storms and wave damage. However, wetland acreage in the continental United States has been steadily decreasing mainly as a result of human activities and sea level rise. Major efforts are being made by federal, state, and local agencies to protect existing wetlands, restore lost wetlands, and improve those stressed by human activities. The restoration process can involve removing exotic plants, removing bulkheads and fill, elevation grading, creating flushing channels, and planting native vegetation. Having developed criteria for selecting wetland sites to be restored or enhanced, wetland managers must prioritize the sites based on ecological and economic considerations. Remote sensing techniques can provide a cost-effective means for selecting restoration sites and observing their progress over time. The objective of this paper is to review airborne and satellite remote sensing techniques for identifying suitable wetland restoration sites and monitoring their progress.

McCloskey, T.A. and Liu, K.-B., 2013. Sedimentary history of mangrove cays in Turneffe Islands, Belize: evidence for sudden environmental reversals.

The Holocene history of the continental margin of Belize has frequently been interpreted as being very straightforward, controlled almost entirely by postglacial sea level rise. Depending upon location, the dominant depositional environment, whether coral or mangrove, is either able to keep up with the rising sea level and thereby maintain its integrity through the present, or becomes drowned. Here we present sedimentary evidence from four mangrove cays situated on Turneffe Islands that shows an unusual pattern wherein early mangrove development is replaced by carbonate sedimentation before reverting back to mangroves in the relatively recent past. The bracketed carbonate layers, up to >2 m thick and resembling lagoon-floor material, display both a rough temporal coincidence across sites and a distinctive geographic signature, thinning landward irrespective of relative elevation. The carbonate sections are often underlain by a mixed sediment layer characterized by a jumble of stratigraphically incoherent mangrove clumps intermingled with carbonates. The replacement of mangrove peat with bottom-style carbonate deposition suggests a lowering of island surface elevation. Seismic activity is identified as the most likely cause, although hurricanes cannot be excluded. In either case the elevational reduction is probably amplified by peat collapse associated with mangrove mortality. The occurrence of such activity and the resulting catastrophic ecological/geomorphic change indicate a need for incorporating these geological perturbations in risk assessment for Turneffe Islands.

Parks, D.; Shaffer, A., and Barry, D., 2013. Nearshore drift-cell sediment processes and ecological function for forage fish: implications for ecological restoration of impaired Pacific Northwest marine ecosystems.

Sediment processes of erosion, transport, and deposition play an important role in nearshore ecosystem function, including forming suitable habitats for forage fish spawning. Disruption of sediment processes is often assumed to result in impaired nearshore ecological function but is seldom assessed in the field. In this study we observed the sediment characteristics of intertidal beaches of three coastal drift cells with impaired and intact sediment processes and compared the functional metrics of forage fish (surf smelt, Hypomesus pretiosus, and sand lance, Ammodytes hexapterus) spawning and abundance to define linkages, if any, between sediment processes and nearshore ecological function. Key findings include: (1) beach sediment characteristics of the northern Washington nearshore are complex, with strong seasonal variation in habitat form and function both within and across geomorphic habitat types; (2) loss of sediment supply to the nearshore due to in-river damming and shoreline alterations results in significantly larger and more variable beach sediment at the drift-cell scale; (3) these differences in intertidal beach sediment characteristics have implications for habitat function as indicated by less forage fish spawning habitat and lower ecological function than intact drift cells; (4) feeder bluffs are important nearshore sediment sources for forage fish spawning beaches. Forage fish may spawn at the base of feeder bluffs if appropriate sediment is available during the spawning season; and (5) seasonal rate, total volume, and grain size of sediment delivery are important for habitat suitability for fish use. Feeder bluffs therefore should be managed more conservatively and understanding and protecting their role in nearshore habitat restoration practices is a high priority.