Houser, C., 2013. Flow separation over a prograding beach step at Pensacola Beach, Florida.

Beach steps are a common feature of poorly sorted intermediate and reflective beaches that can develop as an accretionary wedge from foreshore sediment moved seaward by the backwash. Although there have been several studies describing the development and evolution of steps in response to wave and tidal forcing, characterization of the separated flow and development of the backwash vortex has been limited to a small number of laboratory experiments. This study presents the first field data in which flow separation and the backwash vortex are quantified using a pulse-coherent acoustic Doppler profiler over a 0.10-m prograding beach step. As the step migrated beneath the instrument station under a quasi-steady wave forcing it maintained its height and length, allowing for a space-for-time substitution. Flow separation developed under subcritical flows, when the backwash exceeded ∼0.50 m s⁻¹ and extended over the length of the step early in the backwash cycle. The length of the separation cell scales with the brink angle and step height, consistent with previously published field and laboratory steps and low-angle dunes. The relationship between step height and separation length is used as the basis for a predictive model in which step height is dependent on beach slope and wave period through their control on swash excursion length. Predicted step heights show good agreement with observations from both the field and laboratory.

Cannizzaro, J.P.; Hu, C.; Carder, K.L.; Kelble, C.R.; Melo, N.; Johns, E.M.; Vargo, G.A., and Heil, C.A., 2013. On the accuracy of SeaWiFS ocean color data products on the West Florida Shelf.

Despite the importance of the West Florida Shelf (WFS) on regional ecology and local economy, systematic shelf-wide assessment of the ocean biology has not been conducted, primarily because of budgetary limitations for routine field campaigns and unknown accuracy of satellite-based data products. Here, using shipboard spectral normalized water-leaving radiance (nL_w[λ]) data and chlorophyll-a concentrations (Chl-a) collected regularly during two multiyear field programs spanning >10 years, the accuracies of Sea-viewing Wide Field-of-view Sensor (SeaWiFS) standard data products were evaluated. The in situ data covered a wide dynamic range, with about one order of magnitude in nL_w(490) (0.47 to 4.01 mW cm⁻² μm⁻¹ sr⁻¹) and two orders of magnitude in Chl-a (0.07 to 10.6 mg m⁻³). Near-concurrent in situ and satellite nL_w(λ) data showed absolute percent differences (APD) increasing from 7–9% to 10–14% when data with elevated aerosol optical thicknesses at 865 nm (τ_a865) were included. Most of this uncertainty, however, canceled in the maximal blue-to-green reflectance band ratios traditionally used for estimating Chl-a. SeaWiFS OC4 Chl-a showed a root mean square (RMS) uncertainty of 0.106 for log-transformed data in waters offshore of the 20-m isobath that increased to 0.255 when all data were considered. The increased likelihood for nearshore SeaWiFS Chl-a greater than ∼0.5 mg m⁻³ to be overestimated was shown to be caused by a variety of factors (colored dissolved organic matter [CDOM], suspended sediments, and bottom reflectance) that varied in both time and space. In the future, more sophisticated algorithms capable of taking these factors into consideration are required to improve remote determinations of Chl-a in nearshore waters of the WFS.

Henry, K.M. and Twilley, R.R., 0000. Soil development in a coastal Louisiana wetland during a climate-induced vegetation shift from salt marsh to mangrove.

Mild winter temperatures are facilitating the expansion of black mangrove (Avicennia germinans) into smooth cordgrass (Spartina alterniflora) marshes along the northern Gulf of Mexico. These expansions have the potential to alter soil development because of differences in productivity and tissue chemistry between Spartina and Avicennia. Here, we examined changes in soil-nutrient chemistry at 2-cm intervals in 30-cm soil cores collected from Spartina and Avicennia habitats at two different sites in Fourchon, Louisiana. Beginning in 1959 and continuing through 2009, our chronology shows that the species shift had no effect on bulk density (mean ± standard error [SE]: 0.68 ± 0.02 g cm⁻³), organic matter (mean ± SE: 8.36 ± 0.29 %), or nitrogen content (mean ± SE: 1.15 ± 0.03 mg cm⁻³). Phosphorus densities were significantly greater in Avicennia habitats (mean ± SE: 0.32 ± 0.01 mg cm⁻³) than they were in Spartina habitats (mean ± SE: 0.28 ± 0.01 mg cm⁻³), which we attributed to Avicennia occurring at higher elevations in more oxidizing soils. We observed significant variability with depth (proxy for time) and between sites in all soil properties measured. This variability can be attributed to the dominance of allochthonous sediment deposition from natural and anthropogenic disturbances compared with the lesser influence of vegetation on autochthonous soil development. In the highly disturbed region of Fourchon, Louisiana, the shift from Spartina marshes to scrub Avicennia stands does not appear to affect the chemistry of soil development.

Edwards, B.L.; Schmutz, P.P., and Namikas, S.L., 2013. Comparison of surface moisture measurements with depth-integrated moisture measurements on a fine-grained beach.

Surface moisture measurement on beaches is an important component of beach groundwater and aeolian transport studies. There are several approaches to measuring beach surface moisture, but each has significant limitations. Several recent studies have used techniques that integrate moisture content over shallow depths, and this study aims to assess the utility of these measurements for characterizing moisture conditions at the sediment surface, and also to briefly comment on the usefulness of a handheld spectroradiometer for measuring beach surface moisture. Depth-integrated moisture measurements of the top 1.5 and 6 cm of sediment obtained with a time domain reflectometry probe were compared with collocated surface moisture measurements from the spectroradiometer. Results show that depth-integrated measurements overestimated actual surface moisture by an average of 2.5 and 4.4% moisture content for the 1.5- and 6-cm sampling depths, respectively. The maximum difference between surface moisture and depth-integrated moisture content was about 12% for the 6-cm depth and about 9% for the 1.5-cm depth. These results suggest that moisture measurements integrated over even shallow depths may not depict conditions at the surface accurately enough for some applications and may potentially provide a misleading description of moisture conditions at the surface. The spectroradiometer proved to be a useful method of measuring beach surface moisture (field calibration with an R²  =  0.99 and standard error of ±1.5% moisture content), but from a logistical standpoint, may not be well suited to measuring and mapping surface moisture over large areas.

Anfuso, G.; Gracia, F.J., and Battocletti, G., 2013. Determination of cliffed coastline sensitivity and associated risk for human structures: a methodological approach.

Human developments along the coastal zone have been increasing greatly during the past decades, and many of those developments are now threatened by coastal erosion. Sea cliff sensitivity to such process can be assessed in different ways, e.g. by coastal morphology, elevation, lithologies, etc. Important parameters controlling rock quality, and hence cliff stability, are its lithology and the presence and characteristics of discontinuities. In this article, a methodological approach is proposed for determining cliff characteristics and the probability of collapse, according to the Bieniawski Method, widely used in geotechnical and applied geologic studies, and for assessing the role of cliff verticality and the presence/absence of protective structures. The vulnerability of human structures depends on their distance from the cliff top, which can be expressed according to their location within the Imminent Collapse Zone and the 10-, 20-, and 30-year, predicted coastline positions obtained from aerial photographs.

Fan, S.; Ren, H.; Wang, R.; Pan, C.; Huang, G.; Chen, Y.; Zhan, P.; Yang, J.; Luo, H.; Jian, S., and Wu, X., 2013. Vegetation restoration and conservation plans for integrated coastal management in Hengqin, China.

In 2009, the Chinese government approved the use of Hengqin Island for a large-scale development that will have serious consequences for plant biodiversity and plant communities in the island ecosystem as a whole. To construct an integrated and healthy vegetation ecosystem on Hengqin Island, we investigated the current vegetation and soil and developed a plan for vegetation conservation and rehabilitation. Satellite images captured over the last 30 years show that the island's coastline has changed greatly and that the forest land, water area, farmland, and urban land has greatly increased because of reclamation. The island currently supports 896 species of vascular plants, which are distributed in nine types of community. The plantation is the dominant community, although there are several patches of secondary forest. The typical soil types are lateritic red soil, salt swamp soil, littoral sandy soil, and fill soil. The poor physical and chemical properties of the soil are considered the limiting factors for vegetation restoration and rehabilitation. We propose to protect the secondary forests and mangroves and to improve the terrestrial plantations. We also recommend that, during the process of island urbanization, vegetation in the protected areas and in the newly constructed urban areas should be spatially connected, i.e. the sea should be connected to the mountain, the remnant forests should be connected to new urban green spaces, and the aquatic plant communities should be connected to the terrestrial plant communities. Hengqin government has adopted these plans and implementation has already begun.

Rusu, E. and Guedes Soares, C., 2013. Modeling waves in open coastal areas and harbors with phase-resolving and phase-averaged models.

A wave-prediction system based on spectral models was validated against in situ measurements in the Portuguese continental nearshore and is now operational. As a final extension of this system, the present article describes the implementation and validation of high-resolution wave models. In this connection, the objective of the present work was to evaluate the performance of such models in different coastal environments. The first target was an open coastal area located in the central part of the Portugal continental. An evaluation of the two state-of-the-art phase-resolving wave models, REFDIF1 and FUNWAVE, was carried out, and the results are compared with those from a field experiment. The second target area was the port of Leixões in the north of the Portuguese continental coast. A high-resolution SWAN computational domain that included the harbor area, was implemented and connected to the modeling system that provides ocean forcing. To provide a more realistic picture of the wave conditions inside the harbor area, the FUNWAVE model was also coupled to the wave-prediction system. Comparisons between the results provided by the two wave models provide a better image of the reliability and limitations of both models at the entrance and inside the harbor area.

Naidu, V.S., 2013. Estimation of near-field and far-field dilutions for site selection of effluent outfall in a coastal region—a case study.

Site selection for release of industrial effluents is of prime concern for maintaining the quality of the marine environment. In this study, an attempt has been made to establish the prevailing ecological conditions and to suggest the suitable location for discharge of the effluents into the sea by using near-field and far-field models. Near-field dilutions were calculated using a buoyant jet model, whereas far-field dilutions were estimated using a two-dimensional numerical model. As a case study, the location of outfall is to be suggested to Vapi Waste and Effluent Management Company Ltd. (VWEMCL) for the release of treated effluents. At present, VWEMCL is discharging effluents upstream of the Damanganga estuary. As a result, the entire Damanganga estuary has poor water quality. Field studies conducted in 2009 suggested that the Damanganga estuarine segment is more polluted than coastal waters. Near-field model studies show that the effluent would attain 35–70 times dilution depending on the height of the water column if the release is made at the offshore location. A far-field model study revealed that the effluent would be diluted effectively with ambient currents, and the near ambient conditions would prevail at around 100 m distance. The effluent would move along the coast, and chances of reaching to the estuary are remote. Rise of the biological oxygen demand concentration to 2.9 mg/L above ambient is predicted at the release site. The water quality of Damanganga estuary would be restored to the preindustrial period once the outfall is commissioned.

Zhang, R.; Yan, C., and Liu, J., 2013. Effect of mangroves on the horizontal and vertical distributions of rare earth elements in sediments of the Zhangjiang estuary in Fujian Province, Southeastern China.

To examine the influence of the mangrove environment on the distribution of rare earth elements (REE) in estuarine sediments, surface and core sediments were collected from regions of mangrove forest, forest fringe, and adjacent mudflat in the Zhangjiang estuary, SE China. Concentrations of REE were determined in surface sediments and core samples using inductively coupled plasma mass spectrometry. Light REE were more enriched than heavy REE, with a relatively weak negative europium anomaly with respect to the North American shale composite in sediments of the Zhangjiang estuary. Significant differences for REE were found among sampling sites and locations, following the order mangrove forest, to forest edge, to mudflat. The main source for REE in the estuary is the weathered continental materials from the Zhangjiang River drainage basin. The mangrove environment affected the physicochemical features and thus affected the REE spatial distributions in sediments. Vertical REE distributions in core samples were altered by mangrove root activity. Mangroves played a significant role in controlling the horizontal and vertical distribution of REE in sediments of the Zhangjiang estuary.

Diniz, D. and Medeanic, S., 2013. Palynomorph records from the core of Rio Grande Cone, Brazil: approaches for palaeoenvironmental and palaeoclimatic reconstructions in the Middle Holocene.

Palynomorphs are an important tool for understanding palaeoclimatic and palaeoenvironmental changes in the past. There are no studies in Brazil based in palynomorphs in deep sea oceans. Based on core REG-973, the objective of this study was to determine changes in palaeoenvironments during the Middle Holocene in the Rio Grande Cone, southern Brazil. A total of 39 samples were collected from the core, with intervals of 4 cm. Samples were treated using methodology for palynological analysis. There was ¹⁴C dating at three samples (20, 100, and 200 cm depth) with absolute ages of 2290, 4080 and 5050 ± 40 yr BP, respectively. The analysis of palynomorphs revealed three distinct origins: marine, terrestrial, and freshwater. Much of this material was allochthonous, transported by aquatic currents of palaeorivers and palaeochannels, which were present on the continental shelf of Rio Grande do Sul (RS) in periods when the mean sea level (MSL) was lower than today. The analysis of the taxonomic variety of palynomorphs showed five Palynomorph Zones. These zones were admitted as corresponding to five stages of palaeoclimatic and palaeoenvironmental development. The constant presence of marine indicators pointed out the formation of such sediment in a marine environment but with influences of coastal surroundings. It was concluded that sediment was generated in a marine environment but always influenced by terrestrial material. The preservation of palynomorphs reflected the MSL oscillations. When the source area was more distant, the preservation level was worse. The generation of sediments was found to be very complex, influenced by factors affecting both the terrestrial and marine environments.

Kara, B.; Esbah, H., and Deniz, B., 2013. Monitoring and analyzing land use/land cover changes in a developing coastal town: A case study of Kusadasi, Turkey.

Kusadasi is one of the most famous tourism centers in Turkey and encompasses agricultural, forest, natural, and coastal areas. The town has been facing rapid urbanization owing to tourism development in the region over the last 20 years. The aim of this study is to analyze and monitor the changes in land use and land cover (LULC) in the Kusadasi urban coastal area between 1993 and 2006. To do so, we will use aerial photographs (dated August 1993) and high-resolution IKONOS (dated July 30, 2001) and QuickBird (dated July 24, 2006) satellite images. We classify LULC in the study area using manual on-screen digitizing in accordance with CORINE LULC nomenclature. Our results showed that the surface area of artificial, nonagricultural vegetated areas, arable land, permanent crops, forests, scrub, and/or herbaceous vegetation associations and open spaces with little or no vegetation decreased, whereas that of urban fabric, industrial, commercial, and transport units and mine, dump, and construction sites increased within a 13-year period. It is noteworthy that from 1993 to 2006, artificial, nonagricultural vegetated areas, permanent crops, open spaces with little or no vegetation (beaches, dunes, and sand plains) and inland waters turned into urban fabric and industrial, commercial, and transport units. One of the conclusions from the study is that, in the planning works for Kusadasi, decisions need to be made that reduce the effects of urban fabric, industrial, commercial, and transport units on artificial, nonagricultural vegetated areas and permanent crops in the coastal zone.

González Trilla, G.; Borro, M.M.; Morandeira, N.S.; Schivo, F.; Kandus, P., and Marcovecchio, J., 2013. Allometric scaling of dry weight and leaf area for Spartina densiflora and Spartina alterniflora in two southwest Atlantic saltmarshes.

Southwest Atlantic saltmarshes are characterized by the presence of Spartina alterniflora in the lower intertidal zones and Spartina densiflora in the middle to high tidal elevations. Because of its dominance and productivity and its central role in carbon and energy fluxes, Spartina spp. biomass and primary production have been extensively studied by different techniques. Since nondestructive techniques require relationships between tiller biomass and morphometric parameters, in this work we established allometric relations among biomass, leaf area, and size, in populations of S. densiflora and S. alterniflora from Mar Chiquita and Bahía Blanca, Argentina. We collected 743 standing tillers of S. densiflora and 663 of S. alterniflora from different dates, conditions (green, flowered, and dead), and sources (high and low marsh). We obtained strong correlations between all the morphometric parameters. Leaf area and leaf length were strongly related (R² = 0.84 for S. densiflora and 0.91 for S. alterniflora). Leaf area per tiller and tiller biomass strongly regressed on tiller height (R² = 0.97 and 0.91 for S. densiflora and 0.88 and 0.90 for S. alterniflora, respectively) thereby facilitating estimations of these parameters. The predictive power of the biomass vs. tiller height equations was satisfactory when applied for different data types (date, condition, and source), suggesting that the models can be widely used for estimating the biomass of a tiller from its length. Moreover, the predictive power of the equations was high even for standing dead tillers, allowing us to use the same equation along the tiller's span life and facilitating detritus production estimations. The allometric relations established in this study may be used to estimate Spartina biomass and leaf area at the study sites, with strong implications in the monitoring and assessment of saltmarshes.

Las marismas de Spartina spp. del Atlántico Sur-occidental se caracterizan por la presencia de Spartina alterniflora en la zona intermareal baja y Spartina densiflora, en las zonas medio a altas. Debido a su dominancia, productividad y su papel central en los flujos de carbono y energía, la biomasa y producción primaria de Spartina ha sido ampliamente estudiada por diferentes técnicas. Entre ellas, las mediciones destructivas requieren de relaciones entre la biomasa del vástago y parámetros morfométricos, como la longitud de la hoja, la altura de la planta, el diámetro del vástago. En este trabajo se establecieron relaciones alométricas entre biomasa, área y tamaño, en poblaciones de S. densiflora y S. alterniflora de Mar Chiquita y Bahía Blanca, Argentina. Se recogieron 743 vástagos en pie de S. densiflora y 663 de S. alterniflora de diferentes fechas, condición (verde, florecidos

Shivaprasad, A.; Vinita, J.; Revichandran, C.; Manoj, N.T.; Srinivas, K.; Reny, P.D.; Ashwini, R., and Muraleedharan, K.R., 2013. Influence of saltwater barrage on tides, salinity, and chlorophyll a in Cochin estuary, India.

Thanneermukkam Barrage (TB) is constructed in the southern arm of Cochin estuary. It prevents salt intrusion upstream and regulates river discharge downstream. Characteristics of the estuary when the barrage is opened and closed are discussed. The analysis showed that the closure of the barrage caused amplification of tides in the immediate vicinity and up to 10 km farther downstream. When the barrage was closed, the northern region of the TB transformed from an ebb-dominant system into a flood-dominant system. During high discharge periods, the barrage was opened and salinity intrusion was exponentially dependent on river discharge. During the dry period, the reduction in river flow compounded with closure of the barrage resulted in an increased salinity concentration downstream. Whereas oceanic salinity was observed at the ocean-end station, about 13PSU occurred at the river-end station when the barrage was closed. Hydrodynamic control on phytoplankton biomass was also evident. Higher surface chlorophyll a levels were observed at higher salinity during the closed barrage period, and residence time was estimated for 4 days during this period.

Chua, V.P., 2013. Modeling the variations of freshwater inflows and tidal mixing on estuarine circulation and salt flux.

An idealized estuary model is employed to simulate the effects of freshwater inflows and tidal mixing on estuarine circulation and salt flux. The model is forced with idealized tides at the coastal ocean boundary, and constant freshwater inflows are imposed at the river end to allow steady state conditions to be achieved. The dependence of length scale L and diffusive fraction ν is stronger with tidal mixing compared to inflows, and this indicates that estuarine circulation and salt flux have a stronger dependence with tidal mixing than inflows. L is proportional to inflows to the −1/3 power and is proportional to tidal mixing to the −2/3 power, while ν is proportional to inflows to the −0.5 power and is directly proportional to tidal mixing. The importance of tidal mixing in estuarine circulation as a result of the coupling between vertical mixing and stratification is reinforced. This suggests that the assumption in classical estuarine theory of parameterizing the influence of tides in mixing coefficients and removing the direct effect of tidal motions by taking averages is insufficient. The relationships derived from the idealized model study may be applied to increase our understanding of estuaries with realistic coastlines and bathymetry and to improve our ability to protect and maintain the health of estuaries, many of which are highly dynamic and rapidly changing systems.

Martínez-Díaz-de-León, A.; Castro, R.; Santamaría-del-Ángel, E.; Pacheco-Ruiz, I., and Blanco-Betancourt, R. 2013. Sea surface heat fluxes and fortnightly modulation of the surface temperature within Ballenas Channel, Gulf of California.

Sea surface temperature (SST) and meteorological information from July 2004 to July 2005 for Alcatraz Bay, which is located within the Ballenas Channel (BC) in the Gulf of California, was used to investigate the occurrence of sudden and drastic drops of almost 7°C in the SST. This occurrence was previously observed in the analysis of SST time series that were recorded simultaneously in six bays along the western coast of the BC. Contrary to previous observations, wind speed showed a weak seasonal variability, with a directionality that departed from the typical monsoonal behavior of wind throughout the Gulf. Although the presented ocean surface heat flux calculations were obtained from coastal data, the results are in agreement with previous estimates, as the net heat flux mainly went into the sea for the whole year, with an annual mean heat gain of 197 W m⁻². SST analysis showed that along with a marked seasonal cycle, there are also four main periods of variability: quarter-diurnal, semidiurnal, diurnal, and fortnightly, corresponding to the main timescales of variability induced by tides. The sudden and drastic drops observed in the SST are clearly related to the intensification of the vertical mixing that is induced by tides and are enhanced at a fortnightly tidal period. MODIS-Aqua SST imagery was used as a supporting, indirect evidence of the mesoscale representativeness of our results, which we suggest can be considered valid for the whole BC.

Bai, X.; Liu, Z.; Li, X.; Chen, Z.; Hu, J.; Sun, Z.; and Zhu, J., 2013. Observations of high-frequency internal waves in the southern Taiwan Strait.

Based on in situ hydrographic measurements at a station at about 60 m depth near the local shelf break in July 2011 and a satellite image of the sea-surface roughness, we present the evidence of existence and characteristics of high-frequency internal waves (HIWs) in the southern Taiwan Strait. Variations of the thermohaline structure at the observational site were revealed by repeating conductivity-temperature-depth (CTD) profiling measurements of every 2 hours, while fluctuations of the isothermals due to the passage of HIWs were recorded by continuous CTD measurements with a probe positioned approximately in the middle of the pycnocline. A fast sampling frequency of 8 Hz allows the structure of the HIWs to be captured in great detail. The waves were depression waves, with a period of about 6.2 min and an amplitude of about 25 m. The propagation speed of the waves is estimated to be 0.56 m/s by solving the KdV equation with the observed background stratification. The frequent occurrence of HIWs in the Taiwan Strait is evidenced by the analysis of a MODIS true color image of the sea-surface roughness. The possible generation mechanism of the HIWs is discussed based on a MODIS image and the perturbed KdV equation.

Kim, D.; Choi, S.-H.; Yang, E.-J.; Kim, K.-H.; Jeong, J.-H., and Kim, Y.O., 2013. Biologically mediated seasonality of aragonite saturation states in Jinhae Bay, Korea.

Aragonite saturation states (Ω_arag) were estimated for the surface and bottom waters of Jinhae Bay over four seasons to assess the major controlling factors. The surface and bottom waters of Jinhae Bay were highly supersaturated with respect to aragonite in spring, autumn, and winter. In summer, however, most of the bottom waters were undersaturated, even though the surface waters were supersaturated. This can be explained by the phytoplankton–carbonate saturation state interaction; high primary production increases Ω_arag in surface waters, whereas vertical export and the subsequent remineralization of organic matter decreases Ω_arag in subsurface waters. A strong linear correlation between the Ω_arag values and dissolved oxygen concentrations supported the idea that biological activity is a major factor controlling Ω_arag in Jinhae Bay. The ocean acidification induced by the invasion of anthropogenic CO₂ also considerably affected the aragonite saturation state in all seasons, particularly in winter, when the Ω_arag values have been reduced by 32–35% in the surface waters and 33–37% in the bottom waters since the preindustrial era. In Jinhae Bay, the undersaturation with respect to aragonite in summer can have large impacts on the calcifying benthic organisms; mussel calcification may no longer occur, and the oyster calcification rate is probably reduced by 50%. In addition, the pH and Ω_arag decreases associated with the anthropogenic CO₂ increase may reduce the calcification rates of oyster and mussel in all seasons, particularly in winter.

Bayram, B.; Seker, D.Z.; Acar, U.; Yuksel, Y.; Guner, H.A.A., and Cetin, I., 2013. An integrated approach to temporal monitoring of the shoreline and basin of Terkos Lake.

In this study, the combinatorial shoreline and land-use/cover (LULC) changes in the shoreline and basin of Terkos Lake were examined using Landsat satellite images taken in 1986, 2001, and 2009. Terkos Lake is one of seven freshwater-supplying reservoirs of Istanbul, and its borders are very close to the Black Sea. Terkos Lake is in danger because of the approach of its borders to the Black Sea. Changes in the lake's shoreline have been measured using an algorithm based on a hybrid region growing image-segmentation method. The LULC changes have been monitored using object-oriented image-processing software to provide understanding of the impact of these changes on the shoreline. Overall accuracy of the classification reached 92% for 1986, 94% for 2001, and 93% for 2009. The maximum shoreline change measured was 280 m in 23 years. Also, the obtained shoreline and LULC changes have been integrated into the long-term analysis of wave and wind characteristics and sediment-transport calculations. The calculations have been validated with shoreline changes, which have been automatically extracted from Landsat satellite images. The basic outcomes and proposals have been suggested to deal with uncontrolled human activities in the study area.

Liang, S.-J.; Lin, C.-Y.; Hsu, T.-W.; Ho, C.-R., and Chang, M.-H., 2013. Numerical study of vortex characteristics near Green Island, Taiwan.

Vortex shedding downstream of Green Island due to passing of the Kuroshio is numerically studied. The numerical model is based on depth-averaged shallow-water equations with the space-time least-squares finite-element method. Vortex characteristics, such as spatial scales (aspect ratio and dimensionless width), temporal scale (Strouhal number), and propagation speed of the vortices are quantified. It is found that aspect ratio = 2.4, dimensionless width = 1.1, and Strouhal number = 0.157 for Reynolds number 100. The computed spatial scales and temporal scale agree reasonably with available satellite images and in situ measurements, as well as other simulation results. The magnitude of the propagation speed of the vortices is found to be of the same order as that of the Kuroshio, implying that the nonlinearity of vortices as well as the interactions between vortices and the Kuroshio are strong.

Cornejo-Ortega, J.L.; Chávez-Dagostino, R.M., and Massam, B.H., 2013. Sustainable tourism: whale watching footprint in the Bahía de Banderas, México.

The discussion about nonsustainable ecological systems is in vogue. The debate has led to the biophysical analysis of “human-nature” relationships. This analysis is an important way to determine human impacts on the Earth, based on the colonization of nature and social activities that consider matter and energy flows through appropriation, transformation, distribution, consumption, and excretion. Tourism has appropriated and characterized various types of ecosystems that represent the use of a finite set of spatially distributed resources. The observation of marine mammals, such as whales, in natural protected areas attracts many tourists each year, and this activity indirectly generates carbon dioxide that is released into the atmosphere. This carbon emission, which is accompanied by the increased scale of tourism, may hamper global conservation goals. We describe the use of the Ecological Footprint tool as a sustainability indicator of humpback whale–watching activity in Bahía de Banderas, Marietas Islands National Park, in Nayarit, México, to examine the global impact of this tourist activity on ecosystems. Calculations are based on the Ecological Footprint method using the consumption/productivity ratio—converting costs of goods and services into consumption of resource inputs and then translating these to surface units. The findings show that the mean whale-watching footprint in the study area is 46.85 ha. This figure is low when compared to other estimated footprints of ecotourism activities in the world. The discussion examines how the results of this type of analysis can be used to improve tourism planning with a view to promoting sustainability.

Li, J. and Gao, S., 2013. Estimating deposition rates using a morphological proxy of Spartina alterniflora plants.

Based on field investigations at five sites on the southern Jiangsu coast, eastern China, we propose a new method for estimating the deposition rate using the morphological data of Spartina alterniflora Loisel plants. This species was introduced to the region in the 1980s. The separating point of the root and stem (SPRS), below the bed surface, is quite stable for living plants. Furthermore, the distance between the present-day bed surface and the SPRS of the buried, oldest plants can be measured. Hence, the difference between these two distances represents the thickness of newly accumulated materials. If the colonization time of this species is known, then the deposition rate can be deduced. In the study area, at one of the sites with a relatively short history (<10 y) of S. alterniflora colonization, the deposition rate thus obtained is close to the value ²¹⁰Pb measurements. Similarly, at a site with a relatively long colonization history, similar mean deposition rates have been estimated. This method enables researchers to easily determine the deposition rate in the field, if the time of initial colonization by the S. alterniflora plant is known.

Hwang, S.-W.; Kang, H.-K.; Son, Y.-B.; Jang, M.-C., and Choi, K.-H., 2013. Collapse of the crustacean mesozooplankton in the northern East China Sea: effects of Three Gorges Dam?

The damming of major rivers can have broad impacts on ecological processes in adjacent marine ecosystems. Thirty years of sampling data from the northern East China Sea show that the recent impounding of water by the Three Gorges Dam on the Changjiang River (Yangtze River) might have had dramatic impacts on the mesozooplankton community. The reduction in freshwater discharge and subsequent increases in phytoplankton biomass have resulted in a substantial increase in total mesozooplankton wet weight but sharp declines in the abundance of all of the crustacean components. The increase in mesozooplankton biomass is probably associated with an increase in small, gelatinous zooplankton. Together with an increase in sea surface temperature in the region, the reduced freshwater and sediment discharge might have led to the proliferation of gelatinous mesozooplankton in this historically overfished region, generating significantly increased grazing pressure on planktonic crustaceans.

Kenov, I.A.; Deus, R.; Alves, C.N., and Neves, R., 2013. Modelling seagrass biomass and relative nutrient content.

A generalized model was developed for the simulation of Zostera noltii dynamics by considering the plant's growth and decay in response to light, temperature, space availability, photoperiodicity, and dissolved nutrients in water and in sediment. Sensitivity analysis was carried out to establish the influence of model parameters on the overall results. It was found that the most sensitive parameters were those related to mortality, internal nutrient content, and translocation of carbon from leaves to roots. A preliminary calibration of the model was carried out to estimate parameters specific for Z. noltii. Afterward, the model was verified with experimental data of Z. noltii biomass. The verification results showed that the set of parameters found by calibration enabled the simulation of the Z. noltii biomass. The proposed model was used to simulate both nitrogen and phosphorus metabolism in the plant. The results of the simulations revealed that the plant was limited by nitrogen and phosphorus in the spring/summer and was less limited by nutrients in the winter. In the future, the model can be improved in terms of both description and parameterization of the processes.