Phan, L.K.; van Thiel de Vries, J.S.M., and Stive, M.J.F., 2015. Coastal mangrove squeeze in the Mekong Delta.

The role of mangrove forests in providing coastal zone stability and protection against flooding is increasingly recognized. The specific root, stem, and canopy system of mangroves is highly efficient in attenuating waves and currents. The sheltered environment created by a healthy mangrove forest offers great sedimentation potential in case a sediment source is available. However, the once-abundant mangrove forests in the Mekong coastal delta are becoming rapidly depleted. Especially along the Mekong eastern and southeastern coast, mangrove degradation and rapid coastline erosion are observed at many locations. At these locations, the mangrove forests usually consist of a narrow strip only, sometimes as narrow as 100 m. This mangrove squeeze is mainly due to the construction of sea dikes in a quest for the creation of space for cultivation and the prevention of salinity intrusion. The basic assumption behind our work is that there is a critical minimum width of a coastal mangrove forest strip to keep its ability to stay stable or, once surpassing the minimum width, to promote sedimentation. The larger the width the more efficient the attenuation of waves and currents will be, offering both a successful seedling and sedimentary environment. Our analysis of available data both from literature and from satellite observations supports our basic assumption: an average critical width of 140 m is found for the southeastern and eastern Mekong Delta coast as a minimum width to sustain a healthy mangrove forest. To further our insights into the efficiency of mangrove to attenuate wave energy as a function of their width we have applied a state-of-the-art wave propagation model that includes both short and long waves. Our results confirm earlier results from the literature that short waves are indeed attenuated very rapidly over distances shorter than the critical width, but as we show for the first time infragravity waves penetrate over much larger distances. We therefore hypothesize that the decay of long waves plays a crucial role in the health of the mangrove.

Stadler, M.; Salmon, M., and Roberts, C., 2015. Ecological correlates of green turtle (Chelonia mydas) abundance on the nearshore worm reefs of southeastern Florida.

Juvenile green turtles (Chelonia mydas) differ in abundance on nearshore reefs, but why some sites are preferred over others is unknown. Our study had two objectives: to quantify site-specific differences in turtle abundance over time (1 y) and to determine what ecological factors were correlated with those differences. We conducted quarterly surveys on reefs in Palm Beach and Broward Counties, Florida, and compared reef sites with respect to (1) water depth, (2) algal abundance, (3) algal species richness, and (4) fluctuations in reef area caused by sand burial (which kills the algae used as forage by the turtles). Turtles were most abundant on reefs located in shallow water and exposed to bright ambient light. More turtles were also seen at sites where algae were both abundant and composed of many species. Reefs with those characteristics tended to remain uncovered by sand (“stable”) for longer time periods. We hypothesize that foraging by turtles on preferred reefs may prevent any one species of algae from dominating the site, making room for others to colonize. If true, then both physical stability (reef exposure time) and biological activity (turtle grazing) may make some reefs more attractive to turtles than others.

Evelpidou, N.; Pirazzoli, P.A., and Spada, G., 2015. Origin and Holocene evolution of a slightly submerged tidal notch in the NE Adriatic.

A puzzling, slightly submerged, single tidal notch has been reported from the carbonate coasts of the northeastern Adriatic Sea. This paper attempts to explain the origin and the recent evolution of this marine erosion feature and the reasons for its uniqueness in the late Holocene. After reviewing how tidal notches are usually formed, a comparison of recent measurements of bioerosion rates carried out in the area show that when the contribution of dissolution processes can be neglected, bioerosion rates of the deepening of tidal-notch profiles appear to be very low (often <0.1 mm/y) along the coasts of Istria, in contrast to higher rates (between 0.2 and 1.0 mm/y) generally reported in other Mediterranean areas. Such a low rate of bioerosion implies a long period favourable to tidal-notch development. Several glacial isostatic adjustment computations show that relative sea level changes in the area during the last few millennia may correspond to a period of equilibrium between the regional tectonic subsidence and hydro-isostatic emergence during which relative sea level changes were limited, permitting development of the tidal notch observed. The submergence of the notch is consistent with a coseismic subsidence in late Roman time. After this, a new tidal notch could not form at the present sea level because of the limited amount of local bioerosion and the relatively large rate of sea level rise.

Lewis, M.J.; Neill, S.P., and Elliott, A.J., 2015. Interannual variability of two offshore sand banks in a region of extreme tidal range.

Offshore sand banks play important roles for coastal flood protection and fisheries, and they are sources of marine aggregates. An 11-year record (1991–2002) of annual bathymetric surveys from two sand banks (Nash and Helwick) in the Bristol Channel (U.K.) were analysed. Both sand banks have a history of commercial dredging, and have dimensions of the order 10 km by 1 km, with a crest height rising to around 20–25 m above the surrounding sea bed. The crest at Nash Bank is exposed on the lowest spring tides, while Helwick Bank is always covered to a depth of at least 3 m. The volume of Nash Bank decreased over 10 years, and dredging was estimated to be responsible for around one third of this reduction. The volume of Helwick Bank also decreased over an 8-year period, but at a rate six times greater than the loss due to dredging. Significant interannual variability of sand bank morphology was calculated at both sites. The time during which waves alone could induce sediment transport over the sand banks was calculated between each survey date (the effective wave climate). The change in sand bank volume correlated well to the effective wave climate: a linear regression score of 77% (−0.88 Pearson correlation at the 95% significance level) and 69% (0.83 Pearson correlation at the 95% significance level) were found at Helwick and Nash, respectively. A one-dimensional morphodynamic model (UNIBEST-TC), simulated storm wave–induced changes to sand bank morphology that were consistent with those observed. Therefore, the interannual variability within storm wave events could be responsible for the observed natural variability of sand bank volume and morphology observed at both sites. We conclude that it is important to understand anthropogenic impacts upon sand banks within the context of natural variability.

Wynja, V.; Demers, A.-M.; Laforest, S.; Lacelle, M.; Pasher, J.; Duffe, J.; Chaudhary, B.; Wang, H., and Giles, T., 2015. Mapping coastal information across Canada's northern regions based on low-altitude helicopter videography in support of environmental emergency preparedness efforts.

In the face of increasing economic opportunities in Canada's northern regions, the need to improve our state of preparedness for oil spill–related emergencies is critical. While significant efforts have been put toward documenting baseline coastal information across Canada's southern regions, there is a large information gap regarding Arctic shorelines. Baseline coastal information, such as shoreline form, substrate, and vegetation type, is required for prioritizing operations, coordinating onsite spill response activities (i.e. Shoreline Cleanup Assessment Technique [SCAT]), and providing information for wildlife and ecosystem management. Georeferenced high-definition videography was collected during the summers of 2010 to 2012 along coastlines within six study sites across the Canadian Arctic. Detailed information describing the upper intertidal, supratidal, and backshore zones was extracted from the video and entered into a geospatial database using a data collection form. This information was used to delimit and map alongshore segments in the upper intertidal zone. Almost 15,000 km of northern shorelines were mapped, including 25 shoreline types based on the upper intertidal zone. This information will feed into a larger ongoing project focused on Arctic coastal ecosystems and oil spill response planning should the need arise.

Saravanan, S. and Chandrasekar, N., 2015. Wave refraction pattern and littoral sediment transport along the SE Tamilnadu coast, India.

The objective of the paper is to understand the wave refraction pattern and littoral sediment transport along the SE coast of India. There are areas of erosion and accretion observed along the coastal stretch that depend primarily the direction of wave approach, the wave period, and the wave refraction pattern. In the nearshore zone of the study area, the movement of sand alongshore is due to the action of waves and currents. Wave refraction is an important process responsible for effecting changes in coastal configuration. Based on this study, the wave convergent and divergent zones are identified with reference to wave refraction. Longshore sediment transport is higher in the northerly direction than in the southerly direction. The present study of littoral sediment transport implies that the beaches of Kanyakumari, Navaladi, and Ovari have greater transport rates.

Hwang, S.W.; Choi, K.H.; Hwang, H.; Kim, C.K., and Lee, T.W., 2015. Migration history and habitat use by Javelin goby Synechogobius hasta as inferred from otolith Sr : Ca ratios.

The habitat use and migration of Javelin goby Synechogobius hasta that were collected from the estuaries of the Geum River and the Mangyeong River of Korea were examined on the basis of the environmental signature of otolith strontium and calcium concentrations determined by laser ablation–inductively coupled plasma mass spectrometry. The otolith Sr : Ca ratios suggested that S. hasta spawned in brackish water, and inhabited a broad range of salinities, including seawater, brackish water, and freshwater, during their lifetime. The migration histories of S. hasta were highly variable within habitats, indicating flexible movement patterns that permit use of the full range of salinity throughout their lifetime.

Lau, A. and Dodd, C.K., Jr., 2015. Multiscale burrow site selection of gopher tortoises (Gopherus polyphemus) in coastal sand dune habitat.

The gopher tortoise (Gopherus polyphemus) is a keystone species in upland sandhill ecosystems of the SE United States, and its habitat requirements have been well documented. Few studies have been conducted on populations that occur in coastal sand dunes. Because of close proximately to the ocean and highly fragmented linear habitat, coastal populations of gopher tortoises are affected by unique landscape factors that are not observed in upland contiguous populations. In this study, burrow site selection of gopher tortoises in a coastal sand dune site was quantitatively modeled. Significant biological, environmental, and anthropogenic factors that may influence burrow site selection at fine and coarse spatial scales were identified. Land cover type, distance to edge, soil resistance, percentage of herbaceous cover, slope angle, and number of tortoise burrows have significant influences on burrow site selection probability. Factors that influence burrow locations in coastal populations thus might differ in importance from those that influence burrow locations in more spatially contiguous upland populations. Our results indicate that coastal gopher tortoise populations require site-specific management that focuses on the limited availability of optimal burrow construction sites.

Chen, Q.; Li, J.; Zhang, L.; Lu, H.; Ren, H., and Jian, S., 2015. Changes in the macrobenthic faunal community during succession of a mangrove forest at Zhanjiang, South China.

A chronosequence was used to study the community structure of the macrobenthic faunal community during succession of the mangrove forest at Zhanjiang, South China. The four successional stages studied were (from primary to late) unvegetated shoal, the Avicennia marina community, the Aegiceras corniculatum community, and the Bruguiera gymnorrhiza Rhizophora stylosa community. Faunal density, the diversity index, species richness, and evenness index were highest in the unvegetated shoal (189 individuals/m², 1.97, 3.48, and 0.74, respectively, in the wet season; 105 individuals/m², 1.77, 2.20, and 0.84, respectively, in the dry season) and lowest in the B. gymnorrhiza R. stylosa community (35 individuals/m², 1.04, 1.10, and 0.57, respectively, in the wet season; 46 individuals/m², 0.86, 1.16, and 0.66, respectively, in the dry season). The values for these community parameters decreased with succession. Hierarchical clustering indicated that the distribution of the macrobenthic fauna closely corresponded with the successional stages. Correlation analysis and canonical redundancy analysis (RDA) indicated that the changes in the macrobenthic fauna with mangrove succession were associated with the aboveground vegetation (mainly crown breadth and tree height) and soil physicochemical properties (mainly soil organic matter and total nitrogen content). Several species of macrobenthic fauna were only detected in certain stages of succession, suggesting that they may be biological indicators of succession.

Gonçalves, M.; Rusu, E., and Guedes Soares, C., 2015. Evaluation of two spectral wave models in coastal areas.

The objective of the present work is to evaluate two wave models, SWAN and STWAVE, considering various coastal areas with different bathymetric features. Although both models are based on the spectrum concept and integrate the action balance equation over the computational domain using rectangular grids, there are also fundamental differences between them induced by the propagation schemes implemented and also by the different formulations considered for the basic source terms. The two models are evaluated in four coastal areas, three of them belonging to the Portuguese continental coastal environment and the other one located in the nearshore of Sardinia Island. The bathymetric characteristics of the computational domains considered are rather different. Two of them have smooth contours, another is characterized by very high bathymetric gradients, and finally the last one includes a harbor area. Comparisons of the models' predictions against measurements were carried out in both intermediate and very shallow water. Besides these, comparisons between the two models as regards the field distributions of the main wave parameters were also performed. The results of the work show that SWAN is a more complex model that can be better calibrated and adapted for a specific site, especially due to the multitude of options available. On the other hand, STWAVE is simpler, more robust, and quicker and can be used effectively in various coastal environments.

Cuc, N.T.K.; Suzuki, T.; Ruyter van Steveninck, E.D. de, and Hai, H., 2015. Modelling the impacts of mangrove vegetation structure on wave dissipation in Ben Tre Province, Vietnam, under different climate change scenarios.

Mangroves are widely distributed along the coastline of Vietnam, where they provide protection against sea waves caused by extreme weather. Impacts of climate change, together with population growth and economic development, are expected to exert pressure on these vulnerable systems. In this study the numerical wave-propagation model SWAN-VEG (Simulating Waves Nearshore–Vegetation) was used to simulate the possible impacts of climate change on the wave-dissipation capacity of different types of mangrove vegetation. Vegetation characteristics were assessed in planted plots (Rhizophora apiculata and a mix of R. mucronata, Sonneratia caseolaris, Avicennia alba, and Nypa fructicans) and in natural regenerated areas (A. alba and S. caseolaris) in Thanh Phu Natural Reserve, Mekong Delta, Vietnam; these assessments were used as model input. Different sea levels and mangrove vegetation characteristics were used to simulate the potential impacts of climate change. Planted plots with a cover of 70% reduced the height of incoming waves by 60%, compared with 40% for natural regenerated forest. Reducing the vegetation cover in planted plots from 70% to 50%, 35%, and 0% resulted in wave-height reductions of 51%, 42%, and −4%, respectively. A sea level rise (SLR) up to 0.96 m did not change the wave-dissipation potential of R. apiculata planted in the plots. However, an assumed decline in the width of vegetation from 1.5 km to 0.5 km, e.g. as a consequence of coastal erosion, reduced the height of incoming waves 21% (no SLR) and 29% (0.96 m SLR), as compared to 60% and 59%, respectively, without erosion.

Robertson, B.; Hall, K.; Nistor, I.; Zytner, R., and Storlazzi, C., 2015. Remote sensing of irregular breaking wave parameters in field conditions.

The analysis of wave breaking in shallow water has been ongoing for almost 150 years. Numerous research papers have been published that approximate both the local conditions and geometric characteristics of breaking waves. However, much of this knowledge is based on laboratory results or limited field investigations because traditional methods of extracting breaking wave measurements from the surfzone are expensive, dangerous, and feature low-resolution data. Unfortunately, laboratory studies are prone to scaling and friction effects that introduce unwanted variability in the data. This study presents a novel, safe, and low-cost method of extracting relevant breaking-wave properties from irregular waves in the surfzone, using optical and in situ measurement systems. Published, contradictory breaking-water depth definitions are compared, and the water depth at the wave-trough depth, corrected for optical offsets using a still-water correction of one-third of the wave height, is found to exhibit the least variability. A new, effective seafloor-slope definition, based on individual, breaking wavelength-to-depth ratios, was found to increase predictive ability over previously variable seafloor slope extraction methods. Collected field data are compared against established breaking-wave height formulas with the general exponential form consistently finding the best correlation. Finally, an optimized breaking-wave height-prediction method finds a root mean square relative error of just 1.672% within the ranges of the measured data set. Irregular waves investigated on an individual wave basis are shown to follow regular wave-breaker height and depth prediction methods.

Numanoğlu Genç, A., 2015. A model to simulate yacht movements in enclosed bays.

In this article, a computer model developed to simulate the movements of yachts (boats) in enclosed bays is discussed. The computer model uses multinomial logit model to find the probabilities for the boaters to select the next bay to visit. The model predicts the number of boats in each bay at the end of a day, the number of boats that visited each bay during the day, and the distribution of boater categories among the bays throughout the simulation time. As a case study, the model is applied to Göcek bays located at the west Mediterrnean coast of Turkey. To obtain the input data, a questionnaire was formed, and a detailed survey was carried out in Göcek bays. In addition to the questionnaires, the number of the boats anchored in the bays were observed in the field studies. The results obtained by the model are compared with the data obtained in the field. Comparisons show that the yacht movements and distributions at various anchor locations can successfully be predicted with the model. This model can be used as an effective tool in the management of coastal areas.

Bu makalede, yatların hareketlerini inceleyen bir öykünüm modeli geliştirilmiştir. Yatçıların koy seçimlerindeki olasılıkları belirleyebilmek için matematiksel model olarak çok terimli logit model kullanılmıştır. Geliştirilen öykünüm modeli gün sonunda her koydaki tekne sayısını, gün içerisinde koylara girip çıkan tekne sayısını ve tüm öykünüm süresi için yatçı gruplarının koylara dağılımını hesaplamaktadır. Bu model için gerekli olan girdileri elde edebilmek amacıyla, Göcek Koylarında kapsamlı bir anket çalışması yapılmış ve ayrıca koylardaki tekne sayıları farklı zamanlarda gözlemlenmiştir. Bu öykünüm modelini baz alan bilgisayar programı Göcek Koylarına uygulanmış ve model sonuçları, saha incelemelerinden elde edilen veriler ile karşılaştırılmıştır. Gelecek yıllar için daha çok sayıda yatın bulunacağı durumlarda, bu modelin yardımıyla dağılım tahminleri yapılabilecektir. Bu tahminler yat trafiğinin ve konaklamanın denetlenmesini amaçlayan bir yönetim planı çerçevesinde yararlı bir araç olacaktır.

Jia, M.; Wang, Z.; Liu, D.; Ren, C.; Tang, X., and Dong, Z., 2015. Monitoring loss and recovery of salt marsh in the Liao River Delta, China.

Coastal salt marsh plays an important role in the aquatic food web and the export of nutrients to coastal waters. The salt marshes in the Liao River Delta of China, dominated by Suaeda heteroptera, experienced a dramatic loss in the 1990s and then recovered in the 2000s. This study investigates these changes of salt marsh using a time series of Landsat Thematic Mapper (TM) images acquired in 1988, 1995, 2000, 2004, 2007, and 2009. The classification tree method was used on these TM images to extract S. heteroptera, and an interactive self-organizing data analysis algorithm was used to determine other land cover types. The conversions between salt marsh and other land cover types were described with conversion matrices. The classification results show that, during 1998–2004, salt marsh decreased dramatically at an average rate of 662.68 ha/y. However, during the period 2004–2009, salt marsh recovered gradually at a rate of 115.51 ha/y. The conversion matrix indicates that, from 1988 to 2004, a large area of former salt marsh was directly replaced by man-made landscape types, such as reed field (5111 ha), aquaculture pond (2655 ha), reservoir (1720 ha), and paddy field (729 ha). In contrast, the result for the period from 2004 to 2009 shows that salt marshes were recovered by the conversion of some areas of former barren beaches and river back to salt marsh. Driving forces analysis suggests that salt marsh dynamics were mainly caused by human activities, with the secondary drivers being climatic warming and dry conditions.

Rodrigues-Filho, J.L.; Branco, J.O.; Monteiro, H.S.; Verani, J.R., and Barreiros, J.P., 2015. Seasonality of ichthyofauna bycatch in shrimp trawls from different depth strata in the southern Brazilian coast.

Changes in the species composition and ecological descriptors of fish assemblages in terms of abiotic factors such as depth, temperature, salinity, and granulometry were analyzed. Monthly trawls, from October 2003 to September 2004 (30 minutes each) were analyzed in two areas covering an important shrimp fishing site of the Brazilian coast. Results using bifactorial analysis of variance revealed a seasonal variation of environmental variables (p < 0.05), and granulometry analyses showed that the composition of the fishing grounds was similar—mostly sand. A total of 12,613 fish were collected: 7880 in area I and 4733 in area II. The highest values of capture in numerical abundance (catch per unit effort) occurred during winter. Fifty taxa were caught in area I, and 53 taxa were caught in area II. Both values are considered high when compared to previous studies conducted in nearby areas. Sciaenidae was the most speciose family in all samples and in both areas were dominant in number of species (37 species in area I and 42 species in area II). Cynoscion striatus was the most abundant and dominant species in both areas. Estimates of ecological descriptors, such as richness, diversity, and evenness, showed that the ichthyofauna structure was strongly influenced by climatic factors, and all values were more pronounced during fall and winter. The permutational multivariate analysis of variance demonstrated that ichthyofauna species composition differs among seasons. The Student's t test applied a posteriori showed that the community composition differed (significantly) in the following comparisons: spring vs. fall (p < 0.05) and winter vs. summer (p < 0.05). According to similarity percentage analysis, changes in the community structure were mainly correlated with species classified as abundant, which occurred unevenly during the different periods. Our results show that the fish community is influenced by seasonal variations such as salinity and temperature but not by depth or sand grain sizes.

As alterações na composição específica e nos descritores ecológicos das assembleias de peixes em função dos fatores abióticos, tais como profundidade, temperatura, salinidade e granulometria, foram analisadas no presente trabalho. Arrastos mensais de trinta minutos de duração foram realizados em duas áreas com diferentes profundidades em um importante ponto de pesca camaroeira do litoral sul brasileiro. Paralelamente, registrou—se os valores de temperatura e salinidade da água, bem como foi amostrado o tipo de substrato dos fundos de pesca. A aplicação do teste t de Student demonstrou variação sazonal dessas variáveis ambientais no estudo (p < 0,05) e a análise granulométrica demonstrou que a composição dos fundos de pesca foi bastante similar, sendo composta principalmente por areia. No total foram capturados 12.613 exemplares, sendo 7.880 na área I e 4.733 na área II. Os maiores valores de captura (CPUE) ocorreram no inverno. Foram capturados 50 táxons na área I e 53 na área II, um alto valor quando comparado com estudos pretéritos em localidades próximas. A família dos sciaenideos foi a mais representativa nas coletas, predominando em ambas as áreas espécies incidentais (37 na área I e 42 na área II). Cynoscion striatus foi a espécie mais abundante e predominante em ambas as áreas. As estimativas dos descritores ecológicos, tais como a riqueza, a diversidade e equitabilidade, evidenciaram que a estrutura da ictiofauna foi fortemente influenciada pelo fator tempo e que os valores mais acentuados ocorreram no outono e inverno. A aplic

Rahaman, S.M.B.; Rahaman, M.S.; Ghosh, A.K.; Gain, D.; Biswas, S.K.; Sarder, L.; Islam, S.S., and Sayeed, A.B., 2015. A spatial and seasonal pattern of water quality in the Sundarbans river systems of Bangladesh.

Comprehensive field measurements were made in three major river systems (RSs) of the Sundarbans during October 2010 to August 2011 under post-monsoon, dry winter, and monsoon seasons to assess the pollution status. Fifteen experimental sites were set for collection of water samples from discrete layers under different tidal conditions. Salinity, temperature, pH, and dissolved oxygen (DO) were determined in situ and chemical oxygen demand (COD), biological oxygen demand (BOD), total nitrogen (TN), total phosphorus (TP), nitrate, phosphate, and ammonium were measured through laboratory analysis. Mean DO was recorded between 3.93 and 7.37 mg/L with an average 5.44 mg/L. Highest average DO was noticed at Rupsha-Passur RS during post-monsoon, whereas the lowest was in Kholpetua-Arpangashia RS during monsoon. Mean BOD ranges between 0.3 and 4.1 mg O₂/L, with an average of 2.04 mg O₂/L, where maximum and minimum concentrations were measured at Kholpetua-Arpangashia RS in monsoon and dry winter respectively. Mean COD was found to vary from 20 to 240 mg O₂/L, with an average 121.33 mg O₂/L, exceeding the permissible range of 4–8 mg O₂/L. Rupsha-Passur RS shows lowest average COD during post-monsoon, whereas Kholpetua-Arpangashia RS indicated highest COD in winter. Measured COD was higher in the dry season than in the wet season because of precipitation that causes dilution in the RSs. The study indicates the existence of organic pollution, though the DO concentration was within the permissible limit. Analyzed water samples showed nitrate, phosphate, and ammonium values in the range of 0.083 ± 0.03 to 0.627 ± 0.42 mg/L, 0.011 ± 0.005 to 0.449 ± 0.26 mg/L, and 0.038 ± 0.018 to 0.176 ± 0.16 mg/L respectively. TN and TP concentrations were not high enough in most cases, as there is a chance of eutrophication due to algal pollution. Study results will help identify factors responsible for affecting the biodiversity of the Sundarbans intertidal mangrove forest.

Sarangi, R.K.; Thangaradjou, T.; Poornima, D.; Shanthi, R.; Kumar, A.S., and Balasubramanian, T., 2015. Seasonal nitrate algorithms for the southwest Bay of Bengal water using in situ measurements for satellite remote-sensing applications.

Monthly coastal sampling and ship-cruise-measured in situ datasets of nitrate, sea surface temperature (SST), and chlorophyll in the SW Bay of Bengal covering Tamilnadu and Andhra Pradesh coasts of India were used to develop nitrate algorithm. A total of 15 datasets prepared during 2009–11 covered cruise data and all monthly datasets, nine datasets followed with better results with paraboloid function, and others followed linear, Gaussian, and Lorentzian function regression fits. Data collection through cruises (397 points), monthly (482 points) coastal sampling, total monthly and cruise (879 points) covering four seasons were used, and the three-dimensional (3D)-paraboloid function showed better results during the seasonal scale study with the R² values 0.670, 0.635, 0.465, and 0.693 for the postmonsoon, summer, premonsoon, and monsoon seasons respectively. In the current study, there has been considerable improvement in R² (0.670 with 236 points) than the earlier study using postmonsoon data (0.560 with 105 data points). Through this algorithm, a nitrate map was generated for 11 March 2011 using Oceansat-2 Ocean Color Monitor (OCM) and MODIS-aqua-derived chlorophyll and SST data, respectively. The retrieved nitrate map has been validated with in situ dataset of the same date with an R² value of 0.718, which suggests that the developed nitrate algorithm was statistically significant with mean normalized bias (MNB) = 0.078, root mean square error (RMSE) = 0.412, and standard error of estimate (SEE) = ±0.4032, and the algorithm was observed to be working satisfactorily over the SW Bay of Bengal region.

Steichen, J.L.; Denby, A.; Windham, R.; Brinkmeyer, R., and Quigg, A., 2015. A tale of two ports: Dinoflagellate and diatom communities found in the high ship traffic region of Galveston Bay, Texas (USA).

Ballast water (BW) discharge by shipping vessels is a known transport vector of harmful species of dinoflagellates and diatoms. With a steady growth in global commerce, ship traffic to ports worldwide has intensified, increasing the risk of invasion by nonindigenous species. From 2008–12, >140 million metric tons of BW was discharged into Galveston Bay, Texas, much more than reported in other highly invaded Bays: San Francisco (96 × 10⁶ mt) and Chesapeake (25 × 10⁶ mt) during the same period. Studies conducted specifically on the dinoflagellate and diatom communities within Galveston Bay have been lacking until the present effort, which used both microscopic and genetic methods. Within one year of sampling, 35 genera of dinoflagellates and diatoms were identified from the two deepwater ports of Houston and Galveston. Seven of the genera are known toxin producers, three of which have formed harmful algal blooms within the Bay: Alexandrium, Gymnodinium, and Prorocentrum. Two genera identified from the ports (Takayama and Woloszynskia) have not been previously reported. This study provides a baseline of the phytoplankton community within these major ports in Galveston Bay before foreign shipping traffic increases due to the expansion of the Panama Canal.

Hsu, T.-W.; Hsieh, C.-M., Tsai, C.-Y., and Ou, S.-H., 2015. Numerical simulation for wave breaking on bar/step-type beach profile.

A two-dimensional numerical model was developed to simulate wave breaking on a barred/stepped beach profile. The volume of fluid with piecewise linear interface calculation (VOF/PLIC) is employed to a track-free surface configuration. The embedding (EB) method is used to describe complex bottom topography without imposing boundary conditions on the bottom. The present model shows significant improvement for describing both wave profile and flow fields for spilling breakers when compared with laboratory observations. Based on numerical results, flow characteristics of the free surface profile, mean velocities, vorticities and turbulence transports under spilling breakers traveling over a bar/step-type beach profile were discussed.

Ertek, A.; Kılıç, E.; Erginal, A.E.; Ekinci, Y.L., and Demirci, A., 2015. Preliminary assessment of submerged beachrock and tsunamigenic deposit, Hasır Island, Marmara Archipelago, Turkey.

A preassessment of coexisted submerged beachrock and a fossil-laden near-shore deposit on the coast of Hasır Island, SW Marmara Sea, is presented based on depositional characteristics, two-dimensional electrical resistivity tomography (ERT) survey and accelerator mass spectrometry (AMS) radiocarbon ages. ERT-derived geophysical images clearly showed the subsurface position and contact relationship of submerged beachrock under the studied beach. Textural features of beachrock are typical solely of marine-phreatic cementation, including consecutively developed cement fabrics, i.e. micrite coatings, radial aggregates consisting of scalenohedral high-Mg calcites, and reticulated needles of aragonite. The intertidal cementation of beachrock took place between 2940 and 2470 YBP when the level of the Marmara Sea was about 1.5 m lower than that of the present. Its purely submerged nature is likely concerned with rise in sea level in pursuit of the cementation period. Though dated between 2340 and 1590 YBP, the fossil-rich near-shore deposit behind the studied beach could be of a tsunamigenic origin based on its sequence characteristics typical of such a high-energy event.

Amos, C.L.; Martino, S.; Sutherland, T.F., and Al Rashidi, T., 2015. Sea surface temperature trends in the coastal zone of British Columbia, Canada.

Coastal sea surface temperature (SST), measured daily at the British Columbia (BC) Lighthouse network of stations, has been analyzed in this paper. A network of 14 of the 27 stations had (near) continuous data sets. These stations were clustered previously into exposed (northern/outer) and sheltered (southern/inner) sites. SST trends, evaluated between 1973 and 2010, show that the temperature contrast between these clusters is becoming greater: The northern/exposed stations are strongly influenced by interdecadal (Pacific Decadal oscillation [PDO]) and multidecadal oscillations in the north Pacific that are coherent with HadISST1.1 data for the region. There is no statistically significant warming trend for this region. The stations in the Strait of Georgia are much less influenced by the PDO and show a statistically significant mean increase in SST of up to 0.56°C/decade (Anomaly 1). This is higher than the global average and contrasts markedly with the trends from the northern stations. The warming trends of the southern stations are significant at all months of the year but are most evident during summer (July–September). The summertime anomalies in temperature at Active Pass are significantly correlated (p < 0.001) with the temperature of the Fraser River water. Temperature differences between the Strait of Georgia and the outer shelf (Anomaly 2) are increasing in time; this is particularly evident since 2000. Monthly averaged MODIS satellite data (4×4-km resolution) show that trends in SST at two selected sites in the Strait of Georgia are very similar to the BC Lighthouse measurements and support the spatial extrapolation of the Lighthouse measurements. At present rates of SST rise, the southern coastal waters of BC will be about 3°C warmer by the end of the 21st century.

Kämpf, J. and Ellis, H., 2015. Hydrodynamics and flushing of Coffin Bay, South Australia: A small tidal inverse estuary of interconnected bays.

Using a three-dimensional hydrodynamic model and the concept of water age, this study explores the hydrodynamics and flushing characteristics of Coffin Bay, South Australia, which is a small inverse estuary of interconnected bays. Model findings suggest that the estuary is mainly tidally flushed throughout the year. Despite the existence of strong tidal flows >1 m/s in passages between bays of the estuary, the resultant tidal stirring zones are largely disconnected from each other. This disconnection induces a relatively slow flushing of the estuary's inner bays, where maximum water ages are 80–100 days. Given the tidal dominance in the flushing dynamics, a simple diffusion equation based on a total effective transverse diffusivity D (estimated from the model predictions) can be used to describe the flushing behaviour of the estuary. This equation is applied to derive the thermal response of Coffin Bay to either temperature variations in ambient shelf water or changes in surface heat fluxes. Findings indicate that, on timescales of 30 days, the inner bays of Coffin Bay respond predominantly to changes in surface heat fluxes, whereas the outer bay is more responsive to temperature variations in ambient shelf water. We quantify these individual responses in terms of spatially variable “thermal response factors,” which are fundamental properties inherent in the estuary's flushing dynamics.

Hwang, S.W.; Lee, T.W.; Hwang S.D.; Lee, E.K., and Yoo, J.M. 2015. Habitat use patterns of Chelon haematocheilus, as revealed by Sr:Ca ratios in otoliths.

We measured Sr:Ca ratios in otoliths to examine the habitat use patterns of 50 Chelon haematocheilus collected from two estuaries of the Geum River and the Mangyeong River on the midwest coast of South Korea. The average ratio was 5 × 10⁻³ ± 0.6 × 10⁻³ (mean ± SD) in the core of the otolith and ranged from 3 × 10⁻³ to 7 × 10⁻³ in the opaque zone surrounding the core. We applied the criteria used to analyze otoliths in the closely related species Mugil cephalus in a previous study and concluded from the otolith Sr:Ca ratios that C. haematocheilus spawns and grows in brackish water during the early part of its life cycle. Most fish showed otolith Sr:Ca ratios ranging from 3 × 10⁻³ to 7 × 10⁻³, indicating that they primarily live in brackish water. Some fish had ratios outside that range, indicating that they had potentially spent time in the upper, less-saline or lower, more-saline parts of the estuaries. Of C. haematocheilus in the Mangyeong River estuary, 34.8% had inhabited freshwater, but of those in the Geum River estuary, where a dike causes the water to be more saline, only 22.2% had inhabited freshwater. The findings of our study offer useful new information on the habitat choice of C. haematocheilus, allowing more sustainable use of the species.

Anderson, T.R.; Frazer, L.N., and Fletcher, C.H., 2015. Long-term shoreline change at Kailua, Hawaii, using regularized single transect.

Traditional long-term (decadal) and large-scale (hundreds of kilometers) shoreline change modeling techniques, known as single transect, or ST, often overfit the data because they calculate shoreline statistics at closely spaced intervals along the shore. To reduce overfitting, recent work has used spatial basis functions such as polynomials, B splines, and principal components. Here, we explore an alternative to such basis functions by using regularization to reduce the dimension of the ST model space. In our regularized-ST method, traditional ST is an end member of a continuous spectrum of models. We use an evidence information criterion (EIC = −2 times the log of the prior predictive distribution) to select the optimal value of the regularization parameter, instead of the usual L-curve method, because the EIC can also be used to evaluate basis function models yet does not require counting model parameters. To test the method, we apply it to historical shoreline data from Kailua, Hawaii, comparing the results with those from B splines (basis functions) and traditional ST. As expected, the regularized-ST and B-spline models both give shoreline change rates that vary more smoothly alongshore than the rates from ST. The regularized-ST model, along with the B-spline model, also shows significantly better predictive capability over the traditional ST model from a fivefold cross-validation. The regularized-ST model is more straightforward to implement than splines and may be attractive to users because of its continuous connection with the familiar ST method.

Yuan, R.; Zhu, J., and Wang, B., 2015. Impact of sea-level rise on the saltwater intrusion in the Pearl River Estuary.

A three-dimensional numerical model was established based on the Finite Volume Coastal Ocean Model to study the impact of sea-level rise (SLR) on saltwater intrusion in the Pearl River Estuary. The model domain covered the entire river network, estuary, and offshore sea, and the model grid fit well with the coastlines, with a high resolution of ∼100 m in the river mouths. The model validation process showed that the model results fit the observed data fairly well. Results showed that saltwater intrusion in the river mouths was highly sensitive to SLR. Higher SLR enhanced saltwater intrusion, especially in the Modaomen waterway during neap tide. SLR enhanced the landward residual current in the Hongwan waterway and the landward bottom residual current in the Modaomen waterway, both of which carried high salinity water landward and thus made salinity higher. Isohaline of 0.45 (which is the salinity standard for drinking water) moved seaward in the Jiaomen and Hongqili outlets, whereas it moved landward in the Modaomen and Hutiaomen outlets in response to SLR. This pattern was well explained by the net water-flux changes in this branching estuary.

Makowski, C.; Finkl, C.W., and Vollmer, H.M., 2015. Geospatially integrated seafloor classification scheme (G-ISCS): A new method for cognitively interpreting benthic biogeomorphological features.

Because benthic environments show ecotonal successions that biophysically fuse geomorphological units with biological coverages, there is a need for cognitive biogeomorphological classification methods. This study introduces a new geospatially integrated seafloor classification scheme (G-ISCS) methodology for cognitively interpreting geomorphological components and dominant biological covers from a variety of remotely sensed imagery within a geographic information system interface. An ordered, hierarchical classification scheme was thus developed to discriminate various categories such as physiographic realm, morphodynamic zone, geoform, landform, dominant surface sediment, dominant biological cover, and density of dominant biological cover. When applying the G-ISCS method to multispectral satellite imagery (e.g., GeoEye IKONOS-2), individual raw scenes were imported into IDRISI^© Taiga to enhance frequency distributions of spectral reflectance through contrast stretching. Image enhancement was applied to blue, green, and red wavelength bands and combined to create 24-bit color composite images that were suitable for interpretation. Using ESRI ArcGIS^® ArcMap software, raster catalogs were created for enhanced imagery data sets and projected on an interactive SmartBoard^® overlay system for real-time, on-screen digitizing of seafloor feature boundaries at a nominal scale of 1:6000. Differentiation of marine environments was based on spectral reflectance characteristics of color, tone, saturation, pattern, and texture of the seafloor topology. Individual thematic subset maps were then created by hierarchical category and amalgamated in ArcMap to create interactive benthic environment maps. Attribute tables were compiled in conjugation with thematic map products to quantify relationships between mapping units, as well as to generate accurate biogeomorphological spatial statistics. Overall, the new G-ISCS method can be applied across multiple remote sensing platforms to cognitively delineate and interpret benthic biogeomorphological features along shelf environments.

Rahn, J.L.; Lannon, H.J.L., and Mossa, J., 2015. Diver depth-gauge profiling beyond wading depths: A new simple method for underwater surveying.

Surveying subaqueous beach profiles and features beyond wading depths can be a costly process, requiring use of expensive equipment and boats. This paper describes the materials and methods of a simple, low-cost technique for underwater bathymetric surveying, herein named the diver depth-gauge profiling (DDGP) method. Although accuracy of depth data depends on the quality of the depth gauges used, it is commonly within 0.3 m. Data collection reliability was evaluated by repeated underwater beach profile surveys, and an example of its use in the Caribbean is provided.

The outside reviewers of the Journal of Coastal Research (JCR) have generously donated their time to conduct the review process, which includes the thorough evaluation of manuscripts by providing comments and recommendations to the Editor-in-Chief concerning the ultimate disposition of submitted material. Because we frequently receive reviews from specialists outside of our own Editorial Board, we acknowledge with thanks the following reviewers who have vetted papers submitted to the JCR. Their interest and cooperation are much appreciated.