Spatially and temporally high-resolution video imagery was combined with traditional surveyed beach profiles to investigate the evolution of a rapidly eroding beach nourishment project. Upham Beach is a 0.6-km beach located downdrift of a structured inlet on the west coast of Florida. The beach was stabilized in seaward advanced position during the 1960s and has been nourished every 4–5 years since 1975. During the 1996 nourishment project, 193,000 m³ of sediment advanced the shoreline as much as 175 m. Video images were collected concurrent with traditional surveys during the 1996 nourishment project to test video imaging as a nourishment monitoring technique. Video imagery illustrated morphologic changes that were unapparent in survey data. Increased storminess during the second (El Niño) winter after the 1996 project resulted in increased erosion rates of 0.4 m/d (135.0 m/y) as compared with 0.2 m/d (69.4 m/y) during the first winter. The measured half-life, the time at which 50% of the nourished material remains, of the nourishment project was 0.94 years. A simple analytical equation indicates reasonable agreement with the measured values, suggesting that project evolution follows a predictable pattern of exponential decay. Longshore planform equilibration does not occur on Upham Beach, rather sediment diffuses downdrift until 100% of the nourished material erodes. The wide nourished beach erodes rapidly due to the lack of sediment bypassing from the north and the stabilized headland at Upham Beach that is exposed to wave energy.

The Golden Horn estuary has been one of the worst-affected coastal areas of Istanbul (Turkey) as a result of heavy and unplanned commercial and industrial activities along the shoreline, in particular, since the early 1950s. The estuary is an internal port, heavily polluted by creek discharges conveying domestic and industrial loads. It has also been affected by the implementation of ill-adapted coastal structures and upstream activities. Increased sediment deposition coupled with weakened water circulation has hindered the self-purification capacity of the estuary owing to its particular oceanographic features.

In view of the amount of work already undertaken and valuable information already available, and on the basis of our observations related to the water mass structure and circulation of the Golden Horn, it has been demonstrated that the estuarine waterbody is governed by the hydrodynamic conditions of the Strait of Istanbul that are dependent on atmospheric factors, water budget, and nonlinear transient variances such as temporary blocking of the lower or upper layers of flow. The primary objectives set forth are, as a first step, to understand what problems this estuary faces and to suggest a comprehensive management and research program in which scientists, relevant organizations, local communities, and individuals with diverse expertise could collaborate in a partnership approach to promote and ensure the rational and efficient management of the Golden Horn estuarine system as a whole.

An extended period of marine-dominated back-barrier sedimentation, truncated by the deposition of two large-volume, laterally extensive sand sheets that extend up to 3 km inland from the modern coastline, is present at Minnamurra in southeastern Australia. The sand sheets are anomalous as they drape the entire back-barrier succession and infill the estuary. The lower sand sheet contains mud clasts and significant amounts of organic matter including coastal dune grasses indicating that significant overwash and erosion incorporated material from both the barrier and estuary into the lower sand sheet deposit. The first sand sheet is overlain by a poorly developed soil that records a time break before the now infilled system was inundated once more. The second sand sheet covers the poorly developed soil and incorporates a number of erosional features, such as ripped-up soil clasts, cobbles, and organic-rich sand. Along this part of the coast, large laterally extensive sand sheets are spatially and sedimentologically unique, occurring only in embayments that face southeast. This, along with a lack of evidence of wave action or beach structures, suggests that the deposits are not evidence for higher Holocene sea level but are the result of overwash sedimentation from the southeast. The sand sheets share many of the characteristics of those emplaced by tsunami waves, although the possibility of exceptionally large storm events cannot be entirely discarded. However, such a storm would have to be several orders of magnitude higher than those in recorded history.

Recent bathymetric surveys help us to understand morphological features of the Marmara Sea. Marmara Sea has unique and complex morphological features and active tectonics. In this study, morphologic features of major submarine landslides of the Marmara Sea were studied using advanced visualization and geomatic systems (digital terrain models, DTM; geographic-information systems, GIS; image-processing systems; high-resolution seismic and bathymetric data).

The high-angle continental slopes of the Marmara Sea are produced by submarine landslides and slumps, which have potential tsunamis generations. In this study, tectonically active major submarine landslides were investigated in the Marmara Sea. Three of them are observed along the slopes, one is on the Eastern Ridge and the fifth forms the Western Ridge of the Marmara Sea. They are interpreted as rotational and translational slides, debris flows, and mudflows controlled by slope and tectonic activity. On the northern slope of Çınarcık Basin, rotational slide and debris flows, which are activated by faults, affect the current shape of this slope. Hence, we interpret that the present morphology of the slopes of the Marmara Sea may not be only controlled by faults but also the landslides. On the other hand, mudflows in Tekirdağ Basin and in the Marmara Sea entrance of Izmit Bay (Çınarcık Basin) may be controlled by slope inclination and sediment supply rather than tectonics. Another mudflow on the Eastern Ridge initiated by the inclination of the ridge by a reverse fault in the northwest side of the ridge, thus, slope inclination controlled by tectonic activity affects the origination of this landslide. One of the largest landslides in the Marmara Sea forms the Western Ridge as a translational slide. Its initial shape has been destroyed by the new rupture of the North Anatolian Fault Zone, thus, it may be one of the oldest submarine landslides of the Marmara Sea.

The data from 161 quantitative sandy beach transect surveys from a wide variety of locations were examined to identify trends and relationships between total marine macrofauna species richness, abundance, and biomass and physical variables. Several physical variables were correlated, especially sand particle size and beach face slope, and spring tide range and beach face slope. Higher latitudes experienced larger waves, and flatter beaches had finer sands, larger waves, and larger tides. Strong correlations were found between species richness and beach slope, tide range, and sand particle size, as well as various indices of beach state. Tropical regions harbored significantly more species than other regions. A new Beach index (BI), based on tide range, beach face slope, and sand particle size, correlated well with species richness, explaining 56% of the variability in the data without considering latitude. Abundance and biomass were best correlated with log(1/beach face slope) and tended to be higher in temperate regions. General patterns are discussed; the new index is evaluated; and the roles of sand, tide, slope, and latitude are considered. It is concluded that for regional studies log(1/beach face slope) is the most useful index to compare beaches, whereas for wider comparisons covering areas of differing tide range, BI might be most useful. These patterns have implications for global biodiversity management on sandy beaches.

Analysis of shoreline variability and shoreline erosion-accretion trends is fundamental to a broad range of investigations undertaken by coastal scientists, coastal engineers, and coastal managers. Though strictly defined as the intersection of water and land surfaces, for practical purposes, the dynamic nature of this boundary and its dependence on the temporal and spatial scale at which it is being considered results in the use of a range of shoreline indicators. These proxies are generally one of two types: either a feature that is visibly discernible in coastal imagery (e.g., high-water line [HWL]) or the intersection of a tidal datum with the coastal profile (e.g., mean high water [MHW]). Recently, a third category of shoreline indicator has begun to be reported in the literature, based on the application of image-processing techniques to extract proxy shoreline features from digital coastal images that are not necessarily visible to the human eye.

Potential data sources for shoreline investigation include historical photographs, coastal maps and charts, aerial photography, beach surveys, in situ geographic positioning system shorelines, and a range of digital elevation or image data derived from remote sensing platforms. The identification of a “shoreline” involves two stages: the first requires the selection and definition of a shoreline indicator feature, and the second is the detection of the chosen shoreline feature within the available data source. To date, the most common shoreline detection technique has been subjective visual interpretation. Recent photogrammetry, topographic data collection, and digital image-processing techniques now make it possible for the coastal investigator to use objective shoreline detection methods. The remaining challenge is to improve the quantitative and process-based understanding of these shoreline indicator features and their spatial relationship relative to the physical land–water boundary.

The US Geological Survey is systematically analyzing historical shoreline changes along open-ocean sandy shores of the United States. This National Assessment of Shoreline Change Project is developing standard repeatable methods for mapping and analyzing shoreline movement so that internally consistent updates can periodically be made to record coastal erosion and land loss along US shores. Recently, shoreline change maps and a report were published for states bordering the Gulf of Mexico. Long-term and short-term average rates of change were calculated by comparing three historical shorelines (1800s, 1930s, 1970s) with an operational mean high water shoreline derived from lidar (light detection and ranging) surveys (post-1998). The rates of change, statistical uncertainties, original shorelines, and complementary geographic information system layers, such as areas of beach nourishment, are available on an Internet Map Server (IMS).

For the Gulf of Mexico region, rates of erosion are generally highest in Louisiana along barrier island and headland shores associated with the Mississippi delta. Erosion also is rapid along some barrier islands and headlands in Texas, whereas barrier islands in Mississippi are migrating laterally. Highest rates of erosion in Florida are generally localized around tidal inlets. The most stable Gulf beaches generally are along the west coast of Florida, where low wave energy and frequent beach nourishment minimize erosion. Some long beach segments in Texas have accreted as a result of net longshore drift convergence and around tidal inlets that have been stabilized by long jetties. Individuals and some communities have attempted to mitigate the effects of erosion by emplacement of coastal structures, but those efforts largely have been abandoned in favor of periodic beach nourishment.

Spit-platforms have not drawn much attention, despite their expected importance for understanding sediment transport mechanisms leading to siltation of tidal channels. In this article, the complex sediment transport pattern on a shallow spit-platform in the Danish Wadden Sea is described based on measurements from four current meters deployed on the spit-platform in a low- and a high-energy period. The hydrodynamic characteristics at the four stations are different in terms of impact from tidal and wave-induced currents. The sediment enters the spit-platform as sandbars oriented perpendicular to the shore migrating alongshore, because of wave activity, until the sediment reaches an ebb-dominated tidal channel. In and near this channel, the sediment is transported downdrift by the ebb-tidal currents until the sand enters a shallow dissecting ebb channel, where the sand is transported obliquely offshore and deposited on a small ebb-tidal delta. This zigzag pattern of sediment transport continues until all ebb channels (up to four) are bypassed. On the subtidal flats between the most downdrift ebb channel and the main tidal channel, the sediment is transported the remaining distance into the main tidal channel or onto the tidal flat in the lagoon landward of the spit-platform. During higher-energy conditions, the sediment transport is more affected by wave-induced currents, leading to high transport rates in the shallow parts of the spit-platform and less transport in the horizontally restricted channels.

The muddy Guyanas coastline in South America experiences significant short-term change involving alternations of accretion and erosion as a result of the influence of mud from the Amazon River. In French Guiana, the dynamic changes due to mud banks permanently migrating alongshore have a considerable impact on both coastal ecology and economic activities. As a result, monitoring of these mud banks constitutes an important coastal management issue. In this article, focus is placed on the development of a method for the monitoring mud bank migration rates since 1986 between the coastal cities of Cayenne and Kourou, spaced 60 km apart and using for the first time high temporal resolution satellite images rather than aerial photographs. To achieve this, 16 satellite pour l'observation de la terre (SPOT) images and one Landsat image covering the period 1986–2002 were acquired and integrated in a geographical information system (GIS). Because of tidal range variation on this mesotidal coast, mud bank characteristics cannot be objectively quantified using classical methods. Mathematical processing of the satellite imagery data, including correction for tides, was performed to obtain a set of coherent data for analysis of parts of the mud bank associated with intertidal mudflat development, from which quantification rates of mud bank migration becomes feasible.

Rates of long shore migration of the mud bank recorded up to 2002 are highly variable. The intertidal part of the bank has slowed down in the past years, resulting in a cross-shore extension of the bank. This slowdown occurred following a rate of migration much higher than those reported in the literature. Seasonal events are also recorded between 2001 and 2002. The variability in rates of migration deduced from the method reported in this study corroborates a pattern reported from earlier studies in Guyana, Surinam, and French Guiana based on more traditional methods, notably aerial photographs. This variability is tentatively attributed to changes in wind intensity and to local environmental parameters, such as coastline orientation, and the occurrence river estuary outflow and bedrock headlands.

The physical processes in a number of Canadian fjords have received considerable study over the years. The fjords tend to be tidally energetic and can be highly stratified because of freshwater runoff. Observations from instruments such as cyclesondes (profiling current meters), acoustic Doppler current profilers (ADCPs) and S4s (InterOcean vector averaging current meters) have yielded observations of the circulation over almost the entire water column. Combined with simulations from analytic and numerical models, these observations have allowed the partition of tidal energy in the fjords to be examined in some detail. The net tidal energy flux into a fjord (i.e., the rate at which energy is removed from the surface tide), and the cause of the energy flux, can vary significantly between fjords. The energy can be removed from the surface tide by boundary friction or by the generation of internal motions (i.e., the internal tide, hydraulic jumps etc.). In this paper the partition of tidal energy in five Canadian fjords and the techniques used to determine the partition will be reviewed. The analysis techniques will be described in some detail and, where possible, the relationship between the various analysis techniques will be pointed out. The fjords discussed are Observatory Inlet, Knight Inlet, Burrard Inlet/Indian Arm, Sechelt Inlet and the Saguenay Fjord.

Along-channel velocity, salinity, and total suspended sediment concentration profiles were measured during 15 complete neap and spring tidal cycles in the dry and rainy seasons in four cross-sections in a tropical estuary, Itamaracá, Pernambuco, Brazil. The net longitudinal fluxes of salt and sediments were decomposed into advective, tidal, and cross-sectional shear transports. The advective transport of both salt and suspended sediments were for most parts export-directed and greater than the combined river discharge, suggesting a non-steady state. The dispersive tidal transport was decomposed into four separate mechanisms of which tidal pumping transport and tidal wave transport (similar to transport by Stokes’ drift) are the main transport mechanisms. The cross-sectional shear transport was negligibly small, and thus, vertical nor lateral effects are significant with respect to longitudinal dispersion in the case of Itamaracá.

The necessity of improving our understanding of mixing, dispersion of salt, sediment, larvae and pollutants, and the increasing need of offering safe navigation conditions in the Patos Lagoon access channel highlighted the need of increasing knowledge on the flow spatial gradients in the area. Three-dimensional simulations were carried out using the TELEMAC-3D model (EDF, Paris, France) in order to simulate the estuarine flow features in the vertical.

Results indicate that the basic mechanism controlling the along-estuary flow and salinity distribution in the estuarine zone during the studied period is given by the pressure gradient generated between the coastal ocean and the lagoon, resulting from the local and non-local wind action and freshwater discharge. Results also show that whatever be the cause of the transverse flow, the strength of lateral circulation is important. The transverse flow in the main lagoon is driven by the local wind forcing and is manifested as a series of gyres. Results show that in shallower areas, lateral pressure gradients resulting from the interaction between longitudinal barotropic pressure gradients and the morphology seem to control the transverse flow. In areas of complex morphology and subject to density stratification, however, the transverse flow results from the interaction between barotropic and baroclinic forces and bathymetry. Results also indicate that the presence of transverse density gradients reduce vertical momentum exchange and inhibit mixing in some areas due to damping of turbulent diffusion and internal friction.

Previous works show that wind forcing is the main source of circulation seasonal variability in the Río de la Plata estuary, located on the southeastern coast of South America. Wind forcing exceeds by far the role of fresh water discharges. However, due to a lack of enough observations, the features and causes of surface wind variability are not well understood yet. Therefore this paper presents a comprehensive study of surface wind variability over the Río de la Plata estuary using the National Center for Environmental Prediction-National Center for Atmospheric Research (NCEP/NCAR) reanalysis data between 1948 and 1997. It is expected that this study contributes to better understand, model and thus predict the estuary circulation.

An onshore to offshore rotation characterizes the seasonal variations of the surface winds from summer to winter. A linear trend analysis shows a displacement of the summer–winter seasonal features to earlier months. On inter-annual time-scales, the first leading pattern describes east–west changes of surface winds that seems to be forced by the quasibiennial tropospheric oscillation excited in the western tropical Pacific and previously identified by many authors. The conditions over the South Atlantic and in particular the Río de la Plata are influenced by such oscillation through an atmospheric Rossby wave train propagating out of the tropics. This result is very important for its implication on the predictability levels in the region. The second leading mode is associated with anticyclonic/cyclonic wind rotations off the estuary on interannual times scales which are related with changes in both atmospheric and oceanic surface conditions at Southern Hemispher high-latitudes.

Two-dimensional data of mean and sediment flow collected at a natural confluence of channels in the inner Bahía Blanca Estuary are presented. We describe the two-dimensional flow field to assess the role of changes in bed morphology occurring during transport-effective events on the structure of flow at a confluence; and to examine how the flow structure varies with changes in the ratio of momentum flux. At each station, vertical profiles of velocity, salinity, temperature and suspended sediment were obtained during the whole tidal cycle and residual fluxes were obtained. Lagrangean flux is higher than possible fresh water input, denoting an extra output of water which is the flux over the tidal flats along the southern and northern coasts of the channel. The effect of the junction produces a distortion of the vertical profile flow and in the suspended sediment transport. The effect of the particular conformation of the system makes necessary for consider the lateral effect of the tidal flats in the circulation of the estuary which exerts a significant influence.

Water quality within the Rio Chone estuary, a seasonally inverse, tropical estuary, in Ecuador was characterized by modeling the distribution of biochemical oxygen demand (BOD) and dissolved inorganic nitrogen (DIN) within the water column. These two variables are modeled using modified advection-diffusion equations within a two-dimensional, laterally-averaged hydrodynamic model.

The model includes sources of salt, BOD and DIN from shrimp mariculture ponds in the region surrounding the estuary. The model was successful in simulating seasonal concentrations in DIN and BOD over a range in source concentrations. Seasonal BOD measurements along the length of the estuary were coincident with dissolved oxygen concentrations in the estuary (high BOD generally corresponding to low dissolved oxygen). Results suggest that the citing of shrimp ponds near the head of the estuary should be avoided in order maintain estuarine water quality and to maximize production.

The coastal area of Niterói is marked by intensive naval activities and holds one of the countries main naval estates. The harbour and dockyards have been sited in the international literature as potential sources and sinks for accumulation of heavy metals and hence contaminated sediments. The aim of this paper is to assess the concentrations of heavy metals in Niterói Harbour and verify their bioavailability by determining the catalytic effects of the bacteria using esterase activity (EST) and electron transport system activity (ETSA). Samples were analysed for Ni, Zn, Pb, Cr and Cu and normalisation procedures were used to assess whether their concentrations represent background or contamination of the sediment. Heavy metal concentrations, especially for Cu, Zn and Pb were found to be much higher than natural background levels and the index of “geoaccumulation” shows moderate to extreme contamination. However, the absence of the inhibition of dehydrogenase activity indicated that the analysed heavy metals are not bioavailable in the EC₅₀ values.

The concentration and distribution of nutrients (nitrate, nitrite, phosphate, silicate) in water, photosynthetic pigments (chlorophyll a and phaeopigments) in suspended particulate matter (SPM), and phytoplankton from Mar Chiquita Coastal Lagoon, in Argentina, was studied along six (6) sampling stations during a year in order to know their spatial and temporal variations. Internationally standardized analytical methods were applied in order to reach these objectives. The use of soils for farming and continental runoff of the adjacent terrestrial systems close to the coastal lagoon seemed to be a significant nutrient source for this water body, which is able to support its own dynamic of phytoplankton within this water body.

Results obtained regarding nutrient and pigment distribution allowed the identification of two different systems within the coastal lagoon: one under marine influence and the other under inland influence, with different ecological and environmental characteristics. Temporal trends of the corresponding phytoplankton development have been identified, and it has been observed that the biological production which occurred within the coastal lagoon along the whole year was higher than corresponding ones from other coastal environments in Argentina. Moreover, nutrient occurrence within the internal region favored the development of the highest biomass detected within the whole lagoon. The system seems to function as a transition zone, which profits from unusual nutrient inputs, together with other environmental conditions (salinity, temperature), bringing continuous nutrient availability for phytoplankton and consequently food supply for marine and estuarine organisms.

A long-term study programme has evaluated heavy metals in the Bahía Blanca estuary, considering occurrence, concentration and distribution in the estuarine sediments, as well as their corresponding geochemical partitioning in the <62 µm grain size fraction of the sediment. Total concentrations of heavy metals (Cd, Zn, Cu, Cr, Pb, Fe) have been determined through flameless atomic absorption spectrophotometry (AAS). Geochemical partitioning of these metals was determined following a sequential extraction technique. Furthermore, heavy metal distribution was studied against organic matter concentration within the sediments.

The results allow the characterization of the spatial distribution of the metals, together with their accumulation areas and potential sources. Bahía Blanca estuarine sediments have low to medium heavy metal concentrations. The geochemical partitioning indicated that many bioavailable species occur within the system, including those of highly toxic elements such as cadmium. Moreover, a theoretical scheme of transference of these metals to other compartments within the system was proposed. Finally, the environmental status of the estuary was addressed within the described framework.

Between June 1995 and November 1998, eight Patagonian rivers were sampled for the suspended and dissolved loads delivered to the SW Atlantic. The most important rivers (Negro and Santa Cruz) jointly deliver ∼90% of the total Patagonian freshwater budget (∼60 km³ y⁻¹). Of the total sediment load (∼1.7 10¹² g y⁻¹), 2.8% was accounted for by particulate organic carbon (POC), 0.9% by inorganic particulate carbon (PC), 0.7% by particulate nitrogen (PN), and 0.7% by particulate phosphorus (PP). The mean dissolved organic carbon (DOC) yield was ∼0.50 g m⁻²y⁻¹, and POC ∼0.3 g m⁻²y⁻¹. Nitrogen is the limiting nutrient in all rivers; the mean molecular C:N:P ratio is 37:1:1. POC:PN ratios (4.4–10) indicate an autochthonous origin for the organic matter in suspended particulate matter (TSS). Many factors, such as proglacial oligotrophic lakes, coal-bearing strata, wetlands, aridity, as well as various human impacts, suggest a complex typology. The analysis (Euclidean distance cluster analysis) of biogeochemical variables [SiO₂, NO₃⁻, PO₄₃⁻, DOC, POC, PC, PP, PN, C:N, DOC:POC, PC:POC, POC (%)] indicates that runoff, superimposed on biogeochemical variables, plays an important role in Patagonian riverine typology: a) Low runoff rivers (<100 mm y⁻¹): the Chubut, Chico, Deseado are characterized by low yields and POC:PN ratios; the Coyle River, by high DOC:POC; b) Medium discharge rivers (100–300 mm y⁻¹): the Negro River has high dissolved yields and high POC_(%TSS); the Colorado is distinguished by high PP and PC specific yields, and POC:PN ratio; c) High runoff rivers (>1000 mm y⁻¹): Santa Cruz and Gallegos rivers, are both characterized by above-average specific yields; the Gallegos has high POC_(%TSS), POC:PN and DOC:POC.

Field data from 27 estuaries of the Americas are used to show that, in broad terms, there is a large difference in turbidity between the analyzed east and west-coast estuaries and that tidal range and tidal length have an important influence on that turbidity. Generic, numerical sediment-transport modeling is used to illustrate this influence, which exists over a range of space scales from, e.g., the Rogue River Estuary (few km, few mg l⁻¹) to the Bay of Fundy (hundreds of km, few g l⁻¹). The difference in Pacific and Atlantic seaboard estuarine turbidity for the analyzed estuaries is ultimately related to the broad-scale geomorphology of the two continents.

Foraminiferal characteristics of 11 surface sediment samples collected from the Mandovi estuary during 2001 have been compared with similar data based on samples collected during 1994. The study reveals drastic fall in total foraminiferal number in the lower reaches of the Mandovi River estuary, from 138/g dry sediment sample in 1994 to 41/g sediment sample in 2001. The decline is also noted in diversity from 22 in 1994 to only 5 species in 2001. The ever-increasing suspended load in Mandovi estuary, probably due to mining activities in the catchment area of the Mandovi River estuary, is suggested as the plausible reason for the decline of fauna. An intriguing finding of the present study is the presence of substantial amount of reworked/older specimens, at the lower reaches of the estuary, that could be indicators of Holocene high sea stand.

The article by Paskoff (2004)—Paskoff, R., 2004. Potential implications of sea-level rise for France. Journal of Coastal Research, 20(2), 424–434—is discussed is this paper. We present evidence that a geomorphological analysis of the coastal and deltaic processes gives different results than those exposed by Paskoff (2004).