The Cape Lookout cuspate foreland has undergone significant offshore accretion since the first rudimentary field studies were conducted in the 1800s. Despite the wave-dominated setting, however, little is known about littoral processes under the wide range of wave conditions that impact the complicated coastal geometry at the cape. In this study we examined littoral processes, driven by longshore currents, using a numerical wave refraction/diffraction model (Ref/Dif 1) and through use of aerial photographs and nautical charts. Results show that longshore current direction and speed, as expected, are highly variable and depend primarily on incoming wave direction. Southerly longshore currents on Core Banks predominate under northeast and east wave approaches, whereas weaker northerly currents are generated under southeast and south wave approaches. The result of these patterns provides a source of sediments to Cape Lookout Shoal. Results show the sediment input from Core Banks to the shoal is of the order 512,000 to 581,000 m³/yr. The western limb of the system receives a portion of these sediments, which are released from the shoal and transported north by waves that approach from the southeast, south, and southwest. Predicted longshore currents on the shoal indicate that repeated extension and retreat of Cape Lookout Point would result from the imbalance between southerly longshore currents on the east side of the shoal and northerly longshore currents on the west side. Cape Lookout Shoal may play a role in protecting sections of adjacent barrier islands by interfering with shoreward wave propagation and by allowing waves to focus energy onto their offshore subaqueous areas. It is still unclear, however, how sediments on the northern proximal regions of the shoal are transported to the distal regions farther south.

Vertical distribution of Turbulent Kinetic Energy (TKE) at coastal NE-Brazilian waters was evaluated using a combination of field data and numerical modelling. Microestructure temperature profiles obtained with a SCAMP probe were used to estimate the rate of TKE dissipation at coastal waters off Suape Harbour. SCAMP measurements and field cinematic information were then used as input data to a turbulence model and numerical results used to obtain simple eddy-viscosity formulations as a function of low-order parameters associated to measured characteristics of velocity profiles. Stronger TKE dissipation rates at Suape waters showed to be associated to surface and bottom boundary layers during spring tides, with values ranging between 5 × 10⁻⁷ m²s⁻³ ≤ ϵ ≤ 3 × 10⁻⁶ m²s⁻³. Less accentuated dissipation rates were found at the interior regions of the flow, with 5 × 10⁻⁸ m²s⁻³ ≤ ϵ ≤ 2 × 10⁻⁷ m²s⁻³. Numerical results indicated that energy balances immediately near boundaries are mainly driven by an equilibrium between production and dissipation of TKE, reflecting classical log-layer behaviours near a wall. Diffusion of TKE acts as an important process for vertical energy distribution all over the interior flow depth at Suape area. Vertical distributions of TKE point out highest energy intensities at central part of the flows, which is reflected at the eddy-viscosity profiles. Outside bottom and surface regions the turbulence production induced by velocity rotation is predominant. Model results and a performed scale analysis indicate the maximum eddy-viscosity for each situation is v_t = O((Δθ)^5/2), where Δθ(rad) is the global current field rotation observed along water depth. This analysis is expanded to find a simple bilinear expression for eddy-viscosity along water depth.

Despite the recognition that intertidal surfaces play an important role in dissipating wave height and energy, few previous field measurements have been undertaken to directly quantify this effect. This paper presents the results from a one year data collection campaign in the macrotidal Wash tidal inlet, eastern England, during which wave measurements were taken at lower, mid and upper recording stations along three different shore-perpendicular intertidal transects.

It has been found that the intertidal environment of The Wash is effective in dissipating wave height by, on average, 83% and in dissipating wave energy by, on average, 91% with respect to the incident wave conditions.

Based upon the results from this study, it is recommended that flood defence management practice in The Wash moves away from focusing on the defence of a structural line towards the management of a defence zone, comprising both natural and structural elements.

Coastal landscapes evolve over wide-ranging spatial and temporal scales in response to physical and biological processes that interact with a wide range of variables. To develop better predictive models for these dynamic areas, we must understand the influence of these variables on coastal morphologies and ultimately how they influence coastal processes. This study defines the influence of geologic framework variability on a classic mixed-energy coastline, and establishes four categorical scales of spatial and temporal influence on the coastal system. The near-surface, geologic framework was delineated using high-resolution seismic profiles, shallow vibracores, detailed geomorphic maps, historical shorelines, aerial photographs, and existing studies, and compared to the long- and short-term development of two coastal compartments near Charleston, South Carolina.

Although it is clear that the imprint of a mixed-energy tidal and wave signal (basin-scale) dictates formation of drumstick barriers and that immediate responses to wave climate are dramatic, island size, position, and longer-term dynamics are influenced by a series of inherent, complex near-surface stratigraphic geometries. Major near-surface Tertiary geometries influence inlet placement and drainage development (island-scale) through multiple interglacial cycles and overall channel morphology (local-scale). During the modern marine transgression, the halo of ebb-tidal deltas greatly influence inlet region dynamics, while truncated beach ridges and exposed, differentially erodable Cenozoic deposits in the active system influence historical shoreline dynamics and active shoreface morphologies (block-scale). This study concludes that the mixed-energy imprint of wave and tide theories dominates general coastal morphology, but that underlying stratigraphic influences on the coast provide site-specific, long-standing imprints on coastal evolution.

On bimodal microtidal beaches, there are grain-size segregations and the relationship between mean size and foreshore slope is not clear. Dealing with macrotidal beaches composed of gravel and sand, the dynamics vary in response to the tide: reflective conditions at high tide, and a dissipative behaviour during low tide. These dynamic changes are related to grain-size segregations: the upper beach is dominated by gravel (or gravel with coarse sand) and the low-tide terrace is exclusively composed of fine sand. Along the Atlantic coast of Tierra del Fuego, nineteen beaches analysed vary in mean grain size between −4 and 4 phi units. The slope of the foreshore (reflective portion) is linearly related to grain size. The slope of the low-tide terrace (dissipative portion) has no relationship to grain size (fine to very fine sand). These segregations cause temporal changes in the composition of the groundwater sceping at the low-tide terrace. Test experiments performed at the beach permitted to recognise the relationships between coastal and ground water. Salt groundwater similar to the sea (31 practical salinity units; psu) seeps at the initial stages of the dropping tide. Seeping groundwater salinity diminishes progressively, and at low tide it arrives to a minimum of 10 psu. Tidal effects are therefore conditioning (chemically and physically) the water exchange between the beach and the nearshore areas.

Benthic macrofaunal community structure was related to vegetation and sediment properties along a low to high marsh elevational gradient in Scirpus mariqueter marsh on the eastern coast of Chongming Island in the Changjiang estuary, China. Multivariate analysis indicated that there were significant differences in macrofaunal community structure between the marsh zones sampled. There were positive relationships between attributes of salt marsh vegetation and macrofaunal community. The main factors explaining macrofaunal community structure along the habitat gradient were shoot height and below-ground plant biomass. In the Scirpus mariqueter marsh studied, above-ground and below-ground plant structure formed a complex habitat, adding structural heterogeneity to the surface sedimentary environment. Habitat heterogeneity is important for supporting diverse macrofaunal assemblages.

Changes of sea-level, retreat of shorelines have occurred throughout geological times. They have taken a special significance since Man has appeared. Man has been simultaneously awed by the sea and attracted by its shores. He has consistently attempted to protect his settlements against the onslaughts of the sea. Coastal defenses can be traced back to remote times. It is probable that dams or walls were erected before the Frisians did, but their “defenses” were described by Pliny, and, jusqu'à preuve du contraire, are considered as the first “dike builders”.

Earthen artificial hillocks are the forerunners of stone constructions built to hold back the advances of the sea, particularly when sizeable areas of land were gobbled up by the waters along coasts, but also in estuaries, witness i.e. the Dutch Verdronken Land van Saeftingen. The groins, seawalls, breakwaters and the like proved to be illusory shields, to solve little, but to create new problems.

Engineers and scientists tried different approaches, inspired by Nature's own ways, nourishment for instance. Other methods are being honed. They must as well consider the economic and social impacts of coastal erosion. The paper follows the historical evolution of man's attempts to retain his “land”.

The reasons for the erosion problems being experienced on a popular tourist beach in Jersey, Channel Islands, have been determined using a thorough geomorphological assessment. This assessment has been founded upon sound geomorphological principles and a sediment budget approach. It has been found that the beach lowering and sediment losses being experienced are primarily related to the cessation of sediment input from the finite offshore sources, the construction of a seawall which has exacerbated the erosion and the mining of beach sand. The geomorphological assessment provides a fundamental baseline upon which coastal management options can be proposed which offer a sustainable solution to the problems being experienced.

Quantitative data on beach changes caused by coastal storms is critical to the understanding of coastal morphodynamics and mitigation of coastal erosion hazards. Recent advances in airborne LIDAR technology allow large-scale mapping of beach erosion, dune scarping, and overwash deposition with incredible detail. By comparing 40 km of beaches along the central Florida Atlantic coast surveyed before and after Hurricane Floyd in 1999, we found that most beaches experienced erosion; about −18 to 1 m³/m of sediment per unit shoreline length were removed or deposited. Beach erosion is not spatially uniform, and variations in magnitude occur three dimensionally. The high-density LIDAR data provided accurate information about shore changes both at small and large scales.

The water quality in an enclosed bay with the limited exchange of water between the ocean and bay is strongly affected by water stratification. Omura Bay in Japan is a highly enclosed bay with a very narrow entrance to the ocean and is an ideal bay to examine the water stratification and its effect on water quality. The characteristics of water and currents in Omura Bay can be divided into two regions. One is the bay mouth region where strong tidal currents cause vertical mixing all the year round. The other is the region of the center and end of the bay where strong stratification is formed in summer and anoxic water occurs in the bottom layer every summer. This occurrence of the anoxic water is related strongly to the thermocline in the bottom layer. The currents associated with the difference of the vertical structures of water density in the two regions influence the formation of stratification. When the stratification in the center and end of the bay is the strongest in July, the density of bottom water in this region becomes larger than that of the mixed water in the bay mouth region. The mixed water flows into the middle layer of the stratified region due to the similarity of the water density above the bottom layer. This inflow with limited vertical mixing causes the water in the center and end of the bay to outflow through the surface and bottom layers. The shear boundary between the inflow and outflow currents near the bottom layer reduces the bottom stratification very slowly. When the stratification becomes weak in August, the water in the bay mouth region flows into both the middle and bottom layers and the bottom thermocline disappears eventually. During this period from July to August, the retention time of water under the bottom thermocline becomes the longest. The amount of consumption of oxygen in the bottom water results in the formation of anoxic water due to no or litter supply of oxygen from the surrounding areas.

This work aims to improve the knowledge of sediment circulation in the coastal zone, focusing on the quantification of sediment movement due to longshore drift. The studied field site is the Praia de Faro beach on the Peninsula do Ancão in Algarve (Portugal), which is located on the updrift coast of the Barra Nova tidal inlet. The main objective of the study was to quantify the sediment transport rate that will enter in the inlet system.

Measurements were undertaken during low hydrodynamic conditions prevailing in this area and permitted to estimate a longshore transport rate of 2.6–4.2 m/s, consistent with other transport estimations in Algarve. Four theoretical models for longshore transport rate calculation were confronted to tracer results to choose a extrapolation tool. Kamphuis (1991) formula appeared to be the more appropriate in this area. It was used to extrapolate the results in order to be compared to the observed morphological evolution. The calculated short term sediment flux (10500 m³/month) corresponds to the accretion on the updrift swash platform of the Barra Nova tidal inlet and is thus considered to be the contribution of the adjacent coast to this system. Moreover, the estimated longshore transport rate permit us to predict a spit progradation of 60–70 m/year. This result is consistent with the observed migration rate of the Barra Nova inlet during the last 25 years. This study shows that, with a good knowledge of the environmental context, sediment fluxes obtained by sand tracers are accurate enough to estimate the long term longshore transport and long term morphological response of a stretch of shoreline.

Limestone rocky shores constitute ca 90.5% of the 272km coastline of the Maltese islands. Only some 40% of this rocky coastline is gently sloping and easily accessible. Such shores are heavily impacted with 96% of the accessible coastline dominated by tourist-related or by maritime activities. We characterised the biotic assemblages of lowland Maltese rocky shores and tested the popularly held view that given the scarce variation in physical characteristics, such shores form a homogenous habitat.

Belt transects were laid perpendicular to the shoreline from biological zero to the adlittoral zone on seven Coralline Limestone and one Globigerina Limestone shores. Cover (for algae and encrusting species) or population density (for animals except sponges) were estimated using 0.5m X 0.05m quadrats placed contiguously for the first few metres and then at regularly spaced intervals.

Overall, 19 faunal and 47 floral species, and 10 faunal and 8 floral species were recorded from the Coralline and Globigerina transects respectively, with 60.8% faunal and 25.6% floral species common to the two substrata. Hierarchical clustering showed that the Coralline and Globigerina transects harboured distinct biotic assemblages and identified an upper shore assemblage dominated by the littorinid Melarhaphe neritoides and barnacles, and a lower shore assemblage dominated by algae and molluscs; a mid-shore transition zone where certain species from both assemblages reached peaks of abundance was present in almost all Coralline and the majority of Globigerina transects. Differences in biota between the two types of shore are most likely primarily related to differences in microtopography and, to a lesser degree, to exposure.

It is concluded that in spite of gross physical similarity, Maltese lowland rocky shores are biotically inhomogeneous, making conservation of individual sites much more important than previously thought.

In coastal Louisiana, bulltongue (Sagittaria lancifolia L.) has greatly expanded its distribution while broadleaf arrowhead (Sagittaria latifolia Willd.) and delta duck potato (Sagittaria platyphylla Engelm.) have decreased in abundance. Several factors may be important in these distributional patterns, including increased salinities, altered hydrologic regimes, and changed substrate types. In this study, we simultaneously manipulated these three factors under controlled greenhouse conditions. This three-year study consisted of an experiment that included equal amounts of each of the three species of Sagittaria planted approximately 15 cm apart in 200 liter mesocosm vessels. Dead aboveground biomass was harvested regularly and above- and belowground biomass was harvested at the end of the study. All three species began with relatively high turnover across salinities. While S. latifolia and S. platyphylla only grew well in the freshwater treatments, S. lancifolia grew in all three salinity levels (0, 3, and 6 ppt) and showed decline in the 6 ppt treatment, but not until the third year. Both S. latifolia and S. platyphylla produced less belowground biomass than aboveground biomass while S. lancifolia produced much more belowground biomass in comparison to above-ground biomass. These results suggest that the pattern of replacement of S. latifolia and S. platyphylla by S. lancifolia in coastal Louisiana may be a result of locally increased salinities. Because Sagittaria lancifolia produces massive tubers and rhizomes (belowground biomass) and is somewhat flood- and salt-tolerant, it may be a good candidate for use in restoration of freshwater marshes that are susceptible to saltwater intrusion.

The present study (1) describes the rates and patterns of Ammophila arenaria (marram grass) invasion in a large transgressive dune system (Mason Bay) and on a prograding foredune-ridge barrier (Doughboy Bay), Stewart Island, New Zealand; (2) examines the impact of Ammophila on dune morphology and indigenous dune biota; and (3) assesses the significance of geomorphic processes in accounting for the patterns observed. Processes of Ammophila invasion are interpreted from evidence of landform development and vegetation change; field observations and survey of dune landforms and dune vegetation; the aerial photographic record and historic accounts of the local botany.

The area dominated by Ammophila in the Mason Bay study area has increased from 1.4 ha in 1958, to 17.8 ha in 1978, to 74.9 ha in 1998; a 5,204 percent increase. Ammophila invasion of active dune systems in the study areas is clearly associated with dune forming processes—shadow dune development; migration of long-walled parabolic dunes; stoss face blowout development; and barrier progradation. The primary mechanism of native species displacement appears to be burial rather than competition for nutrients. Ammophila traps sand and builds dunes at rates that may exceed the threshold of tolerance of local native species. Desmoschoenus spiralis, the dominant indigenous foredune species, cannot co-exist with Ammophila in the active dune systems investigated.

The composition, distribution and abundance of the chaetognaths collected at Bahía de la Ascensión, eastern coast of the Yucatan Peninsula, were analyzed during three climatic periods (rainy, dry, and “northerlies”) of a year cycle (August, 1990–July, 1991). Highest mean chaetognath abundance was observed during the rainy period (209 ind./100m³), while lowest values occurred during the dry season (124 ind./100m³). Six species were identified, Sagitta hispida being the most abundant and widely distributed. It represented more than 95% of the total chaetognath numbers. Variations of the spatial distribution of the group throughout the year cycle seemed to be related to the three seasonal regimes. Cluster analysis (Jaccard Index) revealed two main faunistic assemblages clearly defined during the three seasons. The first one was representative of the resident fauna, characterized by the dominant S. hispida. The second one was a group of several oceanic species with a seasonally variable influence in the bay fauna. This influence generated a transitional assemblage, detected during the rainy and nortes seasons. These faunistic assemblages showed seasonally variable distributional patterns which were related to shifts of the hydrologic conditions and the wind regimes. As it considers three distinct seasons, the pattern described herein differs from those previously depicted for chaetognaths in other coastal systems.

The European Space Agency (ESA) funded two projects in 1991 and 1994 concerning the observation of the Argentine coastal environment with synthetic aperture radar (SAR). Studies were carried out for the periods 1992–1994 and 1994–1997. Several ERS-1/2 satellite SAR images were acquired over the San Matías Gulf in the Patagonian coast during these two periods. SAR is a side-looking imaging radar that operates from either a satellite or an aircraft. The instrument emits a series microwave pulses toward the earth in a direction perpendicular to the flight path. Imagery is constructed from the strength and time delay of the returned signals, which depend primarily on the roughness and dielectric properties of the surface under observation and the distance from the radar.

Ocean surface roughness wave-like patterns, imaged as a series of bright and dark linear features by SAR, are persistently observed over the San Matías Gulf mouth region. A total of thirty-three (33) ERS-1/2 SAR images (100 km × 100 km) from 15 different orbits from 1992 to 2000 were analyzed. This series of observations has allowed for a detailed examination of the location, persistence, and the conditions involved in the imaging of the observed wave-like patterns. Very strong tidal currents of the order of 2 m/s characterize the gulf region. The characteristics of recurrent surface patterns in the SAR images indicate that they are caused by the interaction of the tidal currents with bed forms in the bottom topography of the gulf. The location of these bed forms is poorly documented in the available bathymetric charts of the region. The SAR images show the significant potential that satellite radar observations have as a tool for detecting unmapped coastal ocean bottom features, particularly, where bathymetric mapping activities can be extremely difficult, dangerous, or costly.