A numerical hydrodynamic model is used to investigate the sensitivity of a morphologically complex and heavily “engineered” mesotidal estuary to idealized sea-level rise scenarios and to evaluate the appropriateness of managed realignment as an adaptive response to sea-level rise. The hydrodynamic regime of the Blyth estuary (Suffolk, eastern England) is governed by a distinctive morphology that has resulted from the abandonment of a reclaimed midestuary tidal floodplain in the 1920s and 1940s. Hypsometric characteristics (extensive intertidal area and constricted inlet dimensions) make the outer estuary potentially sensitive to sea-level rise. Model results indicate that a sea-level rise of 0.3 m (as a best estimate scenario for 2050) could increase peak tidal current velocities and discharges by up to 20% and 28%, respectively. Extensive areas of potential tidal floodplain remain protected by embankments that will require upgrading to cope with sea-level rise. Realignment (or “managed retreat”) of these defences can reduce local flood defence costs by eliminating unsustainable seawall but needs to be evaluated in the light of wider impacts. Modelling of hypothetical realignment scenarios shows that restoration of tidal exchange to the largest flood compartments could have an immediate effect on outer estuary hydrodynamics that is larger than worst case scenarios for half a century of accelerated sea-level rise (peak velocity and discharge increased by up to 35% and 32%, respectively). More generally, incompatibilities are apparent between flood defence and habitat restoration objectives, such that the appropriateness and feasibility of large-scale flood defence realignment could be questionable in estuarine contexts.

Orissa, the maritime state along the east coast of India, has a coastline of 480 km. The southern part of the coast has a narrow shelf, but the north Orissa coast has an extended continental shelf. The coastline is bestowed with six major estuaries, India's second largest mangrove forest (Bhitarkanika Sanctuary), Asia's largest brackish water coastal lagoon (Chilika), extensive sandy beaches rich in heavy minerals, the world's largest rookery for the Olive Ridley sea turtle (Gahirmatha sandy beach within Bhitarkanika sanctuary), and two species of horseshoe crabs. In the last few decades there has been tremendous pressure on the coastal zone for the development of fisheries, aquaculture, ports, harbours, and urban settlements. These developments have led to environmental changes, some of which are irreversible, and thus have become issues of concern for the public as well as the state government. Some of the important environmental changes taking place, and which seriously affect the economy of the region, are tropical cyclones and associated storm surges, floods, decline in mangrove forests, accelerated shoreline changes, and transformation of the coastal lagoon ecosystem. This paper documents different coastal environmental features and their changes, observed during the last few decades through secondary data, field surveys, and remote sensing observations, and suggests a framework for a coastal zone management programme in the state.

Ria de Aveiro, a Portuguese coastal lagoon that exchanges water with the Atlantic Ocean, received the effluent from a chloralkali industry for over 50 years; consequently several tons of mercury had been buried in the sediments of an inner basin. To assess the importance (and seasonal variation) of the lagoon waters as carriers of mercury to the nearby coastal area, we measured total mercury levels in several compartments: in surface sediments, in surface and deep waters (including dissolved and particulate matter), and in biota. Dissolved (reactive and total) mercury concentrations both in surface and deep waters were low (<1 to 15 ng L⁻¹). Mean mercury values in suspended particulate matter varied between 0.2 and 0.6 μg g⁻¹ and in sediments between 1 and 9 ng g⁻¹. Aquatic organisms displayed levels below regulatory limits but exhibited some bioaccumulation of mercury, with concentrations ranging from 0.05 to 0.8 μg g⁻¹ [dry weight (dw)]. No seasonal pattern was found in this study for mercury-related determinations. Levels found in the estuary mouth during ebb tide provide evidence for the transport of mercury to the coastal zone. No significant changes in the partition of mercury between dissolved and particulate phases were found in the coastal waters in comparison with the values found in the estuary mouth. In spite of the high levels of mercury found inside some areas of the lagoon, the wide web of islands and channels allows some spreading of contaminants before they reach the coastal waters. Moreover, the low efficiency of local marine sediments in trapping mercury contributes to a dilution of mercury transported in suspended particulate matter over a broader area, reducing the impact in the nearby marine coastal zone.

Seabed roughness was measured over an area of the south shore of O'ahu, Hawaii, with a boat-mounted acoustic altimetry system. The study site is characterized by a highly inhomogeneous rough seabed. Roughness was resolved in the 40–200-cm range over an area extending from the wave breaking zone to a depth of 20 m. Theory suggests that roughness length scales and distribution both play an important role in wave energy dissipation mechanisms. In this paper, we investigate methods for quantifying bed roughness within this range of scales. Various methods for quantifying roughness are examined, including spectral and statistically derived variables. These methods are compared qualitatively with sidescan imagery and quantitatively via in situ diver-based roughness surveys. Results show that wavenumber spectra can effectively differentiate smooth from rough areas. Results also suggest that the bed roughness in the study site exhibit a high spatial variability within the examined range, with no dominant length scale but with a characteristic spectral slope. In addition, roughness also exhibits variation between the shallow and deep ends of the study site.

A systems method based on a Boolean approach is used to predict medium- to long-term behaviour of estuary morphology. Boolean networks are formed for various types of generic estuaries by taking into account the feedback involved between various estuary elements and external forcing which drive morphological evolution. A logical framework is then developed, and the Boolean matrix is derived. Various different potential morphological evolutionary pathways are then selected from the Boolean matrix, analysed, and discussed.

The Boolean method provides a complementary approach for qualitative modelling of complex estuary systems. The method was applied to the Ribble Estuary in northwest England, and the predictions from the Boolean approach were in very good qualitative agreement with the observed morphological evolution of the Ribble Estuary during the last 150 years.

Longshore sediment transport in the surf zone on Galveston Island, Texas, was studied to develop a new technique involving optical instruments rapidly calibrated in situ and to compare measured transport rates with those predicted by the well-known Coastal Engineering Research Center (CERC) formula. This method used an instrumented sled equipped with a LISST-100 for particle size distribution determination, four optical backscatter sensors (OBSs) for turbidity measurements, and two velocity sensors for longshore current measurements. The sled was pulled across the surf zone, occupying 10 to 15 stations spaced about 10 m apart, for approximately 3 minutes each.

The OBS data were calibrated with the LISST-100 particle size distribution data, thereby overcoming the difficulties associated with the use of these sensors in the presence of a mix of sand and fine particles. Subsequently, these data were fit to a logarithmic profile to determine the average vertical distribution of suspended sand concentration, assuming that the fine particles were vertically well mixed at each station. A logarithmic profile of average longshore current was also computed based on the measured velocity data. The longshore sediment transport rate was calculated as the spatial integral of the product of suspended sand concentration and velocity and related to the wave conditions at the point of breaking. Measured rates ranged from 86,000 to 231,000 m³/y, and transport was found to be greatest in the vicinity of the sand bars. The popular CERC formula gave sediment transport rates significantly greater than the observed values, with the difference between the two on the order of 100%. The average CERC transport coefficient, K₁, computed from our measurements was determined to be 0.19 ± 0.12.

Surface sediments collected from the shoreline area between Abu Dhabi and Dubai, United Arab Emirates (UAE), were analysed to determine their textural and compositional characteristics. The relatively heterogeneous sediments of the UAE coastal areas present a broad spectrum of grain sizes and mineralogical compositions, which have potential as discriminates for depositional environments. The trends in textural characteristics of the sampled sediments include (i) a systematic decrease in mean grain size from Dubai to Abu Dhabi, (ii) a systematic increase in the content of evaporite minerals from Dubai to Abu Dhabi, and (iii) a relative increase in degree of sediment sorting from Dubai to Abu Dhabi. The results also indicate that the sediments of both areas are marine in origin and were delivered to the coastal area during large tidal events. Results of compositional analyses reveal (i) a decrease in abundance of shell fragments from Dubai (>55%) to Abu Dhabi (<9%) and (ii) a complementary increase in percentage of mineral fragments (aragonite, halite, plagioclase, and gypsum, except calcite) in Abu Dhabi sediments compared with Dubai sediments. Geochemically, the coastal sediments from Abu Dhabi have higher concentrations of major and trace elements, except for Pb, than sediments from Dubai. The reported results set the background information of the studied sediments, and could be useful for ongoing development activities.

The late Holocene evolution of the former coastal lagoon of Vilamoura was reconstructed according to sediment cores and geophysical profiles. According to sedimentological analyses of the cores, five palaeoenvironmental stages were defined. (1) The pretransgression stage is represented by an erosive surface formed during incision of the river into the basement because of a lower sea level. This palaeosurface was retraced by refraction seismic profiles, showing that the marine transgression took place on a wide plain with several incised channels. (2) The development of an estuary started by transgression into the river valley corresponding to the postglacial sea level rise. Radiocarbon dating indicates a sea level not lower than −4 m at a minimum age of 4716 ± 72 Cal BP. After the transgressive maximum, infilling of the estuary started, beginning with (3) subtidal infilling related to the formation of a sandy barrier followed by (4) supratidal infilling with further accretion of the barrier, changing the previous open bay into a coastal lagoon. (5) Finally, the lagoon was fluvially filled with terrestrial sediments, changing the marine to a fluvial milieu with floodplain deposition. Analysis of benthic foraminiferal and ostracod assemblages revealed additional information about the environmental conditions during evolution of the estuary, which led to a further subdivision of the marine facies into stages with mainly estuarine, lagoonal, or marine influence. The end of the marine stage was dated at 2895 ± 48 Cal BP, indicating a pre-Roman onset of human-induced soil erosion.

Previous studies of Holocene sea-level change along the Yellow Sea coastline present conflicting reconstructions, and such investigations have invariably used peat as well as other biological markers as paleo-indicators of relative sea level. An alternative proxy indicator of sea-level change is employed in this study by applying the luminescence dating technique on quartz sands retrieved from relict foredune structures on a tectonically stable section of the west coast of Korea. The chronologies obtained are consistent with a relative sea level that was very close to or higher than present during the period ca. 6–5 ka. Such ages do not accord with a sea level that rose continuously throughout the Holocene, as is suggested by some earlier studies. The mid-Holocene highstand identified in this study indicates that sea-level change along the Yellow Sea shoreline is congruous with sea-level curves reported from other far-field sites at which crustal hydroisostatic adjustment presumably led to the transient regression of coastlines during the late Holocene.

Barrier islands are popular recreational areas of economic importance and are constantly undergoing change. Costly efforts are made to maintain beaches and stabilize dunes within this dynamic environment. Light detection and ranging data collected in September 1997 and 1998 along a 175-km stretch of the Atlantic coast of the Outer Banks, North Carolina, provide the basis for quantitative determination of the changes in beach morphology. The 1998 survey was conducted just after the passage of Hurricane Bonnie. During the 1-year study interval, beach widths throughout the study region tended to decrease. Maximum dune retreat was determined for each 1-m bin of 1997 beach width. For comparable beach widths, maximum dune retreat increased from south to north. The maximum dune retreat was greatest for supratidal beaches with widths of ∼20 m. For wider supratidal beaches, from 20 to 60 m, the associated maximum dune retreat gradually decreased. There was no further decrease in maximum dune retreat for beaches wider than ∼60 m. Relatively little change in beach width, dune height, and dune base position occurred along the less developed beaches of the Core Banks. The greatest morphological changes occurred on Ocracoke Island and Hatteras Island. Of the geomorphic parameters examined, preexisting beach width and the dune base elevation were the best indicators of vulnerability to dune retreat.

Coastal areas are sensitive systems suffering both natural and anthropic pressures. Specifically, coastal sand dune dynamics is related with observable modifications in plant communities, and this relationship is being pointed out in recent years as a monitoring tool in littoral areas. Plant community types, with a relatively stable floristic composition related to specific ecologic conditions (“plant associations”), provide a suitable tool for bioindication within monitoring processes and in the management of littoral areas. In this regard, recent bio-geologic studies performed in dune systems of Southwest Europe allowed the identification of a number of specific bioindicators for both mobile and interior dunes.

In Northwest Iberian Peninsula, sand dune vegetation is distinguished by its transitional character between typical Atlantic and Mediterranean vegetation types, and its originality is still enhanced by the occurrence of narrow endemic species and by the fact that most vegetation types are endemic to the territory. The organisation of these community types within dune systems is strongly determined by specific dynamic processes mediated by both natural and anthropic disturbances, so they present a large potential for bioindication of coastal dynamics and conservation status. In this paper, the most significant ecologic, floristic and biogeographic characters of sand dune vegetation in Northwest Iberian Peninsula are discussed with the purpose of demonstrating the usefulness of well-defined vegetation types for bioindication within the context of both short- and long-term monitoring of coastal sand dune systems.

The use of coastal sediment budgets has garnered wide acceptance since its inception nearly 40 years ago. Since then, many researchers have used sediment budgets to quantify littoral transport rates and understand coastal processes on diverse coastlines including the high-energy Pacific coast of North America, the Black Sea, the Nile Delta and beyond. Here, we suggest further improvement on an already successful conceptual tool by questioning the broad definition of sand set forth by the classic Wentworth grain size scale (63–2000 microns) that is often used in quantifying coastal sediment budget inputs from sources such as coastal-draining rivers and eroding sea cliffs. A smaller range of sediment sizes is found on many beaches in California. This range is defined by a minimum grain size threshold, termed the littoral cutoff diameter. Sediment contributed to the littoral system that is smaller than this threshold, even if defined as sand by the Wentworth scale, may not remain on the beach in any significant quantity. The littoral cutoff diameter ranges from 88 to 180 microns on the California beaches studied herein, and results from a variety of locations show that yearly littoral sediment flux from coastal-draining rivers and eroding sea cliffs can be overestimated by 16–300% percent if the littoral cutoff diameter is not considered. The presence of the littoral cutoff diameter suggests that quantifying sediment inputs within the context of preexisting littoral sediments is of first-order importance when constructing sediment budgets in California and in other analogous coastal environments.

The northwestern coastal zone of Portugal between Mondego cape and Minho River preserves a series of fluvio-aeolian, lagoonal, and dune formations that are archives of evolution during the late Pleistocene and Holocene. The existing chronology of these formations is based mainly on radiocarbon dating of in situ organic materials. In this study, we present the results of optically stimulated luminescence (OSL) dating of these formations and discuss their implications for the existing chronostratigraphy, climate, and neotectonic changes in this area since the late Pleistocene. Three major periods of aeolian activity have been identified based on the OSL ages and are bracketed to 25–14 ka, 9.9–3.4 ka, and 1.4–0.1 ka. These OSL ages suggest intense sand deposition during oxygen isotope stage 2, the mid-Holocene, and the Little Ice Age. The dune ages in the last 500 years provide temporal constraints on the initiation of coastal erosion in the area. Further, the chronostratigraphic correlations suggest tectonic uplift in the coastal sections, between ca. 17 ka and 14 ka, and erosion due to eustatic sea-level rise.

Textural characteristics of the surficial sediments around Perumbalam Island located within the Vembanad Lake, southwest coast of India, were studied on a seasonal basis to understand the geomorphic response of the region. Sediment grain size increased from the northern to southern end of the island, indicating a progressive sorting by tidal currents. In contrast, an increase in the clay and organic carbon content in the sediments of the northern part of region suggests that their distribution is controlled by the productivity of the overlying water column. The evolution of this island is believed to be due to fluvial inputs from Muvattupuzha River. The braid shape of the island is attributed to the high-energy flow along the wedge of the estuary facing the river mouth, which has resulted in a build up of land along the southern boundary. The intense accretion on the southeastern and western sides of the island observed through satellite imagery reveals the fluvial influence on the evolution and morphology of this coastal lagoon.

This contribution investigates the hypothesis that incident wave power is modulated by the tide. Eulerian measurements of wave height recorded by three wave buoys in intermediate water depths (8–45 m relative to the lowest astronomical tide), over a 7-year period were analysed in a search for evidence of this semidiurnal variability in incident wave heights. The study site (Perranporth, U.K.) was a highly macrotidal environment with a maximum spring tidal range of approximately 7.5 m. Autospectra of wave height time series displayed a significant peak at semidiurnal frequencies that was coherently coupled to the tidal displacement. At this site maximum wave power was seen to occur on the rising tide, on average 1 hour 6 minutes before high water. The observed semidiurnal variability in wave height increases in magnitude toward the shoreline. This contribution presents field evidence for tidal modulation of incident wave power by the tide and suggests a possible explanation for the observations in terms of an analytical model for attenuation of wave power by contratidal flows.

Coastal plains are in the frontline of climate change. Predicted increase in recharge and sea level rise will alter groundwater flow, water quality distribution, recharge, and discharge considerably. This is simulated here in the Belgian western coastal plain. It consists of a shore, dunes, and polder (low-lying area) with a heterogeneous ground-water reservoir of quaternary age. A three-dimensional density-dependent groundwater flow model based on numerous (hydro)geologic observations was made. First the current groundwater flow and distribution between fresh and salt water was simulated. Then the effects of a 15% recharge increase and 0.4 m of sea level rise in the next 100 years were modelled. Sea level rise results in an increased flow of fresh water toward the polder and a decreased flow toward the sea. An increase in recharge results in more water flowing toward both the polder and the sea. Brackish water present in the polder will be pushed back as is a current saltwater intrusion from the polder in the dunes. The simulations also show that groundwater levels will rise. This will put strain on the ecologically valuable dunes and the drainage system in the polders.

The Andaman Sea is known for the genesis of many severe cyclones that traverse the Bay of Bengal. The Andaman Islands face the surge disaster threat as their north-south orientation comes across the eastward path of severe cyclones moving from the Andaman Sea and western Pacific Ocean. In this study, we investigated the potential of a storm-induced surge—a natural disaster due to short-duration sea-level rise—to affect the Andaman Islands. A two-dimensional hydrodynamic model was employed to simulate storm surge characteristics and demarcate the coastal flooding extent of the highly inhabited Port Blair region of the Andaman Islands in the case of the severe cyclone of November 1989. A storm surge disaster mitigation plan is also proposed for the group of Andaman Islands.

A multidisciplinary team of researchers from the humanities and social sciences, including geographers, sociologists, and economists, worked together to develop a tool for evaluating coastal zone vulnerability. The results of this collaboration are presented in this article. Clearly, the vulnerability of the coastal zone is exacerbated by the combination of increasing socioeconomic stakes and high-level natural risks that come together in this limited geographical area. Whereas natural dynamics make the shoreline intrinsically mobile, with, in most cases, a tendency to drift inland, the evolving human activity in this zone adheres to a contrary logic; it progresses toward the sea, often working to define the coastline permanently through seawalls and jetties, for example.

This highly developed coastal area is today at risk, the result of telescoping natural and anthropogenic forces. Given the risk, the notion of sustainable coastal development within the framework of integrated coastal zone management (ICZM) needs to be considered. If truth be told, the socioeconomic breaking point has apparently already been reached at several sites, where the cost of defending the coastline sometimes exceeds both the value of the property threatened and the financial means of the various local authorities, particularly the coastal communities. Certain imminent dangers have forced municipal governments to take emergency measures and the national government to resort to expropriation. Evaluating the risks of erosion and submersion thus appears to be an inevitable part of any forward-looking, strategic approach to coastal zone management.

The method presented in this paper permits coastline vulnerability to erosion and submersion to be analyzed and evaluated from several different angles: the exposure to risk, which concentrates on the hazards and the stakes; the management of risk, which seeks to minimize risk through public policies of prevention and restoration; the remembrance of risk, which works to learn from past hazardous events; and the perception of risk, which focuses on how the different actors and users perceive the diverse risks. From these four approaches to risk analysis come five factors—hazards, stakes, management, events, and perceptions. Each one is analyzed and evaluated on a separate grid, facilitating the development of vulnerability indicators from detailed lists of descriptors. Elaborated in collaboration with risk managers and local authorities (elected officials), these grids are designed to become a decision support tool within the ICZM framework.

Undertaken as part of the French National Coastal Environment Program, this research seeks to promote coastal risk management within a more integrated coastal zone management approach.

Nutrient loading and eutrophication in coastal waters are the causes of water quality degradation and loss of marine biota, which has led to ecological imbalance. Understanding and modeling the level of eutrophication as a function of environmental parameters can be beneficial to coastal ecosystem management. The limitation of deterministic and empirical models in accurately predicting the level of algal blooms, and the nonlinear relationship between the water quality and environmental parameters and that of the level of chlorophyll a necessitate a new approach using machine learning and data-driven modeling. A multilayer perceptron-back propagation (MLP-BP) algorithm of artificial neural network (ANN) was used to predict the level of eutrophication (chlorophyll a) from water quality parameters monitored at two Florida Bay water quality monitoring stations (FLAB03 and FLAB14). Based on the correlation of monthly nutrients (total phosphate, nitrite, ammonium) and other water data (temperature, turbidity, and dissolved oxygen) to the level of chlorophyll a, an input-output data structure was selected. Seven input data scenarios were studied, and model performance was compared using four indices. Monthly data from 1992 to 2004 were partitioned into training and testing subsets. Results show that chlorophyll a was predicted well with the selected inputs, with an average R² and model efficiency (E) of 0.856 and 0.582, respectively. Prediction with antecedent chlorophyll a alone gave a stable result with smaller error and higher performance attributed to easier and more efficient training. It was also found that ANN performed better at FLA03 than at FLA14. It is shown that the MLP-BP technique is applicable to the monitoring and prediction of algal blooms and will be crucial to coastal watershed management.

A multilevel breadth-averaged numerical model has been developed and applied it to the Gulf of Khambhat to study the tidal circulation, salinity, and suspended sediment transport. The model is fully nonlinear and uses a semiexplicit finite difference scheme to solve mass, momentum, and advection diffusion equations in a vertical plane. A turbulent kinetic-energy scheme is used to parameterize the vertical transfer of momentum, salinity, and suspended sediments. The model is forced by prescribing the tidal elevations along the open boundary of the analysis region. The tide in the gulf is mainly represented in the model by the semidiurnal M₂ constituent. A freshwater discharge from the landward end is also considered for this study. The erosion and deposition are computed by empirically developed source and sink terms in the suspended sediment equation. Numerical experiments were carried out to simulate the tidal circulation, salinity intrusion, and suspended sediment transport in the gulf region. The computed M₂ tide and salinity at two different sets of coastal stations were validated with the available observations.

The influence of the El Niño–Southern Oscillation (ENSO) on NSW coastal storm severity was investigated by comparing the yearly mean Southern Oscillation Index, , with the yearly averaged storm severity Ω measured at the NSW coast. It was found that Ω correlates well with , i.e., Ω generally increases with . The probability distributions of storm peak wave height and yearly mean SOI were also studied and were found to follow a Gumbel distribution. A simple linear relationship between extreme wave height and yearly mean SOI was then derived. At the NSW coast or at other coasts with similar wave climates, coastal recession and increased coastal damage may be expected in La Niña years, while beach recovery and reduced coastal threat may be expected in El Niñ o years.

Time series at eight locations in Chesapeake Bay and the adjacent inner shelf were used to determine the relative influence of the wind and barometric pressure effects on subtidal sea-level variability and slopes in the estuary. Special emphasis was placed on the lower Chesapeake Bay, where inverse barometric effects accounted for up to 32% of the subtidal sea-level variations, and wind forcing accounted for more than 67% of the variance. The wind frequency from any given direction varied from one station to another due to the nonsynoptic characteristics of atmospheric pressure in Chesapeake Bay. In the northern bay, northwesterly winds were most frequent in winter, and southerly winds were most frequent in summer. In the southern bay, northeasterly winds were most frequent in fall and winter, and southwesterly winds dominated in the summer. These winds produced sea-level responses as follows: northeasterly winds caused water to pile up in the southwestern corner of the bay, whereas southwesterly winds produced water-level depressions in the same area. This study is one of the few to document the influence of atmospheric pressure gradients on estuarine sea-level slopes. It was found that atmospheric pressure gradients produced sea-level slopes of the same order of magnitude (10⁻⁷) as those induced by westerly–easterly winds. In contrast to previous studies, the volume fluxes calculated here, with geostrophy, geostrophy plus wind stress, and the continuity constraint, showed drainage of the bay with northerly and northwesterly winds and filling of the bay with southeasterly winds.

Recent investigations of tide gauge and hydrographic data point to the conclusion that twentieth-century global sealevel rise was about 1.8 mm/y, with significant decadal and longer variability. Ocean thermal expansion can account for about 0.5 mm/y of the trend, leaving an additional ∼1.3 mm/y water equivalent that must have come from other sources. Greenland, Antarctica, and small glaciers are obvious candidates, and “fingerprints” of their contributions must occur because additions of glacial ice or meltwater to the oceans will not cause a globally uniform rate of sealevel rise. As ice melts or is discharged, Earth will respond elastically, and the geoid will also adjust. The result is that large changes in relative sea level will occur near the area of melting or discharge, and significant (∼20%) deviations from a uniform global rise will occur antipodal to the source. Thus, several authors have used trends of relative sea-level rise obtained from tide gauge data to investigate possible contributions from Greenland, Antarctica, and other sources of global sea-level rise. In this paper, we consider the fingerprint question morphologically by examining the regional variations of relative sea-level change for evidence of these fingerprints. Unambiguous evidence for fingerprints of glacial melting was not found, most likely due to the presence of other signals present in sea-level records that cannot easily be distinguished.

Determination of the impacts of underwater explosions on animals has focused upon the mortality of adult fish, turtles, and marine mammals. For these animals, mortality can be predicted and abundance and distribution in the impact area can be determined with acceptable accuracy. The sensitivity of larvae and small juveniles, however, has not been adequately examined, and the abundance and distribution of young fishes is difficult to estimate. We determined sensitivities of the larvae and small juveniles of two species of fishes to shock wave exposure under experimental conditions. This determination was used to develop models that relate larval and small juvenile fish mortality to shock wave exposure. Resulting shock waves were monitored at three distances from the blast. Injuries were assessed by gross examination and by histopathology. Specific impulse was determined the critical parameter for injury assessment because it was of high magnitude over a longer distance when compared with pressure maxima or energy flux density. Impulse ranged from 1.855 to 12.080 Pa s. The proportion of fish lethally injured by these impulses ranged from 0.14 to 1.00. Total injury doses of 50% ranged from 5.286 to 8.910. Total injury doses of 50% were applied to an engineering blasting project in Wilmington Harbor, North Carolina. This application indicated that nearly 8.2 × 10⁸ larvae could be killed over the duration of the project. This represents 2–3% of the larvae in the system and is unlikely to seriously affect fishes at the population level.

Beach traffic can substantially modify the physical environment on sandy beaches. Vehicle impacts on beaches were quantified on North Stradbroke Island, a barrier island on the east coast of Australia where large volumes of recreational off-road vehicle (ORV) traffic are concentrated on two beaches (Flinders Beach and Main Beach). The distribution, density, and depth of vehicle ruts on these beaches were quantified during the peak holiday period around late December and early January 2005–06. The density of tyre tracks per meter of beach face ranged from 2.69 to 6.35 on Flinders Beach and from 2.38 to 8.06 on Main Beach, and substantial areas (54–61%) of each beach were covered withy tyre tracks up to a maximum of 90% in some areas. ORVs corrugated the sand as deep as 28 cm (mean depth: 5.86 ± 4.72 cm), with the deepest rutting occurring between the foredunes and the drift line. On a volume basis, vehicles disrupted 5.8% (Main Beach) and 9.4% (Flinders Beach) of the available faunal habitat matrix (top 30 cm of the sand) in a single day. Traffic density was higher on the lower shore, but ruts were significantly deeper in the soft sand of the upper shore. Thus, half of all sand displaced by vehicles on Flinders Beach originated from the upper shore, although this section represents only 36% of beach width. Similarly, the narrow (13% of beach width) upper shore on Main Beach contributed 55% of the total volume of sand dislodged by ORVs. Beach traffic overlapped to a large extent with the distribution of the invertebrate infauna, and vehicles routinely disturbed the drift line and the base of the foredunes. This study emphasizes the need to develop multifaceted management strategies for recreational ORV use on beaches that balance ecological requirements with sociocultural and economic demands.

The Bruun/Dean relation between water depth and distance from the shore with a constant profile shape factor is widely used to describe shoreface profiles in temperate environments. However, it has been shown that the sediment scale parameter (A) and the profile shape factor (m) are interrelated variables. An analysis of 63 Arctic erosional shoreface profiles shows that both coefficients are highly variable. Relative frequency of the average m value is only 16% by the class width 0.1. No other m value frequency exceeds 21%. Therefore, there is insufficient reason to use average m to characterize Arctic shoreface profile shape. The shape of each profile has a definite combination of A and m values. Coefficients A and m show a distinct inverse relationship, as in temperate climate. A dependence of m values on coastal sediment grain size is seen, and m decreases with increasing grain size. With constant m = 0.67, parameter A obtains a dimension unit m^1/3. But A equals the water depth in meters 1 m from the water edge. This fact and the variability of parameter m testify that the Bruun/Dean equation is essentially an empirical formula. There is no need to give any measurement unit to parameter A. But the International System of Units (SI) has to be used in applying the Bruun/Dean equation for shoreface profiles. A comparison of the shape of Arctic shoreface profiles with those of temperate environments shows surprising similarity. Therefore, the conclusions reached in this Arctic paper seem to apply also to temperate environments.

Output is compared from four methods used to estimate the overtopping rate at seawalls subject to random wave action: two empirical models, a semiempirical model, and a numerical model. The empirical models were developed by fitting dimensionless groups to data derived from physical model tests. The semiempirical model was derived from consideration of the unsteady flow of water over a weir. However, like the empirical models, it was calibrated with the results of physical model tests. In contrast, the numerical model AMAZON is a high-resolution two-dimensional finite volume model based on the nonlinear shallow-water equations.

In this study, we calculated the mean overtopping discharge for a range of seawalls with front slopes from 1 : 1 to 1 : 20 and for incident wave steepnesses from 0.01 to 0.03. The results are considered alongside four sets of data from physical model tests. They show general agreement between the output from the numerical and semiempirical models and the data. Agreement with the empirical models depends principally on the value of the surf similarity parameter. The empirical models substantially overpredict discharges for some conditions.

The ability of the dune grass Panicum amarum to resprout from vegetative fragments as well as the response of this species to a commercially available soil conditioner (humic acid) were evaluated using a factorial design in a greenhouse setting. A general trend of greater P. amarum biomass production with humic acid amendment was noted. Panicum amarum growth did not demonstrate either an asymptote or decline with the highest level of humic acid addition, indicating that its growth may potentially be further enhanced by humic acid levels greater than those used in this study. The survivorship of P. amarum fragments (belowground fragment material only and aboveground material fragment only) were comparable with whole-plant planting success with high survivorship noted for all three planting approaches. As anticipated, the whole-plant planting treatments resulted in the greatest total biomass, followed by the belowground-only plantings, which had greater biomass production than the aboveground-only plantings. Overall, the addition of commercial humic acid to the soil during the planting of P. amarum appears to have the potential for enhancing establishment and growth. Importantly, this research demonstrates that the use of P. amarum fragments may be a successful alternative approach in projects where it may be desirable to double planting densities or in situations where whole plant transportation is logistically difficult. Further evaluations of these restoration methods under more realistic field scenarios with longer monitoring of effects are required to determine fully the benefits of these techniques.