Long Stretch Of Coast Research Articles

“Can seawalls help American cities adapt to coastal flooding?”

PurposeThis study aims to combine information about sea level rise (SLR), the probability distribution of storm surge, a flood damage function and the value of property by elevation along the coast of selected cities to measure expected flood damage. The selected six cities all have nearby long-term tidal stations that can be used to estimate the probability distribution of floods. The model is calibrated to each city. The study then compares the cost of building higher seawalls today along the coast versus the benefit of each wall (the reduction in expected flood damage).Design/methodology/approachThe combination of coastal storms and SLR has led to extensive flood damage across American cities. This study creates a simple generic model that evaluates whether seawalls would be effective at addressing this flooding problem. The paper develops an approach that readily measures the expected flood benefits and costs of alternative coastal seawalls. The approach takes account of near term SLR and the probability distribution of storm surge. The model finds seawalls are effective only in cities where many buildings are in the 25-year flood plain.FindingsCities with many buildings built on land below 2 m in elevation (the 25-year flood plain) have high expected flood damage from storms and SLR. Cities which already have many buildings in this flood plain would benefit from seawalls. Assuming seawalls are built above the high tide line, the optimal wall height that maximizes net benefits is between 0.9 to 1.2 m. These relatively low seawalls block 70%–83% of expected flood damage in these cities. Fair flood insurance is the least cost strategy for handling the remaining damages that overtop the optimal seawalls.Research limitations/implicationsThe analysis evaluates whether or not to build a seawall the length of each city at high tide lines. However, the analysis also finds several long stretches of coast in two cities where a wall is not warranted because there are few vulnerable buildings. Future analyses should consider seawalls in more spatially detailed sections of each city. Each section could then be analyzed independently. Whether or not more complex hydrodynamic models are needed to evaluate coastal resilience planning should also be explored. Alternative solutions such as planned retreat and nature-based solutions should be compared with seawalls in future studies as well.Practical implicationsCities should be careful to avoid development in the 25-year flood plain because of high expected flood damage. Cities that have low elevation areas subject to frequent flooding should consider seawalls to reduce frequent flooding. Because they are very costly and have low expected benefits, high walls that can stop a one-hundred-year storm are generally not worth building.Social implicationsThe analysis reveals that the most important factor determining the vulnerability of cities along the eastern coastline of the USA is the number of buildings built below 2 m in elevation (the 25-year flood plain). Cities should use zoning to discourage further development in the 25-year flood plain. Cities which already have many buildings in this flood plain would benefit from city-wide seawalls. Assuming these walls are built at mean high-high tide, the optimal height of current seawalls should be relatively modest – averaging about 0.9–1.2 m above ground. Using fair insurance for the remaining risk is less expensive than building taller walls. In particular, the cost of seawalls that protect against a major hurricane surge are over three times the expected benefit and should not be built. As decades pass and observed sea level progresses, seawalls and the boundary of the 25-year flood plain should be reevaluated.Originality/valueThis paper develops a coastal flood model that combines SLR and the probability distribution of storm surges with the value of property by elevation to estimate the expected damage from storm surge. The model is relatively easy to calibrate making it a practical tool to guide city flood planning. The authors illustrate what insights such a model gives about coastal resilience to flooding across six cities along the Eastern US coastline.

Phylogeography of Aphanius fasciatus (Osteichthyes: Aphaniidae) in the Mediterranean Sea, with a focus on its conservation in Cyprus

Aphanius fasciatus is a small fish occurring in Mediterranean brackish environments. In Cyprus it is known from three localities separated by long stretches of coast. The genetic diversity of these populations was evaluated using fragments of two mitochondrial genes. A comparison with the other available data showed that Cyprus populations represent a distinct lineage. The other lineages are concentrated in a relatively small area between the Strait of Sicily and the Western Ionian Sea, while all other areas include a subset of these lineages, suggesting that the aforementioned area might have acted as a glacial refugium. Landlocked North-African populations diverge from all other populations, suggesting that they might have originated in the Late Pleistocene, during transgression events of the Mediterranean Sea in North-African inland water bodies. The genetic diversity of A. fasciatus varied across different Cyprus populations, with a pattern mirroring the degree of environmental degradation, which likely affected population genetic variability through demographic reductions. The three Cyprus populations showed genetic uniqueness, suggesting the need of population-based management practices; the low genetic diversity of two populations, and the number of threats affecting them, suggest that the species should be considered endangered at national level and deserves protection measures.

Aeolian Deposition and Barrier Stratigraphy of the Transition Region between a Regressive and a Transgressive Barrier: an example from Southern Brazil

Dillenburg, S.R., Barboza, E.G., Tomazelli, L.J., Rosa, M.L.C.C., Maciel, G.S., 2013. Aeolian Deposition and Barrier Stratigraphy of the Transition Region between a Regressive and a Transgressive Barrier: an example from Southern Brazil.The transition region between regressive and transgressive barriers on the northern and central coastal sectors of Rio Grande do Sul (RS) in southern Brazil is represented by a 170 km long stretch of coast where the barrier shows a general aggradational/stationary (a/s) behavior on a long term time scale. In this study, approximately 50 km of this transition region was analyzed at four sites: Tramandaí, Jardim do Éden, Cidreira and Dunas Altas. All barriers began forming around 7.8 - 7.2 ka. The northernmost site (Tramandaí) has a typical a/s stratigraphy, and barrier morphology is dominated by transgressive dunefields. Ten km to the south, at Jardim do Éden, the barrier shows a transgressive stratigraphy, and barrier morphology is also dominated by transgressive dunefields. At Tramandaí the maximum barrier height is around 4 m, with a maximum of 6 m, while at Jardim do Éden it averages 6 m, with a maximum of 11 m. Further to the south, 10 km from Jardim do Éden, the barrier at Cidreira shows a dominant transgressive stratigraphy developed in the last 7 ka, but with evidence of a relatively small regression (~600 m). Barrier height averages 10 m, reaching 20 m due to the existence here of a large transgressive dunefield. And finally, at around 30 km to the south of Cidreira, the a/s barrier of Dunas Altas occurs. Barrier morphology here is dominated by transgressive dunefields, with a surface height of around 8 m, but fronted by the largest and highest foredunes (around 8–10 m) in Rio Grande do Sul. The Dunas Altas coastline has regressed around 600 m in the last 7.8 ka. The Holocene barrier analyzed in this study, along a 50 km segment shows a general a/s behavior in the last 7.8 ka. The long time of a relatively stationary condition allowed the barrier to grow vertically by accumulation of aeolian deposits of at least four phases of transgressive dunefield development.

Changes in trace metals in Thalassia testudinum after hurricane impacts

Major hurricanes Emily and Wilma hit the Mexican Caribbean in 2005. Changes in trace metals in the seagrass Thalassiatestudinum prior to (May 2004, 2005) and following passage of these hurricanes (May, June 2006) were determined at four locations along a ∼130km long stretch of coast. Before the hurricanes, essential metals were likely limiting and concentrations of potentially toxic Pb were high in a contaminated lagoon (27.5μgg−1) and near submarine springs (6.10μgg−1); the likely sources were inland sewage disposal or excessive boat traffic. After the hurricanes, Pb decreased to 2.0μgg−1 in the contaminated lagoon probably through flushing. At the northern sites, essential Fe increased >2-fold (from 26.8 to 68.3μgg−1 on average), possibly from remobilization of anoxic sediments or upwelling of deep seawater during Wilma. Thus, hurricanes can be beneficial to seagrass beds in flushing toxic metals and replenishing essential elements.

Implementation of the European Water Framework Directive: Natural variability associated with the CARLIT method on the rocky shores of the Ligurian Sea (Italy)

AbstractThe Water Framework Directive (WFD) 2000/60/EC, adopted by the European Community in 2000 with the goal of maintaining and improving the aquatic environments, requires that member states achieve and maintain a good ecological status of all water bodies by 2015. In the marine context, the ecological status has to be quantified applying indexes based on appropriate key biological elements, which allow the categorization of water bodies into five Ecological Status (ES) classes. The CARLIT index is a cartographic monitoring tool enabling the Ecological Quality Ratio (EQR) to be calculated using macroalgae in coastal hard bottoms as a key biological element; at present it is being applied in Spain, France and Italy. To detect actual changes of water quality and, consequently, rely on the application of indexes for the assessment of the ecological status in the marine environment, it is necessary to evaluate their sensitivity to natural variability at different temporal and spatial scales. In this study we present a first quantification of natural (spatial and temporal) variability of EQR‐CARLIT quality assessment in 2006 and 2007 along the Ligurian coast (North‐Western Mediterranean, Italy). The EQR‐CARLIT values recorded along the Ligurian coastline show that natural variability of EQR‐CARLIT is low and that it does not affect the attribution of a given stretch of coast to a particular ES class, in agreement with the major human pressures acting in the area (urbanization, river load, sea‐farming). A small‐scale variability was detected, strengthening the use of cartography of the whole rocky shore, whenever possible, or, alternatively, the assessment of the ecological status for long stretches of coast, to encompass the small‐scale variability due to local factors.

 Coastal Recovery following the destructive tsunami of 2004: Aceh, Sumatra, Indonesia

We describe the recovery of coastal landforms in Aceh, Sumatra after the hugely destructive Indian Ocean tsunami of December 26, 2004, using three sets of IKONOS images at a resolution of 1 m.The image sets were taken about two years before the tsunami, immediately following the tsunami, and about one year after the tsunami.We found a remarkably efficient recovery in progress, building new depositional forms seaward of the eroded coastline that effectively obliterate the morphological signals of the tsunami. Such detailed observations covering a long stretch of coast are now possible due to the availability of high-resolution satellite images.To the best of our knowledge this is the first time-based study of the recovery of a long stretch of coast (175 km) after catastrophic destruction by a tsunami.We suggest that tectonic coasts, like the one discussed here, may undergo similar changes periodically on a geological time-scale.Thus, it is possible that morphological evidences of catastrophic tsunamis are not necessarily preserved in the geological record.

Indian Food Production in the Caribbean

THINK for a moment of the map of the world, of the globe. Think of South America as accessible on land, and see how it is the farthest end of the world that was available to the dispersal of mankind. Now there are the difficulties of the high latitudes; there are the difficulties, less it is true, of the desert, and then there is the difficulty of the tropical rain forest. And I want to speak about that for a moment. At least the eastern half of Panama, perhaps more than that, and the western part of what we know as Colombia and a long stretch of coast down to the south are one of the rainiest areas that we have, and it can hardly have been anything else than a very great tropical forest at the time that human migrations began into South America. Yet the curious thing about South America is that of all the world it has perhaps the greatest linguistic diversity and in an extreme degree, which probably means that people had been coming in little bands for a long time, pushing through and getting into South America and staying there. There were good opportunities for some of them down there. But here is an extraordinarily, almost fantastically diversified lot of people and language, and this is, after all, one of the ways in which we recognize old, old differences in people. They must have gotten through many, many times for a quite long period of time. There is one thing that eased it a bit; there is little doubt that these migrations were under way before the sea levels reached their present level. There is probably not much hazard in saying that the sea was at least 100 feet lower in the early part of this migration than it is now, and that under these circumstances two of the obstacles, the great marshes and estuaries of the drowned country that we know as the Gulf of San Miguel [southeastern Panama] were drained, as was the very great marsh and forest land of the Rio Atrato. But still you have the formidable problem of a tropical rain forest than which there is almost nothing that is less providing for man in the way of sustenance. Probably you are better lost in the desert if you have water than if you are in a tropical rain forest in terms of living off the country. And yet we have this indirect but quite interesting illustration of the many kinds of people and the many times in which people came through there quite freely. I am saying that the beachcombing opportunities, the strand-living opportunities, were the first decisive things in admitting man into this area, and they are quite interesting. On the Pacific side, we have the advantage of an ocean with a high tidal range, with a relatively large vertical difference for tidal collecting. The collecting from a tidal fauna is of considerable diversity and quite large amount. And back of the strand line you have the beach which is also of considerable interest, especially in this part of the world because of the fact that we are in one of the great sea-turtle areas of the world. The harvest

Recolonization of Rocky Shores in Cornwall After Use of Toxic Dispersants to Clean Up the Torrey Canyon Spill

Fourteen thousand tons of Kuwait crude oil, reduced from 18 000 tons by weathering at sea, was stranded along 150 km of the coast of West Cornwall, England, in March 1967. The oil was treated with 10 000 tons of toxic dispersants during cleaning operations. By itself the oil was not very toxic, although it killed some limpets and barnacles, and most of the mortalities that followed cleaning were due to the dispersants. There was a graded effect. Most animals and some algae were killed on the shores treated heavily with dispersants, while a few animals and most algae survived in places less heavily treated. However, long stretches of coast were contaminated to some extent by drifting of patches of oil and dispersants along the shore and by indiscriminate dispersant use in remote coves. The general sequence of recolonization was similar to that which has been found after small-scale experiments, where the rocks were scraped clean, or where limpets were removed, but took longer to complete. There was first a rapid "greening" by the alga Enteromorpha; then a heavy settlement and growth of perennial brown algae (Fucus species), leading to loss of surviving barnacles. A settlement of limpets and other grazing animals followed, with eventual removal or loss of the brown algae. The final phases were a reduction in the limpet population and a resettlement of barnacles. Lightly oiled, wave-beaten rocks that received light dispersant treatment showed the most complete return to normal, taking about 5–8 yr; heavily oiled places that received repeated application of dispersants have taken 9–10 yr and may not be completely normal yet. Most common species returned within 10 yr, but one rare hermit crab is still missing from places directly treated with dispersants. The early recolonization by algae resulted in a raising of the upper limit of Laminaria digitata and Himanthalia elongata by as much as 2 m in wave-beaten places, demonstrating that grazing pressure by limpets must be one of the factors controlling the zonation of these plants. Later, other species of plants and animals were found higher up the shore than usual, under the shade and shelter provided by the dense canopy of Fucus. Fluctuations in the populations of algae and herbivorous animals during the course of the recolonization illustrate the importance of biological interactions in controlling the structure of intertidal communities. Pollution disturbance affects the herbivores more than plants, hence the point of stability of the community is shifted towards the sheltered shore condition of low species richness and greater biomass. Key words: petroleum, dispersant, rocky shore, Torrey Canyon, recolonization, coastal ecology, pollution

THE SEA-GRASSES OF BRAZIL

There is still hardly anything known about the occurrence of sea-grasses in South America. The number of records is extremely small. Therefore, one wonders whether these plants are extremely rare or absent along long stretches of coast, or whether it is just that they have been overlooked by botanists. It seems that the latter applies to the coast of Brazil, from where up to now only two collections had been recorded (Setchell 1934; den Hartog 1970). Thanks to the active, gratefully acknowledged co-operation of Dr. Liliane Forneris (Universidade de Sao Paulo) I received a number of sea-grasses from several places along the Brazilian coast. I am also indebted to Dr. Emilia Santos (Museu Nacional, Rio de Janeiro) and Dr. Graziela M. Barroso (Jardim Botanico, Rio de Janeiro) for sending me a specimen and a photograph, respectively, of Halophila decipiens. Further, I am grateful to Dr. V. J. H. de Jilovice de Sternberg (Companhia ‘Algimar’, Rio de Janeiro) for his co-operation in obtaining material. At present there are 5 species now known from Brazil.

Damage between Westport and Greymouth

Except for the adjoining coal-mining townships of Runanga and Dunollie, five miles north of Greymouth, buildings in the fifty mile long stretch of coast between Westport and Greymouth occur only in small groupings widely scattered along the coastal highway, Runanga and Dunollie are located two miles inland, and are situated partly on soft and saturated soil.

The Universal Features of Zonation Between Tide-Marks on Rocky Coasts

So much has already been discovered about life between tide-marks that it has become difficult to see the wood for the trees. Yet despite the host of publications dealing with intertidal life, the field untouched is so vast that our knowledge of the natural laws which control intertidal affairs is still elementary. For these reasons we must examine intertidal arrangements, where possible, on a broad scale as well as intensively. Until recently there has been a stronger tendency to study the problems of tidal biology in great detail on a small scale than in less detail on a large one. This has resulted in many accounts of the natural history of individual plant and animal species, and in numerous descriptions of the occurrence of plants, animals (or both) in small areas varying in size from square yards, individual rock-pools or narrow traverses to short stretches of coastline, estuaries and similar areas. The general examination of long stretches of coast, or of the coastlines of whole countries, has lagged far behind the more detailed studies, and there have been few examples of it. We have, it is true, such surveys as those of Fischer-Piette on the European coasts, of Ricketts on the Pacific coast of North America, and of the present authors and their collaborators in South Africa; but the list is not a long one. Recent progress in intertidal studies has been ably summarized by Fischer-Piette (1940), and the volume in which his paper appears represents, as a whole, an important contribution to the subject. At the present time there is evidence of a tendency to undertake the examination of long coastlines more readily than before, and this is of course facilitated by car and plane travel, and by the construction of roads in many places which were previously inaccessible. An example of such work is the survey, by Dakin and his assistants, of 1000 miles of coastline in New South Wales, the results of which were published in 1948. A series by R. G. Evans on parts of the British coast is at present appearing, and while this deals with much shorter stretches, its point of view is a broad one, looking towards an eventual general account of the British coasts. There is similar work now progressing in several parts of the

Volcanic vents at Longskelly Rocks and at Yellow Craig Plantation, west of North Berwick

On the long stretch of coast between Weak Law and Longskelly Point there are a few interesting sections, but especially at the latter place, where evidence has been found pointing to the presence of a rather large volcanic vent, a great part of the area of which is much obscured by an extensive intrusion of basalt approaching monchiquite in type (see map, Fig. 1). Also at a place called Yellow Craig Plantation, a short distance inland from Longskelly Point, there is good reason to believe that a volcanic vent exists, either connected with the one on the shore, or separated from it (see map, Fig. 2). The deposits in connection with these vents, both on the shore and on the ground round about Yellow Craig Plantation, are mentioned in the Geological Memoir for East Lothian, 1910, p. 82, and are there regarded as beds of conglomerate containing boulders and fragments of trachyte and basalt, having occasionally an ashy appearance, and as being an upper representative of the sedimentary rocks lying above and in contact with the Markle basalt lava at Cowton Rocks. According to the map ( Geological Survey, East Lothian, 1910, p. 59), these rocks occupy in horseshoe form the southern edge of a shallow syncline which extends westwards from the Cowton Rocks, as far as and embracing Yellow Craig Plantation, and on the shore to the west of the Longskelly intrusion. The deposits on the shore at Longskelly, which occupy an area somewhat raised above the level of the