Beach Protection Research Articles

SAMSUNG SECURES POLYETHYLENE CONTRACT

This study attempts to integrate environmental economics and coastal engineering in managing port-induced coastal erosion occurring at a common beach by using Map Ta Phut port in Thailand as a case study. The existence of the port creates coastal erosion which can be considered an externality that affects local inhabitants, and a port owner and shipping companies can be seen as “polluters”. Overlaying of aerial photographs provided strong evidence that the coastline was severely eroded after the construction of the port. Coastal engineering softwares, LITPACK and MIKE 21 PMS, were utilized to predict future shoreline positions and investigate wave patterns around the port. The port alters wave climate and the port-induced erosion is jeopardizing a local recreational beach called Nam Rin, which is projected to disappear in 5 years. A valuation of Nam Rin beach using single-bounded dichotomous choice contingent valuation method revealed individual willingness to pay (WTP) for the beach, being 867.5 baht (approximately US$ 24.8) per year. Multiplying the individual WTP with the appropriate number of population to acquire the beach protection benefit and dividing such benefit by construction and maintenance costs of a particular beach protection measure, the polluters can select a proper beach protection approach that fulfills their benefit–cost requirement.

EXPERIMENTAL INVESTIGATION ON THE APPLICATION OF GRAVITY DRAINAGE SYSTEM FOR BEACH STABILIZATION TO THE FIELD

The seawall has been constructed at Karasu district of Tsu-Matsusaka port on the west side of Ise bay, because of the present seawall is getting decrepit. In front of the seawall is sandy beach, however, the sand fill will be done as an Integrated Shore Protection System at the part where less beach width, and also the Gravity Drainage System for beach stabilization will be constructed to keep the fill sand. Gravity Drainage System is the beach protection technique of controlling a groundwater level by burying a permeable layer under the foreshore. The design method of Gravity Drainage System is not established because there are less construct precedents of this system at the field. Accordingly, they buried permeable layer partially at the field and carried out the field observation for designing the Gravity Drainage System. But they could not take enough data to investigate the plane arrangement because of the field observation carried out narrow area. This three dimensional hydraulic model experiment were done to investigate the necessity of beach protection works and the adequate plane arrangement.

Short‐term epidemic dynamics in the Cakile maritima–Alternaria brassicicola host–pathogen association

Summary Studies combining within‐ and among‐population processes are crucial for understanding ecological and co‐evolutionary dynamics in host–pathogen interactions. We report on work over an 18‐month period involving multiple beach populations of the plant Cakile maritima and its fungal pathogen Alternaria brassicicola along the south‐east coast of Australia. Results from permanent transects replicated on several beaches show that disease incidence and prevalence vary significantly with plant age, class and distance from the sea, as well as time during the season. Plant density is also positively related to disease levels. Results from three subregions indicate that disease persistence depends on survival of infected plants behind the foredunes of protected beaches. Population extinction was more likely on beaches with greater wind exposure and sea access, with the latter also related to colonization consistent with the dispersal of Cakile seeds via ocean currents. Although disease dynamics during the epidemic were similar across subregions, the severity of the epidemic varied significantly among these areas, suggesting that large‐scale environmental factors may influence the timing and development of the epidemic. Estimates of synchrony in disease dynamics indicated that populations within a subregion were significantly correlated with respect to epidemic development. There was, however, no evidence for spatial synchrony in disease dynamics based on among‐population covariances in disease prevalence and interbeach distances. Populations within a subregion were thus often at quite different phases of the epidemic at any given time.

Disturbance to wintering western snowy plovers

In order to better understand the nature of disturbances to wintering snowy plovers, I observed snowy plovers and activities that might disturb them at a beach near Devereux Slough in Santa Barbara, California, USA. Disturbance (activity that caused plovers to move or fly) to wintering populations of threatened western snowy plovers was 16 times higher at a public beach than at protected beaches. Wintering plovers reacted to disturbance at half the distance (∼40 m) as has been reported for breeding snowy plovers (∼80 m). Humans, dogs, crows and other birds were the main sources of disturbance on the public beach, and each snowy plover was disturbed, on average, once every 27 weekend min and once every 43 weekday min. Dogs off leash were a disproportionate source of disturbance. Plovers were more likely to fly from dogs, horses and crows than from humans and other shorebirds. Plovers were less abundant near trail heads. Over short time scales, plovers did not acclimate to or successfully find refuge from disturbance. Feeding rates declined with increased human activity. I used data from these observations to parameterize a model that predicted rates of disturbance given various management actions. The model found that prohibiting dogs and a 30 m buffer zone surrounding a 400 m stretch of beach provided the most protection for plovers for the least amount of impact to beach recreation.

SEASONAL BEACH PROCESS AND WAVE DEFORMATION AT IDA COAST IN SHICHIRI-MIHAMA

This paper is intended to estimate seasonal beach process and wave deformations at the Ida coast in the Shichiri-Mihama coast in Mie Prefecture. Field investigation by using an aerial photography technique is conducted along the Shichiri-Mihama coast from the Kumano river mouth to the Onigajo cape. It is clear that almost regions occurred beach erosion, especially Udono port region located on the left bank of the Kumano river, as the coastal line faced to sea, the beach protection works were struck by strong storms. Based on bottom sounding survey, maximum shoreline retreat was about one hundred meter for five years immediately after extend construction of breakwater around Udonoh arbor.It is necessary to predict wave deformation for erosion control around coastal protection facilities. It is presented a time-depend mild slope equation for estimating wave deformation. Some simple calculations were conducted for modeling artificial reefs at the severe beach erosion area where located northern Udono port. The numerical model has well explanations for generation of partial standing waves, drop of mean sea level behind artificial reefs.

Experimental investigation of vanes as a means of beach protection

Vanes are essentially flat vertical flow guiding structures. In the beach protection application vanes are placed, inshore of the breaking zone, in the upper part of the vertical water column and with a predefined angle of attack to the design wave orthogonal. They are thus subjected to a generally inshore-directed flow, which induces a lift, and drag force on the vane. These forces, in turn, induce a flow that counteracts the wave-induced longshore current, thus decreasing the longshore current velocity, which facilitates sediment deposition. Two experiments were conducted in a small-scale wave basin with the purpose of investigating the vane function. Both experiments were conducted with a movable bed that formed a crenulate-shaped bay between two headland structures. The first experiment showed that the vanes created a salient upstream of the vanes. This result is also supported by initial prototype results. The second experiment showed that the longshore velocity was reduced upstream of the vane and that the bulk of the velocity reduction took place in the nearshore part of the breaking zone. The main flow feature is identified as a large horizontal vortex inshore of the vane.

STUDY ON IMPACTS OF SEA-LEVEL RISE ON COASTAL ZONE

This paper is intended to discuss impacts of sea-level rise, which is one of the exposures of the global warming, on coastal zone and provide fundamental data for assemble adaptation technique. Shichiri-mihama coast has been chosen as a coast of case study and present situation of the coast has been investigated. Then, impacts of sea-level rise on this coast have been discussed and evaluated. As a result, it has been found that impacts of sea-level rise are very significant and may cause sever damages. Moreover, it has been confirmed that the beach protection from erosion is very important to reduce the effects of sea level rise.

BEACH PROCESS AND WAVE DEFORMATION AROUND UDONO HARBOR AT SHITIRI-MIHAMA COAST

This paper is intended to estimate beach process and wave deformations at the Shitiri-mihama coast in Mie Prefecture. Field investigation by using an aerial photography technique is conducted along the Shitiri-mihama coast from the Kumano river mouth to the Onigashiro cape. It is clear that almost regions occurred beach erosion, especially Udono harbor region located on the left bank of the Kumano river, as the coastal line faced to sea, the beach protection works were struck by strong storms. Based on bottom sounding survey, maximum shoreline retreat was 100 meters for 5 years immediately after extend construction of breakwater around Udono harbor. It is necessary to predict water deformation for erosion control around coastal protection facilities. It is presented a time-depend mild slope equation for estimating wave deformation. Some simple calculations were conducted for modeling breakwater at the worst beach erosion area where located northern Udono harbor. The numerical model has well explanations for generation of partial standing waves, drop of mean sea level behind breakwaters.

Threatened Fishes of the World: Carcharias taurus (Rafinesque, 1810) (Odontaspididae)

Threatened Fishes of the World: Carcharias taurus (Rafinesque, 1810) (Odontaspididae)

A Cost—Benefit Study of Protection of the Northern Beaches of Australia's Gold Coast

Ocean beaches are a valuable recreation asset for local residents and tourists, and beachside communities throughout the world have adopted a variety of engineering strategies to protect this asset from the natural forces of erosion. Increasingly the proponents of such schemes are expected to demonstrate the economic benefits of these projects. The study reported is a benefit—cost assessment of beach nourishment works planned for the northern beaches of the Gold Coast region in Queensland, Australia. Data covering past beach erosion events in the region are used to estimate the effects of beach erosion on tourism receipts and public assets located at beachside. Losses in these two areas are seen to far exceed the cost of protecting the beaches from storm damage, and of restoring them quickly after damage, and expenditure on such programmes has high ratios of benefit to cost.

The Effectiveness of Coastal Zone Management in the United States

The Coastal Zone Management Effectiveness Study was undertaken between 1995 and 1997 to determine how well state coastal management programs in the United States were implementing five of the core objectives of the U.S. Coastal Zone Management Act (CZMA). The five core objectives studied were: (1) protection of estuaries and coastal wetlands; (2) protection of beaches, dunes, bluffs and rocky shores; (3) provision of public access to the shore; (4) revitalization of urban waterfronts; and (5) accommodation of seaport development (as an illustration of the policy to give priority to coastal-dependent uses). Separate articles in this issue of Coastal Management report the findings of the five studies, each dealing with one of the core objectives. Each of the articles assesses issue importance, processes and tools used, and the limited outcome data available for that objective. This article provides an overview of the purposes of the study, the methodology used, the summary findings of each study, and overall conclusions and recommendations of the study team. State coastal programs are found to be effective in addressing the five CZMA objectives examined, but this conclusion is based on very limited information about program outcomes. A more definitive conclusion will require better outcome information. Coastal managers in the United States have not agreed upon indicators of success, which severely inhibits systematic and sustained collection of outcome information. A national outcome monitoring and performance evaluation system is recommended to address these deficiencies and allow better determinations of program effectiveness in the future.

Establishing Fees for Beach Protection: Paying for a Public Good

Costs of controlling shoreline erosion are not allocated equitably. Using estimates from Seabrook Island, South Carolina, we provide a method to set fees based on proximity to the beach. Equitable fees will encourage efficient beach protection policy. This method is also applicable to other areas that require beach maintenance.

Integrated theory of coastal management regarding protection of beaches and dunes

State adoption and implementation of coastal management program components regarding the protection of beaches and dunes vary among the coastal states with federally-approved coastal zone management programs. The level of development of state coastal management programs is influenced by a variety of political, economic, social, and environmental factors. Ordinary Least Square (OLS) regression analyses were employed to determine which of these state factors influence the level of development of coastal management programs. The state factors associated with highly developed coastal management programs were identified as pro-environmental, activist citizenry and history of adopting environmental policies.

Experimental Study on Sediment Movement in a Channel with Model Reef

An artificial beach has been constructed in coastal region facing to a coral reef. To prevent beach erosion, characteristics of sediment movement on the beach should be investigated in flume experiments. The watervelocity becomes very large with wave breaking zone on the reef. Therefore, the critical amplitudes of velocity on reef should be defined for the promotion of beach protection methods. The-experiment results demonstrate that the critical velocity is related to the shields number.

DISTRIBUIÇÃO ESPACIAL DE POLYCHAETA (ANNELIDA) EM DIFERENTES AMBIENTES ENTREMARÉS DE PRAIAS DE SÃO SEBASTIÃO (SP)

Five sandy beaches of São Paulo, Brazil, were sampled in order to determine whether different beach morphodinamics support different macroinfaunal compositions. Density and diversity patterns of Polychaeta from five beaches were compared with some physical and chemical characteristics of those sites. Two patterns were distinguished through examination of diagrams based on muitivariate techniques: (1) in protected beaches with high sand content there is the dominance of Laeonereis acuta : (2) in very protected beaches with high silt and clay content there is the dominance of smaller species. Organic-rich sediments supported a more diverse fauna showing the importance of this source of food on occurrence of many deposit-feeding species. It is suggested that low salinity can determine L . acuta abundance, due to high correlation between this parameter and the density of this specie. The dominance of smaller species on finer sediments, Heteromastus filliformes and Sternaspis capillata , could be due to mechanisms of exploitation of food resources. Principal component analysis showed that sand, silt-clay as well as organic contents and salinity were the most important variables accounting for the spatial variability of polychaetes on the studied beaches.

Spatial distribution of Polychaeta in intertidal sandy beaches at São Sebastião (SP)

Five sandy beaches of Sao Paulo, Brazil, were sampled in order to determine whether different beach morphodinamics support different macroinfaunal compositions. Density and diversity patterns of Polychaeta from five beaches were compared with some physical and chemical characteristics of those sites. Two patterns were distinguished through examination of diagrams based on muitivariate techniques: (1) in protected beaches with high sand content there is the dominance of Laeonereis acuta : (2) in very protected beaches with high silt and clay content there is the dominance of smaller species. Organic-rich sediments supported a more diverse fauna showing the importance of this source of food on occurrence of many deposit-feeding species. It is suggested that low salinity can determine L . acuta abundance, due to high correlation between this parameter and the density of this specie. The dominance of smaller species on finer sediments, Heteromastus filliformes and Sternaspis capillata , could be due to mechanisms of exploitation of food resources. Principal component analysis showed that sand, silt-clay as well as organic contents and salinity were the most important variables accounting for the spatial variability of polychaetes on the studied beaches.

Podial Particle Picking in Cassidulus caribaearum (Echinodermata: Echinoidea) and the Phylogeny of Sea Urchin Feeding Mechanisms.

Selective particle-picking mechanisms of clypeasteroid echinoids (sand dollars and related taxa) are well-known. Those of the extant outgroup to clypeasteroids, the cassiduloids (lamp urchins), have not been analyzed to determine the origins of this sophisticated feeding mechanism. Cassidulus caribaearum Lamarck, 1801, is a small cassiduloid living in the coarse, carbonate sands of protected beaches. The total gut contents of 24 specimens of C. caribaearum, representing a full size range, were studied. The distribution of particle sizes in this sample was not significantly different from that of beach sediment, indicating that C. caribaearum is probably not a selective deposit feeder. Juveniles with a test length of less than 3.5 mm do not feed, but all echinoids that are at least 5 mm long have full, or almost full, guts. The size of the mouth does not limit the sizes of particles eaten, regardless of the size of the animal. Allometric analyses suggest that podial size is also not a strong predictor of ingested particle size. In vivo and histological observations differentiate between the test cleansing functions of the spines and ciliary currents and the feeding activities of specialized podia. The new role played by accessory podia in food-collection by C. caribaearum is a synapomorphy for cassiduloids and clypeasteroids, whereas the exclusive use of phyllopodia seen in earlier irregular echinoids is plesiomorphic.

The biology and conservation status of the grey nurse shark ( Carcharias taurus Rafinesque 1810) in New South Wales, Australia

1. This paper summarizes aspects of the biology and conservation of the grey nurse shark (Carcharias taurus) in south-eastern Australian waters. This species has been a totally protected species in the State of New South Wales since 1984 and, as far as is known, was the first protected shark in the world. 2. Aspects discussed include systematics and taxonomy, distribution and biogeography, morphology and behaviour, reproduction and migrations, feeding habits, fisheries value and claims of attacks on humans, and impacts of protective beach meshing, spearfishing and SCUBA diving. The background to, and history of, moves to protect and conserve the species in New South Wales waters are also covered. 3. Results of surveys of the abundance of this species at Seal Rocks, an area off the mid-north coast of New South Wales where grey nurse sharks are known to aggregate, are reported. Also, a summary of the results of a telephone survey of commercial dive shop operators regarding the occurrence of grey nurse sharks along the New South Wales coastline is presented. 4. Finally, recommendations are made concerning the need for further research on, and management of, this species in Australian waters.

Population model analysis for the loggerhead sea turtle, Caretta caretta, in Queensland

Worldwide declines of marine turtle populations have forced a need for sound conservation policies to prevent their extinction. Loggerhead turtles, Caretta caretta, are declining rapidly at eastern Australian nesting beaches, which are visited by females from all feeding areas for the stock. In some feeding areas of eastern Australia, loggerheads have been protected from deleterious anthropogenic effects. Using long-term mark-recapture data from one such protected group of turtles feeding on Heron Island Reef, Queensland, we created a matrix model to analyse loggerhead demography. We also produced a model for the females nesting at Mon Repos, Queensland, a major rookery where the annual nesting population has declined at rates approaching 8% per year. As indicated by a similar model for loggerheads in the USA, our models predicted that small declines in annual survival rates of adult and subadult loggerheads can have a profound impact on population dynamics. A loss of only a few hundred subadult and adult females each year could lead to extinction of the eastern Australian loggerheads in less than a century. Survival in the first year of life is relatively less important in these long-lived and slow-maturing animals. At Mon Repos, nesting female survival is apparently so low that even beach protection efforts resulting in 90% hatchling emergence success would not prevent population decline. Our research suggests that continued mortality pressure on subadult and adult turtles in their dispersed feeding areas of eastern and northern Australia is a major threat to the eastern Australian loggerhead turtle population. Measures that protect adult and subadult loggerhead turtles should be supported, including the use of turtle excluder devices (TEDs) on prawn trawls.

1993 Student Professional Paper: Graduate Division: Processes and Rates of Shoreline Bluff Recession at Lake Sharpe, South Dakota

Lake Sharpe is the center of three reservoirs formed by dams built by the U. S. Army Corps of Engineers on the Missouri River in South Dakota in the early 1960's. The design service life of the reservoir is 400 to 700 yr based on the expected rate of shoreline erosion to the boundary of the Federally purchased land. In only 30 yr however, this buffer zone has already been eroded and the shoreline continues to retreat into private land at some locations. Processes of shoreline erosion at Lake Sharpe were observed in the field and correlated to bank geology. Active processes of erosion observed included: slump, block slide, debris flow, toppling, slaking, and gullying. Each process was unique to a single bank material. Long term rates of erosion were measured at representative sites from historical profile surveys conducted by the U. S. Army Corps of Engineers. Total shoreline retreat at each site is not related to bank material or retreat process. Total shoreline losses varied from 28 ft to 622 ft since the filling of the reservoir. This makes an average rate of retreat of 1 to 22 ft/yr. Most sites had a generally constant retreat rate after an initial high rate except the gravel sites where retreat is decreasing in rate. The factor causing the extreme erosion is the ease of erosion of the bank materials and their tendency to stay in suspension until they reach deep water. Because the fine-grained bank materials are carried away in suspension rather than be deposited to form a protective beach, the toe of the bluff is continuously subjected to wave action and retreat continues. Only at the shorelines where there is a significant sand or gravel layer does a protective beach develop to slow the retreat rate.