The East Greenland Coastal Current: Structure, variability, and forcing

The subtidal circulation of the southeast Greenland shelf is described using a set of high-resolution hydrographic and velocity transects occupied in summer 2004. The main feature is the East Greenland Coastal Current (EGCC), a low-salinity, high-velocity jet with a wedge-shaped hydrographic structure characteristic of other surface buoyancy-driven currents. The EGCC was observed along the entire Greenland shelf south of Denmark Strait, while the transect north of the strait showed only a weak shelf flow. This observation, in conjunction with water mass considerations and other supporting evidence, suggests that the EGCC is an inner branch of the East Greenland Current (EGC) that forms south of Denmark Strait. It is argued that bathymetric steering is the most likely reason why the EGC apparently bifurcates at this location. Repeat sections occupied at Cape Farewell between 1997 and 2004 show that the alongshelf wind stress can have an influence on the structure and strength of the EGCC and EGC on timescales of 2-3 days. Accounting for the wind-induced effects, the volume transport of the combined EGCC/EGC system is roughly constant (∼2 Sv) over the study domain, from 68°N to Cape Farewell near 60°N. The corresponding freshwater transport increases by roughly 60% over this distance (59-96 mSv, referenced to a salinity of 34.8). This trend is consistent with a simple freshwater budget of the EGCC/EGC system that accounts for meltwater runoff, melting sea-ice and icebergs, and net precipitation minus evaporation.     

Coastal ecosystem change in Asia: hypoxia,eutrophication, and nutrient conditions

Journal of Oceanography -     

Coastal management in Tanga, Tanzania: a decentralized community-based approach

This paper describes a new initiative in coastal management in northeastern Tanzania. The region is within the equatorial part of the Western Indian Ocean. The priority environmental issues being faced include declining fish catches, use of destructive fishing techniques, mangrove cutting and coastal erosion. There is a widespread perception among the users of the coastal resources that management of these issues is inadequate. This programme initiative is developing flexible, community-based approaches to identifying the problems and to take achievable actions. The programme provides training in a wide range of skills and appropriate technical methods for government officials, extension workers and villagers. A collaborative process is evolving that includes participatory appraisals, village environmental committees, facilitation by government extension workers, technical advise and supervision by district technical teams, and regional-wide workshops with key players. Village initiatives taken so far include new by-laws, gear inspection, reef zoning and closures. A number of village mariculture projects are being piloted.     

融合地学知识的海岸带遥感图像土地利用/覆被分类研究

针对海岸带地理环境的特殊性和城区海岸带地物的复杂性,应用Landsat7 ETM+遥感影像,结合地物光谱特征分析,融合地物的空间属性、地带性分布规律、物候规律等多种地学知识,建立特定的规则,逐级分层次地提取海岸带土地利用/覆被信息。结果表明:在没有任何人工修正的前提下,总体分类精度达95.8%,总体Kappa系数为0.944,实现了研究区域较快速和较高精度的地物自动化信息提取。     

Discussion on Coastal Erosion Near Xizhuang, Penglai, China

-In this work, on the basis of the characteristics of coastal erosion near Xizhuang (Penglai, Shandong, China) and the in-situ measured data and theoretical calculation, the causes of coastal erosion there are obtained: (1) natural erosion, (2) beach sand borrowing, and (3) sand borrowing at the Dengzhou shoal near Xizhuang, which results in the loss of the function of the wave force resistance of the shoal. Since the wave energy is increased, the longshore sediment transport rate is increased. Coastal erosions are more and more serious. A scientific basis to reduced the calamity of coastal erosion in local area is presented. Some experiences are accumulated for studying coastal erosion.     

Coastal planning on the Atlantic fringe,north Norway: the power game

The article describes an on-going struggle between local planning authorities, regional fishery authorities and environmental authorities over the management of the Norwegian coastal zone. Particular reference is made to a recent planning project in Nordland County where 18 peripheral communes with weak planning traditions joined forces to produce structure plans for their coastal areas. Concepts of rationality and power are used as points of departure for an interpretation of the actions of the parties involved. The discursively rational nature of the planning project, embodying principles of consensus building, social integration and personal growth, is contrasted to the strictly instrumental behaviour of regional fishery and environmental authorities. The article also relates conflicts between communes and regional sector authorities to the power structure of the field of coastal management and the habitus of the different institutional actors. The actions of the fishery authorities are seen as a defence of their monopoly of the production of ideology in marine management, while the actions of the communes are interpreted as a bid by the periphery for greater control over local resources.     

河口岸滩侵蚀研究进展

系统了介绍了几十年来岸滩侵蚀的研究进展,认为大部分研究成果多是对岸滩侵蚀的机理和侵蚀过程的研究,主要采用定性的或者定性—半定量的研究方法,因为横向输砂的机理还不是很清楚,定量分析的数学模型研究较多但不成熟。在深入分析的基础之上,就今后岸滩侵蚀的研究工作进行了讨论,并提出了几点建议。     

中国海岸侵蚀治理和海岸保护

加强海滩和海岸侵蚀的研究，组织建筑用砂资源的调查，进一步完善海洋环境保护法或制定海岸环境保护法以便制止不合理的采砂和保护沿岸单位和居民的合法权益，使出现环境问题后的赔偿有确定保证，防止人工海岩进一步扩大，发展偏僻海岸地区的发候旅游，让沿岩居民能从保护海岩中得到实际利益，以便使我国海岸侵蚀治理和海岸保护达到一个新水平。     

Coastal fishing: resource's enhancement and preservation

The recession in the French fishing industry in the early 1990s led to disastrous human and economic situations. In response to this crisis some groups of commercial fishermen committed themselves to finding a way to enhance their profitability and adapt their production to meet the demand. Their efforts led to the implementation of a quality scheme (Bretagne Qualité Mer, Ligneurs de la Pointe de Bretagne, etc.) to ensure the freshness and quality of their products.The relationship between the enhancement project fishermen's incomes and the consequences for resource usage are analysed in the Valpêche research programme (Rapport final du programme Valpêche, 2002, 340 [1]). The fishermen's attitude towards the enhancement programme was analysed with surveys of 185 and 60 skippers working along the Channel, from Brest to Boulogne. The surveys were designed to investigate the success of the enhancement programme and its knock on effects. At first, we focus on the question of the relative adaptability of official certification standards for aquatic products, then, we analyse the level of uptake from the industry. We also use a preliminary cost–profit and cost–efficiency approach to interpret the impact that such programmes have on fishermen's incomes. Finally, we focus on the impact of such a programme on the level of effort expressed by the fleet, in other words the incentive to fish more or less. The paper ends by considering how a product enhancement programme could be combined with increasing incomes and better management of the resource? In this respect, we rely on the results of the survey that was done among fishermen adhering to the marketing programme “Ligneurs de la Pointe de Bretagne”.     

Scientific research in the Tamaulipas Coastal Zone,Mexico:: implications for its coastal management

The perspectives of an efficient coastal management organization for the Tamaulipas Coastal Zone in Mexico are analyzed. With seven coastal municipalities, Tamaulipas has nevertheless 430 km of littoral and the largest estuarine area in the country (231,200 ha). The main activities there are: cattle breeding, fisheries and local manufacturing and urban development is actively increasing, concentrating in the Tampico-Ciudad Madero “Metropolis.” All of this affects significantly the many important natural ecosystems present. Following a comprehensive literature search and field visits to the area, it was made clear that the State's coastal zone is largely unknown scientifically. The organization of the Country Administration for its management of natural resources is overviewed and the criteria for the selection of the nine areas considered prioritary for ecological protection or conservation are explained. The main challenges facing the area with respect to an efficient coastal management are: (1) to close the gap in its scientific knowledge and make available all existing and future information to interested parties, (2) to modify the Administration organization to make the application of legal tools more efficient (3) to encourage open discussion, exchange of ideas and interactive forums among the different sectors (scientific, administrative, public and private organizations).     

Iran's Integrated Coastal Management plan: Persian Gulf,Oman Sea,and southern Caspian Sea coastlines

Iran, having two separate coastlines at its north and south of about 3000 km length, with very different characteristics, suffers from various coastal problems. While its northern coastal area is over-populated and its sensitive and unique habitats must be protected from destruction, most of its southern coastal areas are undeveloped and deserted. Intense oil and gas exploitation activities in the Caspian Sea region and occurrence of two wars in the Persian Gulf during the last two decades have rendered hydrocarbon pollution a major issue for this country's marine and coastal environment. Biodiversity is under threat in some areas and natural resources are deteriorating. To overcome the problems, Integrated Coastal Management has been considered by Iran's government as a long-term solution. In Iran's ICZM study project, baseline studies along with social, economical, and spatial planning studies in the coastal provinces are carried out in order to achieve the desired outcomes as a number of strategic plans for the coastal areas that are to be implemented by a coastal management entity. Providing the required laws and regulations for establishing such a management body is also under way. In this paper after reviewing Iran's coastal zone characteristics and problems, the long-term goals, strategies, and policies for sustainable management of Iran's coastal areas are outlined. Then, the ICZM study procedure and its prospected outcomes are explained, and importance of some of the findings of Iran's ICM is emphasized. Finally, some challenges including having two separate and different coastlines at the north and south of the country and their effects on the Iran's ICZM plan are discussed.     

Hydrology and Salt Balance in a Large, Hypersaline Coastal Lagoon: Lagoa de Araruama, Brazil

Lagoa de Araruama in the state of Rio de Janeiro, Brazil, is a hypersaline coastal lagoon as a result of semi-arid climate conditions, a small drainage basin and a choked entrance channel. The lagoon has been continuously hypersaline for at least 4·5 centuries, but the mean salinity has varied substantially. It has recently decreased from 57 to 52 as indicated by density (salinity) measurements between 1965 and 1990.Analysis of more than 20 years of salinity time series data, in addition to monthly lagoon cruises to measure the spatial salinity distribution, indicate that the lagoon salinity largely fluctuates in response to the difference between evaporation and precipitation. The major factor explaining the long-term trend of decreasing salinity in the lagoon is the constant pumping of 1 m³s⁻¹of freshwater to the communities surrounding the lagoon from an adjacent watershed, and subsequent discharge of this water into Lagoa de Araruama. The net salt budget is primarily a balance between the advective import of salt from the coastal ocean and eddy diffusive export of salt to the ocean, although the extensive mining of salt from the lagoon during past decades is also a small but significant contribution to the salt budget. The flushing half-life is proposed as a useful time scale of water exchange, is calculated based on a combination of hydrological and tidal processes, and is excellent for comparison of lagoons and assessing water quality changes. The flushing half-life measures 83·5 days for Lagoa de Araruama, considerably longer than for most other coastal lagoons. The proposed dredging of a second ocean channel to Lagoa de Araruama is probably not a good idea. It is likely to accelerate the decrease of lagoon salinity and somewhat improve the lagoon water exchange. At the same time, this will eliminate the apparent buffering capacity provided by the hypersaline environment, and thus may potentially cause water quality problems.     

Coastal Placer Deposits of Central Tamil Nadu, India

Placer mineral exploration has been undertaken along the beach of Central Tamil Nadu coast from Pondicherry to Vedaranyam. On the basis of the drainage network, geomorphology, and the coastal environment, the study area has been grouped into three sectors, North, Central, and South. Heavy mineral by Wt% shows a slightly higher abundance in the Northern sector, an enrichment of opaques in the Central sector from stations between Poompuhar and Karaikal, and a total depletion in the Southern sector. An abundance of heavies in the Northern sector is considered to be the result of a higher wave energy, and the cymatogenic downwarping of the basin during the present transgression. An enrichment of heavies in the Central sector from Poompuhar to Karaikal is attributable to the reworking of the beach ridges, which were submerged during the present transgression, and to the role of density sorting. A depletion of heavies in the Southern sector is accounted for by the absence of a terrigenous supply and the prevalence of wave shadow conditions throughout the year. The nature of the heavy mineral assemblage reflects the derivation of sediments principally from khondalites, granites, metamorphic rocks and paleo-sediments. Factor analysis also supplements the predominant role of a density factor in the segregation of heavy minerals in the study area. A five-stage model is proposed for the formation of placer deposits in the study region. The present study has disclosed rich concentrations of ilmenites in the central sector between Poompuhar and Karaikal that can be commercially exploited.     

Coastal Placer Deposits of Central Tamil Nadu,India

ABSTRACT

Placer mineral exploration has been undertaken along the beach of Central Tamil Nadu coast from Pondicherry to Vedaranyam. On the basis of the drainage network, geomorphology, and the coastal environment, the study area has been grouped into three sectors, North, Central, and South. Heavy mineral by Wt% shows a slightly higher abundance in the Northern sector, an enrichment of opaques in the Central sector from stations between Poompuhar and Karaikal, and a total depletion in the Southern sector. An abundance of heavies in the Northern sector is considered to be the result of a higher wave energy, and the cymatogenic downwarping of the basin during the present transgression. An enrichment of heavies in the Central sector from Poompuhar to Karaikal is attributable to the reworking of the beach ridges, which were submerged during the present transgression, and to the role of density sorting. A depletion of heavies in the Southern sector is accounted for by the absence of a terrigenous supply and the prevalence of wave shadow conditions throughout the year. The nature of the heavy mineral assemblage reflects the derivation of sediments principally from khondalites, granites, metamorphic rocks and paleo-sediments. Factor analysis also supplements the predominant role of a density factor in the segregation of heavy minerals in the study area. A five-stage model is proposed for the formation of placer deposits in the study region. The present study has disclosed rich concentrations of ilmenites in the central sector between Poompuhar and Karaikal that can be commercially exploited.     

Coastal erosion risk assessment of Hainan Island,China

Coastal erosion on islands is increasing due to sea level rise, frequent extreme events, and anthropogenic activities. However, studies on the multifactorial coastal erosion risk and the vulnerability of islands are limited. In this study, the Coastal Erosion Risk Assessment(CERA) method was applied for the first time to the study area in China to assess the erosion risk on the coast of Hainan Island; to explore the effects of coastal ocean dynamics,sediment movement characteristics, and anthrop...     

Coastal lagoon habitat re-creation potential in Hampshire,England

The Solent region in southern England represents one of the highest concentrations of coastal lagoons and saline ponds in the UK. Four lagoon complexes within the region comprise a Special Area of Conservation (SAC), under the European Habitats Directive. The ephemeral nature of coastal lagoons presents a particular management challenge in terms of retaining designated sites in “favourable conservation status”. Consequently, in addition to sensitive management of existing sites, it is important to identify sites for habitat re-creation. A site-specific investigation of Hook Lake in Hampshire is presented. Previously, on the basis of salinity measurements alone, this site was deemed to have progressed naturally through brackish conditions to a freshwater habitat overgrown by reeds Phragmites sp. A more detailed survey, which considered salinity measurements together with an analysis of substratum heterogeneity and invertebrate fauna diversity, suggests that it is still predominantly a freshwater system with an adjacent brackish/saline ditch. Future management, linked to local biodiversity action plan targets, could proactively support the development of this site as a coastal lagoon in order to secure its integration as part of the international conservation designation. However, this is complicated by the need to then recognise and compensate for loss of freshwater habitat, the need to persuade the local community that any change would not compromise coastal defence integrity and ultimately by medium to long-term coastal defence investment decisions.