Port authorities view state coastal management programs

Abstract

An estuarine sanctuary is a store of public values due to the ecological, cultural, recreational, aesthetic, historic, and economic services provided by the preserve. These values may be expected to increase over time because of (1) growth in the population demanding estuarine services, (2) growth in the willingness to pay for such services, and (3) growth in the actual quality and quantity of services which are provided by a protected natural system. Thus an estuarine sanctuary will be more valuable to future generations than to current generations. When weighing the cost and benefits of a preservation or development decision, a preservation decision which seems currently undesirable may in fact be socially beneficial when growth in the value of estuarine services is included.     

Title iii of the marine protection,research and sanctuaries act: Issues in program implementation

Abstract

Legislation authorizing the national marine sanctuary program was enacted a decade ago. Since this time, six national sanctuaries have been designated and several additional offshore sites have been reviewed. This paper reviews issues associated with implementation of the program since its inception and focuses on four sites which have undergone review as illustrative of primary programmatic issues: The Channel Islands and Point Reyes‐Farallon Islands National Marine Sanctuaries; the Flower Garden Banks; and Georges Bank.     

The U.S. national marine sanctuary program: An analysis of the program's implementation and current issues

Abstract

The U.S. National Marine Sanctuary Program was established in 1972 by Title III of the Marine Protection, Research, and Sanctuaries Act (16 U.S.C. §1431 et seq.). In this article, we discuss the development of the sanctuary concept, and the original intent of Congress, and analyze how it was applied by the sanctuary program. Differences in interpretation of the program's purpose are examined, including discussion of the multiple‐use management concept, an important but controversial management technique used in the sanctuaries. The continuing efforts by Congress and the National Oceanic and Atmospheric Administration to clarify the program's purpose are investigated. The program's administrative history is explained and the current sanctuaries and active candidates are briefly described. In light of the 1988 reauthorization of the Marine Sanctuary Act, the current issues facing the program are analyzed. Finally, we draw conclusions and make recommendations for the program's future.     

Land use pressures on coastal estuaries in Atlantic Canada

Abstract

The management of estuarine areas in Canada has received little attention; this is specifically the case along the Atlantic coast. This article reviews the importance of estuaries as resources and analyzes the land‐use pressures which can affect them. Specific emphasis is placed on the results of a recent study of estuaries in Atlantic Canada. The incidence of the closures of shellfish areas is used as a measure of the impact of land development on estuaries.     

Duplin river estuarine sanctuary—a description

Abstract

The Duplin River Estuarine Sanctuary was dedicated by Governor George Busbee of Georgia in December 1976. The sanctuary includes the entire Duplin river, related wetlands, and much of the contributing uplands, which extend over 7500 acres. Much of the upland lies on Sapelo Island, neighboring a state wildlife management area, a state natural area, and a community of black families that have lived and worked on the island for many generations. The sanctuary was acquired, in part, with funds from the National Oceanic and Atmospheric Administration, and will be managed for research and educational purposes. The management policy will be designed to avoid artificial or manipulative management control, to protect natural processes and systems, and to promote attainment of scientific objectives.     

建闸河口闸下淤积问题研究综述*

挡潮闸作为河口治理的一项重要措施,在我国广泛采用。河口建闸在为河口地区的经济发展做出积极贡献的同时也带来了严重的闸下泥沙淤积问题,限制了河口资源的综合利用。介绍我国建闸河口闸下淤积情况,并阐述国内外学者针对闸下淤积问题进行的机理探讨和模拟研究。总结出影响闸下淤积形态的多个因素,包括潮流作用、闸下引河长度、河口泥沙的动力特性、闸下港道类型以及建闸位置等。提出以前的研究中存在的缺陷并针对性地建议今后的研究方向和研究途径。     

河口航道整治水位及宽度研究

对河口整治水位的确定进行了一些初步的分析,并基于输沙平衡原理,借助于挟沙力公式,推导了河口整治线宽度计算式.运用前述的方法和公式,给出了虎跳门河口段(横山-虎跳门口)整治水位及整治线宽度.分析了虎跳门(南门涌～虎跳门口)河段航道整治工程的整治效果,结果表明,整治工程达到了预期的效果.同时,把整治后整治线内的实际冲刷厚度与利用整治线宽度计算式反推的计算冲刷厚度进行了分析比较.综合分析表明,整治水位和整治线宽度的确定方法和公式是合理的,可以给类似河口的航道整治提供参考.     

Nutrient dynamics and phytoplankton development along an estuary–coastal zone continuum: A model study

This study presents a first attempt to quantify the biogeochemical transformations and fluxes of carbon and nutrients along the entire mixing zone of the shallow, tidally-dominated estuary–coastal zone continuum of the Scheldt (Belgium/The Netherlands). A fully transient, two-dimensional, nested-grid hydrodynamic model of the continuum is coupled to the biogeochemical MIRO model for the coastal zone and the CONTRASTE model for the estuary. Transient model simulations are performed with a high spatial (80–750 m) and temporal (30 min) resolution over a period of one year (January–December 1995). The high temporal resolution allows including the short-term variability triggered by the tides, the freshwater discharge and the wind stress. System scale simulations provide time series of nutrient transformations and fluxes along the entire estuary–coastal zone continuum, as well as highly resolved nutrient inventories for the estuarine and the coastal zone sub-domains. Simulation results reveal that the balance between highly variable estuarine nutrient inputs and physical constrains set by the unsteady residual transport field exert an important control on the magnitude and succession of phytoplankton blooms and the ecosystem structure in the coastal zone. In addition, they suggest that the poorly surveyed estuarine–coastal zone interface plays a central role in the continuum. In this dynamic area, marked spatial concentration gradients develop and episodically lead to a reversal of material fluxes from the coast into the estuary. During distinct episodes of the productive period, euryhaline coastal diatoms intrude far upstream into the saline estuary. This intrusion reduces the estuarine nutrient concentrations and export fluxes, thereby reinforcing the nutrient limitation in the coastal area. As a consequence, the estuarine filter does not operate independently from the processes in the coastal zone. The dynamic interplay between the two ecosystems and the intense process rates operating at their transition, therefore, strongly supports our continuum approach.     

围垦工程对温州近海及河口悬沙场的影响

在温州市瓯江河口及近海水域大范围连续大、中、小潮实测水文泥沙资料及水下地形资料的基础上,建立包括瓯江、飞云江及鳌江在内的大范围平面二维潮流及悬沙输运数学模型,并进一步以2002年为基准水平年,在温州市滩涂资源利用现状的基础上,就近期、中期和远期规划的围垦工程的实施对温州市3大主要入海河流——瓯江、飞云江及鳌江河口及近岸水域的悬沙场分布、断面输沙率、海床冲淤演变等方面的影响进行研究。研究表明:远期工程由于围垦区域较大,影响相应也最大,而中期和近期工程的影响则相对较小。     

上海崇明越江通道工程环境地质问题及其防治

上海崇明越江通道工程是长江河口地区重要的国家基础性建设项目,所在区域不良地质条件易给工程施工带来不利影响。文章阐述软土变形、水土突涌、水下砂体运移、浅层天然气、岸带冲淤、砂土液化、地面沉降等环境地质问题及其潜在的工程危害,提出相应的防治对策与技术措施。     

Water quality and shellfish management in tillamook bay,Oregon

The contamination of shellfish by pathogenic bacteria and viruses is a concern of shellfish producers, distributors, and consumers. To address these water quality concerns, the National Shellfish Sanitation Program has classified shellfish growing waters as approved, conditionally approved, or prohibited. The Tillamook estuary is one of Oregon's primary shellfish harvest areas. Degradation of water quality in Tillamook Bay has been linked to oyster bed closures, declines in salmonid populations, and decreases in recreational use of estuarine resources. In this study, water quality concerns related to shellfish management are addressed by examining the patterns of fecal coliform bacteria (FCB) concentration in Tillamook Bay. A oneway analysis of variance was used to compare log‐transformed FCB concentrations in prohibited, restricted, and conditional shellfish management areas. We found (I) a difference in Tillamook Bay water quality between all three areas and (2) a change in FCB concentrations through time in each management area. Since the designation of shellfish management areas affects the economy and public health, monitoring practices need to be reevaluated in order to draw more refined conclusions about water quality trends in Tillamook Bay.     

Challenges and Myths in Norwegian Coastal Zone Management

Abstract

This paper is written in response to a recent publication (Walker, 1973) which questions both the biological basis for wetlands preservation and the usefulnesss of scientific participation in the formulation of management policies. Our major points are that: (1) considerable evidence exists linking wetlands primary production to aquatic secondary production, (2) all available information suggests that large‐scale wetlands destruction results in lowered production of estuarine organisms of interest to man, (3) more than economics needs to be considered in attempts to analyze the procedures by which the wetlands controversy is to be resolved, and (4) uncertainty about the applicability of scientific findings to a particular problem situation does not destroy the usefulness of those findings in reaching a solution to a public controversy.     

Submerged Geosynthetic Reef as Shore Protection Measure for Islands

The Sagar Island, located north of the Bay of Bengal, intercepts the flow in the Hoogly estuary that comprises a network of several estuarine distributaries and...     

The importance of estuarine gravitational circulation in the early life of the Bohai Penaeid Prawn

Estuaries along the southern shore of the Bohai Sea are the major habitat of the Bohai Penaeid Prawn (Penaeus chinensis). Since the 80's, however, many of the rivers have been dammed. Field observations, as well as laterally integrated 2-D numerical experiments, were conducted to understand both the role of estuarine gravitational circulation and the impact of the damming of the rivers on the early life of the Bohai Penaeid Prawn.For a river with runoff, especially for small discharge, the gravitational circulation tends to transport the planktonic larvae in their metamorphosis phase near the river mouth where condition is favorable for survival. The gravitational circulation inside the estuary tends to transport the mysis phase larvae towards the upstream end of the estuary when the most part of the larvae suspended in the bottom layer, and it transports the post larvae to the low salinity near upstream side of the estuary when the larvae become benthic, if the larvae enter the estuary.Damming causes long periods of zero runoff in the river, resulting in the alteration of the estuarine circulation and in the change of the estuarine environment. In addition, excess evaporation may prematurely transport the planktonic larvae into the estuary. On the other hand, sudden release of a large volume of freshwater from behind the dam may exert undesirable stress on the larvae.     

不同导堤高程下射阳港区进港航道的淤积变化

粉沙质海岸泥沙具有易起动、易沉降、密实快的特点,对港口航道维护具有较大影响。通过双导堤布置形式来降低港池航道的回淤,是射阳港区进港航道整治工程中的关键。采用模型试验对不同堤顶高程下港区进港航道的泥沙淤积量及分布情况进行研究。分析表明,堤顶高程在平均高潮位附近可在工程造价和减淤效果两方面均取得较好的结果,可供类似工程设计时参考。     

Residence time,exposure time and connectivity in the Scheldt Estuary

Residence times and exposure times are computed for 13 boxes in the Scheldt Estuary, using the high-resolution tracer-transport model SLIM. The concepts are clearly defined and related to how they should be computed. First, the timescale values are compared with results published previously that were obtained with a simple box model, and an unexpected difference is revealed. This may suggest that a high-resolution model is necessary, even for the computation of such integrated quantities as residence or exposure times. Secondly, the newly computed residence times are compared to the exposures times to illustrate their intrinsic differences. From this difference, it is possible to propose a return coefficient, expressing the fraction of the exposure time that is due to “returning water”, i.e. water which has already left the estuary at least once. Finally, the estuarine exposure times are decomposed into the different box exposure times, resulting in a connectivity matrix. This matrix expresses how much time is spent in each of the estuarine subdomains during the water parcels' journey through the estuary.     

Ground truthing sediment profile imagery with traditional benthic survey data along an established disturbance gradient

Macrobenthic surveys are an expensive, slow and labour intensive means to establish the health of benthic communities. Sediment profile imagery (SPI) is a means of rapid reconnaissance for monitoring large areas of the benthos. SPI has often been used to monitor gross anthropogenic disturbance. The aim of this study is to determine if SPI can be used as a tool to reliably map change in communities along natural estuarine gradients. Macrobenthic sampling was carried out at five stations along an established estuarine gradient. This faunal data was analysed using standard multivariate techniques and to ground truth a concurrent SPI survey. Faunal analysis showed that habitat quality in Inner Galway Bay was generally good, with some localised disturbance from the River Corrib and the sewage out flow exterior to the city dock. Four distinct groups were identified with a degree of overlap occurring between stations 3 and 4. While existing SPI indices mapped habitat quality in the same manner as the faunal data for end member stations, the level of distinction between the habitats of an intermediate staging was found to be poor. This lack of distinction amongst the stage 2 and 3 stations was overcome by developing a tailored index, the Galway Bay index of habitat quality (GBHQ). This index was derived from the 5 observed variables in the SPI data that were determined to best match the faunal distribution by permutative mantel testing. The 5 observed variables from the SPI data were the depth of the apparent redox potential discontinuity (aRPD), the depth of penetration by the prism, and the presence/absence of infauna, surface faecal pellet layer and biogenic mounding. The GBHQ was able to distinguish between the 5 stations to a greater extent than previously described indices, showing clearly the separate groupings defined by the faunal data. The index was tested on a follow up SPI survey and shown to be applicable in mapping a broader range of habitats in Galway Bay. Indices generated for localised mapping of estuarine gradients should be derived from observed features and be ground truthed using faunal data. Some aspects of the GBHQ should be generally applicable to fine grained boreal estuarine sediments (aRPD/penetration), while others may be of limited utility in other locations depending on the digging characteristics of the particular SPI camera, and local factors influencing the persistence of biogenic features in the profile. This derivation technique provides a simple way to optimise SPI to particular studies and localities.     

登陆台风对长江口口门水域的影响

针对登陆台风对长江口口门水域产生的影响问题,采用统计学方法对3次登陆台风期间现场采集的长序列定点观测资料进行系统分析。结果表明,台风登陆后有效波周期减小至常态天气水平,未出现长周期涌浪;台风登陆前水位抬升,最大增水与最大有效波高均出现在登陆前高潮时;台风登陆前有效波高在2 m以上时,波浪对口门处由南向北的横向流速分量起到抑制作用;其他时段,口门处由南向北的横向流速分量变化与涨潮过程一致。     

潮汐河口长航道乘潮问题研究

针对潮汐河口长航道乘潮计算的潮位资料代表性问题,提出了潮汐河口乘潮水位的多站联合计算法。该方法利用多站同步潮位资料,综合考虑船舶通航方式与潮波传播速度等因素,可合理计算潮汐河口乘潮水位。长江口深水航道的有关计算表明,相同乘潮历时和累积频率对应的乘潮水位,进河口大于沿程单站的乘潮水位,且明显大于出河口。潮汐河口长航道设计,应根据当地河口的潮汐性质、强度及其与径流的对比,以及船舶航行的特点包括航速、进出港载货情况和航道沿程水深,确定合理的乘潮方式,即选择合适的航道乘潮长度。     

Coastal Ecosystems and Agricultural Land Use: New Challenges on California's Central Coast

This article uses the Central Coast region of California as a case study to examine the challenges of protecting coastal ecosystems near areas of intensive agricultural production. Coastal water quality and biodiversity are greatly impacted by regional land use. Agricultural land use can have significant impacts on water quality through erosion and the runoff of agricultural chemicals. While the Central Coast region of California is a center for intensive agricultural production, it is also home to the largest marine sanctuary in the United States. This combination has resulted in intensive efforts from government agencies and conservation organizations to reduce pollution associated with agriculture. Efforts have focused on education and incentives, but are recently facing increasing challenges stemming from new standards created by the produce industry in response to food safety concerns. Personal interviews with crop growers were used to explore these challenges and to better understand the range of possible environmental impacts resulting from new food safety standards. Results indicate that substantial management changes are taking place that are likely to impact regional water quality and wildlife. This case study also explores the role of policy networks in shaping management decisions and illustrates how certain approaches to addressing agricultural pollution may be vulnerable to external policy changes.