珠江口红树林基围养殖生态开发模式评述

起源于珠江三角洲的红树林基围(land-based enclosure)养殖传统模式是红树林可持续利用和生态开发范例之一。本文介绍了珠江口红树林基围养殖生态开发模式的3个个例: 仅存香港米埔红树林自然保护区的传统基围养殖运作历史和演变, 及其候鸟生境、养殖、观鸟、环境教育综合功能的实现; 珠海淇澳岛大围湾红树林传统和粗放式基围养殖试验和围内水位盐度等环境条件变化对红树林生长影响的研究; 伶仃洋东岸海上田园红树林海水种植-集约式养殖系统试验和红树林净化水质研究。在珠江口红树林保护管理及海域污染防治过程中建议重视红树林可持续利用模式的研究和推广, 建立新的基围养殖示范区, 大力推广红树林基围养殖的生态开发模式, 探索毁林养殖区红树林友好式整治模式, 改善红树林基围养殖技术提高养殖产量, 加强红树林基围养殖系统相关科学研究。     

深圳香港海域可能最高潮位和浪高计算分析

基于历史数据的分析,选择历史上强度最强的台风"荷贝"作为设计超强台风的强度,最不利路径的台风"雪莉"作为设计路径,作为深圳香港海域设计超强台风。采用海洋-陆架区-海岸三重嵌套网格建立的天文潮-风暴潮-台风浪耦合模型计算设计超强台风遭遇天文大潮的高潮位登陆时深圳香港海域的可能最高潮位和浪高。计算结果表明,大鹏湾北部和香港吐露港内,可能最高风暴潮位在3.00 m以上,浪高达到4.0～5.0 m;香港维多利亚港风暴潮位2.92 m,深圳香港水域东部南部在2.50 m以上,浪高3.0～5.0 m。可能最高风暴潮位比大鹏湾防潮警戒水位高1.62 m左右,比香港维多利亚港200年一遇的潮位高0.50 m。     

粤港澳大湾区红树林时空分布演变及现存林龄遥感分析

红树林作为热带、亚热带以红树植物为主体的海岸带生态系统,是重要的海岸湿地类型之一。本文使用多源、多时相遥感数据,形成了1969-2020年粤港澳大湾区岸线、围填海、养殖区、红树林分布数据图集,并利用联合红树林识别指数(CMRI)对大湾区现存红树林进行时序分析得到红树林林龄数据集。结果表明,通过多源遥感数据解译得到现存红树林数据集,结合CMRI时序数据可以建立现存红树林变迁历史,进而有效估算红树林林龄。粤港澳大湾区红树林的时空分布发生了明显变迁,现存红树林面积约为3 316 hm²,大湾区内部各地区存量林龄差异较大,整体林龄均值为20 a。近50年间,岸线整体向海移动,岸线变迁、围填海和养殖区变化显著影响红树林面积、空间分布及林龄大小,人工种植是近20年红树林恢复的主因。     

香港红树林区软体动物生态研究

1994年夏季(6月至9月)和冬季(1994年12月至1995年2月)对香港14片红树林的软体动物作了定性和定量调查。调査期间采到的软体动物已鉴定52种,其中腹足类45种,双壳类7种。采用 Bray-curtis 相似系数和逐步形成分类系统的方法进行聚类分析。基本上可分为4组断面,分别以粗束拟蟹守螺(Cerithidea djadjariensis )、奥莱彩螺(Clithon oualaniensis )、沟纹笋光螺(Terebralia sulcata )和红树拟蟹守螺(Cerithidea rhizophorarum)为第一密度优勢种。不同底质的红树林区软体动物组成有显著差异。污染可能是造成沙头角红树林区软体动物多样性低的重要环境因子。盐度和潮汐制约一些软体动物的垂直分布和水平分布,纵带滩栖螺(Batillaria zonalis )和多形滩栖螺(Batillaria multiformis )在红树林区海缘高密度栖息,分别高达120个/㎡和240个/㎡。在淡水注入的红树林区常有广盐性软体动物栖息,如中国绿螂(Glauconme chinensis)。     

粤港澳大湾区港口供应链优化研究

为充分发挥粤港澳大湾区港口的竞争优势,促进港口经济的协调发展,文章基于粤港澳大湾区主要港口的实际情况,构建供应链博弈模型并进行数值仿真,研究相关因素对深圳港和香港港绩效的影响。研究结果表明:随着商品价格和库存成本的提高,货物从深圳港向香港港转移,但转移幅度逐渐趋缓;深圳港在中低端商品的货源收集方面具有明显的竞争优势,而香港港对高端商品的吸引力更强;货运结构逐渐向中高端商品过渡对于提高港口收益具有促进作用,其中深圳港应通过降低商品库存成本而降低经营风险;深中通道和港珠澳大桥通车有效缩短腹地运输时间,对于绝大部分商品价格和库存成本组合都将提高粤港澳大湾区港口的总收益。     

Oil-Spill Monitoring in the Coastal Waters of Hong Kong and Vicinity

In this study, we applied the edge-detection method of oil-spill monitoring to extract oil-spill features observed by the ENVISAT Advanced Synthetic Aperture Radar (ASAR) images over the coastal waters of Hong Kong and vicinity in northern South China Sea. Two examples in 2007 and 2008 over the coastal waters of the study area show that oil spills can be successfully detected by ASAR images at wind speeds around 4～ 6 m/s independent of wind direction. The study also shows that it could be helpful for evaluating the potential impacts of oil spills on the coastal environment in Hong Kong and vicinity.     

Remote Sensing of Mangrove Change Along the Tanzania Coast

This article contributes to the understanding of the changes in distribution and total area of mangrove forests along the mainland Tanzania coast over the past decade. Mangroves are recognized as critical coastal habitat requiring protection and special attention. The Tanzania coastline forms a suitable habitat for establishment of mangrove forests. Mangrove forests are distributed from Tanga in the north to Mtwara in the south covering approximately 109,593 hectares from 1988-1990 and about 108,138 hectares in 2000. The largest continuous mangrove stands are found in the districts of Rufiji, Kilwa, Tanga-Muheza, and Mtwara. Comparison of data between these two time periods shows that the geographic coverage of mangroves has no dramatic change in the past decade. The Tanzania Mangrove Management Project and other closely related programs and efforts pertaining to mangrove conservation contribute to direct restoration and natural regeneration of mangroves. This study documents the changes of mangroves and demonstrates that remote sensing and GIS offer important data and tools in the advancement of coastal resource management and ecosystem monitoring. Application of geographic information technologies is critical for improved coastal resources management and decision making for sustainable development in Tanzania.     

A model study of influence of circulation on the pollutant transport in the Zhujiang River Estuary and adjacent coastal waters

A tracer model with random diffusion coupled to the hydrodynamic model for the Zhujiang River Estuary (Pearl River Estuary, PRE) is to examine the effect of circulations on the transport of completely conservative pollutants. It is focused on answering the following questions: (1) What role does the estuarine plume front in the winter play in affecting the pollutants transport and its distribution in the PRE ? (2) What effect do the coastal currents driven by the monsoon have on the pollutants transport? The tracer experiment results show that: (1) the pollutant transport paths strongly depend on the circulation structures and plume frontal dynamics of the PRE and coastal waters; (2) during the summer when a southwesterly monsoon prevails, the pollutants from the four easterly river inlets and those from the bottom layer of offshore stations will greatly influence the water quality in Hong Kong waters, however, the pollutants released from the four westerly river-inlets will seldom affect the water quality of Hong Kong waters due to their transport away from Hong Kong; (3) during the winter when a northeasterly monsoon prevails, all pollutants released from the eight river gates will be laterally transported seaward inside the estuary and transport westward in the coastal waters along the river plume frontal zone. However, pollutants released from the surface layer of offshore stations near or east of the Dangan Channel will be carried into the coastal waters of Hong Kong by the landward component of the westward coastal current driven by the winter northeasterly monsoon. But the pollutants from the bottom layer of the offshore stations will be carried away from the offshore by the bottom flow driven by the northeasterly monsoon. This implies that only surface-released matter from offshore stations will affect the water quality of the coastal waters around Hong Kong during the winter when a northeasterly monsoon prevails.     

基于无人机高光谱特征的红树林种群识别研究

红树林种群的组成和分布对于红树林生态系统的保护和恢复至关重要。本研究以漳江口红树林保护区为研究对象,通过获取无人机高光谱影像,进行光谱特征分析、光谱微分变换和包络线去除,提取了911组17个光谱特征参数,通过逐步判别分析筛选出13个用于决策树构建的特征参数,最终通过C5.0决策树模型获得了研究区红树林种群的分布状况。结果表明,漳江口红树林保护区植被种群呈现自上到下不同类型的分布情况,研究区上部以桐花树和秋茄混合类型为主,中间区域呈现白骨壤、桐花树和秋茄三者共生的现状,研究区下部则以白骨壤分布为主,伴生有少量的秋茄。通过混淆矩阵计算,得到研究区总体分类精度为 87.95%,Kappa系数为 83.81%,具有较好的精度。研究结果可为区域红树林湿地保护提供数据支撑,为红树林种群识别研究提供方法参考。     

深圳香港海域浪潮耦合模型的建立及其应用

以河口海岸海洋模型ECOM和第三代海浪模型SWAN为基础,以全球天文潮预报模式TPXO6.2和台风参数模型风场及气压场作为驱动,采用海洋-陆架区-海岸三重嵌套网格,建立了适用于深圳香港水域天文潮-风暴潮-台风浪耦合模型。以0814号台风"黑格比"为算例,进行了耦合模拟计算,计算结果显示,天文潮、风暴潮位和浪高与实测值符合良好,天文潮的均方根误差小于0.15 m,有效波高误差0.9 m,风暴高潮位平均误差0.23 m;并分析了风暴潮位和波浪的相互影响,以及深港水域波浪场的分布,4 m水深考虑风暴潮位影响有效波高提高0.40 m,沿岸波浪增水在0.20 m以内。     

The state of legislation and policy protecting Australia's mangrove and salt marsh and their ecosystem services

Saline coastal wetlands, such as mangrove and coastal salt marsh, provide many ecosystem services. In Australia, large areas have been lost since European colonization, particularly as a result of drainage, infilling and flood-mitigation works, often starting in the mid-19th century and aimed primarily towards converting land to agricultural, urban or industrial uses. These threats remain ongoing, and will be exacerbated by rapid population growth and climate change in the 21st century. Establishing the effect of wetland loss on the delivery of ecosystem services is confounded by the absence of a nationally consistent approach to mapping wetlands and defining the boundaries of different types of coastal wetland. In addition, climate change and its projected effect on mangrove and salt marsh distribution and ecosystem services is poorly, if at all, acknowledged in existing legislation and policy. Intensifying climate change means that there is little time to be complacent; indeed, there is an urgent need for proper valuation of ecosystem services and explicit recognition of ecosystem services within policy and legislation. Seven actions are identified that could improve protection of coastal wetlands and the ecosystem services they provide, including benchmarking and improving coastal wetland extent and health, reducing complexity and inconsistency in governance arrangements, and facilitating wetland adaptation and ecosystem service delivery using a range of relevant mechanisms. Actions that build upon the momentum to mitigate climate change by sequestering carbon – ‘blue carbon’ – could achieve multiple desirable objectives, including climate-change mitigation and adaptation, floodplain rehabilitation and habitat protection.     

Lessons learnt from a collaborative management programme in coastal Tanzania

The Tanga Coastal Zone Conservation and Development Programme, initiated in 1994, was among the first such projects to make livelihoods improvement a key objective, and to use a community-based approach. It developed an approach to coastal management planning that is broadly satisfactory to both communities and the government. Six fisheries management areas and two mangrove management areas were established. Institutional arrangements for the collaborative approach were strengthened and community leaders and local government officers were trained in a range of relevant skills. A coastal environmental education programme for primary schools involved several thousand schoolchildren, and a gender programme built the confidence of women. Implementation of the management measures was noticeably harder than planning, particularly elimination of destructive fishing methods. Fishers and coastal communities now however have a much greater involvement in, and understanding of, coastal management and consequently a greater sense of ownership.     

Nursery function of mangrove: A comparison with mudflat in terms of fish species composition and fish diet

Shallow soft-bottom habitats including mangroves and mudflats provide important nursery functions for juvenile fishes, but little information exists concerning the relative nursery value of these habitats for juvenile fishes. We compared the potential of a mangrove and a mudflat in a semi-enclosed bay in Hong Kong to serve as fish nurseries by measuring species composition, dietary composition, gut fullness and diet breadth of juvenile fishes. Fish abundance was higher in mangrove than mudflat, but species richness was almost similar between the two habitats. After excluding Ambassis gymnocephalus, which was found mainly in the mangrove, difference in fish abundance between the two habitats was small. The gut fullness and diet breath of most species did not differ between mangrove and mudflat, suggesting that the two habitats were very similar in terms of providing feeding opportunity for juvenile fishes. While the importance of mangrove as nursery of fishes has been repeatedly emphasized, our data suggest that other soft-bottom habitats, such as mudflats, are also important and need to be protected.     

A model study of influence of circulation on the pollutant transport in the Zhujiang River Estuary and adjacent coastal waters

A tracer model with random diffusion coupled to the hydrodynamic model for the Zhujiang River Estuary (Pearl River Estuary, PRE) is to examine the effect of circulations on the transport of completely conservative pollutants. It is focused on answering the following questions: (1) What role does the estuarine plume front in the winter play in affecting the pollutants transport and its distribution in the PRE? (2) What effect do the coastal currents driven by the monsoon have on the pollutants transport? The tracer experiment results show that: (1) the pollutant transport paths strongly depend on the circulation structures and plume frontal dynamics of the PRE and coastal waters; (2) during the summer when a southwesterly monsoon prevails, the pollutants from the four easterly river inlets and those from the bottom layer of offshore stations will greatly influence the water quality in Hong Kong waters, however, the pollutants released from the four westerly river-inlets will seldom affect the water quality of Hong Kong waters due to their transport away from Hong Kong; (3) during the winter when a northeasterly monsoon prevails, all pollutants released from the eight river gates will be laterally transported seaward inside the estuary and transport westward in the coastal waters along the river plume frontal zone. However, pollutants released from the surface layer of offshore stations near or east of the Dangan Channel will be carried into the coastal waters of Hong Kong by the landward component of the westward coastal current driven by the winter northeasterly monsoon. But the pollutants from the bottom layer of the offshore stations will be carried away from the offshore by the bottom flow driven by the northeasterly monsoon. This implies that only surface-released matter from offshore stations will affect the water quality of the coastal waters around Hong Kong during the winter when a northeasterly monsoon prevails.     

Remote Sensing of Mangrove Change Along the Tanzania Coast

This article contributes to the understanding of the changes in distribution and total area of mangrove forests along the mainland Tanzania coast over the past decade. Mangroves are recognized as critical coastal habitat requiring protection and special attention. The Tanzania coastline forms a suitable habitat for establishment of mangrove forests. Mangrove forests are distributed from Tanga in the north to Mtwara in the south covering approximately 109,593 hectares from 1988-1990 and about 108,138 hectares in 2000. The largest continuous mangrove stands are found in the districts of Rufiji, Kilwa, Tanga-Muheza, and Mtwara. Comparison of data between these two time periods shows that the geographic coverage of mangroves has no dramatic change in the past decade. The Tanzania Mangrove Management Project and other closely related programs and efforts pertaining to mangrove conservation contribute to direct restoration and natural regeneration of mangroves. This study documents the changes of mangroves and demonstrates that remote sensing and GIS offer important data and tools in the advancement of coastal resource management and ecosystem monitoring. Application of geographic information technologies is critical for improved coastal resources management and decision making for sustainable development in Tanzania.     

Occurrence and distribution of vibrios in fishes and shellfishes in coastal waters of Hong Kong

INTRODUCTIONTheoccurrenceanddistributionofhalophilicvibriosinthecoastalwatersofHongKonghasbeenrePorted(Chanetal.,l986).Theresultsshowedthatvibrioswerepresentduringthesum-mermonthsinHongKongcoastalwatersatconcentrationsof9oto67ooind./cm3,accountingo.4l%~4o%ofthetotalbacterialPOpulationofthe48isolatesexaminedindetail.Theyob-servedV.Paraheamolyticus,V.harvha,V.vulnfficus,V.camPbelliandV.fiuvialis.Becausemanyofthevibri0species,includingsome0ftheisolatesbyChanetal.(1986)fromHongKongwate…     

2010—2018碳收支的变化分析年海南东寨港红树林湿

红树林生态系统在全球气候变化和碳循环过程中发挥着很重要的作用,准确评估红树林湿地的碳收支,对于保护和恢复海洋蓝色碳汇以及全球气候治理工作具有重要的意义。本研究以海南东寨港国家级自然保护区的红树林湿地为研究对 象,采用 《对 2006 IPCC 国家温室气体清单指南的 2013 增补：湿地》 （简称 《湿地指南》） 中的计算方法,利用野外现场调查数据及已有的研究成果作为参数,评估和量化海南东寨港红树林湿地在 2010—2018 年期间的碳收支情况。研究表明：（1） 2010 年红树林面积为 1 627.21 hm2,全部为成熟红树林,碳储量为 5.85*105t C;2018 年红树林面积为 1 665.42 hm2,其中 1 625.84 hm2为成熟红树林,碳储量为 6.71*105t C,39.58 hm2为过渡期红树林,碳储量为 4.36*103t C,总碳储量为6.75*105t C。 （2） 2010—2018 年期间红树林碳储量增加了 9.0*104t C。另外,有 1.37 hm2的红树林湿地退化为水域,释放了81.36 t 的碳储量。因此,2010—2018 年期间东寨港红树林湿地碳收支为+8.99*104t C,整体上表现为净碳汇生态系统。本研究结果可为气候变化背景下海南红树林湿地的保护与恢复、风险评估以及气候治理提供科学参考。     

Barnacles as biomonitors of trace metal availabilities in Hong Kong coastal waters: changes in space and time

The use of selected organisms as biomonitors of trace metal bioavailabilities allows comparisons to be made over space and time. The concentrations of 11 trace metals (arsenic, cadmium, chromium, cobalt, copper, iron, lead, manganese, nickel, silver, zinc) were measured in the bodies of two barnacle species, Balanus amphitrite and Tetraclita squamosa, from up to 18 littoral sites from Hong Kong coastal waters in April 1998. These data provide evidence on the geographical variation in metal bioavailabilities at this time, and are compared selectively against historical data sets for 1986 and 1989. Geographical variation in bioavailabilities is clear for several metals, with hotspots for arsenic, copper, nickel and silver at Chai Wan Kok, and for lead in Junk Bay. Victoria Harbour sites head the rankings for silver and arsenic, and Tolo Harbour sites exhibit relatively elevated cobalt, manganese and zinc. Many bioavailabilities of trace metals to barnacles are lower in Hong Kong coastal waters in 1998 than in 1986. The two barnacle species are widespread and the extensive data set presented is a benchmark which can be compared to the results of similar biomonitoring programmes elsewhere in the Indo-Pacific and beyond.     

唐山市滨海湿地动态演变特征及其机制分析

利用历史资料和Landsat TM卫星遥感图像,研究了唐山市滨海湿地自建国以来的演变特征,着重对1987~2004年陡河———滦河之间的滨海平原湿地类型进行了识别,绘制了不同时期的景观面解译图。利用Mapinfo制图软件计算出两个时期的面积(比例)转化矩阵,显示该区滨海湿地破碎化加重,其动态演变特征呈明显退化趋势,进而提出引起其退化的原因和发展趋势预测。     

广东省红树林资源变化遥感监测

利用1990年的Landsat-5TM、2000年的Landsat-7ETM+和2008年的CBERS-02BCCD 3期遥感影像对广东省近18a来的红树林湿地资源进行监测,并对其时空变化情况进行分析。结果表明:广东省红树林呈现不断增加的趋势,1990年、2000年和2008年的面积分别为7 733.2,8 722.0和9 593.3hm2;红树林由沿岸分散分布趋于集中分布;天然林减少,人工林增加。