厦门湾中华白海豚：面临的威胁与保护对策

中华白海豚(Sousa chinensis)是国家一级重点保护水生哺乳动物,在我国主要分布于东南沿海的近岸及河口水域。厦门湾是中华白海豚重要栖息地之一,同时也是东南沿海经济较为发达的地区。自改革开放以来,厦门进行了高强度的海洋开发活动,对中华白海豚及其栖息地造成了较大影响。为了保护该物种及其栖息地,厦门市制定了一系列的保护措施,如建立自然保护区、跨区域协同管理、鱼类资源管护与增殖放流等,取得了较好成效。本研究总结了厦门湾中华白海豚所面临的主要威胁,以及为保护中华白海豚及其栖息地所采取的保护措施;分析了目前仍然存在的问题并提出改进建议,如保护区优化调整、加强执法监管、开展栖息地生态修复等,可为厦门湾及其他海域中华白海豚的保护与管理提供参考与借鉴。     

厦门中华白海豚的分布和数量

1994～1999年在厦门海域进行84航次中华白海豚船只跟踪和照像,记录392只次。设20个监视站,进行239个月的逐日观察,记录12624只次。整个厦门海域700km2均有中华白海豚分布,它可溯河至近淡水的河道,但不游出外海。厦门西港和同安湾口内的近岸最多,跃出海面的次数有明显的季节差异,4～5月最多。厦门海域中华白海豚数量估计不足100只,仅40只左右有确切记录。种群数量目前仍有减少趋势,因而应就地和迁地保护并举,加强对这种国家一级保护物种的保护。     

海底电缆工程对中华白海豚的影响研究——以厦门英春—围里海底电缆工程为例

中华白海豚是国家一级重点保护水生哺乳动物,厦门湾是中华白海豚的重要栖息地之一。文章以厦门英春—围里海底电缆工程为例,评价工程建设对中华白海豚及其栖息地的影响,并提出中华白海豚的保护措施,以期为海洋工程建设对水生野生保护动物的保护管理提供借鉴。     

中国沿海中华白海豚种群的分布区

中华白海豚Sousa chinensis(Osbeck,1765)首先在我国发现,是我国沿海仅有的定居性海洋鲸豚类.本文根据中华白海豚目击事件和研究报道,分析了中华白海豚在中国的分布、种群隔离及其差异.认为我国南方福建、广东以南沿海为中华白海豚种群的主要分布区,明确指出我国沿海存在5个主要的中华白海豚种群栖息地.通过分析,划分出中华白海豚活动的边缘区和栖息地两个部分.由于中华白海豚种群不断缩小,在保护中华白海豚栖息地的基础上,加强对中华白海豚栖息地外的边缘区的保护显得尤为重要.本文分析将为科学划定中华白海豚保护区提供依据.     

厦门至珠江口间沿岸海域中华白海豚分布的调查研究

厦门海域和珠江口海域是中华白海豚(Sousa chinensis)的2个重要分布区,但对这两地之间沿海白海豚的分布情况还缺乏了解.通过走访厦门至珠江口之间12个渔港码头或渔村的渔民,共获得有效问卷168份,探讨了厦门至珠江口之间沿海历史上和当今中华白海豚的分布情况.结果显示:年龄越大,渔民见过白海豚的比例越高;历史上(20～30a前),东山、汕头、甲子、汕尾和马宫等地沿海曾有较大的中华白海豚种群分布;如今,在东山湾和汕头海域还有中华白海豚的出没.通过进一步的截线抽样法调查,证实了汕头海域还有白海豚的分布,东山湾还有渔民观察到白海豚,但尚待进一步的证实.     

厦门湾常见海洋经济生物重金属污染特征及风险评价

了解厦门湾海域海洋经济生物重金属污染现状及食用风险,于2019年8月至2020年4月分4个季节,在厦门湾海域捕获了常见的13种海洋经济生物,以ICP MS为检测手段分析其肌肉组织中7种重金属（Cr、Ni、Cu、Zn、As、Cd和Pb）的含量,并采用不同评价模型对人类及中华白海豚的健康风险进行评价。结果表明,①鱼类和头足类海洋经济生物体内Zn、As和Cu的含量比较高,而Pb和Cd的含量比较低。②鱼类体内大多数重金属残留量,夏季显著高于其他季节,这可能是由于夏季饵料丰富,生物体代谢旺盛所导致。③单因子污染指数（single factor index, SFI）法和目标危害系数评价（target hazard quotient, THQ）法的评价结果显示,厦门湾常见海洋经济生物样品中As的残留量不仅超出了国家食品安全限量标准,还会对人类的健康造成潜在的风险。厦门湾海洋经济生物As的污染应引起人们的高度关注,后续研究应深入调查厦门湾生物体内As的主要存在形态,进一步提高健康风险评价的准确性,为当地监管部门的监管工作以及相关政策的制定提供数据支撑。因中华白海豚进食方式的不同,相关评价结果仅供参考。     

铜鼓航道建设对珠江口中华白海豚自然保护区的环境影响研究

铜鼓航道是连接大濠水道与深圳西部港口、在原有铜鼓水道的基础上疏浚挖深与拓宽的深水航道,其航道路线穿越珠江口中华白海豚自然保护区,在对珠江河口水域进行生态环境与中华白海豚资源状况调查的基础上,根据中华白海豚的生理与生态特性,结合铜鼓航道工程建设内容、规模、施工方案、航道营运计划等情况,研究分析工程施工与营运分别可能对珠江河口中华白海豚种群及自然保护区生境造成的影响,并分别提出航道施工与营运期间对中华白海豚种群和保护区生境影响的缓解措施,以达到有效保存与保护中华白海豚保护区生境及该种群的目的。     

厦门在中华白海豚保护上取得新进展

中华白海豚是国家一级保护水生野生动物,有“水上大熊猫”之称,闽港台渔民亲切的称之为妈祖鱼、镇港鱼。厦门海域是中华白海豚的主要栖息地之一。近年来,随着厦门及周边海域海洋工程项目的增多,对中华白海豚等海洋生物的生态环境造成了严重的影响。为确保在海洋海岸工程建设过程中加强监管,避免或减少对中华白海豚的伤害,厦门市海洋与渔业局组织开展了     

岩鹭在厦门海岸带的分布及其生态考察

岩鹭是我国二级保护鸟类,处于稀有的濒危状态。１９９３年３￣５月,１９９３年９月至１９９４年９月和１９９５年５￣１０月的考察结果。证实岩鹭在厦门的居留时间为１０月上旬至６月上旬。厦门的岩鹭分布于东部海岸,该区域人为干扰和污染少,潮间带底质以砂砾,岩石为主,厦门的岩鹭为灰黑色型,单独活动,种群总数量只有３￣５只,本文根据岩鹭的生态需求、行为习怀和种群数量特点,对岩鹭的保护也进行了讨论。     

深化海洋管理 发展海洋经济 为把厦门建设成为国际性港口风景旅游城市作出新贡献——厦门市海洋与渔业局

厦门市位于台湾海峡西岸、福建省南部,全市海域面积390km2,海岸线长度234km,海岸曲折,湾中有湾,湾中有岛,自然条件优越,海洋资源丰富,拥有活化石美称的厦门文昌鱼、国家一级保护动物中华白海豚等珍稀和经济价值高的海洋物种60余种。海洋是厦门最大的优势。几年来,厦门市海洋与渔业局全面落实科学发展现,坚持以海洋资源可持续利用为目标,全面实施海洋功能区划,开展用海结构调整,加快海洋资源资产化管理步伐,实施海洋资源有效保护和科学利用并举措施,大力发展海洋经济,促进了海洋资源的可持续利用和海洋生态环境的有效保护。探索建立了“立法…     

Assessing the Validity of Seismo-Acoustic Predictor Equations for Obtaining Seabed and Sub-Surface Sediment Physical Properties

The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths.     

Interannual Sea Level Variations and Annual Tides in the Northwestern Pacific

Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone.     

Flow Cytometric Analysis of Coastal Lagoon Bacterioplankton and Picophytoplankton: Fixation and Storage Effects

The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics.     

INFORMATION FOR AUTHORS

<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology,     

Net Sand Transport Direction in a Tidal Inlet, using Foraminiferal Tests as Natural Tracers

The relationship between the flux of exotic benthic foraminiferal tests (i.e. tests which are supplied from open-sea sources alone) in a tidal inlet and that of bulk sediment was analysed, which can be expressed as two first-order linear equations. According to this relationship, in order to determine net sediment transport directions in the entrance, the test concentration in surficial sediments of the tidal basin can be compared against a ‘ critical level ’. The critical level is determined for the conditions that no net transport of bulk sediment is present within the entrance. If the observed concentration (averaged over the tidal basin) is higher than the simulated critical level, then the net sediment transport is directed to landward. This method is applied to the analysis of net sand transport at Christchurch Harbour, a tidal inlet system located in southern England. In this investigation, concentrations of exotic foraminiferal tests in the surficial sediments of the tidal basin and ebb tidal delta area were obtained from the analysis of sea-bed sediment samples. A series of probable critical levels were calculated based upon the data sets with regard to: (1) sediment discharge from the rivers; (2) magnitude of sediment discharge within the entrance during the ebb; (3) the test concentration outside the harbour; (4) the thickness of the moving layer; and (5) two parameters associated with dispersive processes. The results show that the concentration in the tidal basin sediment is higher than a number of simulated critical concentrations for representative cases. Consequently, the high level of the concentration of exotic benthic foraminiferal tests within the harbour should be explained as a result of landward net transport of sands within the entrance.     

Sea Levels and Coastal Inundation Due to Tropical Cyclones in Indian Coastal Regions of Andhra and Orissa

Coastal inundation associated with extreme sea levels is the main factor which leads to the loss of life and property whenever a severe tropical cyclonic storm hits the Indian coasts. The Andhra and Orissa coasts are most vulnerable for coastal inundation due to extreme rise in sea levels associated with tropical cyclones. Loss of life may be minimized if extreme sea levels and associated coastal flooding is predicted well in advance. Keeping this in view, location specific coastal inundation models are developed and applied for the Andhra and Orissa coasts of India. Several numerical experiments are carried out using the data of past severe cyclones that struck these regions. The simulated inland inundation distances are found to be in general agreement with the reported flooding.     

Role of Siliceous Fossil Dissolution in Downcore Variations of Grain Size and Water Content: Western Margin of Clarion-Clipperton Fracture Zone, NE Equatorial Pacific

Grain size and water content in box-core sediments from the Clarion-Clipperton fracture zone (C-C zone) in the northeast equatorial Pacific were analyzed in detail to understand the downcore variations across a hiatus between Quaternary and Tertiary layers. Grain-size distributions in the topmost core sediments show two modes: a coarse mode (peaked at 50 μm) and a fine mode (at 2-25 μm). The coarse mode disappears gradually with depth accompanied by the dissolution of siliceous fossil tests, whereas the fine mode coarsens due to the formation of authigenic minerals. Water content increases abruptly across a color boundary between an upper pale brown layer and a lower dark brown layer that is the hiatus between Quaternary and Tertiary layers. Abundant smectites and microvoid molds, which are created by the prolonged fossil dissolution in the underlying sediment, are attributed for the abrupt downcore variation of water content. Overall variations in grain size and water content in the topmost core sediments in the western C-C zone are possibly constrained by the dissolution of biogenic siliceous fossils. Variations in geotechnical properties related to these changes must be considered in the design of nodule collectors.     

Sea Levels and Western Boundary Flow Near a Tectonic Zone in the Northern Pacific

This article concerns an interrelation between the sea levels and the western boundary flow near a tectonic boundary in a local zone in the Northwestern Pacific. In this zone, sea level variations at stations located on the coast facing the Pacific are studied to find the interrelation between variations of the Kurosio flow as an index of the distance of the flow axis off a specific coast. The result is discussed after data processing of the monthly means of the sea levels, and a notice is taken of variations caused by active crustal upheavals during a seismic event, a local earthquake.