改性黏土法消除球形棕囊藻赤潮的现场实验与效果评估

球形棕囊藻是一种具有复杂异型生活史的有毒有害赤潮生物,近年来在我国近海频繁暴发成灾,形成的巨大囊体为国内外罕见。迄今还未见到有效消除囊体型球形棕囊藻赤潮的方法报道。本文通过海上围隔实验和现场赤潮消除工程跟踪监测,考察了喷洒改性黏土消除囊体型球形棕囊藻赤潮的可行性与效率,并分析了改性黏土法治理赤潮时对水体及沉积环境的可能影响。围隔实验结果表明,喷洒改性黏土可以有效消除水体中过量的微藻细胞,其中以少量多次喷洒方法的效果最好,生物量(chl a)去除率90%。在对2016年2月广西防城港附近海域球形棕囊藻赤潮消除时的跟踪监测结果表明,改性黏土法适用于工程化消除赤潮作业,能够快速消除水体中的大量球形棕囊藻囊体,随改性黏土絮凝体沉入海底的赤潮藻可以快速分解而失去活性。喷洒改性黏土对于赤潮水体的主要理化指标影响不显著,所监测的水体COD、pH和不同形态氮、磷、硅等生源要素浓度都在原有水质水平范围内波动。     

楚科奇海与加拿大海盆表层沉积物表观特征及其环境指示

通过对中国首次和第二次北极科学考察采集的表层沉积物的观察,根据沉积物的颜色和气味、砾石分布、底栖生物及贝壳分布特征的分析,探讨了该海区表层沉积物表观特征变化与有机质输入、沉积物的氧化还原状态的关系、底栖生物分布范围、冰筏碎屑的分布区域及与海流的关系,指出在研究区软体动物生长的北界位于73．5°N,比浮游动物的北界约低2个纬度。冰筏碎屑的北界可作为融冰水的北界或永久冰区的南界,位置在77°24′N附近。通过对沉积物表观特征的综合分析,结合研究区的海流特征,指出研究区的海流分布对沉积物分布有重要影响,尤其是两股不同性质的海流相遇,对西南部与东部两个区域的沉积物组成及性质具有较强的控制作用。     

绿潮迁移过程中环境要素与浒苔藻体生物学特征的相关性分析

浒苔(Ulva prolifera)引起的大规模绿潮起源于黄海南部,在向北迁移过程中生物量迅速扩增,在海州湾附近(35°N左右)迅速增加达到峰值.在绿潮漂浮迁移过程中,海水表层温度、溶解无机氮(dissolved inorganic nitrogen,DIN)和磷酸盐(PO43--P)变化显著.本文以迁移过程中的浒苔为...     

细菌源3-羟基脂肪酸作为环境变化代用指标的研究进展

细菌源3-羟基脂肪酸(C10-C18)作为环境变化指示指标具有良好的应用前景,但相关研究还很不系统,在海洋环境中的应用刚刚起步.3-羟基脂肪酸主要用于环境中pH和温度的重建,通过其支链比(异构和反异构3-羟基脂肪酸之和/正构3-羟基脂肪酸之和)与pH的显著正相关关系反演环境中的pH,通过其C15和C17同系物的反异构/...     

Multilateralism in the Straits of Malacca and Singapore

This paper analyzes International Maritime Organization (IMO) involvement in maritime cooperation regime in the Straits of Malacca and Singapore through multilateralism. It begins by introducing the maritime cooperation regime prior to 2001, which was mainly trilateral in nature through Tripartite Technical Expert Group on the Safety of Navigation (TTEG). Although TTEG managed to increase the level of safety of navigation in the Straits of Malacca and Singapore through the implementation of the Traffic Separation Scheme (TSS) in 1981 and Mandatory Ship Reporting System (STRAITREP) in 1998, such cooperation was beset by financial strain and conflict of interests. Subsequently, there was a change in the cooperation regime after 9/11 incident. This paper identifies that the change was contributed by the IMO through a methodology called multilateralism. Three important principles were adopted by IMO in implementing multilateralism in the Straits of Malacca and Singapore, namely generalized principles of conduct (respect for sovereignty and compliance with burden sharing principle under Article 43 of UNCLOS 1982), diffuse reciprocity, and indivisibility. This paper concludes that multilateralism by IMO has transformed trilateral cooperation into multilateral cooperation in the Straits of Malacca, combining state actors (littoral states and user states) and non-state actors (non-governmental organizations and international shipping industries).     

内蒙古河套地区陈普海子湖泊沉积物粒度特征及其环境意义

对河套地区陈普海子湖泊及其流域不同类型表层沉积物的粒度特征进行了分析,并结合放射性同位素210Pb测年,探讨了湖泊的沉积演变过程。通过主成分分析,对沉积物剖面粒度不同粒级组分含量进行了研究,分析了湖泊沉积物的物质来源,得到两个主控因子F1和F2,它们控制了湖泊沉积物近98.68%的粒度变化特征。研究表明,F1代表了以6.18 μm为众数粒径的次总体,主要受流水作用控制;而F2为以42.75 μm为众数粒径的次总体,主要来源于地表风沙作用。通过粒径-标准偏差方法,提取了湖泊沉积物中不同时期的环境敏感粒度组分,结果表明:在1996AD之前,流水作用所携带的细颗粒(μm)决定了沉积物的粒级特征,在1960-1985AD期间表现出风沙活动强烈;1996AD以来,由于人类开展了大规模的沙荒土地开垦,流沙活动强烈,流域风沙活动所携带的粗颗粒(14.1~224.35 μm)控制了沉积物的粒度组成。     

Effects of parasitism and environment on shell size of the South American intertidal mud snail Heleobia australis (Gastropoda)

The aim of this work was to evaluate the effects of parasitism and certain environmental factors on the shell size of Heleobia australis (Hydrobiidae, Cochliopinae). We report sporocysts and metacercariae of Microphallus simillimus (Microphallidae, Trematoda) parasitizing the gonad and digestive gland of H. australis specimens from two sites of Bahía Blanca estuary, Argentina. The prevalence of infection was significantly higher (34.17% in winter and 68.14% in late spring) in snails from the outer estuary at Site 2 than in those from the inner estuary at Site 1 (5.88% and 4.71% respectively). The only known definitive host for this digenean is the white-backed stilt Himantopus melanurus (Recurvirostridae, Aves), most abundant in the estuary during winter. Parasitism by M. simillimus causes variations in the shell dimensions of H. australis, the shells of infected snails being narrower than those of uninfected snails. Snails from Site 2 were found in general to be significantly smaller than those at Site 1, possibly as a result of differences in environmental factors such as the degree of exposure to wave energy, the allocation of energy to reproduction rather than growth (induced by predation and/or parasitic castrators) and anthropogenic stressors.     

福建省贝藻类养殖碳汇及其潜力评估

海水贝藻类养殖碳汇是海洋渔业碳汇的重要组成,开展其碳汇研究对服务我国实现碳中和目标有积极的作用.福建省的海水养殖规模和产量居于全国前列,对其海水贝藻类养殖碳汇及潜力评估有重要的意义.本研究分析了2015至2020年度《中国渔业统计年鉴》海水贝藻类养殖数据,估算了2014年至2019年全国及福建省海水贝藻类养殖碳汇强度,...     

Response of BITS (a benthic index based on taxonomic sufficiency) to water and sedimentary variables and comparison with other indices in three Adriatic lagoons

The European Water Framework Directive (WFD, 2000/60/EC) recommends the development of biotic indices for assessing the ecological quality status of water bodies. The Benthic Index based on Taxonomic Sufficiency (BITS) was specifically developed for lagoonal systems, according to the tolerant/opportunistic approach. Macrobenthic data, variables indicative of eutrophication and variables indicative of sedimentary organic matter quality were collected during 18 surveys carried out between 2004 and 2005 in three Adriatic coastal lagoons (Venice Lagoon, Sacca di Goro, Lesina Lagoon). The relationship between environmental variables and biotic indices (AMBI, BENTIX, BITS, BOPA and FINE) was tested using multivariate analyses. Indices based on species classification level appeared to relate better with the variables describing organic matter quality, whereas BITS, which is based on family classification level, seemed related to eutrophication indicative variables, such as sulphide, ammonium, dissolved oxygen and orthophosphate concentrations. The BITS approach reduces the costs associated with sorting and identification of organisms. Providing a rapid assessment of ecological quality, and producing an ecologically relevant classification, BITS seems a promising tool for monitoring programs of Adriatic lagoonal ecosystems. Its sensitivity in reflecting the field conditions elsewhere, however, remains to be assessed.