首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 234 毫秒
1.
中国近海有害藻华研究现状与展望   总被引:7,自引:0,他引:7  
海洋或淡水环境中的一些藻类生物量暴发性增长会形成有害藻华(harmfulalgalblooms,HAB),对人类健康、生态安全和社会经济发展构成威胁。近50年来,近海有害藻华问题不断加剧,已经成为一类全球性的海洋生态环境问题。在"全球有害藻华生态学与海洋学研究计划(GEOHAB)"和"全球变化下有害藻华研究计划(GlobalHAB)"支持下,有害藻华研究不断深入,在"有害藻华原因种多样性、生物地理分布特征与适应策略"、"典型有害藻华的生态学与海洋学研究"、"富营养化和气候变化对有害藻华的影响"、"藻毒素与人类健康"、"有害藻华的监测、预警和防控"等方面取得了重要进展。有害藻华是我国近海最突出的生态灾害之一,自2000年以来,我国近海大规模有害藻华不断出现,藻华原因种表现出多样化、小型化和有害化的演变趋势,对沿海地区社会经济发展和生态系统健康构成严重威胁。针对我国近海的有害藻华,本文从有害藻华原因种基础生物学研究、有害藻华生态学与海洋学研究、近海有毒藻和藻毒素研究、有害藻华监测与治理研究等四个方面对主要研究进展进行了总结和分析。综合国内外有害藻华现状和相关研究进展,建议进一步深化对我国近海有害藻华形成及演变机理的研究,高度关注全球变化和人类活动对我国近海有害藻华的影响,推动有害藻华监测预警体系建设,持续提高对藻华灾害的防控能力,积极参与有害藻华领域国际合作,更好地应对有害藻华问题。  相似文献   

2.
Screening bioactive natural products from bacteria is a determinative step in the drug discovery programs. The present study aim to isolate actinobacteria from the Oman Sea sediments for determining the effects of different culture media and treatments on the yield of the isolation process, and measure the DPPH radical scavenging and Artemia cytotoxic activity of culture extracts of the actinobacterial isolates. A total of 290 actinobacterial isolates were collected from 14 sediment samples. Heat treatment(40.68%) and M_4 medium(29.31%) exhibited the maximum isolation rates of actinobacteria. Streptomyces isolates were dominantly distributed in all of the investigated stations according to 16 S rRNA gene sequencing. The distribution pattern of Streptomyces followed a depth-dependent frequency trend, whereas the members of rare genera including Micromonospora, Nocardia Actinoplanes, Nocardiopsis, Saccharopolyspora and Crossiella were distributed in deeper stations. Approximately,25% of the examined isolates could scavenge 90% of 10~(–4) mol/L DPPH solutions at 1 250 μg/mL final concentration of their ethyl acetate culture extracts. Furthermore, the most potent extracts could scavenge DPPH radicals with IC50 ranges from 356.8 to 566.4 μg/mL. Brine shrimp cytotoxicity tests showed that 38.88% of the examined culture extracts exhibited LC_(50) lower than 1 000 μg/mL against the Artemia cells. Moreover, the most potent culture extracts exhibited LC_(50) range from 335.4 to 534.4 μg/mL. Phylogenetic analysis by 16 S rRNA gene sequence revealed that the OS 005, OS 263 and OS 157 closely related to Streptomyces djakartensis, Streptomyces olivaceus and Nocardiopsis dassonvillei respectively. These results suggested the widespread distribution of the antioxidant and cytotoxic producing actinobacteria in the Oman Sea sediments, which could be considered as promising candidates for the discovery of microbial bioactive compounds.  相似文献   

3.
Paralytic shellfish poisoning (PSP) toxins have been implicated as the causative agent of a number of fish kills. Exposure experiments indicate that fish are susceptible to PSPs by intraperitoneal (i.p.) and oral administration, while sampling of fish affected by toxic blooms reveals that these toxins can be accumulated. In spite of the potential impact to marine fisheries, little research has been conducted on the potential metabolism and detoxification of PSPs in marine fishes. Previous work by this group has shown that the xenobiotic metabolising enzyme (XME) cytochrome P-450 (CYP1A) is induced in Atlantic salmon (Salmo salar) following i.p. exposure to saxitoxin (STX). Salmon injected i.p. with sub-lethal doses of STX show a four- to eight-fold induction of hepatic CYP1A (as shown by ethoxyresorufin-O-deethylase activity) over controls after 96 h. Results presented here show that the phase II XME glutathione S-transferase (GST) is also induced in salmon following PSP exposure. Post smolts were exposed to three injections of PSPs (2 micrograms STXeq/kg) over 21 days. Injection of both STX and PSPs extracted from a toxic strain of dinoflagellate (Alexandrium fundyense, CCMP 1719) resulted in induction of hepatic GST, as measured by activity for 1-chloro 2,4-dinitrobenzene. Such inductions indicate a potential role for XMEs in PSP metabolism. Possible roles for other enzymes are also discussed.  相似文献   

4.
Parent and alkylated polycyclic aromatic hydrocarbons (alkyl-PAHs), which are a class of important toxic components of crude oil especially in the marine environment, exhibit adverse effects on aquatic life and potentially pose a human health risk. However, the lack of chronic toxicity data is one of the hindrances for alkyl-PAHs when assessing their ecological risks. In this study, predicted no-effect concentrations (PNECs) in seawater and marine sediment for ten parent- and alkyl-PAHs were derived by applying species sensitivity distributions (SSDs) and quantitative structure?activity relationships (QSARs). The local area, Dalian Bay, where an oil-spilled accident happened in 2010, was chosen as a case site to assess ecological risks for ten PAHs in surface seawaters and marine sediments. Their PNECs in seawater and sediment for protecting aquatic organisms in marine ecosystems were calculated and recommended in the range of 0.012?2.79 μg/L and 48.2?1337 ng/g (dry weight), respectively. Overall, the derived PNECs for the studied PAHs in seawater and marine sediment were comparable to those obtained by classical methods. Risk quotient results indicate low ecological risks to ecosystems for ten parent- and alkyl-PAHs in surface seawaters and surface sediments from the Dalian Bay. These findings provide a first insight into the PNECs and ecological risks of alkyl-PAHs, emphasizing the role of the computational toxicology in ecological risk assessments. The use of QSARs has been identified as a valuable tool for preliminarily assessing ecological risks of emerging pollutants, being more predictable of real exposure scenarios for risk assessment purposes.  相似文献   

5.
Toxic algal species of marine and brackish-water plankton, as well as nontoxic microalgae, which are capable of initiating harmful blooms, cause a detriment to human health (seafood poisoning) and often lead to a total crisis of coastal water ecosystems. The Russian coastal waters are inhabited by dozens of toxic and bloom-causing algal species, their toxins are accumulated in the tissues of edible mollusks, and there have been incidents of human poisonings and marine fauna mortality due to these blooms. An analysis of the current situation concerning the problem of toxic algae and harmful blooms of nontoxic species in the seas of Russia provides evidence that it is necessary to create a system of compulsory governmental monitoring of the exploited marine areas to serve as the basis of ecological safety control in the exploitation of the biological resources of the Russian Federation, as well to introduce compulsory sanitary control of diarrheic, paralytic, and amnesic phycotoxins. The compiled summary of algal toxic and potentially toxic species met in the European and Far Eastern seas of Russia is given with notes on their toxicity type and its manifestations.  相似文献   

6.
Virtually every coastal country in the world is affected by harmful algal blooms (HABs, commonly called “red tides”). These phenomena are caused by blooms of microscopic algae. Some of these algae are toxic, and can lead to illness and death in humans, fish, seabirds, marine mammals, and other oceanic life, typically as a result of the transfer of toxins through the food web. Sometimes the direct release of toxic compounds can be lethal to marine animals. Non-toxic HABs cause damage to ecosystems, fisheries resources, and recreational facilities, often due to the sheer biomass of the accumulated algae. The term “HAB” also applies to non-toxic blooms of macroalgae (seaweeds), which can cause major ecological impacts such as the displacement of indigenous species, habitat alteration and oxygen depletion in bottom waters.Globally, the nature of the HAB problem has changed considerably over the last several decades. The number of toxic blooms, the resulting economic losses, the types of resources affected, and the number of toxins and toxic species have all increased dramatically. Some of this expansion has been attributed to storms, currents and other natural phenomena, but human activities are also frequently implicated. Humans have contributed by transporting toxic species in ballast water, and by adding massive and increasing quantities of industrial, agricultural and sewage effluents to coastal waters. In many urbanized coastal regions, these inputs have altered the size and composition of the nutrient pool which has, in turn, created a more favorable nutrient environment for certain HAB species. The steady expansion in the use of fertilizers for agricultural production represents a large and worrisome source of nutrients in coastal waters that promote some HABs.The diversity in HAB species and their impacts presents a significant challenge to those responsible for the management of coastal resources. Furthermore, HABs are complex oceanographic phenomena that require multidisciplinary study ranging from molecular and cell biology to large-scale field surveys, numerical modelling, and remote sensing from space. Our understanding of these phenomena is increasing dramatically, and with this understanding comes technologies and management tools that can reduce HAB incidence and impact. Here I summarize the global HAB problem, its trends and causes, and new technologies and approaches to monitoring, control and management, highlighting molecular probes for cell detection, rapid and sensitive toxin assays, remote sensing detection and tracking of blooms, bloom control and mitigation strategies, and the use of large-scale physical/biological models to analyze past blooms and forecast future ones.  相似文献   

7.
采用高效液相色谱-串联质谱方法对我国近海贝类中腹泻性贝毒成分进行研究,结果发现采自北黄海大连附近海域的海湾扇贝和虾夷扇贝含有25~41μg/kg的虾夷扇贝毒素(yessotoxin,YTX),在虾夷扇贝体内还含有37.2μg/kg的45-OH-YTX,并在5种贝中发现微量的Homo-YTX毒素组分,这是首次报道在我国贝中检出此类毒素。虾夷扇贝毒素YTXs是一类含有2个磺酰基的脂溶性多环聚醚类化合物,对小鼠的腹腔注射急性致死毒性很高,毒理作用机制尚不清楚。本研究的结果说明我国贝类体内生物毒素成分复杂,亟需进行毒素成分结构、来源生物、生态毒理效应、分布规律及安全限定标准的研究。  相似文献   

8.
中国近海藻毒素及有毒微藻产毒原因种调查研究进展   总被引:2,自引:0,他引:2  
麻痹性贝类毒素在我国近海污染问题已十分突出,基本呈现逐年加剧的趋势。20世纪90年代,南海麻痹性贝类毒素污染较重; 21世纪初,北黄海麻痹性贝类毒素污染较重;近几年,渤海和福建近海麻痹性贝类毒素污染较重;可产生麻痹性贝类毒素的微藻有亚历山大藻和裸甲藻等。采用小鼠生物法检测我国近海腹泻性贝类毒素超标率32%左右,采用液相色谱/质谱法检测,仅有3起超标的研究报道;现行小鼠生物法检测腹泻性贝类毒素假阳性问题十分突出,应尽快废除;腹泻性贝类毒素均是脂溶性的,脂溶性海洋生物毒素在我国近海常年可检出,偶有虾夷扇贝毒素和鳍藻毒素超标现象。可产生脂溶性毒素微藻有鳍藻和原甲藻及网状原角藻等。失忆性贝类毒素在我国近海常有检出,但无超标现象;产毒微藻有拟菱形藻等。西加鱼毒素在我国南海污染较重,但毒素标准物质的匮乏,限制了西加鱼毒素的调查研究;至今尚未确定产生西加鱼毒素的微藻。酶联免疫吸附法和液相色谱串联质谱法相结合已成为藻毒素快速准确检测成熟的技术,逐渐代替小鼠生物法和液相色谱法。  相似文献   

9.
有害藻华是海洋中最为常见的一类生态灾害问题,对养殖业、旅游业和公众健康等造成了严重威胁,也给海洋管理带来了巨大的挑战。近年来,与有害藻华相关的生物、化学、水文、气象等观测数据以及有害藻华发生记录等统计数据不断积累,统计学方法、地理信息系统(Geographic Information System, GIS)等数据分析方法也在快速发展,为深入挖掘有害藻华时空演变特征、提高有害藻华监测预警水平奠定了重要基础。该研究综合应用数据库、地理信息系统及可视化技术,设计了一套集有害藻华多源异构数据管理、分析与可视化为一体的综合平台,能够实现对有害藻华相关数据的存储和动态关联,并集成了空间分析方法,实现了数据和分析产品的可视化。该研究以渤海有害藻华长期时空演变特征探究为案例,展示了该平台在有害藻华数据分析与可视化方面应用效果。该平台可望为公众科普、科学分析和政府决策等提供支撑。  相似文献   

10.
我国近海有毒藻和藻毒素问题的研究现状与展望   总被引:2,自引:0,他引:2  
于仁成  罗璇 《海洋科学集刊》2016,51(51):155-166
海洋中的一部分微藻能够产生藻毒素,导致鱼、贝类等养殖动物染毒或死亡,甚至危及人类健康和海洋生态安全。近20年来,随着对有害藻华(Harmful algal bloom, HAB)问题关注程度的不断提高和研究手段的快速发展,对我国近海有毒藻和藻毒素的认识也在不断深入。本文针对常见的几类藻毒素,从贝类中藻毒素污染状况、毒素来源、有毒藻藻华状况等角度,对我国当前相关研究工作进展进行了综述。大量研究表明,麻痹性贝毒毒素(paralytic shellfish toxins, PSTs)和腹泻性贝毒毒素(diarrhetic shellfish toxins, DSTs)在我国近海最为常见,其中,麻痹性贝毒主要由有毒亚历山大藻(Alexandrium spp.)产生,产毒藻种常见于南海海湾、福建沿海、长江口邻近海域、海州湾、北黄海和秦皇岛近海等,中毒事件也时有发生。常见的大田软海绵酸、扇贝毒素等腹泻性贝毒毒素多由鳍藻(Dinophysis spp.)产生,我国近海贝类沾染藻毒素的现象也非常常见。近年来,随着高效液相色谱和质谱技术的发展,在我国近海发现了越来越多的有毒藻和藻毒素。在对文献进行综合分析的基础上,简单探讨了有毒藻与藻毒素对海产品食品安全的影响及风险,以及未来研究发展方向。  相似文献   

11.
我国近海镉的水质基准及生态风险研究   总被引:3,自引:1,他引:2  
以镉为研究对象,在分析我国海水水生生物区系特征的基础上,筛选了栖息我国境内的海水水生生物物种的毒性数据,采用基于物种敏感度分布(SSD)模型不同拟合曲线(log-logistic、log-normal、 Gumbel、Weibull和Burr Ⅲ)的方法分别推导了保护水生生物的海水水质急性基准值和慢性基准值,并分析了引入淡水数据推导海水水质基准的可行性;同时,结合我国海水中镉的分布特征,对海水中镉的生态风险了初步评价。结果表明:Burr Ⅲ对各组数据拟合的效果最佳;引入淡水数据可能会对海水生物造成"过保护"风险;基于Burr Ⅲ对海水数据所推导的急性和慢性基准推荐值分别为63.0 μg/L和8.0 μg/L;将我国近岸水体中镉的浓度与基准值比较显示,我国近岸水体中镉对水生生物的潜在风险较低。研究结果有望为我国水质基准研究及标准制定提供参考。  相似文献   

12.
舟山渔场及其相邻赤潮高发区麻痹性贝类毒素研究   总被引:2,自引:0,他引:2       下载免费PDF全文
采用小白鼠生物检测法和高效液相色谱荧光检测法,对采自舟山渔场及其相邻赤潮高发区贝类的麻痹性贝毒素进行了调查分析与研究。结果表明,浙江舟山海域有毒贝类检出率为7.0%。利用高效液相色谱荧光检测法对2006年5月份采集的六横的西格织纹螺、岱山的毛蚶组织提取液进行麻痹性贝毒素测定,结果显示,六横的西格织纹螺体内麻痹性贝毒素含量为0.178Mu/g,毒力值为0.0356μg STXeq/g,其毒素成分由GTX2、GTX3、STX、dcSTX、C2组成:岱山的毛蚶体内麻痹性贝毒素含量为3.494Mu/g,毒力值为0.6987μg STXeq/g,其毒素成分由STX、NEO、C1、C2组成。浙江中、南部海域有毒贝类检出率为2.2%,利用高效液相色谱荧光检测法对2006年10月份在南麂列岛采集的棒锥螺的组织提取液进行麻痹性贝毒素的测定,结果显示棒锥螺体内麻痹性贝毒素含量为0.705Mu/g,毒力值为0.1409μg STXeq/g,其毒素成分有GTX1、GTX2、GTX3、NEO、C1、C2组成。  相似文献   

13.
为探究多环芳烃(Polycyclic aromatic hydrocarbons,PAHs)污染对海洋桡足类的毒性效应,本研究以日本虎斑猛水蚤(Tigriopus japonicus)为受试生物,选取菲(Phenanthrene,Phe)作为PAHs的代表开展暴露试验.急性毒性试验测得Phe对日本虎斑猛水蚤的96 h半...  相似文献   

14.
The change in concentration of the disulfated polyether yessotoxin (YTX) produced by a culture of the marine dinoflagellate Protoceratium reticulatum was measured in laboratory experiments under light and dark conditions. Experimental cultures were inoculated and grew at a growth rate of 0.14 d(-1) until stationary phase was reached, after approximately 21 days. Cultures were maintained in the stationary phase until 31 days after inoculation. Cells of P. reticulatum contained a concentration of approximately 10-15 pg YTX cell(-1) during stationary phase but this was considerably lower (<5 pg cell-1) during the growth phase. Low amounts of 45-hydroxy-YTX were also detected. At day 32, P. reticulatum was killed by cooling to 1 degrees C (confirmed microscopically) and YTX concentrations were measured periodically under light and dark conditions. YTX concentrations decreased rapidly to approximately 10% of the initial concentration within the first 3 days and depleted to near zero within a week in the light treatment. In the dark environment, YTX persisted longer with approximately 10% of the initial YTX concentration still remaining after 18 days.  相似文献   

15.
Abstract

Oxygen consumption, grazing rate, and byssus production of the greenshell mussel Perna canaliculus were measured following exposure to bloom concentrations (106 cells l?1 ) of a toxic clone of the dinoflagellate AIexandrium tamarense (GT429), using anon‐toxic clone of the same species (PLY173) as control. Following feeding for 1 h on GT429, mussels (dry weight 54–127 mg) showed significantly increased oxygen uptake at 15°C (0.08 μl O2 (mg dry tissue weight)?1 ) compared with control mussels. However, following 24 h recovery, oxygen uptake was similar to initial values in all experimental conditions. The grazing rate of P. canaliculus fed upon toxic clone GT429 was 4.58 ± 0.76 cells mg?1 h?1 compared with 1.99 ± 0.47 cells mg?1 h?1 for PLY173. On exposure to A. tamarense, mussels maintained normal opening behaviour and there was no change in the byssus production over 24 h. It was concluded that P. canaliculus showed no dramatic physiological effects following short‐term feeding on the toxic strain of A. tamarense. During 2 weeks’ exposure to twice daily bloom concentrations of GT429, there was no mussel mortality. Toxicity in the tissues was 1295 μg STX equivalent per 100 g tissue, levels at which these mussels would be unsuitable for human or animal consumption.  相似文献   

16.
我国近海赤潮灾害发生特征、机理及防治对策研究   总被引:2,自引:0,他引:2  
高波  邵爱杰 《海洋预报》2011,28(2):68-77
近海赤潮灾害的频繁暴发严重破坏海洋生态平衡和海洋环境.根据2000~2009年的统计数据,从赤潮灾害发生时间、地域分布、赤潮生物优势种和规模变化4个方面分析了我国近海赤潮灾害的发生特征,同时探究了赤潮生物、营养物质(氮、磷、铁、锰、维生素、特殊有机物等)和外部环境(气象条件、水动力条件、海水理化因子等)引发赤潮灾害的机...  相似文献   

17.
浮游植物薄层是指位于水体次表层、厚度从几厘米到几米的高丰度浮游植物分布层。与大洋相比,在河口、海湾和近海的浮游植物薄层往往分布浅、强度大,具有明显的时空变化。浮游植物薄层的形成和维持不仅受到层化、楔入、剪切等物理过程的调控,也与浮游植物的生长、聚集及浮游动物的差异化捕食等生物生态学过程有关,目前围绕浮游植物薄层的形成机制已提出了趋旋俘获等假说。浮游植物薄层对其生长、繁殖、防御等具有重要意义,有的浮游植物薄层聚集了大量的有毒有害藻,与有害藻华的发生关系密切。深入研究浮游植物薄层的成因,将为阐明有害藻华的发生机制和有效监测提供重要依据。  相似文献   

18.
近年来,全球近海海域有害藻华频发,导致严重的环境问题与经济损失,如何有效地治理有害藻华引发全球关注。抑藻微生物可以通过细胞接触等直接方式及分泌胞外活性物质等间接方式破坏藻细胞的细胞结构、生理过程和遗传功能,进而抑制藻细胞的生长。本文总结了抑藻微生物控制有害藻华的主要作用原理和研究进展,综述了当前以微生物为基础的控制藻华的方法和技术,探讨了其在有害藻华治理方面的发展方向与应用前景,以期为有害藻华的防控提供参考。  相似文献   

19.
库里亚藻(Coolia)是一类广泛分布且具有生物毒性的海洋底栖甲藻。本研究对近年来在中国南海西沙群岛海域采集分离的4株库里亚藻, 通过光镜及电镜下的形态学观察, 并结合基于核糖体大亚基(large subunit, LSU)rDNA(D1-D3)和内部转录间隔区(internal transcribed spacer, ITS)的序列进行系统发育分析, 鉴定该4个株系为热带库里亚藻(Coolia tropicalis)。在卤虫(Artemia salina)生物毒性试验中, 热带库里亚藻不同株系毒素提取液对卤虫幼虫表现出了毒性差异, XS554株系的48h半致死浓度(LC50)为1.42mg·mL -1(约相当于1.1×10 5cells·mL -1), 5XS15株系的LC50为1.92mg·mL -1(约相当于1×10 5cells·mL -1)。  相似文献   

20.
邹晓梅  林广发  陈志彪 《海洋科学》2018,42(11):110-117
赤潮是海洋生态系统异常的重要指标。本文收集1986~2017年闽三角海域的赤潮事件,基于GIS技术分析赤潮的时空分布特征。结果表明:32年来,闽三角海域赤潮发生98次,赤潮高发区在厦门西海域、同安湾和泉州湄洲湾海域;闽三角海域赤潮年际发生次数呈波动变化,一年中赤潮高发期集中在5~8月;中肋骨条藻、角毛藻及旋链角毛藻是闽三角海域的赤潮优势种,具有一定的区域分布特征;有毒赤潮事件发生频率有增加趋势。本文系统性地总结了闽三角海域赤潮时空特征,为该区域的赤潮风险分析和预防提供依据。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号