春季海州湾临洪河口浮游植物粒级结构及环境因素

2017年4月作者对海州湾临洪河口海域16个站位的常规理化因子以及浮游植物粒级结构进行了采样和分析,结果表明:调查海域盐度和温度均值分别为35.2和11.2℃,均由近岸到外海逐渐增大;悬浮物质量浓度在3.4 mg/L～137.6 mg/L变化,均值为22.8 mg/L,由近岸到外海逐渐减少,水体逐渐清澈; pH均值为8.29,近岸低,外海高; DO均值为9.8 mg/L, COD在0.34 mg/L～6.55 mg/L变化,均值为3.42mg/L,DO和COD分布规律不明显;浮游植物粒级组成以微型与小型浮游植物为主,其叶绿素a质量浓度平均值与范围分别为1.48μg/L(0.68μg/L～3.13μg/L)、9.14μg/L(2.69μg/L～25.50μg/L),且呈现自沿岸河口向外海逐渐递减的趋势;而微微型浮游植物叶绿素a质量浓度平均值仅为0.27μg/L,且分布较不规律;小型浮游植物对浮游植物总生物量的贡献率最大,高达83.89%,微型及微微型浮游植物的贡献率分别为13.60%和2.52%;在相关性分析中,各项环境因子对小型浮游植物的分布有较大的影响,其中悬浮物、pH与小型浮游植物叶绿素a浓度表现出显著相关(P0.05),溶解氧、盐度与小型浮游植物叶绿素a质量浓度呈极显著相关(P0.01),微型、微微型浮游植物的分布与各项环境因子的相关性不明显。     

厦门岛西北海域浮游植物生物量粒级结构及其环境影响因素

文章利用2018年9—11月厦门岛西北海域的现场调查资料,在对海域水质污染状况和富营养化水平进行评价的基础上,分析并讨论浮游植物生物量粒级结构及其环境影响因素。研究结果表明:同安湾在11月处于富营养水平,属于中度或严重污染海域;九龙江口和西海域在9-11月均处于磷中等限制潜在性富营养或磷限制潜在性富营养水平,属于严重污染海域。同安湾和西海域浮游植物分粒级的生物量占比与九龙江口存在明显差异,前者由大到小依次为微型、小型、微微型,后者由大到小依次为小型、微型、微微型。小型浮游植物生物量与硝酸盐和亚硝酸盐、溶解无机氮、溶解无机磷以及活性硅酸盐呈显著正相关,与盐度呈显著负相关;微型浮游植物生物量与真光层深度、铵盐和溶解无机磷呈显著正相关;微微型浮游植物生物量与真光层深度、铵盐和溶解无机磷呈显著正相关,与pH值呈显著负相关。影响浮游植物群落粒级结构的最重要的海洋环境因子是盐度、真光层深度和溶解无机磷,尤其是溶解无机磷浓度,其值一旦升高,浮游植物极有可能从磷胁迫状态发展为赤潮。控制排污、实时监控、增强预警能力和改善生态环境是控制和预防营养盐污染以及赤潮暴发的有效手段。     

中国近海有害藻华研究现状与展望

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...     

微小辐环藻, 我国硅藻藻华的新记录种

2016年5月4日—10日, 海南省海口市红城湖发生了一起硅藻藻华。为明确该起藻华的肇事生物, 于藻华期间采集了水体样品, 经过光镜和电镜下的形态学观察, 确认藻华原因种为微小辐环藻Actinocyclus exiguus Fryxell & Semina, 该种是我国硅藻的新记录种, 其藻华在我国也是首次报道。微小辐环藻隶属于中心纲硅藻, 细胞单独生活或形成胶质状群体, 细胞个体较小, 壳面直径为6.4~11.1μm, 有2个或3个壳缘唇形突, 壳缘处具有眼斑结构。水体中丰富的氨氮(平均值为2880μg•L^-1)和较高的水温(31℃)条件可能是藻华事件的环境诱因。藻华事件导致红城湖40余吨花鰶死亡。经过鱼体检测, 初步排除因为藻毒素、鱼鳃机械性损伤或水体缺氧而致死的可能, 水体盐度剧烈变化等物理应激反应导致鱼类死亡的可能性较大。     

长江口邻近海域春季藻华与水体层化的关系

长江口邻近海域是我国近海有害藻华高发区之一。受长江冲淡水和台湾暖流影响,海域环境条件复杂,有可能影响到藻华的分布状况、动态过程和危害效应。本文利用"藻华973项目"2011年的现场实测数据,从水体层化状况与藻华的关系入手,绘制出各要素的平面及剖面分布图,对比分析了春季硅藻藻华和甲藻藻华期间的温、盐跃层及其变化情况,探讨了硅、甲藻藻华的分布状况及其与温、盐跃层之间的关系。研究发现,2011年春季藻华期间该海域存在明显的温跃层和盐跃层。硅藻藻华期的温、盐跃层主要受到长江冲淡水影响;而在甲藻藻华期,受外海水入侵影响导致的温、盐跃层现象更加显著。藻华期间,浮游植物生物量高值区均出现在跃层上方的长江冲淡水影响区,其中硅藻藻华分布区与高强度跃层区基本一致,而甲藻藻华则主要分布在层化强度相对较弱的近岸海区,其分布可能受到上升流的影响。综合上述分析结果可以看出,长江口邻近海域春季的硅藻藻华主要受到长江冲淡水影响,而甲藻藻华的分布则在一定程度上受到外海水入侵及上升流影响。这一认识为进一步分析该海域春季硅、甲藻藻华演替过程及藻华优势种的长期演变趋势提供了新的思路和依据。     

围隔生态系内富营养对水体营养盐结构的扰动

氮、磷和硅是海洋中植物的主要营养元素.在开放水域,水体营养盐结构比较稳定.但在特定的环境条件下,如封闭或半封闭水体内、跃层形成或水体较为稳定时,原来稳定的营养盐结构则容易被富营养而发生结构上的重大变化.工业化包括近年水产养殖的发达,水体富营养问题已成为半封闭近岸海区的严重问题,已引起人们的注意^[1].     

我国近海米氏凯伦藻(Karenia mikimotoi)藻华发生概况、危害及其生态学机制

米氏凯伦藻(Kareniamikimotoi)隶属于裸甲藻目(Gymnodiniales)凯伦藻科(Kareniaceae)。该藻广泛分布于全球海域,是海洋中的主要有毒有害赤潮藻,也是我国第二大灾害性赤潮肇事种。米氏凯伦藻可产生半乳糖脂、溶血毒素、鱼毒素和部分细胞毒素,当其大规模暴发时会造成严重的生态灾害和经济损失,并危及海产品安全和人类健康。该藻为广温广盐种,光照耐受阈宽,多以光合作用营自养生长,主要繁殖方式为无性繁殖;另外,米氏凯伦藻能吸收利用不同形态的磷盐,并可进行吞噬营养。这些生态学特性使其具有环境适应优势,在适宜条件下过度繁殖引发藻华。     

胶州湾有毒藻华形成种里氏金色藻(Chrysochromulina leadbeateri)的分类学研究

利用光学显微镜和透射电镜对从青岛胶州湾海水样品中分离的一种微型鞭毛藻进行了超微结构和分类学研究。结果表明,该藻为里氏金色藻(Chrysochromulina leadbeateri Estep,Davis,Hargraveset Sieburth)。其特征为:细胞呈球形,直径4—6μm,两条鞭毛略不等长,分别为8—10μm和12—16μm。一条定鞭能够卷曲,完全伸展后约20—30μm。细胞外被两层不同类型的圆形鳞片,都具十字形中央。外层鳞片表面有放射状细纹,内层鳞片在周边环上有25—30个穿孔。细胞一般有两个色素体,每个色素体内有一个包埋的蛋白核。里氏金色藻曾在挪威沿岸形成大规模有毒藻华,并引起养殖鱼类大量死亡。该种为我国的新记录种。     

基于XML的有害藻华监测数据交换机制及灾害预警聚类方法的研究

有害藻华监测数据具有复杂性、数据来源的多源性、数据平台异构、数据格式不规范等特点.而XML具有可扩展性、简单性、开放性、互操作性及支持多国语言等优势.基于此,运用XML技术建立了有害藻华监测数据交换机制模型HABML,有效解决了有害藻华监测数据的管理、传输及交换等问题,为有害藻华的高效预警奠定了基础.同时,将对FCM聚类分析算法进行改进,引入到有害藻华灾害预警中,直观地反映了海洋要素样本的分布规律,为有害藻华的灾害预警提供了一种新的思路.     

2010—2011年东海藻华高发区水体层化对东海原甲藻(Prorocentrum donghaiense Lu)藻华的影响

本文通过2010年和2011年不同时空角度对东海原甲藻藻华进行调查,研究水体层化对藻华发生和发展的影响。结果显示,起初东海原甲藻在50m等深线附近的外海繁殖与聚集,然后随着台湾暖流与长江冲淡水的相互作用,东海区域水体层化现象加剧,其细胞丰度越来越大,直至藻华发生并持续推进到近岸。大部分东海原甲藻细胞位于层化水体上方,而且当水体层化现象明显时,藻华的发展最为迅速且呈大规模爆发状态。结果还显示当出现叶绿素高值层时,总是伴随出现温盐突变现象。本项研究不仅第一次从时间角度记录了东海原甲藻藻华的发展动态,而且还发现了东海水体层化现象为东海原甲藻藻华的发生和发展提供了多种环境因子条件,这为该藻华的监控和预测提供了重要的科学依据。     

The variations in optical properties of CDOM throughout an algal bloom event

For studies in bio-optical oceanography, visible light properties by classes of dissolved organic matter should be characterized. The regional adjustment of model parameters is one approach which is being widely used to refine bio-optical models. In the present study, buoy and laboratory data were acquired, and during the 15-day observation period an algal bloom event occurred. The absorption coefficient of CDOM at 443 nm, a_g(443), changed in the range of 0.09–0.35 m⁻¹ and 0.1–0.34 m⁻¹ for two depths, 0.32 m and 2.3 m., respectively, throughout the entire period. CDOM absorption was larger for bloom conditions than for non-bloom conditions. In addition, the fraction of CDOM in total absorption was higher during the bloom event than that of non-bloom conditions. The spectral slope of CDOM absorption, S_g, regressed over 400–500 nm, ranged from 0.015 to 0.0185 nm⁻¹ with an average of 0.0166 nm⁻¹. CDOM fluorescence intensity (Fcdom) was obtained using an internal Raman standard and varied over the range of 467.44–1538.23 in relative units. Variations in Fcdom showed a similar pattern to that of CDOM absorption. A robust non-linear relationship between Fcdom and CDOM absorption was found, with a correlation coefficient of 0.893, throughout the whole observation. An attempt to describe S_g with absorption showed a promising consequence that can be described with a negative correlation during the bloom, however, without any distinguishable tendency for non-bloom time span. A two-band ratio algorithm was also carried out for retrieving CDOM absorption. The variations in optical properties of CDOM may be related to the complicated environment in the estuarine waters, which may result from different sources of CDOM.     

Urban groundwater as a possible nutrient source for an estuarine benthic algal bloom

The Peel Inlet in Western Australia was used to study the cause of eutrophic conditions in an estuary. In addition to large quantities of nitrogen and phosphorus (at low concentrations) entering the inlet from rivers and drains from agricultural areas, the urban contribution via groundwater was identified. The average nitrogen concentration of urban groundwater under an area serviced with septic tank systems was 12 parts 10^?6. Because of the nature of the soils, very few groundwater samples contained appreciable phosphorus concentrations. However, one area close to the inlet had semiconfined groundwaters with nitrogen and phosphorus concentrations as high as 100 and 0·4 parts 10^?6 respectively. An obsolete dumping site for human excreta was also identified near the urban area, and this is suspected of having contributed to very high concentrations of nitrogen and phosphorus in groundwater which may have already reached the estuary and caused excessive algal growth. Groundwater contours showed the potential for groundwater movement from part of the urban area and also from the obsolete dumping site.     

Identification of dissolved and particulate carbonyl compounds produced by marine harmful algal bloom species

Carbonyl compounds, especially polyunsaturated aldehydes (PUAs), are increasingly reported as teratogenic to grazers and deleterious to phytoplankton. While PUAs have been considered to be mainly produced by diatoms after cell wounding, little is known about whether microalgae other than diatoms, particularly harmful algal bloom (HAB)-forming species, produce carbonyl compounds. In this study, we analyzed the carbonyl compounds from eight common HAB-forming species ( Akashiwo sanguinea , Karenia mikimotoi , Karlodinium venefi cum , Margalefi dinium polykrikoides , Prorocentrum donghaiense , P . minimum , Scrippsiella trochoidea , and Heterosigma akashiwo ) using gas chromatography-mass spectrometry in full scan and selected ion monitoring (SIM) modes. Our results show a ubiquitous presence of carbonyl compounds in both dissolved and particulate forms in all species we examined. In the full scan mode, 133 chromatographic peaks were detected from 51 samples altogether. Both the varieties of carbonyl compounds and their quantities were algal species dependent, although most of the carbonyl compounds could not be fully identifi ed according to the mass spectral database only due to the unavailability of enough standards for all analytes. Aided with nine standards in SIM mode, we further identifi ed and quantifi ed all nine aldehydes (2-methyl-2-pentenal, trans-2-nonenal, cis-6-nonenal, 2,6-dimethyl-5-heptenal, trans-2-hexenal, trans-2- decenal, 2,4-heptadienal, trans-trans-2,4-octadienal, and trans-trans-2,4-decadienal). Four of these nine aldehydes were detected in particulate form, which confi rmed that trans-2-nonenal could be produced by K . mikimotoi , Karl . venefi cum , P . donghaiense , P . minimum , S . trochoidea , and H . akashiwo , 2,4-heptadienal and trans-trans-2,4-decadienal by A . sanguinea , M . polykrikoides , and S . trochoidea , and trans, trans-2,4- octadienal by S . trochoidea , respectively. We proved that some dinofl agellate and raphidophyte species could contribute to the pool of carbonyl compounds including PUAs in a marine ecosystem. Some carbonyl compounds, particularly those in high cell quota and/or dissolved concentration, may be related to fi shkilling or allelopathy which needs further identifi cation and quantifi cation.     

Trophic transfer of methylmercury and trace elements by tropical estuarine seston and plankton

Methylmercury (MeHg) and trace elements (TE), mercury, selenium, cadmium, lead and copper, were determined in a microbial loop composed by three size classes of autotrophic and heterotrophic microorganism samples, 1.2–70 μm (seston, SPM), 70–290 μm (microplankton) and ≥290 μm (mesoplankton) from five sampling stations within a polluted eutrophic estuary in the Brazilian Southeast coast and one external point under the influence of the bay. TE concentrations were within the range reported for marine microorganisms from uncontaminated locations. Microplankton was primarily composed of proto-zooplankton and diatoms (>90%) while approximately 50% of mesoplankton was composed mainly of copepods. MeHg and TE in samples did not differ among the five sampling stations within the bay. Cd, Pb and Cu in seston were higher in the stations sampled inside Guanabara Bay (0.67 μg Cd g⁻¹, 9.26 μg Pb g⁻¹, 8.03 μg Cu g⁻¹) than in the external one (0.17 μg Cd g⁻¹, 3.98 μg Pb g⁻¹ and 2.09 μg Cu g⁻¹). Hg, MeHg and Se did not differ among the five points within the more eutrophic waters of the estuary and the external sampling station. The trophic transfer of MeHg and Se was observed between trophic levels from prey (seston and microplankton) to predator (mesoplankton). The successive amplification of the ratios of MeHg to Hg with increasing trophic levels from seston (43%), to microplankton (59%) and mesoplankton (77%) indicate that biomagnification may be occurring along the microbial food web. Selenium, that is efficiently accumulated by organisms through trophic transference, was biomagnified along the microbial food web, while Hg, Cd, Pb, Cu did not present the same behavior. Concentrations differed between the three size classes, indicating that MeHg and TE accumulation were size-dependent. MeHg and TE concentrations were not related to the taxonomic groups' composition of the planktonic microorganisms. Results suggest the importance of the role of the trophic level and microorganism size in regulating element transfers. Eutrophication dilution may provide a process-oriented explanation for lower MeHg and TE accumulation by the three size classes of microorganisms collected at the five sampling stations within the bay.     

近岸海域自动监测浮标在赤潮预警中的应用及其缺陷

利用位于广西北部湾的自动监测站,研究2012年2月薄壁几内亚藻以及2014年2月球形棕囊藻的赤潮自动监测数据变化的差异。结果表明,薄壁几内亚藻赤潮期间p H、溶解氧以及叶绿素出现同步的变化趋势,溶解氧以及叶绿素显著升高;球形棕囊藻的赤潮期间,p H、溶解氧以及叶绿素未发生明显变化,与棕囊藻自身生理生态习性有关。自动监测浮标在硅藻等高含叶绿素种类的赤潮中能够起到较好的监控和预警作用,但在微微型、混合营养及异养赤潮种类的赤潮预警应用方面仍有待进一步验证及研究。     

春季长江口富营养化水域浮游植物群集对冲淡水和上升流的响应

A comprehensive study on the phytoplankton standing stocks, species composition and dominant species in the eutrophic Changjiang(Yangtze River) Estuary(CE) was conducted to reveal the response of phytoplankton assemblage to Changjiang Diluted Water(CDW) and upwelling in the spring. Phytoplankton presented peak standing stocks(13.03 μg/L of chlorophyll a, 984.5×103 cells/L of phytoplankton abundance) along the surface isohaline of 25. Sixty-six species in 41 genera of Bacillariophyta and 33 species in 19 genera of Pyrrophyta were identified, as well as 5 species in Chlorophyta and Chrysophyta. Karenia mikimotoi was the most dominant species, followed by Prorocentrum dentatum, Paralia sulcata, Pseudo-nitzschia delicatissima and Skeletonema costatum. A bloom of K. mikimotoi was observed in the stratified stations, where the water was characterized by low nitrate, low phosphate, low turbidity, and specific ranges of temperature(18–22 °C) and salinity(27–32). K.mikimotoi and P. dentatum accumulated densely in the upper layers along the isohaline of 25. S. costatum was distributed in the west of the isohaline of 20. Benthonic P. sulcata presented high abundance near the bottom,while spread upward at upwelling stations. CDW resulted in overt gradients of salinity, turbidity and nutritional condition, determining the spatial distribution of phytoplankton species. The restricted upwelling resulted in the upward transport of P. sulcata and exclusion of S. costatum, K. mikimotoi and P. dentatum. The results suggested that CDW and upwelling were of importance in regulating the structure and distribution of phytoplankton assemblage in the CE and the East China Sea.     

台湾海峡小型浮游动物的摄食对夏季藻华演替的影响

于2004年8月1~6日对台湾海峡南部近岸的藻华过程进行了定点连续跟踪观测,用稀释法研究了浮游植物的生长率和小型浮游动物对浮游植物的摄食死亡率,同时运用高效液相色谱(HPLC)技术,分析了浮游植物不同光合色素类群的生长率和摄食死亡率.结果表明,观测期间处于藻华的消退期.8月1日时,浮游植物生物量(叶绿素a)和丰度分别为2.04μg/dm3和2.99×105个/dm3,主要优势种为尖刺伪菱形藻(Pseudo-nitzschia pungens)、冰河拟星杆藻(Asterionellopsis glacialis)和中肋骨条藻(Skeletonema costatum),8月6日时,浮游植物生物量和丰度分别减为0.37μg/dm3和1.54×104个/dm3;而蓝藻和甲藻的丰度和比例则呈现出逐渐增加的趋势,所占的比重分别从1日的0.04%和0.85%增加到6日的9.59%和41.97%.小型浮游动物主要由无壳纤毛虫、砂壳纤毛虫、红色中缢虫(Mesodinium rubrum)和异养甲藻等类群组成,总丰度于8月2日达到最大值,为3640个/dm3,之后逐渐减少,6日时,仅为436个/dm3.观测期间,小型浮游动物在群落组成上虽一直以无壳纤毛虫和异养甲藻为主,但在具体的类群结构上却表现出了一定的差异,30μm以下的无壳纤毛虫和异养甲藻总体呈下降的趋势,而红色中缢虫、砂壳纤毛虫和大于50μm的无壳纤毛虫总体呈增加的趋势.观测期间,浮游植物的生长率为0.40~0.91d-1,小型浮游动物的摄食率为0.26~1.34d-1,摄食率和生长率总体呈逐渐下降的趋势.结果还表明,小型浮游动物的摄食率与叶绿素a具有很好的相关性(R2=0.89),对各光合色素类群的现存量和初级生产力均具有较高的摄食压力(分别为37.97%~82.24%和70.71%~281.33%),是藻华消亡的重要原因之一;此外,小型浮游动物对甲藻和蓝藻的避食行为,可能是观测期间由“硅藻”水华向“硅藻-甲藻”水华转变的重要原因之一.     

孢囊及其与赤潮爆发关系的研究进展

某些藻类(特别是甲藻),在不适宜生长的恶劣环境条件下能形成休眠孢囊。孢囊下沉到海底,以渡过不良的生存条件。一旦环境条件适宜,孢囊就大量萌发形成浮游细胞和优势群体,从而诱导赤潮的形成。简述了当前国际上对孢囊研究的最新进展,从孢囊和营养细胞相互转化的角度探索了孢囊与赤潮形成的关系,以及分子生物学技术在赤潮生物及其孢囊的定性、定量及赤潮发生监测中的应用。