夜光藻高效培养方法建立及其有性繁殖发生机制的初步研究

夜光藻(Noctilucascintillans)是典型的赤潮生物,在世界多个海域形成过大面积赤潮,对海洋生态系统构成一定的威胁。夜光藻赤潮的发生不仅受外界环境因子的影响,其有性繁殖的方式在赤潮发生过程中也起着重要作用。本研究从连云港海域分离获得一株夜光藻,利用自行设计的饵料藻投喂装置,以天然海水为培养基,在温度20～25℃范围内实现了夜光藻的室内长期培养,并观察记录了夜光藻配子发生全过程。研究结果表明,夜光藻不同生长阶段培养体系中配子母细胞与营养细胞密度变化趋势基本一致,显示夜光藻的有性繁殖发生与种群丰度存在一定的相关性,但它们之间的因果关系还有待进一步探讨。本研究结果加深了对夜光藻有性繁殖的认识,有助于阐明其种群增长模式,并深入理解其赤潮暴发机制。     

胶州湾夜光藻种群动态及其大量繁殖的生态机制

为研究胶州湾夜光藻大量繁殖的生态机制,于2015年逐月对胶州湾12个站位进行了多学科综合调查,获取了温度、盐度、营养盐等环境因子的周年数据,分析了夜光藻种群丰度和结构的时空分布特征,探讨了环境因子对夜光藻种群动态的影响,以及夜光藻种群增长与其繁殖方式的相关关系。结果发现:全年各站位夜光藻丰度范围为0—31.17×10~3ind./m~3,月平均丰度呈现双峰分布;二分裂个体比例介于0—31.25‰,有性繁殖个体比例介于0—29.41‰,两种繁殖方式均呈现出季节差异及空间差异。相关性分析表明,影响夜光藻种群动态的主要因子包括水温、叶绿素a、硝氮及亚硝氮。夜光藻是冷水种,水温与夜光藻种群丰度、两种繁殖个体比例均呈显著负相关;叶绿素a反映夜光藻食物的丰富程度,与夜光藻丰度、两种繁殖个体比例呈显著正相关;亚硝氮和硝氮可能对夜光藻代谢繁殖起调控作用,与夜光藻丰度及有性繁殖个体比例呈负相关。     

2013年我国近海赤潮引发种种类和分布研究

对2013年全国海洋环境监测1626个站位生物数据进行分析, 以近2001年～2013年在我国近海海域明确发生赤潮的生物作为赤潮引发种, 开展其种类组成和数量分布研究。结果显示: (1)我国近海赤潮引发种隶属于8门60种, 其中产毒种12种, 甲藻27种, 硅藻20种。(2)2013年共监测到上述赤潮引发种50种, 各监测站位种类数在0～25种之间, 平均密度在84～1.16×10¹¹个/m³之间, 赤潮引发种种类数、密度分布大致都呈现近岸至远海递减的趋势, 但在长江口及其邻近海域, 呈现先增大后减小趋势。(3)2013年各海区赤潮引发种种类数在36～42之间, 平均密度渤海>东海>南海>黄海, 多样性指数渤海>黄海>南海>东海, 都以中肋骨条藻(Skeletonema costatum)为优势种。(4)作为高频赤潮引发种,2013年中肋骨条藻(S. costatum)主要分布在我国近岸及近海海域; 夜光藻(Noctiluca scintillans)在我国近岸、近远海海域都有分布; 东海原甲藻(Prorocentrum donghaiense)主要分布在黄海和东海的近岸和近海海域; 米氏凯伦藻(Karenia mikimotoi)分布较为广泛, 但出现的站位较少; 红色中缢虫(Mesodinium rubrum)、赤潮异弯藻(Heterosigma akashiwo)、红色赤潮藻(Akashiwo sanguinea)只在很少区域有分布。该研究结果有助于摸清我国近海海域赤潮生物种类和分布状况, 可为赤潮的预警及其防灾减灾提供基础科学依据。     

2009 年春季辽东湾网采浮游植物群落结构

分析了2009 年春季(5 月)渤海辽东湾网采浮游植物物种组成, 丰度分布, 生物多样性指数及群落相似性。春季共鉴定出浮游植物3 门23 属32 种, 主要隶属硅藻门和甲藻门, 生态类型多为温带近岸型和广布型种类, 少部分为暖海性物种或大洋性物种。优势种有夜光藻(Noctiluca scientillans)、翼鼻状藻(Proboscia alata)、旋链角毛藻(Chaetoceros curvisetus)、巨圆筛藻(Coscinodiscus gigas)和尖刺伪菱形藻(Pseudo-nitzschia pungens)等。浮游植物在各站位的细胞丰度分布不均匀, 其平面分布呈现由沿岸海域向海湾中部海域递减的趋势。Shannon-Wiener 指数、Pielou 指数较低, 群落结构简单, 稳定性较差。聚类分析结果表明群落之间的相似性较高。     

2014年冬季浙江中部海域网采浮游植物群集

于2014年12月至2015年1月, 在121°42′E～126°18′E, 28°43′N～30°02′N的浙江中部海域, 对97个站位采集的浮游植物的种类组成、群落结构、细胞丰度进行了研究。共鉴定浮游植物6门53属163种(含19未定种), 其中以硅藻为主, 甲藻其次; 浙江中部海域冬季浮游植物群落可分为4种生态类型: 半咸水类群、沿岸广温型、近海广温广盐型、外海高温高盐型, 其中最主要生态类型为近海广温型; 浮游植物优势种为中华齿状藻(Odentella sinensis)、琼氏圆筛藻(Coscinodiscus jonesianus) 、伏氏海线藻(Thalassionema frauenfeldii)、虹彩圆筛藻(Coscinodiscus oculus-iridis)、太阳双尾藻(Ditylum sol)、洛氏角毛藻(Chaetoceros lorenzianus)。浮游植物的细胞丰度范围为0.3×10⁴个/m³～67.1×10⁴个/m³, 平均值为8.8×10⁴个/m³, 呈现近岸>近海>外海的分布特点, 高值区位于三门湾至渔山列岛之间的海域; 生物多样性指数平均值为3.36; Pearson 相关性分析得出: 调查海域浮游植物的细胞丰度与盐度呈负相关,与磷酸盐、硝酸盐成正相关。     

2009 年晚春黄海南部浮游植物群落

在2009 年6 月对黄海南部及中部海域30 个站位进行综合调查, 对获得的131 个浮游植物样品用Uterm?hl 方法进行初步分析, 共鉴定浮游植物4 门51 属73 种(不包括未定名种), 其中硅藻32 属47种(不包括未定名种), 甲藻17 属24 种(不包括未定名种), 定鞭藻1 门1 种, 蓝藻1 门1 种, 硅藻在物种丰富度上占有优势。浮游植物的生态类型主要以温带近岸种为主, 优势物种为具齿原甲藻(Prorocentrum dentatum)、柔弱伪菱形藻(Pseudo-nitzschia delicatissima)、具槽帕拉藻(Paralia sulcata)等。调查区浮游植物细胞丰度介于0.089 × 10³～1 045.200 × 10³ 个/L, 平均为15.941 × 10³ 个/L, 甲藻的细胞丰度要高于硅藻。细胞丰度高值区位于调查区的南部海域, 以具齿原甲藻为主, 垂向上在10 m 层出现最大值, 随着深度的增加丰度降低。调查区的Shannon-winner 多样性指数和Pielou 均匀度指数的平面分布基本一致, 并且与细胞丰度的分布呈相嵌形式, 即在细胞丰度高的区域多样性指数较低。     

2015年春季桑沟湾浮游植物群落研究

2015年春季, 在桑沟湾海域(122.48°E～122.64°E, 37.04°N～37.14°N) 21个站位进行了水文、生物和化学的综合调查, 应用Uterm?hl方法对调查海域浮游植物的物种组成、细胞丰度、优势物种以及群落多样性等相关生态特征进行了分析。结果表明, 本次调查共鉴定浮游植物4门36属70种, 主要由硅藻和甲藻组成, 也有少数的蓝藻和金藻出现, 浮游植物生态类型主要为温带近岸型。硅藻主要优势种为具槽帕拉藻(Paralia sulcata) 和离心列海链藻(Thalassiosira excentrica); 甲藻主要优势种为双刺原多甲藻(Protoperidinium bipes)。调查海域浮游植物细胞丰度范围为3×10³～417.4×10³个/L,平均值为130.76×10³个/L。相比历史资料, 桑沟湾浮游植物物种数整体呈下降趋势。浮游植物细胞丰度的平面分布主要由硅藻分布所决定, 呈现中部较低, 逐渐向西部与东部增加的趋势; 其垂直分布呈现随水深的增加, 先降低后升高的趋势。浮游植物群落Shannon-Wiener多样性指数范围为0.486～2.305, 平均值为1.25; Pielou均匀度指数的区间范围为0.172～0.849, 平均值为0.462。由于Shannon-Wiener多样性指数和Pielou均匀度指数的高值区与浮游植物细胞丰度的低值区相对应, 从而说明优势种的出现会降低浮游植物的多样性。     

大鹏湾夜光藻种群的季节变化和分布特征

于1990年3月－1992年6月对中国南海大鹏湾盐田附近海域的夜光藻种群动态及时空分布进行综合调查。结果表明，夜光藻种群的出现期间一般为每年的1－6月，最早是1991年的12月，数量高峰期为3－5月，种群密度的波动极为显著；调查期间共发生8次赤潮，且都发生在3月初至5月初；大鹏湾夜光藻赤潮的发生特点是，赤潮的发生和消失突然，持续时间短，一般不超过3d；调查海域夜光藻种群的空间分布模式为近岸的高于中央水域的，表面的高于底层的。     

夏季莱州湾浮游动物群落特征

根据2009 年8 月监测资料, 研究了夏季莱州湾海域浮游动物种类组成、生态分布、群落结构及其环境影响因子。共记录包括浮游幼虫在内的浮游动物38 种(类), 优势种类为长尾类幼虫、强壮箭虫、短尾类溞状幼虫及太平洋纺锤水蚤等。浮游动物丰度101.3～3620.0 个/m³, 平均602.8 个/m³, 丰度平面分布呈现湾西部高, 向中东部逐渐降低趋势; 长尾类幼虫、强壮箭虫、短尾类溞状幼虫出现频率100%,太平洋纺锤水蚤出现频率40.9%; 长尾类幼虫丰度7.8～1747.9 个/m³, 平均96.3 个/m³, 高值区分布于莱州湾西部黄河口以南近岸水域; 强壮箭虫丰度2.5～747.8 个/m³, 平均85.4 个/m³, 偏离近岸趋深水、低温区分布; 短尾类溞状幼虫丰度3.3～271.7 个/m³, 平均20.5 个/m³, 主要分布于莱州湾南部近岸水域; 太平洋纺锤水蚤丰度0～968.3 个/m³, 平均29.0 个/m³, 密集分布区在莱州湾西南部小清河外近岸低盐水域。浮游动物丰度分布与NO₂-N、DO、COD 及NO₃-N 呈显著正相关关系, 与盐度呈显著负相关关系(P＜0.01)。等级聚类分析(CLUSTER)将莱州湾的浮游动物分为湾西部和湾中东部两个群落。相比于湾中东部群落, 湾西部群落占据着莱州湾西部近岸较狭窄的地理范围, 其所在水域水浅, 盐度低, 无机氮、活性磷酸盐、叶绿素a、浮游动物丰度高及物种多样性高, 群落内生物相似性弱。     

2014年春季渤海浮游植物群落结构

基于2014年春季在渤海进行的水文、化学和生物方面的综合大面调查，研究了渤海浮游植物群落的结构特征，并结合文献资料，分析影响浮游植物群落结构形成的原因。结果显示：2014年渤海春季共鉴定浮游植物3门29属50种，以硅藻为主，还有少数甲藻和金藻。其中，硅藻门中圆筛藻属的种类最多，共12种，其次为角毛藻属，共5种。浮游植物总细胞丰度介于1.08×10⁴~181.09×10⁴个/m³，平均为25.47×10⁴个/m³。硅藻与甲藻细胞丰度比值为12：1，硅藻在物种数量和细胞丰度上均占有绝对优势，为渤海浮游植物的主要类群。浮游植物优势种主要为密联角毛藻（Chaetoceros densus）、斯氏几内亚藻（Guinardia striata）、具槽帕拉藻（Paralia sulcata）和夜光藻（Noctiluca scintillans）。渤海春季浮游植物群落多样性水平较低，且分布不均。渤海中部和渤海海峡海域由于单一优势种过量繁殖导致群落稳定性较差。与历史同期资料对比，渤海海域浮游植物群落出现明显的物种演替现象，角毛藻的优势地位显著性下降，斯氏几内亚藻首次在渤海大面调查中被记录为优势种。本研究为今后渤海环境生态系统和渔业资源变动的研究提供重要基础资料和参考依据。     

大鹏湾夜光藻种群的季节变化和分布特征

于１９９０年３月－１９９２年６月对中国南海大鹏湾盐田附近海域的夜光藻种群动态及时空分布进行了综合调查，结果表明，夜光藻种群的出现期间一般为每年的１－６月，最早是１９９１年的１２月，娄量高峰期为３－５月，种群密度的波动极为显著；调查期间共发生８次赤潮，且都发生在３月初至５月初；大鹏湾夜光藻赤潮的发生特点是，赤潮的发生和消失突然，持续时间短，一般不超过３ｄ。     

南海大鹏湾夜光藻种群在其生态群落中的地位和功能

分析了１９９１年上半年南海大鹏湾盐田水域夜光菏和浮游动、植物之间的种群动态关系，结果表明，在春季高峰期３月至５月初，调查海域共出现１２个夜光藻和浮游动、植物高峰。其中，以发生４次赤潮的夜光藻种群占主导地位，其次是枝角类的鸟啄尖头蚤，其最高数量高达９６２３８ｉｎｄ／ｍ＾３。相比之下，在夜光藻和枝角类岛啄尖头捕食压力的影响下，浮游植物的春季高峰并不显著。调查结果表明夜光藻的过度繁殖，不但对产浮游性卵的     

山东乳山近海海洋卡盾藻(Chattonella marina)赤潮发展过程及其成因研究

于 2008 年 8 月 10—28 日, 在山东乳山近海赤潮发生海域采用直接采水计数法对浮游植物种类组成进行了 4 次跟踪监测。结果表明, 此次赤潮主要由海洋卡盾藻引起, 面积约 100km², 平均密度 1.46×10⁶ cells/L, 占浮游植物总数的 91.32%。 从 8 月 19 日开始, 海洋卡盾藻赤潮开始消退, 同时中肋骨条藻和尖刺拟菱形藻密度增高, 到 8 月 28 日本次赤潮完全消失。研究发现, 该海域富营养化、低盐度的理     

2021～2022年荣成海域多相赤潮的分子鉴定

山东半岛濒临渤海和黄海,海岸带复杂,海岸线长,近岸海域赤潮事件频发。然而,由于部分赤潮物种的形态难以识别,或易降解不稳定,加上形态鉴定专业要求高,导致致灾赤潮物种未得到准确鉴定。2021年11月至2022年4月间山东荣成海域海带养殖区暴发严重赤潮事件,面积达1 440 km²,导致海带白化、溃烂,造成严重经济损失。对该海域水样固定样本的观察鉴定到两种致灾赤潮物种,红色赤潮藻(Akashiwo sanguinea)和多纹膝沟藻(Gonyaulax polygramma),二者均为山东近海常见的致灾赤潮物种。该研究通过对赤潮样本中活体单细胞的显微观察和单细胞测序分析,根据藻细胞形态特征与分子标记序列相似性鉴定到三种优势致灾赤潮物种,包括红色赤潮藻、多纹膝沟藻和灰白下沟藻(Katodinium glaucum)。其中灰白下沟藻由于在固定过程中不稳定而较少得到鉴定。对该赤潮海域水样开展宏条形码分析,除了发现上述三种致灾赤潮物种外,还发现了另外一个致灾赤潮物种纺锤环沟藻(Gyrodinium fusiforme)。纺锤环沟藻也由于在固定过程中不稳定而较少得到鉴定。由此可见,...     

A potential source of recruitment of Acartia pacifica nauplii: viable benthic resting eggs

Many estuarine and coastal planktonic copepods depend on the hatching of benthic resting eggs for recruitment of nauplii to the water column population. The distribution and abundance of viable resting eggs of Acartia pacifica in the Xiamen Bay were determined by the presence of nauplii in the laboratory. The number of viable eggs varied temporally and spatially. The maximum number (9.2×10⁴m^-2) of viable eggs was in summer. In spring the average abundance of viable eggs was 5.6×10⁴ m^-2. The abundances of viable eggs in fall and winter were similar, respectively 2.7×10⁴ and 3.3×10⁴ m^-2, which were the lowest in the year. The numbers of viable eggs inside the stations of the Xiamen Bay were higher than those outside the stations. The viable eggs were found at all depths (0～10 cm),although not in every station. The maximin number did not necessarily occur in the uppermost centimeter of the sediments but often occurred several centimeters below the water-sediment interface. The accumulation of viable eggs in the seabed of a subtropical bay constitutes a potential source of recruitment of nauplii into the pelagic population.     

獐子岛海域和胶州湾表层微微型浮游植物丰度和生物量的季节变化比较

为全面了解黄海典型海区微微型浮游植物的季节变化特征,于2009年7月至2010年6月在北黄海獐子岛海域和2010年1~12月在南黄海胶州湾进行逐月调查采样,利用流式细胞仪检测了表层海水中微微型浮游植物(picophytoplankton)的丰度,包括聚球藻(Synechococcus,SYN)和微微型真核浮游植物(picoeukaryotes,PEUK),并分析了其与环境因子的关系。獐子岛海域和胶州湾SYN和PEUK全年广泛分布,獐子岛海域SYN丰度范围在0.05×10³~120.00×10³cells/mL之间,丰度在秋季最高;胶州湾SYN丰度范围在0.02×10³~61.80×10³cells/mL之间,丰度在夏季最高。獐子岛海域PEUK丰度范围在0.01×10³~18.76×10³cells/mL之间,丰度在秋季最高;胶州湾PEUK丰度范围在0.25×10³~95.57×10³ cells/mL之间,丰度在春季最高。獐子岛海域微微型浮游植物丰度组成以SYN为主;而胶州湾以PEUK为主。PEUK是两海区微微型浮游植物生物量的主要贡献者。相关性分析结果表明,温度是影响两海区SYN丰度季节变化的最主要因素;影响PEUK季节分布的因素不完全一致,獐子岛海域PEUK丰度主要受温度调控;胶州湾PEUK丰度主要受温度和营养盐浓度影响。与已有研究比较,这两个海区的微微型浮游植物生物量对浮游植物生物量的贡献明显高于其他温带沿岸海域,预示微微型浮游植物在獐子岛海域和胶州湾生态系统中的重要作用,值得进一步深入研究。     

Impact of monsoon-driven circulation on phytoplankton assemblages near fringing reefs along the east coast of Hainan Island,China

Monsoonal hydrodynamic prevails over the east coast of Hainan Island induced by southwest monsoon (SWM) and northeast monsoon (NEM) which drives coastal Ekman divergence/convergence cycle and the reversal of Guangdong coastal current (GCC) between the sGCC in the SWM season and nGCC in the NEM season. We report the control of such hydrodynamics on biological properties such as phytoplankton assemblages in the east coast of Hainan Island. Physico-chemical and biological observations were carried out in two oceanographic cruises along the east coast of Hainan Island during SWM period (July–August) of 2008 and NEM period (March–April) of 2009. Results indicated that phytoplankton assemblages in coastal regions (fringing reefs and coastal shelf) changed dramatically accompanied with the reverse of monsoonal hydrodynamic processes, with chain-forming diatoms (mainly, Pseudo-nitzschia spp. and Thalassionema nitzschioides) dominating during SWM cruise when coastal Ekman divergence and the sGCC were prevailed, but the pelagic Noctiluca scintillans and Trichodesmium erythraeum dominating during NEM cruise when coastal Ekman convergence and the nGCC were prevailed. Furthermore, phytoplankton assemblages in fringing reefs along coastline were somewhat different from ones of coastal shelf, as fringing reefs are just located at dynamic boundary of offshore (or onshore) Ekman transport processes. Offshore diffusion of pelagic cells (such as T. erythraeum) driven by offshore Ekman transport process led to the lower abundance of T. erythraeum in fringing reefs than ones in coastal shelf during SWM cruise; on the contrary, onshore aggregation of pelagic cells (such as N. scintillans and T. erythraeum) driven by onshore Ekman transport process leads to higher abundances of N. scintillans and T. erythraeum in fringing reefs than ones in coastal shelf during NEM cruise; especially, N. scintillans formed bloom in fringing reefs. Last, we suggested that hydrodynamic processes must be taken into account in scientific management of fringing coral reefs health of the east coast of Hainan Island, especially during northeast monsoon season when blooming specie cells (such as N. scintillans) could be introduced from eutrophic South China mainland coast to the east coast of Hainan Island and piled to high-abundance at fringing reefs by monsoonal hydrodynamics.     

Synoptic distribution of crab larvae near the mouth of Delaware Bay: Influence of nearshore hydrographic regimes

In this paper we describe results of a study designed to test the hypothesis that coastal regions with weak subtidal flow (i.e., coastal null zones) may serve as retention areas for estuarine larval forms. Our investigation assessed the distribution of 3 taxa of crab larvae (Callinectes sapidus, Uca spp., and Hexapanopeus angustifrons) within a 200-km² region encompassing the mouth of Delaware Bay (ca. 39° N, 75° W). Previous studies had shown that larvae of C. sapidus and Uca spp. are exported to the coastal ocean, while larvae of H. angustifrons are retained within the estuary. In the present investigation, we conducted simultaneous plankton tows at 3 stations during peak spawning season. Samples were collected from a depth of 1 m every 30 min throughout a complete tidal cycle. One station was located 15 km within the bay and was subjected to strong flow at tidal frequency. A second station was located within a southward-flowing coastal current near the southern terminus of the bay at Cape Henlopen. A final station was located in a coastal area of weak subtidal flow near Cape May at the northern terminus of the bay. Results provide a unique synoptic view of larval distributions in 3 distinct hydrographic regimes in the mouth of a major estuary. The coastal-current station was characterized by low concentrations of newly hatched C. sapidus and Uca zoeae, while the null-zone station had high densities of both early and advanced larval stages of these two taxa. In contrast, the station located within the bay had few C. sapidus or Uca zoeae and was dominated by both early and advanced stages of the mud crab H. angustifrons. These data provide clear evidence for the retention of exported larval forms in a coastal null zone associated with the circulation of a large estuary and thus are consistent with our hypothesis.     

Seasonal and spatial variation in abundance and egg production of Paracalanus parvus (Copepoda: Calanoida) in/out Jiaozhou Bay, China

The spatial distribution of stage-specific abundance and reproduction of the copepod Paracalanus parvus were studied from October 2005 to September 2006 in the Jiaozhou Bay. This copepod occurred continuously in this bay throughout the year. The species reached the lowest abundance in April and peaked in June. From October to December, distribution center mainly occurred in offshore water and at the mouth of the bay. In winter, early copepodites and adults gradually decreased and till February, most of the population was only comprised of CIV–CV stages. Overwintering copepodites matured in March and males tended to mature before female. From May to September, each stage occurred in the population and gradually reached high abundance. Temperature and chlorophyll a (Chl-a) concentration in the three stations can't clearly explain the seasonal variation in stage-specific abundance, so we surmised the important effect of the Yellow Sea. Egg production rate (EPR) reached its lowest in winter and peaked in June at 60.8 eggs female⁻¹ day⁻¹ in nearshore water. In the warming period, EPR in nearshore water was statistically higher and EPR > 10 eggs female⁻¹ day⁻¹ lasted longer than that in offshore water, showing the importance of nearshore water for recruitment of P. parvus. Our study showed that EPR was positively related to temperature and total chlorophyll a in offshore water and mouth of the bay. In nearshore water, the relationships between EPR and temperature and Chl-a in three size fractions were not the same as those in offshore water, suggesting complicated ecosystem in such a eutrophic area in warming period.