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1.
通过4个季节(1991年11月—1992年7月)的现场实验观测,初步研究了胶州湾表层浮游生物群落的NH_4~+-N吸收、再生通量的有关问题。结果表明,NH_4~+-N吸收、再生通量的季节变化为:夏季>春、秋季>冬季;周日变化为:吸收通量在白天大于夜间,再生通量夜间大于白天;全年平均,吸收通量为0.073μ mol/(L·h),再生通量为0.053μ mol/(L·h),再生通量始终小于吸收通量;NH_4~+-N的周转时间最长为16.34d(冬季),最短为0.68d(夏季);吸收通量主要来自Picoplankton(占总量的46％—57％);NH_4~+-N吸收具有光依赖性,不同粒级的光依赖顺序为:Netplankton>Nanoplankton>Picoplankton。 相似文献
2.
厦门港小型浮游生物对可溶性活性磷的吸收和再生通量 总被引：1，自引：0，他引：1
应用＾３２ＰＯ４＾３－同位素稀释技术比较研究了厦门港３个站位４个季节表层浮游生物对可溶性活性磷吸收和再生通量。结果表明,ＳＲＰ吸收和再生通量夏季最大,冬季最小;近河口的Ⅱ站ＳＰＲ一最大且季节波动性大,位于港口外缘的１站ＳＲＰ通量最小且季节波上;各站ＳＲＰ通量变化的差异与其不同的理化环境有关。文中还研究探讨了浮游生物在不同季节、不同站位对ＳＲＰ吸收和再生通量的变化特性及生态适应机制。 相似文献
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对虾养殖生态系不同粒级浮游生物呼吸率和初级生产率测定 总被引：2，自引：0，他引：2
1997年6～8月于山东省海阳市黄海集团公司养虾场,用5个实验围隔研究了对虾池不同粒级浮游生物的呼吸率和初级生产率.结果表明:(1)小型、微型及超微型浮游生物的呼吸率平均分别为0.07,0.38及0.31mg/(dm3·d),占各粒级浮游生物总呼吸率的9%,50%及41%.小型、微型及超微型浮游植物的生产率平均分别为0.04,1.26及0.15mg/(dm3·d),占相应粒级浮游植物总生产率的3%,87%及10%.各粒级浮游生物呼吸率占相应粒级浮游植物生产率的比例为:小型浮游生物175%;微型浮游生物30%;超微型浮游生物207%.(2)小型浮游动物、超微型浮游动物(含细菌)的呼吸率显著高于相应粒级浮游植物呼吸率,微型浮游植物的呼吸率明显高于微型浮游动物呼吸率.不同粒级浮游植物呼吸率的大小顺序为微型、超微型、小型,不同粒级浮游动物呼吸率顺序为超微型(含细菌)、微型、小型. 相似文献
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根据2005年4-5月(春季)、8月(夏季)和11月(秋季)对大亚湾大鹏澳海区表层的现场调查结合营养盐加富实验,探讨了不同季节硝态氮(NO-3)、脲氮(urea)和无机磷(PO3-4)等营养元素对该海区浮游植物叶绿素a含量与初级生产力及它们的粒级结构的潜在影响.调查海区表层海水叶绿素a含量在近岸养殖区较高,季节变化不明显,但其粒级结构有较大的季节差异;初级生产力的平面分布与叶绿素a含量在春、秋季均较一致,其粒级结构与叶绿素a的粒级结构在春季基本一致,但在秋季有较大差异.实验结果表明, NO-3、urea和PO3-4对该海区浮游植物叶绿素a、初级生产力及它们的粒级结构有不同的潜在影响,并存在季节差异.尽管磷被认为是该海区浮游植物生长的主要限制因子,结果显示氮(NO-3或urea)对浮游植物生长仍有潜在限制作用,其中NO-3和urea作为不同氮源的潜在影响有明显区别. 相似文献
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为探究北欧海微微型真核浮游生物多样性和群落结构的分布特征,本研究于2017年6月采集北欧海一个典型断面的表层海水,利用标靶(18SrRNA基因V4区)扩增结合高通量测序技术研究了水体中微微型真核浮游生物的多样性及群落结构,并探讨了群落结构、优势类群与环境因子之间的关系。结果表明:微微型真核浮游生物群落的主导类群为囊泡虫类(54.61%),主要由甲藻纲(18.42%)和海洋囊泡虫新类群I (23.01%)组成;后鞭毛类占21.55%,其中真菌在各站中都有较高的相对丰度,为18.86%;此外,不等鞭毛类中的硅鞭藻和囊泡虫类中的甲藻在温度较低的站位中分布较多,而海洋囊泡虫新类群I则在温度较高的站位中分布较多。典型相关分析结果表明,温度对微微型真核浮游生物的群落结构有重要的影响。北欧海的水文特征复杂,寒暖流在此交汇,造成了微微型真核浮游生物的群落结构有明显的区域差异。 相似文献
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长江河口生态系统鱼类浮游生物生态学研究进展 总被引：12，自引：0，他引：12
鱼类浮游生物群落结构的时空分布和动态变化与其所处水域的环境因子有密切的关系，它的变动受环境因子的变化和时空异质性的制约，而其鱼类浮游生物群落结构的变动最具代表性。研究证明，鱼类浮游生物群落结构对鱼类资源的补充，延续和维持生态平衡具有重要的意义，但尚无系统报道。本文就长江口鱼类浮游生物群落的研究做了阐述。三峡工程建设之后，通过改变长江径流来改变长江口水域的温度、盐度及其他非生物因子，同时由于非生物因子的变化，也引起生物因子的改变，从而使鱼类浮游生物优势种的组成和群落结构的生态性质发生了一定的变化，可以影响到长江口鱼类资源的补充，进一步改变长江口水域生态系统的平衡。 相似文献
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模拟升温和营养盐加富对大亚湾浮游生物群落代谢的影响* 总被引：1，自引：0，他引：1
文章结合模拟升温和营养盐加富, 于2016年8月和2017年1月研究了夏季和冬季大亚湾海域浮游生物群落代谢特征, 以期深入了解浮游生物对升温和富营养化作用的响应机制。结果表明: 升温和营养盐输入均会影响浮游生物总初级生产力(GPP)和群落呼吸率(CR), 且GPP对环境的响应更敏感。夏季GPP除在培养前期(24h)极高温条件下受到显著抑制外, 营养盐输入的影响比温度的影响作用更显著; 而冬季GPP和CR受升温效应的影响显著(p<0.05)。总体看来, 升温效应和营养盐输入均能影响浮游生物群落碳代谢平衡, 导致海洋生态系统的稳定性降低, 进而影响海洋生物多样性以及渔业资源产出的数量和质量。 相似文献
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表层水体中的浮游生物群落在生物地球化学过程中起重要作用,其生物地理分布通常与水文等环境条件相关。近年来DNA测序等方法已成为研究海洋生态系统中真核生物群落的重要工具,在本研究中采用ITS1作为DNA标记评估我国沿海表层水中的真核浮游生物多样性。BLAST结果表明,大部分ITS1序列隶属于6个真核类群,包括浮游动物、真菌和囊泡虫类等。这些主要的真核生物类群可以将采样点分为显著不同的5个聚类,而每个聚类中的特征真核生物门类表现出显著的地理分布差异。总体上,真核浮游生物群落的多样性水平与经纬度、水深、温盐等参数显著相关,自北向南有显著升高的趋势。真核生物群落差异(β-多样性)随地理距离的增加而加大。这提示真核浮游生物在我国沿海表层水中显示出地理限制。本文为中国沿海浮游生物的生物地理研究提供了分子生物学数据基础。 相似文献
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南黄海和东海浮游生物群落的初步探讨 总被引：10，自引：5，他引：10
南黄海和东海位于中国东部的陆架上,这个区域受江河迳流、大陆沿岸流、黄海冷水和黑潮水的影响,明显地反映出其水文、化学要素、浮游生物的分布都比较复杂.如果仅从浮游生物组成看,有暖温带的近海种,有半咸水河口种,有沿岸低盐种;也有外海热带种.它们构成了浮游生物各自的群落分布区,在群落之间由于水团的水平和垂直方向不同程度的混合,存在着一个群落交汇区.群落及其交汇区具有相对的稳定性,但随季节而有变化.本文根据1960年和1971年对南黄海和东海(东经127°以西、北纬27°-34°)进行渔场环境调查时,所获得浮游生物的样品,经分析后提出以下的初步探讨. 相似文献
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《African Journal of Marine Science》2013,35(1):209-221
The size-related activities of important heterotrophs and autotrophs were compared at the surface and at the subsurface chlorophyll maximum (Chlmax) in Agulhas Bank waters. The netplankton fraction was dominated by Nitzschia spp. and ciliates, small (diameter c. 3μm) microflagellates being the most abundant nanoplankton group. Uptake ratios of ammonium to phosphate for the total microplankton community were different at the two depths. With reference to the Redfield ratio, it appears that at least 48 per cent of the nitrogen ration at the Chlmax was regenerated even though nitrate was in ample supply. These assimilation ratios also suggest a very large contribution from recycled nitrogen other than ammonium in surface waters. It is unlikely that phosphorus would ever become limiting, except perhaps at the primary production maximum. Microplankton uptake and regeneration of both ammonium and phosphorus were approximately in balance, indicating that variations in assimilation ratios were the result of heterotrophic excretory activity. The size-fractionation studies show that picoplankton were on average the single most important size class in nutrient assimilation. The netplankton size class was, in terms of regeneration, often the most active in the microplankton community especially within the Chlmax. Heterotrophic microflagellates and picoplankton supplied the bulk of ammonium and phosphorus at the surface. The importance of a particular size class to either ammonium or phosphorus uptake/excretion was quantified as a relative assimilation/regeneration index. These calculations demonstrate size-related differences in the relative importance of the microplanktonic groups to the immobilization and recycling of different nutrients. 相似文献
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东海春季真光层分级叶绿素α分布特点的初步研究 总被引：10，自引：0，他引：10
于 1994年春季调查中 ,对东海海区真光层中的叶绿素 a含量进行了分级 ( 2 0～ 2 0 0μm,2～ 2 0 μm,<2 μm)测定。结果表明 ,在组成上 ,整个调查海域中 ,微微型和毫微型浮游植物是初级生产者中的主要组成者 ,分别占总叶绿素 a含量的 4 7%和 33% ,网采浮游植物平均占 2 0 %。在分布上 ,岸边及内陆架区 ( 50 m等深线以内 )毫微型浮游植物是初级生产的主要承担者 ,内外陆架交界区网采浮游植物占主要部分 ,外陆架区和大洋区微微型浮游植物占绝对优势。 相似文献
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This work investigates the alkaline phosphatase activity in a littoral marine ecosystem (Toulon Bay and Le Niel Bay, France) in order to study its biochemical characteristics with respect to pH, sea water composition and phosphate sensitivity. We also characterise the active forms in sea water and determine the extent to which zooplankton generate phosphatase activity with respect to other plankton classes. In Toulon Bay, phosphatase was produced mostly by the microplankton fraction (>90 μm), accounting for more than 90% of total activity. In contrast, most of the phosphatase activity in Le Niel Bay was generated by the nanoplankton fraction (5–90 μm) and the picoplankton fraction (0.25–5 μm). The microplankton enzymes had non Michaelis-Menten kinetics suggesting the involvement of multiple enzyme processes with distinct kinetic constants. This activity is in major part secreted into the sea water and is stimulated by the ionic strength and the pH of the sea water. Cypris larvae of the genus Balanus played a special role in this release. For the nanoplankton and picoplankton, part of this activity was due to non-secreted enzymes, probably bound to membranes or occurring intracellularly. Moreover, nano and picoplankton phosphatase required higher pH than microplankton enzyme. For all plankton size classes, there was no activity at low pH, suggesting that acid phosphatases were not involved in reactions with substrates dissolved in water. 相似文献
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2012年楚科奇海及其邻近海域浮游植物现存量和初级生产力粒级结构研究 总被引：2，自引：1，他引：2
通过2012年夏季第五次北极科学考察期间在楚科奇海及其邻近海域现场调查所获得的数据分析研究了海域的粒度分级叶绿素a浓度和初级生产力。结果表明,叶绿素a浓度和初级生产力的高值均出现在楚科奇海陆架区,并且远高于深海区。去程时调查海域水层平均叶绿素a浓度的变化范围为0.32~15.66mg/m3,平均(2.77±3.96)mg/m3,高值区出现在南部邻近白令海峡海域、北部阿拉斯加巴罗近岸和冰缘区;初级生产力的范围为50.11~943.28mg/(m2d),高值出现在冰缘水华区。返程时水层平均叶绿素a浓度的变化范围为0.07~1.52mg/m3,平均(0.41±0.40)mg/m3,高值仍出现在陆架区,但比去程时低了一个数量级;初级生产力的分布范围为12.31~41.35mg/(m2d),高值出现在陆架区。浮游植物粒度分级测定结果表明,在生物量较低的深海区,叶绿素a浓度和初级生产力的粒级结构以微微型浮游生物(Pico级份)占优势(其贡献率分别为46.1%和56.9%),小型(Net级份)和微型(Nano级份)对总叶绿素a浓度的贡献差异极小,分别为26.6%和27.3%,对总初级生产力的贡献分别为23.8%和19.3%;而在生物量较高的水深小于200m的陆架区,Net级份叶绿素a浓度所占百分比最高,Pico级份次之,Nano级份最低,分别为59.8%、27.9%和12.3%,初级生产力的粒级结构中叶绿素a浓度所占百分比由高到低同样是Net、Pico和Nano,所占百分比分别为60.6%,32.2%和7.2%。 相似文献
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INTRODUCTIONComparedwithotheroceansintheworld ,thereisrelativelyhigherlevelofnutrients (ni trate ,phosphate ,silicate)intheSouthernOcean .Butprimaryproductivitiesarelow ,andnewproductionisalsoonlyinthemiddlelevelthere .Itiscommonlyconsideredthatthelowerpro ductivitiesintheSouthernOceaniscausedbylowtemperature ,lowlight,lowstabilityofwa ter,scarcityoftraceelementsuchasironandgrazingbyzooplankton (Burkilletal.,1 995) ,etc.ThemostexistedstudiesconcentratedontheAtlanticSectoroftheSouthernO… 相似文献
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南极普里兹湾浮游植物现存量与初级生产力粒级结构和新生产力研究 总被引：9，自引：4，他引：5
报道1998～1999年夏季在南极普里兹湾及其毗邻海域对细胞丰度、优势种类组成、生物量和初级生产力的粒级结构、新生产力及其环境制约机制的研究.结果表明,调查海区具有显著的空间区域化特征.普里兹湾及其毗邻陆架区浮游植物现存生物量和生产力均较高,大陆坡和深海区明显降低;营养盐浓度由于浮游植物的消耗则有相反的分布趋势.浮游植物生物量和生产力受水体的垂直稳定度、浮游动物摄食、水温和光照等环境条件的控制.粒度分级测定结果表明,对调查海区叶绿素a的贡献,小型浮游生物为52.2%,微型为29.4%,微微型为18.4%;对初级生产力的贡献,小型为52.4%,微型为28.7%,微微型为18.9%.研究海区的平均新生产力和f比分别为230.6mg/(m2·d)和0.43. 相似文献
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Abstract Uptake rates of ammonium (NH4 + ), nitrate (NO3 ? ), and urea by three subgroups of phytoplankton (< 200, < 20, < 2 μm) off Westland, were measured using 15 N tracer techniques in midwinter 1988, after a recent upwelling. For all size fractions at surface irradiance (I100), nitrogen (N) was taken up primarily as NO3 ?. This accounted for 67–85% of total N uptake (SρN), whereas at 40 and 7% of surface irradiance, the regenerated N (NH4 + ) and urea) made up 31–72% of SρN. Depth profile experiments for all three size components showed that uptake of NO3 ? was most light‐sensitive, followed by that of NH4 + and urea. The irradiance and nutrient availability plot indicated that light was substantially more important than the nutrient concentrations in controlling the assimilation of N by microplankton (20–200 μm). Nano‐ (2–20 μm) and picoplankton (< 2 μm) however, were not as sensitive to either light or nutrient concentrations. High winds and the resulting deep mixing, combined with offshore and alongshore advection in the midwinter, were suggested to be the major cause of the low biomass and N productivity. 相似文献
18.
Stphane L'Helguen Christian Madec Pierre Le Corre 《Estuarine, Coastal and Shelf Science》1996,42(6):803-818
Uptake rates of ammonium, nitrate, urea and nitrite were measured for 1 year (1988) at a coastal station in the well-mixed waters of the western English Channel. Ammonium was the major form of nitrogen (N) utilized (48%) by phytoplankton, followed by nitrate (32%), urea (13%) and nitrite (7%). Seasonal changes of uptake of ammonium, nitrate and urea showed a broad, intense summer maximum. Nitrite uptake was low throughout the year except for a peak value in June. Uptake rates of ammonium and nitrate were independent of substrate concentrations, whereas those of urea and nitrite were not. The summer maxima of ammonium, nitrate and total N uptake, and the significant relationships of N-uptake index to ambient light, and of chlorophyll-a-specific N uptake to surface-incident light, indicate that light is the major factor controlling N uptake in these waters. This is due to the permanent vertical mixing which reduces the mean light available for N uptake to <15% of the incident light. Mixing also injects regenerated N continuously into the euphotic zone, thus alleviating nitrogen limitation and accounting for the larger proportion of regenerated N uptake in total N uptake. 相似文献
19.
《Deep Sea Research Part II: Topical Studies in Oceanography》1999,46(8-9):1691-1717
Phototrophic and heterotrophic nanoplankton (PNAN, HNAN; 2–20 μm protists) and microplankton (PMIC, HMIC; 20–200 μm protists and micrometazoa) are major components of the producer and consumer assemblages in oceanic plankton communities. Abundances and biomasses of these microorganisms were determined from samples collected along two transects during the Northeast Monsoon and Spring Intermonsoon process cruises of the US JGOFS Arabian Sea Program in 1995. Vertical profiles of these assemblages were strongly affected by the presence of a subsurface oxygen minimum layer. Abundances of all four assemblages decreased dramatically below the top of this layer. Depth-integrated (0–160 m) abundances and biomasses of nanoplankton and microplankton were of similar magnitude for most samples. Exceptions to this rule were primarily due to PMIC (mostly diatom) species which dominated phytoplankton assemblages at a few stations during each season. Depth-integrated biomasses for the combined nano- and microplankton averaged over all stations for each cruise were surprisingly similar for the Northeast Monsoon and Spring Intermonsoon seasons in this ecosystem (2.0 and 1.8 g C m−2 [170 and 150 m moles C m−2] for the two seasons, respectively). Nano- and microplankton biomass for these two time periods constituted a signficant portion of the total amount of the particulate organic carbon (POC) in the water column. Summed over all stations, these assemblages constituted approximately 25–35% of the POC in the top 160 m of the northern Arabian Sea. 相似文献
20.
Abstract. A four-year oceanographic data set from the Northern Adriatic Sea identified the factors favoring development of the nanoplankton or microplankton components of the phytoplankton crop. Latitudinally atypical summer nanoplankton blooms, perhaps of recent origin, develop under vertically stratified conditions in the presence of high nutrient concentrations (including silicates). Including the summer blooms, the nanoplankton were responsible for more than half the total phytoplankton production about 90% of the time. No single mechanism governed phytoplankton cell size or size succession, but rather a number of mechanisms which were not mutually exclusive. 相似文献