长江口邻近海域溶解态铝的分布及季节变化

基于2006年6、8、10月对长江口邻近海域的大面调查资料,分析了溶解态Al的分布及季节变化,讨论了水团混合、悬浮颗粒物及浮游植物水华对溶解态铝分布的影响。结果表明,3个航次溶解态铝的水平分布规律相似,都是近岸浓度最高,随着离岸距离的增加浓度降低,6、8、10月溶解态Al的平均浓度分别为(119±77)、(109±80)和(138±73)nmol/L,统计结果表明该海域的溶解态铝具有明显的季节变化。影响溶解态铝分布的主要因素有水团混合、底沉积物的再悬浮以及浮游植物的调节作用。     

秋、夏季珠江口、南海北部陆坡溶解态铝的分布及其影响因素

于2014年10月和2015年6月对珠江口、南海北部陆坡区域溶解态铝的分布进行观测,探讨影响其分布及季节差异的主要因素,并以其作为示踪因子探讨潜在的陆源物质跨陆架输送途径。研究结果显示,夏、秋季珠江口盐度为0时溶解态铝的浓度分别为690.0 nmol/L和360.0 nmol/L,在淡咸水混合初期溶解态铝迅速自水体清除,夏季的清除率(55.8%)大于秋季(29.7%)。在南海北部陆坡区域,夏季表层溶解态铝浓度表现为沿纬线方向西高东低的分布特点,秋季则相反;夏、秋季底层溶解态铝浓度均呈现出随着离岸距离增加逐渐降低的分布趋势。秋季溶解态铝浓度的分布与盐度呈现显著的负相关关系,表明其行为近乎保守,陆架混合水及黑潮次表层水等水团混合是影响南海北部陆坡区域溶解态铝分布的主要因素。并且以溶解态铝作为示踪因子发现,在21.6~22.2 kg/m^3密度面区间存在自陆架向陆坡方向的跨陆架输送。而夏季陆坡中部受到珠江冲淡水的影响出现低盐水舌,但溶解态铝的浓度相对较低,表现出明显的不保守行为。浮游植物的清除作用是导致夏季陆坡区域溶解态铝分布异常的重要因素。     

胶州湾中溶解态铝的初步研究

本文利用改进的铝-荧光镓(Al-LMG)荧光光度法测定了2001年夏季和秋季胶州湾水样中的痕量溶解态铝,分析了夏、秋季胶州湾内溶解态铝的分布及其影响因素,在此基础上讨论了胶州湾中悬浮颗粒物对溶解态铝的贡献,并进一步探讨了溶解态铝在研究水团运动中的作用。计算了河流输入、大气干、湿沉降向胶州湾中溶解态铝的输送,及湾内外交换对胶州湾内溶解态铝的影响和胶州湾铝的存留时间。     

鸭绿江口溶解态铝的行为

讨论１９９６ 年５ 月枯水期鸭绿江口溶解态铝的含量及其分布特征。结果表明,鸭绿江口溶解态铝的含量介于０．８１ ～３ ．５６μｍｏｌ／Ｌ之间;在河海混合初期铝快速清除,其后则表现为与低浓度海水的简单混合。并认为河口中悬浮颗粒物的吸附解吸作用与胶态和有机结合态铝的絮凝是造成鸭绿江口水体中铝清除的主要原因。     

海南万泉河、文昌/文教河河口溶解态铝的分布及季节差异

本文讨论了2006年12月冬季和2007年8月夏季海南省万泉河、文昌/文教河河流及河口溶解态铝的含量、分布及季节差异。结果发现,万泉河冬、夏两季河流及河口溶解态铝的平均含量分别为(156±127)和(157±97)nmol/L,季节差异不明显。文昌/文教河冬、夏两季河流及河口溶解态铝的平均含量分别为(242±156)和(222±66)nmol/L,冬季溶解态铝的平均含量略高于夏季。万泉河溶解态铝在河海混合初期表现为清除行为,而后表现为保守混合行为,而文昌/文教河则表现出明显的非保守混合行为,在中等盐度区域存在明显外源输入,原因可能是八门湾底沉积物再悬浮过程中释放的影响。部分河流上游采样点由于受到人为活动引起的污水排放的影响,溶解态铝含量明显增加。万泉河、文昌/文教河溶解态铝的平均含量明显低于我国其他及世界主要河流。     

南海中南部溶解态铝初探:促进甲藻生长?

2011年11月28日至2012年1月12日期间,通过对南海18°N至5°N海域25个站点78个溶解态铝样品的采集分析及所获得的浮游植物数据,首次研究报道了南海中南部海域溶解态铝的空间分布特征,探讨其与浮游植物群落结构之间的关系。结果表明,表层海水中溶解态铝平均含量138.3±39.1nmol·L-1,呈现陆架高、海盆和岛礁区低的水平分布特点;表层浮游植物共57属132种,分别属于硅藻门38属72种,甲藻门18属58种,蓝藻门1属2种,细胞总丰度在(0.75~21.09)×103cell·dm-3之间,表层溶解态铝的分布与甲藻总丰度(n=22,r=0.55,p0.01)具有显著的正相关性。就垂直分布而言,溶解态铝在0~100m水深内变化剧烈,在100~300m深度范围内,溶解态铝变化不明显,200m处稍有增加;溶解态铝的垂直分布与营养盐相关性不显著,与叶绿素a浓度(n=16,r=0.58,p0.05)、浮游植物总丰度(n=16,r=0.59,p0.05)和甲藻总丰度(n=15,r=0.69,p0.01)显著正相关,推测冬季溶解态铝对南海甲藻生长具有一定促进作用。     

长江口及邻近海域溶解态锰的分布及影响因素

为研究陆架边缘海锰的生物地球化学循环,利用隐色孔雀绿-高碘酸钠催化动力学方法,对2012-03和2012-07长江口及其邻近海域调查航次采样的溶解态锰浓度进行测定。2012-03长江口及其邻近海域表、底层水体中溶解态锰浓度没有显著性差异。2012-07底层溶解态锰浓度显著高于表层。溶解态锰浓度存在显著的季节差异,2012-07平均浓度显著高于2012-03的。春、夏季溶解态锰浓度在表、底层分布整体上均呈现出由近岸到外海逐渐降低的特征,表明近岸受到河流输入的影响。2012-03长江口及其邻近海域溶解态锰基本表现为保守混合,2012-07盐度2~8海域表层发生明显的清除。两端元混合模型及相关性分析表明,该海域悬浮颗粒物(SPM)是溶解态锰的一个主要汇。此外,水团的物理混合是影响该海域溶解态锰分布的主要因素。     

长江口及其邻近海域2012年3月和7月溶解态铝的分布特征分析

分别于2012年3月和7月对长江口及其邻近海域水体中溶解态铝的分布及其影响因素进行了研究,并在2012年3月至2013年11月期间对长江徐六泾进行了连续观测。结果表明,徐六泾溶解态铝在夏季出现最高值,在冬季呈现最低值,平均值分别为(313±130)nmol/L和(140±43)nmol/L,表现出与径流量相似的季节变化规律。受陆源输入变化的影响,长江口溶解态铝的浓度由近岸向外海逐渐降低,且呈现出明显的季节性差异,即7月明显高于3月。3月表、底层海水中溶解态铝的浓度范围分别为21~129 nmol/L和27~146 nmol/L,平均值分别为(49±21)nmol/L和(59±27)nmol/L;7月表、底层溶解态铝的浓度范围分别为6~332 nmol/L和9~252 nmol/L,平均值分别为(66±69)nmol/L和(83±74)nmol/L。在7月,表、底层溶解态铝呈现显著性差异,底层沉积物的再悬浮可能是造成差异的主要原因。调查结果表明,溶解态铝在长江口呈现出清除型行为,清除主要发生在咸淡水混合初期,初步计算出7月份溶解态铝的清除率约为55%。     

桑沟湾溶解态铝的分布、季节变化及影响因素

基于2011-04,2011-08,2011-10和2012-01对桑沟湾海域大面调查的资料,利用改进的荧光镓(LMG)分子荧光光谱分析法测定溶解态铝的含量,研究了桑沟湾溶解态铝的分布和季节变化特征。结果表明,4个航次桑沟湾溶解态铝的平均浓度分别是(47.3±14.4),(56.0±14.6),(64.5±11.3)和(32.1±6.0)nmol/L,呈现出明显的季节变化,即秋季最高,夏季、春季次之,冬季最低。除几个异常站位外,溶解态铝的分布大致呈现随离岸距离的增加其浓度逐渐降低的趋势。夏季表层溶解态铝的浓度在近岸出现低值,夏、秋季湾口北部均出现高值。影响桑沟湾溶解态铝分布的主要因素包括与黄海的水交换、河流及地下水、浮游植物和养殖生物、悬浮颗粒物。根据简单箱式模型对桑沟湾溶解态铝的通量进行了估算,结果显示,除了河流和大气沉降外,桑沟湾溶解态铝还存在其他的源。与相邻的爱莲湾和俚岛湾相比,桑沟湾溶解态铝的浓度在春季较高,在夏季较低。与世界大洋相比,桑沟湾溶解态铝的浓度全年均较高。     

近岸海域浮游植物水华动力机制研究进展和展望

水华是一段时期内浮游植物种群丰度和生物量快速、显著增加的过程,其对整个海域的初级生产力水平和各生源要素循环等均有重要影响.水华发生的机制非常复杂,通常与水动力条件、气象条件、温度、盐度分布与变化、营养盐的补充与循环、浮游植物种类特征等因素密切相关.本文从湍流混合及垂直对流、浮游动物的摄食作用、光合作用有效光强和营养盐对浮游植物生长的影响和多因素的共同作用等方面综述了国内外水华机制研究的进展和现状,分析了中国近海海域水华机制研究所面临的问题.需要结合海上观测、卫星遥感、模式模拟等手段对浮游植物水华进行综合全面的研究.     

夏季闽东沿海水体中透明胞外聚合颗粒物的分布特征及影响因素

透明胞外聚合颗粒物(TEP)在海洋微食物网和海洋碳循环中发挥着重要作用。本文针对夏季闽东沿海TEP的分布特征及影响因素进行研究。结果表明,闽东沿海TEP含量(以黄原胶为标准物质计算,后同)范围为25.2～935.5 μg/L,平均值为(201.8±177.9) μg/L。整体而言,TEP的分布表现为近岸高、远岸低,表层TEP含量相对于底层要低。相关性分析显示,研究海域TEP含量与浊度和营养盐(硅酸盐、磷酸盐、硝酸盐、亚硝酸盐和铵盐)浓度呈正相关,与pH、溶解氧浓度和小型浮游生物量呈负相关。分级叶绿素a结果显示,相对于其他尺寸浮游植物,调查海域小型浮游生物可能对TEP含量的贡献最大。相比于开阔大洋中TEP主控因素为浮游植物而言,夏季闽东海域TEP主要由浮游植物在衰退阶段产生,其分布主要受颗粒物再悬浮作用影响。该结果不仅进一步阐明了近岸海域与开阔大洋TEP影响因素的区别,并且对我国近海海域不同区域TEP分布研究空白进行了补充。     

北极楚科奇海北部特征水团对浮游植物空间分布的调控

通过楚科奇海北部–加拿大海盆西侧交接地带的生态调查,我们发现0～150 m海域水体中以融冰水(MW,0～20 m)、白令海夏季水(s BSW)和阿拉斯加沿岸流(ACW)等水团为主。水温和营养盐变化与水团息息相关,物理–生化的耦合作用进一步影响了浮游植物分布和群落结构。叶绿素a浓度最大值多位于约50 m深、富含营养盐的s BSW和ACW暖水团中。sBSW和ACW中分别以小型(占比约74%)和微微型(占比约65%)浮游植物为主。藻华初期,溶解无机氮(DIN)虽呈相对限制状态,但仍高于浮游植物生长所需阈值。双单元混合模型显示：浮游植物对氮去除明显,氮吸收量与叶绿素a浓度呈正比,且在温度略高的ACW水团中氮吸收量高于s BSW水团。在北极变暖、波弗特流涡增强以及ACW和sBSW营养盐补给下,该区域的浮游植物的叶绿素a浓度(均值：(0.327±0.163)mg/m³,范围：0.04～0.69 mg/m³)与历史数据相比有所提高。这将增加北极海区的碳吸收通量,有利于其作为碳汇区的发展。     

Variation of dissolved organic matter and fluorescence characteristics before,during and after phytoplankton bloom

The variation of dissolved organic matter (DOM) and fluorescence characteristics during the phytoplankton bloom were investigated in Yashima Bay, at the eastern part of the Seto Inland Sea, Japan. We found significant accumulations of dissolved organic carbon (DOC), dissolved organic nitrogen (DON), chromophoric dissolved organic matter (CDOM) fluorescence, and UV₂₆₀ during the phytoplankton bloom period in 2005, although lower accumulations of DOC and DON and only increases of CDOM fluorescence were observed during the bloom period in 2006. Little or no correlation between DOM and phytoplankton abundance might be due to the composition of DOM, which is a complex mixture of organic materials. The 3D-EEM results revealed that the DOM produced around the phytoplankton bloom period contained tyrosine, tryptophan, and humic-like substances. Our results showed that the occurrence of phytoplankton bloom contributed to the production of DOM in coastal water but the DOM accumulation depended on the type of phytoplankton bloom, the phytoplankton species in particular. From our results, we concluded that phytoplankton have a great role in the dynamics of DOM as a producer in a coastal environment.     

A three-dimensional water quality model and its application to Jiaozhou Bay, China

A three-dimensional coupled physical and water quality model was developed and applied to the Jiaozhou Bay to study water quality involving nutrients, biochemical oxygen demand, dissolved oxygen, and phytoplankton that are closely related to eutrophication process. The physical model is a modified ECOM-si version with inclusion of flooding/draining processes over the intertidal zone. The water quality model is based on WASP5 which quantifies processes governing internal nutrients cycling, dissolved oxygen balance and phytoplankton growth. The model was used to simulate the spatial distribution and the temporal variation of water quality in the Jiaozhou Bay for the period of May 2005 to May 2006. In addition, the effect of reduction of riverine nutrients load was simulated and evaluated. The simulated results show that under the influence of nutrients discharged from river, the concentrations of nutrients and phytoplankton were higher in the northwest and northeast of the bay, and decreased from the inner bay to the outer. Affected by strong tidal mixing, the concentrations of all state variables were vertically homogeneous except in the deeper regions where a small gradient was found. Obvious seasonal variation of phytoplankton biomass was found, which exhibited two peaks in March and July, respectively. The variation of riverine waste loads had remarkable impact on nutrients concentration in coastal areas, but slightly altered the distribution in the center of the bay.     

The Influence of Physical Factors on the Variation of Phytoplankton and Nutrients in the Bohai Sea

The cycle of the phytoplankton in a coastal water is controlled by the biological processes, solar radiation, water temperature and physical transport processes. A three-dimensional ecosystem dynamic model is adopted in this study to investigate the influence of different physical factors on the variation of phytoplankton and nutrients in the Bohai Sea. The simulation is carried out for the year 1982. The simulated annual cycle of the primary production and nutrients are in reasonable agreement with the observations in the pattern. Vertical mixing can both affect the vertical transportation of nutrients and horizontal distribution of primary production. In winter the vertical distribution of nutrients is homogeneous because of the intensive mixing, while in summer there is a high value of nutrients in the depth about 15 m due to the stratification. The high primary production plague and the weak mixing center is positional correspondence. The production of phytoplankton is sensitive to the photosynthetically active radiation, which is strongly influenced by the transparency. The increase of the transparency can promote the production in spring and autumn significantly, but has little effect on the production in summer. The change of the transparency can both affect the occurrence time and the amplitude of the phytoplankton bloom dramatically. Horizontal advection does not affect the variation trend of the annual cycle of chlorophyll-a, but does affect the relative magnitude of the phytoplankton bloom, especially in summer. Horizontal advection can dramatically alter the horizontal distribution of chlorophyll-a. The maximum concentration of chlorophyll-a without horizontal advection in summer is twice as high than that with advection and the high chlorophyll-a areas locate along the coast. The river discharge only has regional influence on the ecosystem. The Huanghe River with high nitrate concentration influ-ences the annual cycle of nitrogen of the Laizhou Bay significantly.     

Description of the oceanographic condition off Sanriku, northwestern Pacific, and its relation to spring bloom detected by the Ocean Color and Temperature Scanner (OCTS) images

We describe the oceanographic condition as observed by hydrographic data and phytoplankton spring bloom detected by OCTS images off Sanriku, northwestern Pacific, during the spring bloom period in 1997. The relationship between the two is discussed. OCTS images detected the bloom in early April in the coastal area around the Izu ridge north of the Kuroshio and the eastern coastal area of Hokkaido to the Oyashio front. The bloom areas were seen along the offshore Kuroshio Extension from the end of April, in the upstream region of the Oyashio south of the Kurile Islands, except for a part of coastal area from the end of May, and in the Kuroshio warm-core ring 93A (KWCR 93A) from early June. The temperature difference between the surface and subsurface layer is used as a stratification index. This was large in the upstream region of the Oyashio south of the Kurile Islands and KWCR 93A from early June. Previous research has pointed out that the spring bloom usually corresponds to the development of stratification in the water column due to seasonal warming. In addition to that, we suggest that the transportation of water containing a high chlorophylla concentration by advection due to strong currents, like the Kuroshio and the Oyashio, is important for the formation of an area of high chlorophylla concentration. These results indicate that the OCTS images are useful for a knowledge of the distribution and the change of chlorophylla concentration in the northwestern Pacific region.     

The cluster analysis of the water masses in western Taiwan Strait from hydrologic and chemical factors

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Study of coastal water zone ecosystem health in Zhejiang Province based on remote sensing data and GIS

The coastal ecosystem health assessment is a field of increasing importance. In this paper, a preliminary assessment of ecosystem health in Zhejiang coastal water zone was made, mainly based on remote sensing data and GIS technique. Its spatial and quantitative evaluation was facilitated by the progress of remote sensing and GIS technique development. Firstly, human activities, hydrology and ecosystem problems in the study area were discussed and analyzed. Secondly, from 4 aspects of human stress, physical, chemical and biological responses to anthropogenic activities and natural stress, several indicators such as water transparency (Secchi Disk Depth, SDD), suspended substance concentration, dissolved inorganic nitrogen, active phosphate, chlorophyll, harmful algae bloom, as well as distribution of sewage, sea lanes and port were employed. Thirdly, the Analytic Hierarchical Process was used for indicator weight calculation, and the ecosystem health criteria were established according to the integrative analysis of national water quality criteria, similar coastal ecosystem health research in other places or data inherent properties. The results indicated that from 2005 to 2007 the coastal water ecosystem health value in Zhejiang Province was unhealthy and needs ecological restoration by human intervention.