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南沙群岛海域沉积物-海水界面间营养物质的扩散通量 总被引：25，自引：1，他引：25
主要研究了南沙群岛海域泻湖及礁外沉积物间隙水生态系中的营养 组份 ＮＯ３－Ｎ， ＮＯ２－Ｎ， ＮＨ４－Ｎ， ＰＯ４－Ｐ， ＳｉＯ３－Ｓｉ及其在沉积物一海水界面间扩散转 移通量，结果表明：（１）该海域间隙水中营养组份的浓度较高，∑Ｎ／Ｐ礁外间 隙水高于泻湖间隙水，相对而言，泻湖间隙水中缺氮，礁外间隙水中缺磷，礁外 间隙水中营养组份的垂直分布各异。（２）该海域沉积物活性明显高于东中国 海，沉积物中大量营养组份向上覆海水扩散转移，Ｈ４ＳｉＯ４是礁外界面扩散是最 大的组份，而在泻湖中ＮＯ３－或ＮＨ４＋是最大扩散量的组份，礁外界面Ｈ４ＳｉＯ４， ＮＯ３－扩散大于泻湖，这些扩散转移特征由组份本身的性质与环境特性决定； （３）该海域水温高是造成间隙水中营养组份大量产出并向上覆海水扩散转移 的主要原因，温度高，沉积物释放出营养组份的表现活化能降低，沉积物的活 性增强，从而释放扩散出大量的营养组份。 相似文献
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于１９９８ 年５ 月～６ 月在温度１８ ±１℃下培养甲藻,以紫外／ 过硫酸钾氧化法测定培养过程中藻液的溶解有机碳（ＤＯＣ） 含量变化。结果发现,在甲藻的指数生长期,ＤＯＣ浓度和甲藻干重呈线性关系。营养盐限制实验表明,海水中没有添加磷酸盐时,甲藻的干重增长得极其缓慢,ＤＯＣ 为负增长。磷酸盐浓度越高,干重增长越快,ＤＯＣ在培养时间内的累积量及平均增长速率也越快。当磷酸盐浓度为１０μｍｏｌ／Ｌ时,藻细胞释放的ＤＯＣ占光合作用碳合成总量的比例最大。 相似文献
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海水中胶体有机碳研究简介 总被引：3，自引：0，他引：3
随着海洋碳通量研究的深入和切向超滤技术的完善,对海洋中胶体有机碳的研究引起越来越广泛的重视,本文介绍了近年来海洋中胶体有机碳研究的发展状况。１胶体有机碳的定义及其研究意义１．１定义海水中的有机碳以溶解有机碳（ＤＯＣ）、颗粒有机碳（ＰＯＣ）和挥发有机碳（ＶＯＣ）３种形式存在［１］。其中,ＤＯＣ和ＰＯＣ之间的区分,在操作上是以能否通过０．４５μｍ孔径的滤膜为标准。近年来,随着对胶体粒子研究的发展,这一标准已不能满足对有机碳分类的要求［３］。水环境中的胶体,被定义为１ｎｍ到１μｍ范围内的粒子,而在分离… 相似文献
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测定了１９９７ 年７ 月份琉球群岛邻近海域的溶解有机碳（ＤＯＣ） ,发现ＤＯＣ的最高浓度存在于表层水中,为１６３μｍｏｌ／Ｌ,底层水ＤＯＣ的平均浓度为５０μｍｏｌ／Ｌ左右,最低为３９μｍｏｌ／Ｌ,且浓度相对保持恒定。黑潮北端ＤＯＣ的浓度要高于南端,研究认为东海是ＤＯＣ的一个源。 相似文献
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9810号台风过程厦门近岸海域POC的变化特征 总被引：2，自引：1，他引：2
本文研究了９８１０号台风影响下九龙江口及厦门西港表层海水颗粒有机碳（ＰＯＣ）的变化特征及其与某些环境因子的关系,除厦门西港低潮水外,台风期间ＰＯＣ含量的迅速增大,此“冲击期”共维持３ｄ后ＰＯＣ值迅速回落,进入“恢复期”。台风期间,九龙江口高低潮,厦门西港高潮表层水ＰＯＣ含量分别为０．７３９、１．３１９和０．８４８ｍｇ／ｄｍ＾３,是非台风状况下的１．１、１．９和１．４倍,陆源有机物的输入和底质再悬浮作用是控制表层水ＰＯＣ含量的主要因素,而厦门西港低潮水ＰＯＣ含量受台风作用影响较小,碎屑ＰＯＣ为厦门近岸海域表层海水ＰＯＣ的主要组成部分。ＰＯＣ与溶解态Ｎ、Ｐ营养盐有一定正相关性,暗示其可能来自颗粒物有机Ｎ、Ｐ的生物降解。 相似文献
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海水中的有机物主要是以溶解形式存在的,溶解有机碳（ＤＯＣ）在全球碳循环中有重要的作用,对于化学海洋学和生物海洋学的研究具有十分重要的意义。Ｓｕｇｉｍｕｒａ和Ｓｕｚｕｋｉ１９８８年用高温催化氧化法（ＨＴＣＯ）测定海水中的溶解有机碳（ＤＯＣ）得到的测定数据比过去传统方法的高２～４倍,这一结果在海洋学界引起人们极大兴趣。然而在１９９１年国际ＤＯＣ测定互校工作后,Ｓｕｚｕｋｉ修订了他早期的工作。近几年来,通过对ＤＯＣ测定方法的重新评价,结果发现用高温催化氧化法和传统的湿氧化法测得的ＤＯＣ数据相似,但下面… 相似文献
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胶州湾海域COD浓度场数值计算应用研究 总被引：3，自引：0，他引：3
ＣＯＤ作为有机污染物，是影响近海海域水质的主要指标之一，本文采用分步杂交数值计算方法，在模拟计算了胶州湾海域Ｍ２分潮潮流场的基础上，根据胶州湾沿岸青岛市排污口的ＣＯＤ排放量，对胶州湾海域中的ＣＯＤ浓度分布作了数值计算对基未来的水质状况作了预测。 相似文献
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东海水体中POC的分布特征 总被引：12，自引：1，他引：12
本文研究１９９４年春、秋季东海陆架海区水体ＰＯＣ的分布特征。０和１０ｍ层的水平分布图呈现：近岸海区水体的ＰＯＣ含量最高，并片外海递减，黑潮区域是ＰＯＣ的低值区。在离岸远的深水海区受长江径流影响削弱，ＰＯＣ分布比较均匀。秋季ＰＯＣ等值线呈现与岸平行并片外海递减，这是受陆地径流、海区生物活动所控制。春季ＰＯＣ的分布呈现受水团推移的迹象，在ＰＮ线上的４０６－４０８－４１１站位附近海区出现ＰＯＣ高值区，与 相似文献
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黑潮水入侵南海的水文分析：Ⅱ.1994年8—9月期间的观测结果 总被引：25，自引：0，他引：25
利用１９９４年８－９月期间，由台湾海峡两岸的４艘海洋调查船在南海东北部海域所获之ＣＴＤ和ＡＤＣＰ资料，并结合１９９２年３月间在同一海域获取的ＣＴＤ资料及部分历史水文资料，对该区域的海水特性以及黑潮水入侵南海等问题进行了分析探讨。 相似文献
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海水中溶解有机碳（DOC）的测定 总被引：18，自引：0，他引：18
本文论述了海水中溶解有机碳(DOC)的测定方法,对DOC的测定原理及氧化方法进行了讨论,并提出了妨碍海水中DOC测定准确度提高的因素,这对于建立高准确度和精密度的新分析方法具有重要的意义。 相似文献
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南沙渚碧礁生态系有机碳的分布及周日变化特征 总被引：4，自引：0，他引：4
1999 年 4 月对我国南沙群岛渚碧礁海水中溶解有机碳的分布及礁坪区颗粒有机碳 (POC) 和溶解有机碳 (DOC) 的周日变化特征进行了观测。结果表明,渚碧礁表层海水 DOC 变化范围为 1.43~3.62 mg/L,平均为 2.16 mg/L,含量分布大致表现为礁坪区>潟湖>礁外。潟湖 DOC 的垂直分布大致表现为表层高于底层,可能与表层浮游植物的光合作用有关。礁坪区 POC 及 DOC 都呈现显著的周日变化特征,POC 呈现夜晚高,白天低的特点,浮游植物的昼夜垂直移动可能是产生该现象的主要原因。DOC 的周日变化则主要受浮游动物昼夜垂直移动及细菌等生物活动的影响。 相似文献
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钛/碳钢在海水中电偶腐蚀的研究 总被引：4，自引：0，他引：4
研究了国产纯钛和碳钢Q235在青岛近海海水中的电偶腐蚀情况。测定这两种金属材料的自然腐蚀电位和失重速率；用IM6e电化学工作站测定两种金属材料在海水中的稳态极化曲线，研究其极化性能；测定了碳钢与钛组成不同面积比、不同温度、不同海水流速时电偶电流的大小、方向，电偶电位，以及不同面积比时阳极的失重速率。结果表明，阳极的腐蚀速率随阴／阳极面积比、环境温度、海水流速的增大而增加，且阳极腐蚀速率随阴／阳极面积比的增大趋于极限值。 相似文献
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Amelia De Lazzari Daniela Berto Daniele Cassin Alfredo Boldrin Michele Giani 《Marine Ecology》2008,29(4):469-482
Meteorological and oceanographic conditions in the Northern Adriatic Sea in a year notable for massive mucilage formation (2004) were compared with those in years where this phenomenon did not occur (2003, 2005 and 2006) to suggest possible links. The months preceding the mucilage event in 2004 were considered the ‘incubation period’ and were characterized by a strong freshet in May which increased the water column stability. Winter cooling and scarcity of freshwater inputs from the Po River triggered the dense water formation and intrusion in the northern basin. Weak southeasterly winds and an increase in surface seawater temperatures contributed to maintain and reinforce the water column stability, and at the same time an intense diatom spring bloom created the conditions for accumulation of organic matter. The interplay of climatological forcings and biological processes caused temporal variations of dissolved organic carbon (DOC) and particulate organic carbon (POC) in the basin, with POC playing an important role in the aggregation process, as suggested by its increase relative to DOC before massive mucilage formation. We therefore suggest that high POC/total particulate nitrogen ratios in the suspended particulate organic fraction, a steep increase of POC/Chlorphyll a, and the decreased DOC/POC ratios represent ‘early warning’ signals of the main processes that lead to mucilage events in the Northern Adriatic Sea. 相似文献
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Review and suggestions for estimating particulate organic carbon and dissolved organic carbon inventories in the ocean using remote sensing data 总被引：2，自引：0，他引：2
Dissolved organic carbon（DOC） and particulate organic carbon（POC） are basic variables for the ocean carbon cycle.Knowledge of the distribution and inventory of these variables is important for a better estimation and understanding of the global carbon cycle.Owing to its considerable advantages in spatial and temporal coverage,remote sensing data provide estimates of DOC and POC inventories,which are able to give a synthetic view for the distribution and transportation of carbon pools.To estimate organic carbon inventories using remote sensing involves integration of the surface concentration and vertical profile models,and the development of these models is critical to the accuracy of estimates.Hence,the distribution and control factors of DOC and POC in the ocean first are briefly summarized,and then studies of DOC and POC inventories and flux estimations are reviewed,most of which are based on field data and few of which consider the vertical distributions of POC or DOC.There is some research on the estimation of POC inventory by remote sensing,mainly in the open ocean,in which three kinds of vertical profile models have been proposed：the uniform,exponential decay,and Gauss models.However,research on remote-sensing estimation of the DOC inventory remains lacking.A synthetic review of approaches used to estimate the organic carbon inventories is offered and the future development of methods is discussed for such estimates using remote sensing data in coastal waters. 相似文献
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Incorporation of 14C-depleted (old) dissolved organic carbon (DOC) on/into particulate organic carbon (POC) has been suggested as a possible mechanism to explain the low Δ14C-POC values observed in the deep ocean [Druffel, E.R.M., Williams, P.M., 1990. Identification of a deep marine source of particulate organic carbon using bomb 14C. Nature, 347, 172–174.]. A shipboard incubation experiment was performed in the Sargasso Sea to test this hypothesis. Finely ground dried plankton was incubated in seawater samples from the deep Sargasso Sea, both with and without a biological poison (HgCl2). Changes in parameters such as biochemical composition and carbon isotopic signatures of bulk POC and its organic compound classes were examined to study the roles of sorptive processes and biotic activity on POC character. Following a 13-day incubation, the relative abundance of the acid-insoluble organic fraction increased. Abundances of extractable lipids and total hydrolyzable amino acids decreased for both treatments, but by a greater extent in the non-poisoned treatment. The Δ14C values of POC recovered from the non-poisoned treatment were significantly lower than the value of the unaltered plankton material used for the incubation, indicating incorporation of 14C-depleted carbon, most likely DOC. The old carbon was present only in the lipid and acid-insoluble fractions. These results are consistent with previous findings of old carbon dominating the same organic fractions of sinking POC from the deep Northeast Pacific [Hwang, J., Druffel, E.R.M., 2003. Lipid-like material as the source of the uncharacterized organic carbon in the ocean? Science, 299, 881–884.]. However, the Δ14C values of POC recovered from the poisoned treatment did not change as much as those from the non-poisoned treatment suggesting that biological processes were involved in the incorporation of DOC on/into POC. 相似文献
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Experiments were conducted using seawater from the Oregon continental shelf to determine: (1) rates of phytoplankton-derived particulate organic matter (POM) and dissolved organic matter (DOM) degradation by natural microbial communities, and (2) whether inorganic nutrients or flagellate grazing limit the bacterial response to, and subsequent degradation of, the DOM. In the initial seawater samples, nutrients were depleted and organic matter concentrations were elevated above concentrations found in upwelled water, indicative of recent bloom conditions. In whole water treatments incubated for 3 d, an average of 24% of the total organic C and 33% of the POC was degraded, with some portion of the POC being converted to DOC. In treatments incubated after POM was removed by filtration, DOC degradation was initially rapid and then proceeded at a slower rate. After 3 d, an average of 41% of the DOC was degraded. Selective degradation of the C-component of both the POM and DOM relative to the N-component was observed. Reductions in flagellate grazing resulted in increases in bacterial abundance and enhanced DOC degradation, while inorganic nutrient amendments had little effect. Overall, these results suggest that a fraction of the phytoplankton-derived POM and DOM can be rapidly degraded, contributing to oxygen consumption on the continental shelf. The long degradation time of a less labile DOC fraction relative to potential offshelf transport mechanisms suggests that Oregon's coastal waters may be a source of DOC to adjacent offshore waters of the North Pacific. 相似文献