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利用现场海水培养实验,结合浮游动物网样数据,研究长江口邻近海域几种优势桡足类(中华哲水蚤、背针胸刺水蚤、太平洋纺锤水蚤和精致真刺水蚤)对微型浮游动物的摄食影响。结果表明,精致真刺水蚤虽然属于肉食性种类,但几乎不摄食微型浮游动物;其余三种杂食性桡足类中华哲水蚤、背针胸刺水蚤和太平洋纺锤水蚤对微型浮游动物(纤毛虫+异养甲藻)的摄食率分别为0.66、0.09和0.59μg C/(ind·d),分别占其日总摄食量的29%、24%和37%。其中,异养甲藻在初始生物量和对桡足类饵料贡献上分别占整个微型浮游动物的30%和28%,是微型浮游动物中一个重要的组成类群。中华哲水蚤对微型浮游动物的摄食率与初始食物浓度有显著的正相关关系,并且对体长20μm纤毛虫的清滤率要明显高于对体长20μm的纤毛虫(P0.01)的清滤率,表明其偏好摄食较大个体的食物。通过Chesson选择性指数显示,尽管微型浮游动物在生物量上远小于浮游植物,但桡足类能优先选择摄食微型浮游动物;进一步结合网采浮游动物数据,获得各站三种优势桡足类丰度平均占桡足类总丰度的77%,但它们对微型浮游动物现存生物量的摄食压力仅为0.8%,表明桡足类对微型浮游动物群落的下行控制作用并不明显,仍有大部分微型浮游动物生物量未通过摄食途径进入到桡足类群落中。 相似文献
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华容东湖围栏生态因子的灰关联分析 总被引：1，自引：1，他引：0
采用灰色系统关联度分析方法,以空间理论数学为基础,依规范性、偶对称性、整体性和接近性原则,计算并分析了华容东湖围栏12个生态因子的关联度,关联序结果为:总磷总氮氮磷比氨氮浮游植物硝酸氮酸碱度浮游动物水温透明度溶解氧水深。结果表明,总磷、总氮(包括氨氮和硝酸氮)和氮磷比是湖泊水体的优势影响因子。通过灰关联分析发现,围栏内水体水质良好,水体的氮磷比及溶解氧都适于浮游生物的生长繁殖,对围栏养殖鳙鱼苗种天然饵料的培育、增加渔产潜力都有重要作用。 相似文献
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益阳大通湖生态因子的灰关联分析 总被引：1，自引：1，他引：0
本文采用灰色系统关联度分析方法,以空间理论数学为基础,依规范性、偶对称性、整体性和接近性原则,计算并分析了益阳大通湖14个生态因子的关联度,关联序结果为:亚硝酸氮氮磷比氨氮总氮硝酸氮浮游动物叶绿素a透明度总磷水深水温浮游植物酸碱度溶解氧。益阳大通湖表现为总氮(包括亚硝酸氮、氨氮和硝酸氮)和氮磷比是优势影响因子。通过灰关联分析发现,大通湖水体水质良好,水体的总氮、氮磷比及总磷都适于浮游生物的生长繁殖,对增加渔产潜力有重要作用。 相似文献
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Nitrogen and Phosphorus Diffusive Fluxes Across the Sediment-Water Interface in Estuarine and Coastal Tidal Flats 总被引：1，自引：0，他引：1
Nitrogen and phosphorus contents are analyzed in the overlying waters and pore waters taken from the Changjiang Estuary and Shanghai coastal tidal flats in this study. In addition, the diffusion fluxes of nitrogen and phosphorus across the sediment-water interface in tidal flats are estimated according to the nutrient concentration gradients at the interface. It has been indicated that the concentrations of ammonium, nitrite, nitrate and dissolved phosphorus in overlying waters range from 0.0082～2.56, 0.03～0.58, 0.69～5.38 and 0.035～0.53 mg/L, respectively, while 0.0025 ～ 1.35 mg/L for NH4+-N, 0. 0055 ～ 0.20mg/L for NO2--N, 0.61～1.14 mg/L for NO3--N and 0.11～0.53mg/L for DP insurface pore waters.The findings have revealed that ammonium, nitrite, nitrate and dissolved phosphorus diffusion fluxes across the sediment-water interface are between -0.024～0.99, -0.39～ -0.0019, -3.09～the source of phosphorus and an important sink for nitrogen in the waters. 相似文献
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黄河干流营养盐分布与变化趋势 总被引：4，自引：0，他引：4
河流是海洋获取陆源物质的主要途径,河流营养盐含量和结构的变化会对海洋生态环境产生重要影响。为了解黄河干流营养盐的基本情况及影响因素,于2012年7月(汛期)对黄河流域水体和土壤进行了综合调查,并结合历史资料分析了悬浮颗粒物和营养盐等的变化特征及对黄河物质输送的影响。结果表明:各参数受地势和人类活动的影响明显,表现出不同的分布特征。营养盐和悬浮颗粒物在上游浓度较低,在中游相对稳定,下游浓度有一定程度升高;相比于贵德而言,黄河利津段悬浮颗粒物、溶解硅和硝酸盐分别增加了近66%、60%和800%。磷限制是黄河营养盐限制的主要特征,且氮磷比呈升高趋势;与资料对比发现,黄河氮增加约1倍,硅下降60%后相对稳定,而磷略有下降。从目前分析看,支流与干流的氮营养盐构成有显著差异。在沿岸表层土壤营养盐含量较高的区域,河段内营养盐含量也较高。流域人类活动是黄河氮营养盐含量增加的重要因素;流域降水减少、水土保持等导致的物理侵蚀作用减弱是黄河硅和磷减少的重要因素;自1986年后,流域泥沙减少导致河流溶解硅降低了约34%,这值得进一步关注。 相似文献
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Xiaodong Lai Kazuhiro Norisuye Michi Mikata Tomoharu Minami Andrew R. Bowie Yoshiki Sohrin 《Marine Chemistry》2008,111(3-4):171-183
The distribution of dissolved (D) and acid-dissolvable (AD) Fe, Ni, Cu and Pb in the upper water column (0–300 m depth) was determined in the Australian sector of the Southern Ocean (140°E meridian) during three cruises conducted between November 2001 and March 2002. For Ni and Cu, there was no significant difference in concentration between dissolved and acid-dissolvable species. DNi and DCu showed significant (P = 0.01) positive correlations with silicate, phosphate and nitrate, reflecting their strong nutrient-type behaviour. For Fe and Pb, the acid-dissolvable concentration mostly exceeded the dissolved concentration, reflecting the importance of labile particulate species for these elements. DPb decreased between January and February in the Polar Frontal Zone and in Antarctic continental shelf water. ADPb maxima occurred in the Antarctic Zone, resulting in a maximum AD/D ratio of 7. The mean DFe concentration in the surface mixed layer was 0.3 nM in the sub-Antarctic zone, 0.4 nM in the Polar Frontal Zone, 0.5 nM in the Antarctic Zone and increased southward beyond the Antarctic Divergence and towards the continent. DFe did not show a clear temporal change in its horizontal distribution, which was in contrast to the other nutrients and trace metals. ADFe substantially increased in Antarctic continental shelf water where the AD/D ratio reached 11. The following conclusions can be drawn from these data. (1) Ni and Cu exist exclusively as dissolved species and their distributions are mainly controlled by their biogeochemical cycling, similar to those of the major nutrients. (2) Pb is dominated by particulate species. The distribution of DPb is temporally and spatially variable due to a sporadic source and strong scavenging. (3) DFe is rather a minor fraction of total Fe in Antarctic continental shelf water where shelf sediments and Antarctic sea-ice appear to be strong sources for Fe. There is substantial temporal variation in the supply of Fe to the upper water column. DFe in the mixed layer of the open Southern Ocean is maintained at low concentrations throughout summer due to uptake by phytoplankton and scavenging. 相似文献
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Thomas E. Jordan David L. Correll Dennis F. Whigham 《Estuarine, Coastal and Shelf Science》1983,17(6):651-667
Tidal exchanges of nitrogen, phosphorus, and organic carbon by a high and a low elevation marsh in the Rhode River estuary were measured throughout the year. Both marshes tended to import particulate matter and export dissolved matter, although they differed in the fluxes of certain nutrients. Compared with tidal exchanges, bulk precipitation was a major source of ammonia and nitrate and a minor source of other nutrients. There was a net retention of nutrients by the portion of the Rhode River that included both marshes and a mudflat. However, the marshes accounted for only 10% of the phosphorus retention and 1% of the nitrogen retention while they released organic carbon amounting to 20% of the retention. This suggests that the mudflat acted as a sink for nutrients. The primary role of the marshes seems to be transformation of particulate to dissolved nutrients rather than nutrient retention or release. 相似文献
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胶州湾营养盐结构变化的研究 总被引：40，自引：5，他引：40
于１９８５年８月－１９８６年１２月和１９９１年５月－１９９３年１１地胶州湾表层海水营养盐的调查，根据Ｊｕｓｔｉｃ等建立的浮游植物生长的化学计量及可能营养盐限制因素标准，并结合海洋硅藻正常所需的Ｓｉ，Ｎ，Ｐ之间的原子比，用数学统计的方法研究了胶放湾表层海不营养盐结构，结果表明，含有丰富溶我机氮和磷的胶州湾，Ｓｉ：Ｐ的值有显著的下降，同时Ｓｉ：ＤＩＮ和ＤＩＮ：Ｐ的值也表现出下降的趋势，使胶州湾水域营养 相似文献
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在实验室内模拟研究了沙海蜇消亡过程中氮与磷的释放特征。模拟结果表明:沙海蜇消亡过程中向水体释放氮、磷可分为两个阶段,且氮的释放速率比磷高一个数量级。在沙海蜇消亡的初期阶段,水体中溶解态氮、磷和总氮、总磷的浓度迅速增高,氮可以达到其消亡过程中的最高浓度;在后期阶段,水体中溶解态氮和总氮的浓度不断下降,但水体中的磷在这一阶段达到消亡过程中的最高浓度碱性条件有利于氮的释放,酸性条件有利于磷的释放;盐度越高氮与磷的释放速率越小;温度对氮、磷的释放影响不大;水体中氮与磷含量越高,沙海蜇消亡的速度越慢,而且氮的浓度越高,氮与磷释放到水体中的速率就越慢。 相似文献
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为加深对海洋生物地球化学循环过程和海洋生态系统功能的认知,并为相关研究提供科学依据,文章综述海洋中碱性磷酸酶及其活性的研究进展,并提出展望。研究结果表明：碱性磷酸酶主要来源于浮游植物、浮游动物和细菌,通常根据滤膜孔径等进行分类,对于海洋碳、氮、磷循环和调节生物群落组成具有重要意义;碱性磷酸酶活性通常采用水解荧光模拟底物法定量研究,并在全球海洋范围具有一定的水平、垂直和季节分布特征,影响碱性磷酸酶活性的典型环境因子包括太阳辐射、海水温度、河流输入、上升流、溶解态有机磷、溶解态无机磷、溶解态无机氮、金属离子以及病毒裂解、浮游动物捕食和排遗作用等。 相似文献
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Carbon, nitrogen, phosphorus, silicon composition of cultured two different sized phytoplankton common species of Thalazsiosira rotula and Skeletonema costatum from the Jiaozhou Bay were measured. Carbon, nitrogen, phosphorus, silicon contents in cell were obvious higher in T. rotula than in S. costatum, but the percents of nitrogen, phosphorus, sihcon contents in cell dry mass in T. rotula were lower than those in S. costatum. The dry mass concentrations of nitrogen,phosphorus, silicon in S. costatum were much higher than those in T. rotula, particularly silicon, the former was 6. 4 times of the latter, showing that S. costatum could more assimilate these elements. Especially, S. costatum had competitive dominance for assimilating silicon, which is beneficial to its becoming a major dominant species in relative short silicon of the Jiaozhou Bay. There were some differences in numerical value of nutrient ratios both laboratory-cultured phytoplankton and different sized suspended particulates （ mainly phytoplankton） in the Jiaozhou Bay, which was caused by the changes of environment. High contents of carbon, nitrogon and relative low phosporus, sil- icon, high molar ratio of nitrogen to phosphorus （far higher than Redfield value） and low ratio of silicon to phosphorus and silicon to nitrogen （far lower than Redfield values） in the two diatoms and different sized suspended particulates were consistent with those in the seawater. Relative short silicon in the seawater and phytoplankton showed that silicon was possibly affectting phytoplankton growth in the Jiaozhou Bay. 相似文献
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长江口及邻近水域氮、磷的形态特征及分布研究 总被引：3，自引：0，他引：3
根据近几年大面调查的监测资料,对长江口及邻近水域氮、磷营养盐的形态组成、时空分布及氮磷比的变动规律及其影响因素进行了分析研究。结果表明,长江口及邻近水域中硝酸盐是水体无机氮存在的主要形态,其约占总无机氮的90%,无机氮含量河口高,向东南方向愈来愈低;从该水域总磷的形态组成来看,磷营养盐主要以溶解态和颗粒态共存的形式存在,TDP略高于TPP,无机磷的平面分布与无机氮十分相似,春季无机磷含量高于夏季;N/P值变动范围大和平均值较高是该水域的主要特征,N/P值与长江径流量的大小有关系,夏季N/P值比春季高,综合分析来看,磷营养盐和光照都有可能成为该水域浮游植物生长的重要限制因子。 相似文献
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广西近海营养盐的时空分布特征 总被引：2，自引：1，他引：1
利用2006～2007年4个航次的大面调查数据,分析讨论了广西近海4个季节营养盐的时空分布变化特征。结果表明,该海域在春、夏、秋三季,活性硅酸盐和溶解无机氮分布趋势是近岸高,远岸低,由北向南呈梯度快速递减,高值区主要出现在廉州湾、铁山港和茅尾海三个区域;夏季磷酸盐在雷州半岛与涠洲岛之间出现高值;冬季3类营养盐在调查海区内分布均匀且为一年最低值。对该海区营养盐结构分析表明,硅在该海区过剩,溶解无机氮基本能满足浮游植物的生长需要,但在春季溶解无机氮和磷浓度都较低,属于寡营养型;夏季该海区磷浓度充足,在秋冬两季磷为该海区的限制性元素。 相似文献
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乳山湾外低氧海域沉积物中有机碳、氮、磷及其形态特征分析 总被引：3，自引：0，他引：3
根据2009年8月在乳山湾及其毗邻海域的综合调查,分析了该海域表层沉积物中有机碳、氮、磷含量及其组成形态的变化,初步探讨了影响底质理化参数变化的原因及对乳山湾外近岸底层低氧形成的影响.结果表明,乳山湾外近海为粉砂质岸滩,以细颗粒为主;底质中有机碳含量介于0.49％ ～0.93％,平均值为0.69％;总氮含量介于382～1020 mg/kg,平均值为671 mg/kg;可溶性总氮含量介于23.0 ～ 60.0 mg/kg,平均值为44.0mg/kg,其中可溶性有机氮和氨氮分别占可溶性总氮的58.8％和38.8％;总磷含量介于138～769 mg/kg,平均值为356 mg/kg,有机磷是占有绝对优势的磷形态(62.5％).研究区域沉积物中总氮和湾内相当,有机碳、总磷含量普遍低于乳山湾内,但均明显高于南黄海区域,且呈还原性状态.调查区域内沉积物中相对较高的有机碳、氮、磷可能是在潮流作用下乳山湾与外海的物质交换所致,其耗氧过程是导致底层溶解氧亏损的重要原因,值得进一步关注. 相似文献
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2015年12月在马里亚纳海沟"挑战者深渊"进行了定点样品采集,对温度、盐度、溶解氧、pH等环境参数进行了分析,讨论了营养盐的垂直分布特征、各形态营养盐结构特征及影响因素。研究发现,溶解氧在表层具有最大值,在1000 m左右出现极小值,而在8700 m深度具有较高溶解氧值(5.79 mg·L^-1),这可能与富氧水团的存在有关。硝酸盐表层含量较低,在1000和5367 m处出现双峰值。在表层水体中,溶解有机氮、磷是溶解总氮、溶解总磷的主要存在形式,表层以深,溶解无机氮、磷逐渐占据主导地位。磷酸盐表层含量最低,在1000 m处达到最大值,之后随着深度的增加浓度逐渐降低;硅酸盐在表层含量较低,在约4000 m处有最大值161.65μmol·L^-1,在4000 m以深,硅酸盐仍维持较高浓度。结果表明马里亚纳海沟"挑战者深渊"的溶解氧、pH及营养盐的垂直分布特征与大洋环流、海沟形态以及生物活动密切相关。 相似文献
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基于中国第30次南极科学考察在南极半岛(60°~63°S)近岸海域获取的调查资料,分析了该海域生物化学要素中溶解有机碳(DOC)、总氮(TN)和总磷(TP)分布特征并讨论地形和水团对其的影响。结果表明:2014年夏季南极半岛近岸海域水体DOC浓度变化范围为40.5~78.1μmol/L,平均浓度为66.3μmol/L;TN浓度变化范围为4.2~29.5μmol/L,平均浓度为14.9μmol/L;TP浓度变化范围为0.8~2.9μmol/L,平均浓度为2.0μmol/L。表层DOC呈现研究海域西北部D1断面和东南部D5断面浓度较高,中部DOC浓度较低;表层TN与TP浓度高值区出现在研究海域西部D1断面北部以及南部,中部和东部浓度较低;DOC,TN和TP浓度的垂直分布与海底地形和水团交汇密切相关,水团运动受阻于地形致使生物化学要素在垂直方向再分布。DOC,TN和TP空间分布反映了南极半岛近岸海域生物化学要素复杂的流通,将为合理开发和利用南极资源及环境影响评价提供科学依据。 相似文献
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M. Falco M.N. Santos T. Drago D. Serpa C. Monteiro 《Estuarine, Coastal and Shelf Science》2009,83(4):451-459
The present study investigates the differences between nutrient fluxes and particulate organic matter within an artificial reef system (AR) deployed in August 2002 off Faro (Algarve, Southern Portugal) and in a non-reef area (NRA), and how fluxes and suspended material may be affected by the hydrodynamic regime. Surveys to collect sediment cores, suspended/settled particles and overlying water samples were carried out by divers, from March (2006) to October (2007) in AR and NRA. Sediment cores and settled particles were collected to determine grain size, organic and inorganic carbon, nitrogen and phosphorus content. Overlying water and pore water samples were analysed for ammonium, nitrite, nitrate, phosphate, silicate, dissolved organic nitrogen, dissolved organic phosphorus and chlorophyll a. Results from the period studied showed that: (1) the benthic export of dissolved N, P and Si was 2–3 times higher at AR; (2) the particulate organic carbon (POC), nitrogen (PON) and phosphorus (POP) in suspended/settled particles were about 1.5 times higher at AR; (3) at both AR and NRA, the benthic export of dissolved N, P and Si, during a calm weather period, was 2–4 times higher than during or immediately after a storm event; and (4) at both sites, particulate organic compounds (POC, PON and POP) increased about 20 times during a storm event. These findings suggest that both the nutrients transport from sediment to water column and the quantity/quality of suspended/settled particles were highly dependent on the existence of reef structures and on the hydrodynamic regime. 相似文献