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21.
Variation of phytoplankton biomass and primary production in Daya Bay during spring and summer 总被引：11，自引：0，他引：11
Song X Huang L Zhang J Huang X Zhang J Yin J Tan Y Liu S 《Marine pollution bulletin》2004,49(11-12):1036-1044
Environmental factors, phytoplankton biomass (Chl a) and primary production of two water areas in Daya Bay (Dapeng'ao Bay and Aotou Bay) were investigated during the transition period from spring to summer. Chl a ranged from 3.20 to 13.62 and 13.43 to 26.49 mg m(-3) in Dapeng'ao Bay and Aotou Bay respectively, if data obtained during red tides are excluded. Primary production varied between 239.7 and 1001.4 mg Cm(-2) d(-1) in Dapeng'ao Bay. The regional distribution of Chl a and primary production were mostly consistent from spring to summer in both bays. Seasonal transition characters have been found in Daya Bay from spring to summer, including high values of DO, nitrate and silicate. Size structures of phytoplankton and its primary production do not change very much from spring to summer, with micro-phytoplankton dominating and contributing about 50% of the whole. In Daya Bay, phytoplankton is limited by nitrogen in spring, and by phosphate in summer. Artificial impacts are evident from high temperature effluent from nuclear power stations, aquaculture and sewage. During the investigation, a red tide occurred in Aotou Bay, with a maximum Chl a of 103.23 mgm(-3) at surface and primary production of 2721.9 mg Cm(-2) d(-1) in the red tide center. Raised water temperature and nutrient supply from land-sources help to stimulate annual red tides. 相似文献
22.
夏季南海北部水体中颗粒有机碳的分布特征 总被引：2，自引：0，他引：2
通过干式燃烧法对2008年8―9月南海北部的颗粒有机碳(POC)进行了分析,得出南海北部表层海水POC的含量范围为37～330μg/l。分析显示:受珠江口陆源输入颗粒物的影响,华南沿岸海域POC含量最高;浮游植物碳是中央海盆北部POC的重要组成;琼东上升流区和吕宋海峡则在一定程度上受陆源物质的影响。华南近岸浅海水域由于垂直混合,水体10 m以下水层POC分布比较一致。琼东上升流区、中央海盆北部及吕宋海峡100 m以浅水层POC总体表现为随深度增加而下降,琼东上升流区和吕宋海峡100～200 m水层POC含量出现波动,可能分别受到沉积物再悬浮和不同水团混合的影响。 相似文献
23.
人类活动引起的营养物质输入导致大亚湾出现海水富营养化、赤潮频发和生物多样性下降等生态问题。为探究陆源输入影响下大亚湾湾顶淡澳河输入对湾内浮游植物粒级结构和种类组成的影响, 2016年10月在大亚湾进行了原位观测和培养试验。原位观测结果显示, 淡澳河口的总溶解态氮、磷浓度分别达到85.3μmol·L-1和1.5μmol·L-1。加富培养试验结果表明, 淡澳河河口水加富对总叶绿素a (Chl a)和总浮游植物丰度有显著促进作用, 并导致浮游植物粒级结构由小粒级Chl a (0.7~20μm)占主导; 浮游植物丰度中甲藻比例升高, 主要种类为锥状斯氏藻(Scrippsiella trochoidea)和原甲藻(Prorocentrum spp.)。同样, 尿素加富也促进了浮游植物群落中小粒级Chl a和甲藻的比例增加, 且主要甲藻种类与河口水加富结果一致。无机氮、磷同时加富促进了总Chl a和浮游植物总丰度增加, 而对浮游植物粒级结构和甲藻丰度则没有明显影响。对照河口水和氮、磷营养盐加富试验结果, 说明河口水携带的溶解性有机氮源可能是导致大亚湾浮游植物群落小型化, 促进甲藻生长的关键营养盐形态, 其携带的无机氮、磷同时促进总浮游植物丰度增加。本研究结果表明有机形态营养组分对大亚湾富营养化和有害藻华可能产生重要影响。 相似文献
24.
Linbin Zhou Yehui Tan Liangmin Huang Xiping Lian Dajun Qiu Zhixin Ke 《Journal of Oceanography》2013,69(4):379-393
Analyzing and evaluating the state and heterogeneity of ecosystems are required for ecosystem-based management. The abundance size spectrum is a promising approach for evaluating pelagic ecosystems. To analyze the heterogeneity of pelagic ecosystems in the northern South China Sea (NSCS) in summer, a simplified abundance size spectrum (SASS) was proposed. Picophytoplankton (0.2–2 μm), microphytoplankton (10–160 μm), mesozooplankton (160–2000 μm), and macrozooplankton (505–8,000 μm) were sampled in the NSCS in August 2007, and used to build the SASS. On the basis of the SASS parameters, spatial heterogeneity in pelagic ecosystems was detected, and the study waters were distinctly categorized into the river plume or upwelling-affected area and its adjacent coastal area, the deepwater area, area near the Luzon Strait, and the offshore shelf area. Contrasts of SASS parameters between the eastern and western pelagic ecosystems out of the Pear River estuary demonstrate the fast ecosystem response to the spreading of the Pearl River plume. These results indicate that the SASS could be a good indicator for the state of pelagic ecosystems in the NSCS. In addition, the SASS approach is easily available and labor- and time-saving, thus the SASS could be a useful tool for monitoring and evaluating the state of pelagic ecosystems and their responses to perturbations. 相似文献
25.
中尺度涡影响下的南海西部活性铝分布 总被引：1，自引：0，他引：1
To understand the distribution of aluminum(Al) under the influence of mesocale eddies in the western South China Sea(SCS), sea level anomaly, geostrophic current, environmental parameters and reactive Al were investigated in the western SCS in August 2013. The highest reactive Al concentration((180±64) nmol/L) was observed in the surface waters, indicating a substantial atmospheric input. Vertically, the reactive Al decreased from the surface high concentration to the subsurface minima at the depth of chlorophyll a(Chl a) maxima and then increased again with depth at most of the stations. The average concentration of reactive Al in the upper 100 m water column was significantly lower in the cyclonic eddy((137±6) nmol/L) as compared with that in the noneddy waters((180±21) nmol/L). By contrast, the average concentrations of Chl a and silicate in the upper 100 m water column were higher in the cyclonic eddy and lower in the anticyclonic eddy. There was a significant negative correlation between the average concentrations of reactive Al and Chl a in the upper 100 m water column. The vertical distribution of reactive Al and the negative correlation between reactive Al and Chl a both suggest that the reactive Al in the upper water column was significantly influenced by biological removal processes. Our results indicate that mesoscale eddies could regulate the distribution of reactive Al by influencing the primary production and phytoplankton community structure in the western SCS. 相似文献
26.
目的：观察卒中进展方联合阿加曲班治疗穿支动脉病变型急性进展型脑梗死痰瘀阻络证的疗效及安全性。方法：选取穿支动脉病变型急性进展型脑梗死痰瘀阻络证患者36 例,按随机对照原则将其分为治疗组和对照组,每组各18 例。2组均给予西医常规基础治疗,对照组加用阿加曲班静脉泵入治疗,治疗组在对照组基础上加服卒中进展方治疗,2组均治疗14 d。比较2组治疗前后美国国立卫生研究院卒中量表（NIHSS）评分、改良运动功能（mRS）评分、中医证候积分、超敏C反应蛋白（hs-CRP）及同型半胱氨酸（Hcy）水平变化,并观察综合疗效及不良事件发生率。结果：总有效率治疗组为94.44%（17/18）,对照组为66.67%（12/18）,差异有统计学意义（P＜0.05）。2组治疗7 d、14 d后NIHSS评分,治疗后3个月的mRS评分,治疗后中医证候积分、hs-CRP及Hcy水平均较治疗前下降,且治疗组下降幅度较对照组更大（P＜0.05）。治疗过程中,2组均未出现肝肾功能损害、出血等不良事件。结论：卒中进展方联合阿加曲班注射液治疗穿支动脉病变型急性进展型脑梗死痰瘀阻络证,可有效改善患者神经功能预后、减轻炎症反应,且安全性较好。 相似文献
27.
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
28.
三亚湾珊瑚礁海区微型浮游动物种群组成和摄食研究 总被引：2，自引：0，他引：2
采用现场稀释法,以叶绿素 a 为检测对象,利用 2006 年 4 月的调查资料对三亚湾珊瑚礁海区微型浮游动物的种群组成和摄食情况进行了研究.结果表明,区内微型浮游动物的组成以纤毛虫为主.微型浮游动物以 Tintinnopsis compressa, Tintinnopsis cylindrical, Tintinnidium semicilidium 三种纤毛虫为优势种,其中 Tintinnopsis 属纤毛虫是优势种群,有 38 种,占总纤毛虫种数的37.3 %.微型浮游动物的摄食率 ( g ) 在 1.28 ～ 2.37 d-1之间,平均值为 0.945 d-1;浮游植物瞬时增长率 ( k ) 为 0.26 ～ 1.44 d-1,平均值为 1.963 d-1;微型浮游动物对浮游植物现存量和初级生产力的摄食压力分别在 72.20 % ～90.65 % 和 113.31 % ～ 315.34 %,平均值分别为 84.56 % 和 177.05 %.三亚湾珊瑚礁海区内,微型浮游动物的摄食水平主要取决于水体中微型浮游动物和叶绿素a之间的相对数量关系.在控制浮游植物生长和转移浮游植物生产力方面微型浮游动物起着相当重要的作用,可以在一定程度上降低潜在的富营养化威胁. 相似文献
29.
基于台湾66个站点年最大日雨量历史资料、台湾中央气象局2009年8月8~10日莫拉克台风暴雨期间251个台湾雨量站逐时降雨资料和香港地区65个雨量站的历史逐时降雨资料,以及与香港相邻的3个广东省雨量站(西沥站、横岗站和深圳站)资料,利用分时段地形增强因子法(SDOIF),将莫拉克台风暴雨最大24h实测暴雨中的辐合雨分量分割,并将其辐合雨成分移置到香港地区,与香港地区24h平均地形增强因子相结合,估算出香港地区的可能最大降水。结果显示,莫拉克最大24h降雨量中地形的增强幅度约为45%;得出香港地区最大24h平均可能最大降水分布图,其最大中心值1230.2mm(未考虑水汽放大),与香港地区历史暴雨中心一致,均发生在大帽山附近。 相似文献
30.