Stable carbon isotope study on trophic relationships of Zhubi reef ecosystem in Nansha Islands

利用稳定碳同位素分析技术研究了南沙渚碧礁生态系食物网主要生物类群之间的营养关系 .结果表明 ,生物的稳定碳同位素组成与其营养来源有密切关系 .浮游植物的δ13C为 - 1 8.3‰ ,与其所处海域的环境条件一致 .浮游动物的δ13C值变化较大 ,范围为 - 2 0 .4‰～ - 1 0 .9‰ ,表明可能存在浮游植物和碎屑两种营养来源 .珊瑚和砗磲的碳同位素组成 (- 1 7‰～ - 1 5‰ )与浮游动物相差较大 ,暗示共生虫黄藻可能在这些珊瑚的营养来源中起重要作用 .底栖海参 (- 9.6‰ )和蜘蛛螺 (- 1 2 .5‰ )的碳同位素组成与它们沉积物食性的营养特征吻合 .鱼类的δ13C值变化范围较大(- 1 7.7‰～ - 1 0 .9‰ ) ,未表现出随营养级升高而增大的趋势 ,说明影响鱼类碳同位素组成的因素比较复杂Trophic relationships among various organisms from Zhubi coral reef ecosystem in Nansha Islands were studied by stable carbon isotope technique. The results showed that δ 13 C of organisms showed a close relationship with their trophic status. δ 13 C of phytoplankton was -18.3‰ , which is consistent with the tropical marine environment. The great variation in δ 13 C of zooplankton(-20.4‰ ～ -10.9‰) was suggested that there may exist two trophic sources -- phytoplankton and detritus. δ 13 C of coral tissue and tridacnids were similar (-17‰ ～ -15‰ ) and showed great difference with zooplankton, suggesting that symbiotic zooxanthellae may play an important role in their nutrition source. Carbon isotope ratios of benthic sea cucumber Bohadshia argus and gastropod Lambis lambis were consistent with their sediment-feeding nutrition characteristics. Great variation and no obvious increase trend with trophic levels of fish δ 13 C values indicated that complex factors controlled their carbon isotope composition.国家重点科技专项专题 (97 92 6 0 2 0 2 ) ;; 厦门大学校级自选课题 (2 0 0 0 5 0 0 2

Distribution and Diurnal Changes of Organic Carbon in Zhubi Reef Ecosystem, Nansha Islands

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。Distribution of dissolved organic carbon (DOC) in seawater of Zhubi Reef, Nansha Islands and diurnal changes of particulate organic carbon (POC) and dissolved organic carbon in reef flat were observed during April, 1999. It was shown that the content of DOC in surface water ranges from 1.43 to 3.62 mg/L, with an average of 2.16 mg/L. In different reef zones, DOC content showed much variation and the decrease order was reef flat > lagoon > outer waters. The vertical distribution of DOC in the lagoon showed a tendency of surface samples higher than deeper samples, which may be caused by higher photosynthesis of phytoplankton in surface. Both POC and DOC in a station on reef flat showed significant diurnal fluctuations. The diurnal change of POC was higher at night than in daytime, which was caused by diurnal migration of phytoplankton and demersal zooplankton while the main cause of diurnal changes of DOC may be diurnal migration of demersal zooplankton and bacteria activity.九五"国家科技攻关项目（97-926-02-02

非水反相高效液相色谱法同时检测人血清中V↓A、V↓D↓3、V↓E和β-胡萝卜素

介绍一种用非水反相高效液相色谱法及外标法同时检测人血清中的视黄醇（ＶＡ）、胆钙化醇（ＶＤ３）、α－生育酚）ＶＥ）和β－胡萝卜素含量的方法。此方法实际用于检测胃癌病例及对照血清标本１８８份，有操作简便，出限低的特点

Spatial-temporal variations of phytoplankton and bacterioplankton biomass and their environmental limiting factors in the Sanya Bay,Hainan Island,China

根据2005年1,4,7和10月4个季度代表月份在海南岛三亚湾进行的现场综合调查资料,分析了海区浮游植物和浮游细菌生物量的空间分布及季节变异特征,探讨了它们与温度,DIN,PO43-,DO,BOD5等生态环境因子的关系.结果表明,三亚湾海区2005年平均叶绿素a浓度为:(2.48±2.97)mg/m3,浮游植物生物量(C)为:(124.2±148.3)mg/m3,浮游植物生物量秋季最高,其他季节差异不大,除夏季外,浮游植物生物量(C)均表现为:表层大于底层;年平均浮游细菌丰度为(6.90±2.95)×108个/dm3,细菌生物量(C)为(13.79±5.90)mg/m3,细菌生物量夏季最高,往下依次为冬季、春季和秋季,且4个季节均为表层大于底层.4个季节表、底层浮游植物和细菌生物量的空间分布特征明显,均表现为从近岸的三亚河口往外海逐渐降低的趋势,三亚河的陆源输送和入海扩散是造成此分布特征的主要原因.无机营养盐中,DIN是调控浮游植物和细菌生物量的主导因子.位于热带的三亚湾,温度不成为影响二者季节差异的主要因子.浮游细菌生物量和浮游植物生物量的比值BB/PB为:0.06~0.15(平均为0.12),三亚湾浮游植物生物量和浮游细菌生物量间的相关性非常显著(Pbottom,except in summer.The annual mean bacterioplankton abundance was(6.90±2.95)×108 cells/dm3,and the mean bacterioplankton biomass(BB,C) was(13.79±5.90) mg/m3,with highest value appeared in summer,and winter,spring,autumn,in turn.The BB at the surface layer was higher than bottom layer in all four seasons.The distribution of PB and BB at the surface and bottom layers in almost demonstrated the same pattern,which showed that the highest biomass appeared in the estuary of the Sanya River,and their abundance gradually declined offshore.The distribution feature mainly resulted from the terrestrial input from the Sanya River and invasion by the offshore oceanic sea water.In the inorganic nutrients,DIN was the leading factor of regulating PB and BB.Temperature almost had no influence on them in the tropical Sanya Bay,with temperature higher than 22 ℃.The correlation was significant between BB and PB(P<0.01),the ratio of BB to PB ranged from 0.06 to 0.15(average value was 0.12).Primary production was an important factor in controlling the distribution of bacterioplankton.厦门大学近海海洋环境科学国家重点实验开放基金项目(MEL0502);; 海南省自然科学基金项目(30518);; 中国科学院海洋研究所海洋生态与环境科学重点实验室开放基金项目;; 中科院广州地化所有机化学国家重点实验室开放基金(OGL200605

非水反相高效液相色谱法同时检测人血清中V↓A、V↓D↓3、V↓E和β-胡萝卜素

介绍一种用非水反相高效液相色谱法及外标法同时检测人血清中的视黄醇（ＶＡ）、胆钙化醇（ＶＤ３）、α－生育酚）ＶＥ）和β－胡萝卜素含量的方法。此方法实际用于检测胃癌病例及对照血清标本１８８份，有操作简便，出限低的特点