Sensitivity to stress of the estuarine bivalve Macoma balthica from areas between the Netherlands and its southern limits (Gironde)     

H. Hummel  C. Amiard-Triquet  G. Bachelet  M. Desprez  J. Marchand  B. Sylvand  J.C. Amiard  H. Rybarczyk  R.H. Bogaards  J. Sinke  Y. De Wit  L. De Wolf 《Journal of Sea Research》1996,35(4):315-321

Variation in the sensitivity to stress of Macoma balthica was measured in several French and Dutch estuaries. For adult and juvenile Macoma balthica exposed to copper under conditions of starvation, differences in mortality rate, condition, glycogen, burrowing rate and copper content were assessed. No significant differences were observed between adults and juveniles; the influence of treatment and origin was always evident. Animals from the most southern estuaries, Loire and Gironde, near to the species's southern limit of distribution, showed, in the field, the strongest deviations for the ecophysiological traits measured, and were in the experiments the most sensitive to stress.  相似文献   

Management of summer-spawning herring off Iceland   总被引：1，自引：0，他引：1  

Jakobsson  J.; Stefansson  G. 《ICES Journal of Marine Science》1999,56(6):827-833

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梭鱼标准代谢、内源氮排泄与体重和温度的关系   总被引：5，自引：0，他引：5  

线薇薇  朱鑫华 《中国海洋大学学报(自然科学版)》2002,32(3):368-374

在 13.5 ,18,2 1.5 ,2 4和 2 7℃ 5个温度条件下测定了梭鱼 (体重范围 1.88～ 14.0 2 g)的标准代谢率和内源氮排泄率。梭鱼标准代谢率随体重的增加而增加 ,二者的关系为幂函数关系 ;随温度的升高而增加 ,二者的关系为指数关系 ;标准代谢率与体重和温度的关系可用如下方程表示 :RS=0 .12 4 6 W0 .9954 e0 .0 84 1T(r2 =0 .92 2 0 )。梭鱼的氨氮、尿素、总氮及能量的排泄率随体重和温度的增加而增加 ,与体重为幂函数关系 ,与温度的关系为多项式形式。梭鱼氨氮和尿素日排泄率的变幅分别为 0 .15～ 0 .88mg N/d和 0 .0 3～ 0 .2 9mg N/d。不同温度下 ,尿素排泄量占总氮比例在 9.9%～2 2 .4 9%之间 ,随温度升高该值有逐渐增大的趋势。  相似文献   

Upstream dams and downstream clams: growth rates of bivalve mollusks unveil impact of river management on estuarine ecosystems (Colorado River Delta, Mexico)     

B. R. Schne  K. W. Flessa  D. L. Dettman  D. H. Goodwin 《Estuarine, Coastal and Shelf Science》2003,58(4):715-726

We studied how the extensive diversion of Colorado River water, induced by dams and agricultural activities of the last 70 years, affected the growth rates of two abundant bivalve mollusk species (Chione cortezi and Chione fluctifraga) in the northern Gulf of California. Shells alive on the delta today (‘Post-dam’ shells) grow 5.8–27.9% faster than shells alive prior to the construction of dams (‘Pre-dam’ shells). This increase in annual shell production is linked to the currently sharply reduced freshwater influx to the Colorado River estuary. Before the upstream river management, lower salinity retarded growth rates in these bivalves. Intra-annual growth rates were 50% lower during spring and early summer, when river flow was at its maximum. Growth rates in Chione today are largely controlled by temperature and nutrients; prior to the construction of dams and the diversion of the Colorado River flow, seasonal changes in salinity played an important role in regulating calcification rates.Our study employs sclerochronological (growth increment analysis) and geochemical techniques to assess the impact of reduced freshwater influx on bivalve growth rates in the Colorado River estuary. A combination of both techniques provides an excellent tool to evaluate the impact of river management in areas where no pre-impact studies were made.  相似文献   

酶解条件对条斑紫菜单细胞成活率影响的比较研究     

杨震  唐学玺  戴继勋  沈颂东  宫相忠  贾鹏举 《中国海洋大学学报(自然科学版)》2001,31(3):407-410

该文分别选用不同浓度的海螺酶 ;葡萄糖、蔗糖、甘露醇、山梨醇、氯化钠 5种渗透剂 ;维生素 C和甘露醇 2种抗氧化剂 ;对条斑紫菜酶解单细胞的成活率进行了研究。实验结果表明 :用浓度为 10 %的海螺酶酶解条斑紫菜 ,成活率最高 ;选用 2 mol/ L葡萄糖作渗透剂 ,效果最好 ,成活率达85.2 % ;加入抗氧化剂对细胞成活率没有影响  相似文献   

Preliminary study on different nutrient pools supplies for the phytoplankton growth in the Jiaozhou Bay in China in the fall of 2004     

WANG Dan  SUN Jun  SONG Shuqun  LUAN Qingshan  Joey McMurdie 《海洋学报(英文版)》2007,26(3):110-120

The source and significance of two nutrients, nitrogen and phosphorous, were investigated by a modified dilution method performed on seawater samples from the Jiaozhou Bay, in autumn 2004. This modified dilution method accounted for the phytoplankton growth rate, microzooplankton grazing mortality rate, the internal and external nutrient pools, as well as nutrient supplied through remineralization by microzooplankton. The results indicated that the phytoplankton net growth rate increased in turn from inside the bay, to outside the bay, to in the Xiaogang Harbor. The phytoplankton maximum growth rates and microzooplankton grazing mortality rates were 1.14 and 0.92 d-1 outside the bay, 0.42 and 0.32 d-1 inside the bay and 0.98 and 0.62 d-1 in the harbor respectively. Outside the bay, the remineralized nitrogen (Kr=24.49) had heavy influence on the growth of the phytoplankton. Inside the bay, the remineralized phosphorus(Kr=3.49) strongly affected the phytoplankton growth. In the harbor, the remineralized phosphorus (Kr=3.73) was in larger demand by phytoplankton growth. The results demonstrated that the different nutrients pools supplied for phytoplankton growth were greatly in accordance with the phytoplankton community structure, microzooplankton grazing mortality rates and environmental conditions. It is revealed that nutrient remineralization is much more important for the phytoplankton growth in the Jiaozhou Bay than previously believed.  相似文献   

Modeling of the eddy viscosity by breaking waves     

ZHANG Shuwen  YUAN Yeli  ZHENG Quan''an 《海洋学报(英文版)》2007,26(6):116-123

Breaking wave induced nearsurface turbulence has important consequences for many physical and biochemical processes including water column and nutrients mixing,heat and gases exchange across air-sea interface.The energy loss from wave breaking and the bubble plume penetration depth are estimated.As a consequence,the vertical distribution of the turbulent kinetic energy(TKE),the TKE dissipation rate and the eddy viscosity induced by wave breaking are also provided.It is indicated that model results are found to be consistent with the observational evidence that most TKE generated by wave breaking is lost within a depth of a few meters near the sea surface.High turbulence level with intensities of eddy viscosity induced by breaking is nearly four orders larger than υwl(=κuwz),the value predicted for the wall layer scaling close to the surface,where uw is the friction velocity in water,κ with 0.4 is the von Kármán constant,and z is the water depth,and the strength of the eddy viscosity depends both on wind speed and sea state,and decays rapidly through the depth.This leads to the conclusion that the breaking wave induced vertical mixing is mainly limited to the near surface layer,well above the classical values expected from the similarity theory.Deeper down,however,the effects of wave breaking on the vertical mixing become less important.  相似文献   

基于MPI的LAGFD-WAM海浪数值模式并行算法研究   总被引：5，自引：0，他引：5  

王关锁  乔方利  杨永增 《海洋科学进展》2007,25(4):401-407

在LAGFD-WAM海浪串行数值模式基础上,利用MPI信息传递机制实现其并行化。通过对模拟区域合理划分,对数据采取分块加载,实现了各个节点的负载平衡;通过对算法的改进实现了粗粒度计算,大幅度减少了通信量,从而提高了程序的执行效率。对串行计算和并行计算的效率比较表明,本文建立的方法能够得到较高的加速比。对全球海浪模式,加速比和CPU数目大致呈线性关系。对高分辨率的区域海浪模式,在128 CPU条件下加速比可以达到91.9。  相似文献   

北太平洋副热带模态水形成区潜沉率的年际变化及其机制     

胡海波  刘秦玉  刘伟 《海洋学报》2006,28(2):22-28

根据Huang和Qiu 1995年的潜沉率计算公式,采用同化的海洋模式资料和海洋-大气界面的通量观测资料,计算了北太平洋副热带海域3个模态水形成区逐年的潜沉率,研究了潜沉率产生年际变化的机制.研究结果表明:西部、中部和东部3个模态水形成区潜沉率的年际变化主要周期分别为6,2~5和2 a;北太平洋副热带模态水的3个形成区的潜沉率都发现年代际的变化特征:在1985年以前,西部模态水形成区的潜沉率年际变化最为显著,但1985后年际变化振幅明显减小;在中部模态水形成区,1975~1992年间潜沉率随时间的变化的振幅较大,潜沉率在这段时间内的平均值也达到33.99 m/a,而在1970~1975年间和1993~1998年间潜沉率都小于20 m/a;西部副热带模态水形成区的潜沉率的年际变化与这里海面的净热通量的年际变化有很好的相关性,中部副热带模态水形成区潜沉率的年际变化则取决于局地Ekman流的年际变化,而在东部模态水形成区局地风应力旋度的变化直接影响潜沉率的大小.  相似文献   

东海浮游翼足类(Pteropods)数量分布的研究   总被引：10，自引：1，他引：10  

徐兆礼 《海洋学报》2005,27(4):148-154

根据1997～2000年东海海域23°30'～33°00'N,118°30'～128°00'E的4个季节海洋调查资料,运用定量、定性方法,探讨了东海浮游翼足类总丰度的平面分布、季节变化及变化的动力学机制.结果表明,东海翼足类总丰度和出现频率有明显的季节变化,均为秋季最高,夏季次之,春季最低;总丰度在各个季节基本上呈东海南部高于北部、外海高于近海的分布趋势;春季的尖笔帽螺(Creseis acicula)、夏季的锥笔帽螺(Creseis virgula)、秋季的蝴蝶螺(Desmopterus papilio)和冬季的马蹄螔螺(Limacina trochiformis)是导致总丰度季节变化的最主要的种类;冬、春和夏3个季节丰度变化及4季总丰度的变化同表层或10m层水温有非常显著的线性相关关系,与底层温度及盐度的相关关系不显著.夏季翼足类高丰度区位于台湾暖流与黑潮暖流的分支处;从夏季到秋季,翼足类随着台湾暖流向北扩展,并在与长江冲淡水,闽浙沿岸水团,黄海水团等交汇处形成高丰度(大于500×10-2个/m3)和较高丰度(250×10-2～500×10-2个/m3)分布区.水温和海流是影响东海翼足类总丰度分布的主要环境因素.  相似文献