福建漳浦前湖湾有孔虫群落及其沉积环境     

王绍鸿  刘剑秋  吴彩容  俞鸣同 《台湾海峡》2007,26(2):151-156

对福建漳浦前湖湾潮间带两个钻孔岩心和表层沉积物中的有孔虫进行分析研究,有孔虫出现在钻孔最上部厚约2.46-2.96m的砂层中.根据群落优势种生态和非种特征判断,该段各样品有孔虫沉积环境均为近岸浅水环境,尽管其间海面有过3次上下波动变化.根据地层关系判断,其当为现代的产物.  相似文献   

Ensuring confidence in radionuclide-based sediment chronologies and bioturbation rates   总被引：1，自引：0，他引：1  

John Crusius  Timothy C. Kenna   《Estuarine, Coastal and Shelf Science》2007,71(3-4):537-544

Sedimentary records of naturally occurring and fallout-derived radionuclides are widely used as tools for estimating both the ages of recent sediments and rates of sedimentation and bioturbation. Developing these records to the point of data interpretation requires careful sample collection, processing, analysis and data modeling. In this work, we document a number of potential pitfalls that can impact sediment core records and their interpretation. This paper is not intended as an exhaustive treatment of these potential problems. Rather, the emphasis is on potential problems that are not well documented in the literature, as follows: (1) the mere sampling of sediment cores at a resolution that is too coarse can result in an apparent diffusive mixing of the sedimentary record at rates comparable to diffusive bioturbation rates observed in many locations; (2) ²¹⁰Pb profiles in slowly accumulating sediments can easily be misinterpreted to be driven by sedimentation, when in fact bioturbation is the dominant control. Multiple isotopes of different half lives and/or origin may help to distinguish between these two possible interpretations; (3) apparent mixing can occur due simply to numerical artifacts inherent in the finite difference approximations of the advection diffusion equation used to model sedimentation and bioturbation. Model users need to be aware of this potential problem. Solutions to each of these potential pitfalls are offered to ensure the best possible sediment age estimates and/or sedimentation and bioturbation rates can be obtained.  相似文献   

海洋生态环境监测的指标体系研究   总被引：1，自引：0，他引：1  

单宇  李正炎 《海洋湖沼通报》2007,200(2):52-56

本文在总结国内外各种海洋生态监测方法的基础上,构建生物分布指数、生物暴露指数和生物反应指数,并由此确定生态质量总指教。生态质量总指数可以综合反映特定海洋环境的生物群落特征,典型污染物在生物体内的蓄积特征以及生物体对环境污染的生理生化反应特征,因此可以应用于近岸海洋环境质量的生态监测。  相似文献   

High-resolution sediment echosounding off Peru: Late Quaternary depositional sequences and sedimentary structures of a current-dominated shelf     

Reinhardt  L.  Kudrass  H.-R.  Lückge  A.  Wiedicke  M.  Wunderlich  J.  Wendt  G. 《Marine Geophysical Researches》2002,23(4):335-351

About 6000 km of both bathymetric and high-resolution acoustic profiles were acquired on the shelf and upper slope offshore Peru between 9° S and 14° S. Two new sediment echosounder systems – SEL-96 and SES-2000DS – provided details of the sedimentary structures of the Quaternary sequences within the Sechura-Salaverry, Huacho and Pisco Basins. To a great extent, the poleward undercurrent determines the distribution of sediments. The undercurrent has generated numerous erosional unconformities, it has winnowed hardgrounds and has created mudwaves common between 250 m and 400 m water depth. Distinct subbottom reflectors within sedimentary units represent hiatuses due to periods of intensified winnowing or non-deposition. Erosional unconformities usually marked by pronounced reflectors suggest shifts of the undercurrent system related to climatic changes and eustatic variations of sea level. On a larger scale, the stacked prograding depositional sequences reflect the sea-level cycles of the Middle Pleistocene to the Holocene. Based on the stratigraphy of our piston cores and that of Ocean Drilling Program (ODP) Site 680, the depositional sequences limited by extended unconformities were assigned to oxygen isotope stages 1 to 7. Other sedimentary structures are small straight channels that were conduits for downslope sediment transport. Deformed sediments associated with synsedimentary normal faults result from creep movements indicating beginning slope failure.  相似文献   

Targeted environmental monitoring for the effects of medicines used to treat sea-lice infestation on farmed fish   总被引：1，自引：0，他引：1  

Davies  I. M.; Rodger  G. K.; Redshaw  J.; Stagg  R. M. 《ICES Journal of Marine Science》2001,58(2):477-485

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青藏高原东部多年冻土退化对环境的影响   总被引：3，自引：0，他引：3  

朱林楠  吴紫汪 《海洋地质与第四纪地质》1995,15(3):129-136

退化是本区多年冻土变化的基本趋势，不同区段退化幅度有差异，影响退化的因素除了全球气候转暖外，还有局地气候和地下水迳流。在退化敏感的地带，工程建设，牧区生态平衡都有不可忽视的影响。  相似文献   

黄、渤海沿岸海冰测点代表性浅析     

彭垣 《海岸工程》1994,(4)

通过分析１９８０年以后的海冰资料和卫星云图照片，对黄、渤海沿岸１１个海冰测点的历史变迁进行了评述，浅析了测点的优劣及使用资料时应注意的事项。  相似文献   

波浪作用下岸坡和海底平衡条件的研究     

沈剑平  范德江 《中国海洋大学学报(自然科学版)》1993,(4)

提出波浪作用下岸坡和海底动态和静态平衡条件的数学模型。在已建立的推移质泥沙体积输沙率基本关系式的基础上,根据连续方程,计算出底坡、泥沙、波浪三要素在动态和静态平衡情况下的关系式,得出反映这种关系的底坡平衡函数曲线图。用实际资料对这一函数曲线进行了验证,并对实际资料相对模型的某些差异作出解释。  相似文献   

湄洲湾表层沉积物中重金属的地球化学特征   总被引：6，自引：2，他引：6  

许爱玉  陈松 《台湾海峡》1993,12(1):16-20

根据1984年湄洲湾表层沉积物中重金属的分析资料,讨论了它们的地球化学特征和主要来源。沉积物中重金属的含量(Fe、Mn、Cu、Ni 的质量分数均值分别为3.21%、730×10~(-6)、19.4×10~(-6)、44×10~(-6)分布比较均匀,Pb、Zn 和Co 含量(质量分数均值分别为47.0×10~(-6)、25.8×10~(-6)和243×10~(-6))偏高,微量金属含量不受Fe-Mn 氧化物和有机物控制,本地区的金属来源受陆源输入的影响明显。  相似文献   

扇贝的养殖环境及其体内的细菌学分析   总被引：1，自引：0，他引：1  

宋庆云  罗挽涛  王文兴  薛清刚 《海洋科学进展》1997,(3)

自1992年9月～1994年11月，对青岛胶州湾养殖的扇贝及环境中的细菌组成和某些生态学特性进行了调查。养殖区表层海水中异养菌和弧菌平均数各波动于（21．2～39．7）×102／cm3和（7．3～19．2）×102／cm3之间。其中1号和4号站位的菌数比其它越位都高，这和它们靠近码头，受到附近的排水污染有关。在扇贝的消化盲囊和性腺内也分离到异养菌和弧菌，分别为103～105个g和103～105个／g。这些细菌可能因扇贝遇到环境改变防御能力下降时，扩散到其它器官并大量繁殖，因而造成感染而死亡。从对分离菌的药物敏感试验结果看，近年一些菌株对原来敏感的药物产生了抗药性，如四环索和链霉素，今后在育苗过程中避免滥用抗菌药物是十分重要的。  相似文献