温度对不同大小墨西哥湾扇贝生长的影响   总被引：2，自引：0，他引：2  

刘志刚  王辉  栗志民  郑云龙 《热带海洋学报》2007,26(5):47-52

在8—32℃实验室控温范围内以2℃为梯度,以壳高及体重增长作为观察指标,研究3个规格墨西哥湾扇贝Argopecten irradians concentricus的适宜、较适宜及最适宜生长温度。研究结果表明,小苗(壳高6.2mm,体重48.3mg)、中苗(壳高18.1mm,体重1191.1mg)、大苗(壳高30.7mm,体重5809.9mg)在8—32℃水温下均能生长,但在水温8及32℃,3种规格增长率均较低;适宜生长温度分别为小苗11.2—31.1℃、中苗9.8—31.8℃、大苗9.8—32.4℃;较适宜生长温度分别为小苗18.1—29.4℃、中苗18.5—29.4℃、大苗16.9—30.4℃;3种苗随规格增大,适温范围扩大(p<0.01);最适生长温度3种苗均为24—28.0℃,其范围向高温端漂移;在水温为8℃时,3种苗存活率均达到97.0%以上,水温在32℃时则小苗为47.0%、中苗为67.5%、大苗为76.0%,表现出3种苗对低温有更强的忍耐力,大苗对高温有更强的适应性。  相似文献   

崇明东滩沉积环境探讨   总被引：8，自引：0，他引：8  

刘清玉  戴雪荣  何小勤 《海洋地质前沿》2003,19(12):1-4

为探讨崇明东滩的沉积环境，了解崇明东滩的植被、水动力等对沉积的影响，对崇明进行了为期一年的实地观测和采样实验分析研究，研究结果表明：①沉积物中含有细砂、粉砂、黏土，其中粉砂是主要组分。塑造滩地的动力以潮汐作用为主，波浪作用居于次要地位；②沉积物的平均粒径自北线断面向南线断面、自高潮向低潮滩有逐渐变粗、分选变差的趋势，且平均粒径具有明显的季节变化；③潮滩季节性冲淤变化主要是与不同季节水文条件的差异性、潮滩植被季节变化及风暴天气等有关。  相似文献   

钛型吸附剂的表面特性     

谢式南  王俊鹤  周英兰  孙爱平 《中国海洋大学学报(自然科学版)》1990,(3)

用自装的BET容量法装置测定了几种粒状钛型吸附剂的比表面及其孔径分布。测定是在常温减压下进行的。结果表明:钛型吸附剂在加铀海水中的吸铀量与样品的比表面及孔径分布有一定的内在联系。这种表面性质的研究对吸附剂的筛选有重要的指导意义。  相似文献   

Measurements of suspended particulate matter with laser in-situ scattering and transmissometry in the Jiaozhou Bay in China     

WEI Jianwei  SHI Xuef  FANG Xisheng  ZHANG Weibin 《海洋学报(英文版)》2007,26(1):55-65

1 IntroductionKnowledge of suspended particle size and distri-bution is the key elements for better understandingthe sediment transport processes ( Wang et al.,2004), primary production (Ning et al., 2004),water quality controlling and pollution predictio…  相似文献   

"有序样品的Fisher聚类"对中华绒螯蟹渔获物的分析     

王宇庭  高天翔  史为良  郑有刚  赵睿 《中国海洋大学学报(自然科学版)》2005,35(2):297-300

为探讨河蟹生长特点以及渔获物与放养规格的关系，用有序样品的Fish聚类分析法首次对中华绒螯蟹的渔获物组成进行分析。结果显示，黄河三角洲广南水库沉砂池2000年河蟹渔获物可以分为3个群体，与其放养的3个不同规格群体相对应；据此推算了不同放养规格的回捕率；并对雌、雄生长和性成熟的差异以及合理的放养规格进行了探讨。  相似文献   

九龙江河口区表层水铀同位素的粒级分布          下载免费PDF全文

吕娥  张磊  陈敏  邱雨生  邢娜  杨伟锋  李艳平  黄奕普 《海洋学报》2007,29(4):59-68

利用微滤和超滤技术研究了九龙江河口区表层水中铀及其同位素组成的粒级分布和地球化学行为.结果表明,溶解态(<0.4μm)中低分子量组分(<10 000 u)占主要份额,胶体态(10 000 u~0.4μm)238U所占比例不足1%,且随盐度的增加其所占份额逐渐降低.溶解态、低分子量组分和胶体态238U的比活度与盐度之间存在良好的线性正相关关系,证实它们在九龙江河口区呈现保守行为.在颗粒态(>0.4μm)中,各粒级组分238U所占份额主要受控于相应颗粒物的浓度,在盐度小于20的区域,各粒级颗粒组分238U占颗粒态的份额有如下变化次序:10~53μm>2~10μm>0.4~2μm>大于53μm,而在盐度大于30的近外海站位,该次序发生一些变化:0.4~2μm>10~53μm>2~10μm>大于53μm,最小粒级颗粒组分238U的贡献有所增加,反映了自生铀贡献的加强.九龙江河口区表层水中溶解态(包括低分子量组分和胶体态)的234U/238U)_A.R.均大于1,显示出234U过剩的特征,而各粒级颗粒组分中的234U/238U)_A.R.则接近于平衡值(1.0).这一现象与陆地岩石风化过程中水体对铀的淋滤释出量及234U的优先浸出有关.对232Th/238U质量比的研究显示,溶解态及其所包括的低分子量组分和胶体态的232Th/238U质量比均小于1,而颗粒态及其所包括的4个粒级组分中的232Th/238U质量比均大于1,反映了向外海输送过程中铀、钍地球化学行为的差异.  相似文献   

Spatial variation in abundance and catch composition of Cancer pagurus in Norwegian waters: biological reasoning and implications for assessment     

Woll  Astrid K.; van der Meeren  Gro I.; Fossen  Inge 《ICES Journal of Marine Science》2006,63(3):421-433

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Depth Zonation, Micro habitat, and Morphology of Three Species of Acanthemblemaria (Pisces: Blennioidea) in the Guif of California, Mexico     

David G.  Lindquist 《Marine Ecology》1985,6(4):329-344

Abstract. The utilization of the spatial resources of refuge type, size and depth placement is investigated in the three sympatric species of Acanthemblemaria at the cape region of Baja California, Mexico. A. balanorum occupies barnacle testes (Balanus tintinnabulum), A. macrospilus occupies barnacles and mollusk tubes (vermetid gastropods and pholadids), and A. crockeri occupies only mollusk tubes (pholadids). Refuge diameter overlap is higher than overlap in depth. A. crockeri consistently occupies depths below 5m. Competition experiments for barnacle refuges among the three species indicate that A. balanorum is a superior competitor for such refuges. Prior residency of a less superior species changes the outcome of refuge competition in its favor. The morphological specialization of A. balanorum and A. macrospilus is evident in a high correlation between head size and standard length. A. balanorum selects refuges with entrance diameters highly correlated to standard length.  相似文献   

Current trends of space occupation by encrusting excavating sponges on Colombian coral reefs   总被引：1，自引：0，他引：1  

Mateo López-Victoria  & Sven Zea 《Marine Ecology》2005,26(1):33-41

Some sponges of the genus Cliona (Porifera, Hadromerida, Clionidae) simultaneously excavate and encrust calcareous substratum, competing aggressively for illuminated space with corals and other organisms. To interpret current trends of reef space occupation, the patterns of distribution and size of three Caribbean species were examined at San Andrés Island and Islas del Rosario in Colombia. While Cliona aprica was ubiquitous, C. caribbaea (= C. langae) preferred deep and protected reef zones, and C. tenuis shallow and wave‐exposed settings. In contrast to the effect on other excavating sponges, chronic exposure to raw sewage did not significantly increase the abundance of the studied sponges. Substratum occupation/availability ratios showed a positive tendency of the sponges toward certain coral skeletons, and a negative or neutral tendency toward calcareous rock, indicating that establishment may be easier on clean, recently dead coral than on older, heavily incrusted substratum. High relief generally limits sponge size to that of the illuminated portions of the substratum. A generally lower proportion of small individuals than of larger ones indicates currently low recruitment rates and low subsequent mortality. Successful events of higher recruitment seem to have occurred for C. tenuis. These are related to the massive acroporid coral die‐off in the early 1980s and to asexual dispersion during storms, resulting in a current 10% substratum cover. Reefs with high coral mortality were and/or are thus more susceptible to colonization and subsequent space occupation by these sponges, although relief may prevent space monopolization.  相似文献   

A requiem for the use of 20 log10 Length for acoustic target strength with special reference to deep-sea fishes     

McClatchie  S; Macaulay  G.J; Coombs  R.F 《ICES Journal of Marine Science》2003,60(2):419-428

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