Relationship between petroleum hydrocarbon and plankton in a mesocosm experiment   总被引：4，自引：0，他引：4  

Shi Xiaoyong  Wang Xiulin  Han Xiurong  Jiang Yu  Zhu Mingyuan  Chen Shang  Koshikawa Hiroshi 《海洋学报(英文版)》2001,20(2):231-240

~IOXWith economic development and consumer demand, oil pollutants have been one of themain marine pollutants in the coastal regal Of China. The oil-contaminated area incrsharply to 69% in 1995 and its average criterion index reached up to 2. 17 in the ChangjiangEstuary (NBEP, 1996). TO assess the influences Of the oil POllutants on the marine ~tern, it is neceSSary to develOP a mathematical kinetic model of the tranSport, distribution andfate in the marine ~teln, espeCially to esthate …  相似文献   

真鲷(Pagrus major)脂蛋白脂肪酶基因表达与内脏脂肪蓄积营养调控定量研究   总被引：7，自引：1，他引：7       下载免费PDF全文

梁旭方  白俊杰  劳海华  李贵生  周天鸿  Hiroshi Y. Ogata 《海洋与湖沼》2003,34(6):625-631

采用竞争性PCR方法 ,进行 4种营养状况对真鲷脂蛋白脂肪酶 (LPL)基因mRNA表达水平与内脏脂肪蓄积影响的定量研究。结果表明 ,真鲷LPL基因在肝脏存在营养诱导性表达 ,饥饿、高脂食物均是其表达诱导因子 ;在腹腔肠系膜脂肪组织存在组成性表达 ,其表达水平受摄食状态的影响 ,但饲料脂肪水平却不起作用。当真鲷喂食高脂食物时 ,诱导产生的大量肝脏LPL将为肝脏提供更多的来源于食物的游离脂肪酸 ,使肝脏有可能出现营养诱导性脂肪蓄积 ,但真鲷腹腔肠系膜脂肪组织LPL基因表达水平未出现适应性变化 ,其腹腔肠系膜脂肪组织将不可能作为营养诱导性蓄脂器官。由于上述营养状况对真鲷体重、腹脂指数、肝指数均没有产生显著性影响 ,说明真鲷具有在不同营养状况下与哺乳类相似的维持其内脏脂肪蓄积稳定的代谢机制 ,推测真鲷应存在某种在功能上与哺乳类相似的肥胖基因。  相似文献   

Observation of the Kyucho in the Bungo Channel by HF radar     

Hidetaka Takeoka  Yoshio Tanaka  Yuichi Ohno  Yukiharu Hisaki  Akitsugu Nadai  Hiroshi Kuroiwa 《Journal of Oceanography》1995,51(6):699-711

Observations of sea surface currents by HF radar were carried out in the Bungo Channel in summer 1992. The current ellipses of M₂ constituent obtained by the observational results agree quite well with those obtained by the ADCP observations, showing that the accuracy of the HF radar measurements is of the same level as ADCP. The results revealed the current structures and their change with the Kyucho in detail. The Kyucho is influenced by the complicated coastal geometry and does not propagate straightly into the Bungo Channel. It propagates further inward after charging the coastal bays with warm water. The current directions change largely, since the currents turn around the stagnant region in the bay filled with the warm water. The northward intrusion begins to be weakened in the southern part of the channel, while it still persists in the northern part. The northward current speeds of the observed Kyucho are about 50 cm/s and sometimes attain 60 to 70 cm/s.  相似文献   

Distribution of the subsurface chlorophyll maximum and its nutrient-light environment in and around the Euroshio off Japan     

Masayuki Takahashi  Toshisuke Nakai  Takashi Ishimaru  Hiroshi Hasumoto  Yoshihiko Fujita 《Journal of Oceanography》1985,41(2):73-80

Continuous distribution of the subsurface chlorophyll maximum (SCM) was confirmed in the Kuroshio and neighbouring areas in observations at 15 to 40 km intervals. Chlorophyll amounts occurring in and immediately around the SCM constituted 60 to 80% of the total chlorophyll in the water column above the 1% light level. The SCM zone received 1 to 10% of the surface irradiance at its center and contained sufficient macronutrients to support approximately one doubling of the existing phytoplankton biomass at most stations. There were several stations where there were higher nutrient concentrations that would support more than one doubling of the existing biomass around the SCM zone, and this was interpreted as resulting from uplift of the SCM zone due to upwelling.  相似文献   

Nonlinearity of the horizontal velocity field under wind-waves     

Norihisa Imasato  Hiroshi Ichikawa 《Journal of Oceanography》1977,33(2):61-66

Using the data from a wind-tunnel experiment, bispectra of orbital-motions of wind-waves and of turbulence are calculated, and nonlinear interaction of wind-waves with turbulence in water are discussed. The wind-waves or the orbital motions of them, at first, produce the turbulence coherent with themselves, and then this coherent turbulence changes to the turbulence noncoherent with wind-waves. Nonlinearity of the velocity fluctuations in the surface layer in water under wind-waves is almost due to the nonlinear energy transfer from the orbital motions of wind-waves to the coherent turbulence. The vertical variations of the power spectra and of the normalized bispectra suggest that the wind driven currents near the surface play an important role in the process from orbital motion of wind-waves to noncoherent turbulence.  相似文献   

Highers—The AVHRR-based higher spatial resolution sea surface temperature data set intended for studying the ocean south of Japan     

Futoki Sakaida  Hiroshi Kawamura 《Journal of Oceanography》1996,52(4):441-455

For the study of the ocean south of Japan, the HIGHER spatial resolution Sea surface temperature (HIGHERS) data have been produced from the AVHRR/NOAA data. The grid size is 0.075 degree and is much smaller than that of the usual sea surface temperature (SST) analysis field, which is gridded at most in 1 degree. In order to calculate accurate SST, the split-window Multi-Channel SST method is applied to cloudless pixels, which are detected with a cloud detection algorithm. The accuracy of the HIGHERS data is checked in comparison with the in-situ observation data.  相似文献   

Geostrophy in the Intermediate and Deep Layers of the Kuroshio and Its Recirculation Regions South of Japan     

Motohiko Kashima  Shiro Imawaki  Shin-Ichiro Umatani  Hiroshi Uchida  Yuji Hashibe  Hiroshi Ichikawa  Masao Fukasawa 《Journal of Oceanography》2003,59(3):291-301

Theoretically, the geostrophic approximation holds for the low-frequency flow field, but no detailed examination has been done on how well the estimated geostrophic velocity corresponds with the observed velocity. Intensive surveys were carried out during 1993–1995 in the Kuroshio and its recirculation regions south of Shikoku, Japan, including repeated hydrographic surveys and direct current measurements at nominal depths of 700, 1500 and 3000 m. For these depth intervals, vertical differences of estimated geostrophic velocity are compared with those of observed velocity. For the intermediate layer (between 700 and 1500 m depths), the slope of the regression line is 0.99, correlation coefficient is 0.98, and the root-mean-square of difference from geostrophic balance is 2.8 cm/s which is close to the estimated error of 2.1 cm/s. For the deep layer (between 1500 and 3000 m depths), the corresponding values are 0.82, 0.93, 1.2 cm/s and 2.0 cm/s, respectively. The results indicate that the estimated geostrophic velocity compares well with the observed velocity in these regions. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Comparison of downward surface solar radiation derived from GMS5/VISSR and of reanalysis products     

Huiling Qin  Yoshimi Kawai  Hiroshi Kawamura 《Journal of Oceanography》2006,62(4):577-586

A high-resolution downward surface solar radiation (DSSR) dataset has been produced using geostationary meteorological satellite measurements. Its validation with in situ observations shows that the daily satellite DSSRs are highly accurate. Comparing the satellite DSSRs with reanalysis DSSR datasets, the former has higher probability density in a low value range, and lower density in a high value range. Overestimations of the reanalysis DSSR are significant in the low range. Correlations between the reanalysis DSSRs and the satellite DSSR are relatively low in the tropics. It is suggested that the satellite DSSRs have good potential to capture cloud behavior in the tropics.  相似文献   

Loss Processes of Sinking Fecal Pellets of Zooplankton in the Mesopelagic Layers of the Antarctic Marginal Ice Zone     

Hidekatsu Suzuki  Hiroshi Sasaki  Mitsuo Fukuchi 《Journal of Oceanography》2003,59(6):809-818

A time-series sediment trap deployment was carried out in the marginal ice zone (MIZ) of the Antarctic Ocean (64°42′ S, 139°58′E; sea depth of 2930 m), during the austral summer. Cylindrical fecal pellets were the predominant sinking particles at 537 m in the middle of January and most of them disappeared below that depth, the loss of which were 25.3 mg C m⁻² day⁻¹ in the depth range of 537–796 m. Small-sized sinking particles other than fecal pellets increased in that depth range. Analyses of fecal pellets for remnant DNA corresponding to 16S mitochondrial RNA and 28S ribosomal RNA suggested that the large cylindrical fecal pellets at 537 m were produced by Antarctic krill (Euphausia superba) and copepods. According to the presence of the DNA associated with sinking particles, E. superba fecal pellets rapidly disappeared below 537 m, while copepod fecal pellets still remained in the mesopelagic and bathypelagic layers. Small-sized amorphous sinking particles at 537 m also contained E. superba- and copepod-derived DNA. The abundance of trap-collected copepods (Oithona spp. and Oncaea spp.) which are known to be coprophagous increased at 796 m where many fecal pellets disappeared. We suggest that those rapidly sinking pellets were fragmented by copepods with intensified coprorhexy activity (fragmentation of fecal pellets) in the mesopelagic layers, reducing their sinking rates. These smaller and slower sinking particles can be important food sources for detritivorus or coprophagous animals in mesopelagic and bathypelagic layers in the MIZ. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Bacterioplankton production in dilution zone of the Changjiang(Yangtze) Estuary   总被引：1，自引：0，他引：1  

Liu Zilin  Koshikawa Hiroshi  Ning Xiuren  Shi Junxian  Cai Yuming 《海洋学报(英文版)》2001,20(1):131-139

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