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1.
INrnODUCTIONTheaqUacultareindustryofChinaedsfirstintheworld-Fertilizationinfreshwatershasalonghistory,andiseffectivelyaPpliedforfishcultUre.Scholarsfromvchouscotm-trieshaveheenstudytngfertiliZationtheory,tecboqUeandaqUactiltUreecologyinfertilizedPOnds-SPecialattentionisgiventothetwncyandaPPlicationlevelwhenmantireisused,andtothekindandN:PraioOfchethecalfertilizersused(Boyd,l99o;li,I993;MoriartyandPullin,l987).Thedrpthecchacteristicsofphosphorus,andtheroleofureaappliedintoPOndswere…  相似文献   

2.
Survey of yellowfin tuna in the west-central Indian Ocean was conducted on board of Chinese longliners during 2003, 2004 and 2005, which is a part of Chinese Tuna Fishery Scientific Observer Program (CTFSOP). The reproductive biology has been investigated. A total of 1 023 samples are collected including 417 ovaries and 606 testes. Spawning activities of yellowfin tuna have been studied for both male and female from January to June. The data showed that the average monthly sex ratio is 0.59, and the minimum length at sexual maturity is 101 cm for female and 110 cm for male respectively. Length at 50% sexual maturity is estimated at 113.77 cm for female and 120.20 cm for male, whereas maturation rate is 0.066 cm−1 for female and 0.091 cm−1 for male. Sex ratio by length class indicates that the proportion of male is higher than female’s along with size increasing; for instance, in the group of the body length longer than 145 cm, some females have their body length from 145 to 160 cm and males have their body length at 160 cm and even longer. Statistically, yellowfin tuna has a significant seasonal reproduction.  相似文献   

3.
东海中南部海域锈斑蟳渔业生物学和数量分布   总被引：2，自引：0，他引：2  
研究了1998—1999年东海区虾蟹类调查所获的部分锈斑蟳样品与1998~2004年在东海拖虾作业与蟹笼作业等周年逐月渔获物中采集的锈斑蟳样品的生物学特性,结果表明:东海锈斑蟳渔获群体的甲长范围为26~105mm,甲宽范围为36~165 mm,体重范围为5~610 g,雄性个体平均要略大于雌性个体;周年雌蟹略多于雄蟹,性比为1∶0.94,繁殖期为7~12月,繁殖高峰期为8~10月,不同个体怀卵量在113 867~1 594 167粒之间;调查海区10月开始出现幼蟹,5月生长加速,最小抱卵个体的甲长为60 mm,甲宽为85 mm,体重为110 g。另根据1998~1999年调查资料分析得知:锈斑蟳主要分布在长江口渔场以南水深60 m以内海域,中心区分布在闽东渔场,渔期为11月~翌年2月,是舟山、长江口渔场三疣梭子蟹汛期结束后,蟹笼、流刺网作业的又一主捕对象。  相似文献   

4.
Survey of yellowfin tuna in the west-central Indian Ocean was conducted on board of Chinese Iongliners during 2003, 2004 and 2005, which is a part of Chinese Tuna Fishery Scientific Observer Program (CTFSOP). The reproductive biology has been investigated. A total of 1023 samples are collected including 417 ovaries and 606 testes. Spawning activities of yellowfin tuna have been studied for both male and female from January to June. The data showed that the average monthly sex ratio is 0.59, and the minimum length at sexual maturity is 101 cm for female and 110 cm for male respectively. Length at 50% sexual maturity is esti- mated at 113.77 cm for female and 120.20 cm for male, whereas maturation rate is 0.066 cm-1 for female and 0.091 cm-1 for male. Sex ratio by length class indicates that the proportion of male is higher than female's along with size increasing; for instance, in the group of the body length longer than 145 cm, some females have their body length from 145 to 160 cm and males have their body length at 160 cm and even longer. Statistically, yellowfin tuna has a significant seasonal reproduction.  相似文献   

5.
Measurement of the surface emissivity of turbid waters   总被引：2，自引：0，他引：2  
For interpreting thermal IR imagery of the ocean surface, the emissivity of the sea surface is usually assumed to be constant, approximately 0.98. However, the emissivity varies with the roughness of the sea surface, and the concentration and type of suspended particulates. The emissivity variations caused by the suspended sediments introduce significant errors in the satellite-derived temperature maps of turbid coastal waters. We measured in the laboratory the thermal IR emissivity of water as the suspended sediment concentration was varied from zero to extremely high values. The results indicated that increasing the sediment concentration decreases the spectral emissivity within the 8–14 μm waveband. Editor’s note A conference on West Pacific Circulation Influence in China Seas (WEPACICS) was held during November 10–14, 1986 in Qingdao, China, under the joint auspices of the Institute of Onceanology, Academic Sinica (IOAS) and the National Science Foundation, United States, and under the convernorship of Ya Hsueh, Florida State University, and Hu, Dunxin, IOAS. The primary subject of the conference is the influence of the West Pacific Circulation in the Yellow Sea and the East China Sea through the intermediary of the Kuroshio. In the conference more than 20 papers were presented, summarizing the works on the interaction between the Yellow and East China Sea, and the oceanic circulation, and the research experiences gained in the studies of the Gulf Stream and its influences in the U.S. Coastal waters were shared. In order to facilitate scientific exchange we chose to published successively the significant papers presented at the conference in the journal.  相似文献   

6.
Introduction The Tibetan Plateau, located in west China, was uplifted during the Cenozoic and became the most youthful plateau in the world. Some researches have also shown that it started to develop into the cryosphere in the beginning of the Middle Pleistocene and became one of the three global cryospheres (two other cryospheres being the Artic and the Antarctic) (SHI et al. 1996). Because of the cryosphere development in the Tibetan Plateau, many periglacial and permafrost geomorpholog…  相似文献   

7.
In order to understand the large-scale spatial distribution characteristics of picoplankton,nanophytoplankton and virio-plankton and their relationship with environmental variables in coastal and offshore waters,flow cytometry(FCM) was used to ana-lyze microbial abundance of samples collected in summer from four depths at 36 stations in the North Yellow Sea(NYS).The data revealed spatial heterogeneity in microbial populations in the offshore and near-shore waters of the NYS during the summer.For the surface layer,picoeukaryotes were abundant in the near-shore waters,Synechococcus was abundant in the offshore areas,and bacte-rial and viral abundances were high in the near-shore waters around the Liaodong peninsula.In the near-shore waters,no significant vertical variation of picophytoplankton(0.2-2μm) abundance was found.However,the nanophytoplankton abundance was higher in the upper layers(from the surface to 10 m depth) than in the bottom layer.For the offshore waters,both pico-and nanophytoplankton(2-20μm) abundance decreased sharply with depth in the North Yellow Sea Cold Water Mass(NYSCWM).But,for the vertical dis-tribution of virus and bacteria abundance,no significant variation was observed in both near-shore and offshore waters.Autotrophic microbes were more sensitive to environmental change than heterotrophic microbes and viruses.Viruses showed a positive correla-tion with bacterial abundance,suggesting that the bacteriophage might be prominent for virioplankton(about 0.45μm) in summer in the NYS and that viral abundance might play an important role in microbial loop functions.  相似文献   

8.
Previous studies have indicated that the Yellow Sea underwent significant environmental changes during the Holocene, but many questions remain concerning the timing of the establishment of the modern circulation system, which would have major implications for the Yellow Sea ecosystem and carbon cycle. In this study, marine and terrestrial biomarkers were analyzed in Core YE-2 from a muddy area in the southern Yellow Sea to reconstruct Holocene environmental and phytoplankton community change. The content of three individual marine phytoplankton biomarkers (alkenones, brassicasterol and dinosterol) all display a similar trend, and their total contents during the early Holocene (362 ng/g) were lower than those during the mid-late Holocene (991 ng/g). On the other hand, the contents of terrestrial biomarkers (C27+C29+C31n-alkanes) during the early Holocene (1 661 ng/g) were about three times higher than those during the mid-late Holocene (499 ng/g). Our biomarker results suggest that the modern circulation system of the Yellow Sea was established by 5-6 ka, and resulted in higher marine productivity and lower terrestrial organic matter inputs. Biomarker ratios were used to estimate shifts in phytoplankton community structure in response to mid-Holocene (5-6 ka) environmental changes in the Yellow Sea, revealing a transition from a dinoflagellate-diatom dominant community structure during the early Holocene to a coccolithophore-dominant community structure during the mid-late Holocene.  相似文献   

9.
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10.
With the decline in the most fisheries resources in the Yellow Sea,the yellow goosefish Lophius litulon has increased in commercial and ecological importance in recent years.We studied the length distribution,length-weight relationship,age composition,growth pattern,mortality,and exploitation rates of the yellow goosefish in the Yellow Sea.Total length(TL) of females and males ranged from 173 to582 mm and 178 to 500 mm,respectively.The length-weight relationships were also estimated for females and males.Age classes from 2 to 4 years predominated in the samples.The von Bertalanffy growth function(VB GF),estimated based on non-linear least-squares methodology,showed significant differences between sexes.Females attained a greater estimated asymptotic total length(765 mm TL) compared to males(579 mm TL).The VBGF did not differ significantly between stocks of the northern Yellow Sea and the southern Yellow Sea.Estimated natural instantaneous mortality rate(M) ranged from 0.25/a to 0.33/abased on four age-and length-based methods.Total instantaneous mortality rate(Z) of total samples calculated by the age-based catch curve method was 0.591/a and the average fishing mortality(F) was 0.30/a.Estimated exploitation rate(E) was approximately 0.5,indicating that the population of L.litulon in the Yellow Sea may be sustainable.These results provide a reference for the present status of L.litulon and information for the management.  相似文献   

11.
Fenneropenaeus chinensis distributed in the Yellow Sea and Bohai Sea of China and the west coast of the Korean Peninsula. Different geographical populations represent potentially different genetic resources. To learn further the characteristics of different geographical population, crosses among two wild and three farmed populations were produced. The two wild populations were from the Yellow Sea and Bohai Sea （WYP）, and the west coast of the Korean Peninsula and coast （WKN）. The three farmed populations included the offspring of first generation of wild shrimp from coast in Korea （FKN）, the Huang Hai （the Yellow Sea in Chinese） No.1 （HH1）, and JK98. The phenotypes growth and survival rates of these populations were compared to confirm the feasibility for crossbreeding. The body length （BL）, carapace length （CL）. carapace width （CW）, height of the second and third abdominal segment （HST）, width of the second and third abdominal segment （WST）, length of the first abdominal segment （LF）, length of the last abdominal segment （LL）, live body weight （BW）, and survival rate were measured, Different combinations were statistically performed with ANOVA and Duncan＇s Multiple Range Test. The results show that the survival rate of JK98（♀）×WKN（♂） was the highest, followed by WYP（♀）×WKN（♂）, FKN（♀）×WYP（♂）, FKN（♀）×HHI（♂） and WYP（♀）×FKN（♂）; the body weight of FKN（♀）×HHI（♂） was the highest, followed by FKN（♀）×WYP（♂）, WYP（♀）×WKN（♂）, WYP（♀）×FKN（♂） and JK98（♀）×WKN（♂）; the total length had the same ranking as the body weight. All growth traits in hybrids JK98（♀）×WKN（♂） were the lowest among all combinations. F1 hybrids had significant difference （P〈0.05） in BL, CL, HST, LL, and BW; and insignificant difference （P〉0.05） in other growth traits and survival rate. The results of Duncan＇s Multiple Range Test are that BL and CL of J  相似文献   

12.
The Huanghe (Yellow) River, with annual sediment discharge about 11 ×108tons, contributes about 17% of the fluvial sediment discharge of world's 21 major rivers to the ocean because its middle reaches flow across the great Loess Plateau of China. Sediment discharge of the Huanghe River has a widespread and profound effect on sedimentation of the sea. The remarkable shift of its outlet in 1128-1855 A.D. to the South Yellow Sea formed a large subaqueous delta and provided the substrate for an extensive submarine ridge field.The shift of its outlet in the modern delta every 10 years is the main reason why with an extremely heavy sediment input and a micro- tidal environment, the Huanghe River has not succeeded in building a birdfoot delta like the Mississippi. The Huanghe River has consistently brought heavy sediment input to sea at least since 0.7 myr.B.P. Paleochannels, paleosols, cheniers and fossils on the sea bottom indicate that the Yellow Sea was exposed during the late Quaternary glacial low-sea l  相似文献   

13.
The fundamental principle for differentiating water masses is a strict consideration of their “relative interier homogeneity” and obvious exterior differences with others in characteristics. The conceptions of water type, water mass and water system are dealt with on the basis of the theory of fuzzy sets. A proposal to apply the theory of fuzzy sets to define the water mass and its core, independent area, boundary and mixing area is put forward. As an example, the membership function of the surface water masses in the Yellow Sea and East China Sea in August, 1979, are considered. Their cores, independent areas, boundaries, mixing areas and the approximation degrees between different water masses are calculated respectively. The water masses are ranged according to their fuzzy degrees. This paper was published inOceanologia et Limnologia Sinica, 1986,17(2): 102–110. This study was financially supported by National Natural Sciences Foundation of China.  相似文献   

14.
In this paper, a new polychaete species, Eranno carrerai sp. nov. from coastal areas of China, is described based on specimens deposited in the Marine Biological Museum of the Chinese Academy of Sciences, Qingdao, collected during 1957 to 1976 from the Yellow Sea, East China Sea and South China Sea at depths of 9–210 m.  相似文献   

15.
A numerical model is developed to explain the response of the shelf sea to the abrupt imposition of a steady, secular mean windstream field and the basic characteristics of the wintertime circulation in the Northern Huanghai Sea (Yellow Sea) and the Bohai Sea by using equidistant, staggered grid points, an implicit finite difference scheme and our new “splitting computational method” of adjustment, development, and dissipation processes. So far as the major tendency of the circulation is concerned, the numerical result agrees with the observational data. The computational results show that the eastern anticyclonic and the western cyclonic circulations constitute the main body of the wintertime circulation in the Northern Huanghai Sea, and that the northern anticyclonic and the southern cyclonic circulations constitute the main body of the wintertime circulation in the Bohai Sea. Contribution No. 1508 from the Institute of Oceanology, Academia Sinica  相似文献   

16.
The CTD (conductivity, temperature and depth) data collected by six China-Korea joint cruises during 1996-1998 and the climatological data suggest that the seasonal variability of average salinity in the Yellow Sea (Sa) presents a general sinusoid pattern. To study the mechanism of the variability, annual cycles of Sa were simulated and a theoretical analysis based on the governing equations was reported.Three main factors are responsible for the variability: the Yellow Sea Warm Current (YSWC), the Changji-ang (Yangtze) River diluted water (YRDW) and the evaporation minus precipitation (E-P). From December to the next May, the variability of Sa is mainly controlled by the salt transportation of the YSWC. But in early July, the YSWC is overtaken and replaced by the YRDW which then becomes the most important controller in summer. From late September to November, the E-P gradually took the lead. The mass exchange north of the 37癗 line is not significant.  相似文献   

17.
Mass occurrence of Salpa fusiformis was observed in the Southern Yellow Sea in May and June 2007. In order to investigate its population recruitment and environmental adaptation, temporal variation of abundance, diel vertical migration (DVM) and length frequency distribution of both aggregate and solitary forms were studied with samples collected from eight months during September 2006 to August 2007. S. fusiformis presented in six months other than September and October 2006, and average abundance of aggregate and solitary forms peaked in June and May, respectively. In December, aggregate forms were absent in the bottom layer and performed irregular DVM from surface to 50 m depth, while solitary forms was too scarce to perform diel vertical distribution analysis. Both aggregate and solitary forms presented reverse DVM in May and June. They migrated upwards during daytime and concentrated in surface layer at sunset. The bimodal distribution of aggregate forms was found in April and the average size was largest in this month. In other months, the smaller aggregate forms (1-5 mm) dominated in populations except for May, when the modal size ranged from 2 to 8 mm. The average size of solitary forms was largest in December, followed by April. The skewed nomal distribution of solitary forms was found in May and June, with the modal size of 2-7 mm and 5-13 mm, respectively.  相似文献   

18.
Rainwater samples were collected in series in Qianliyan Island (southern Yellow Sea) and Shengsi Archipelago (East China Sea) between May 2000 and May 2002, chemical analysis for pH values,concentrations of heavy metals (Cu, Pb, Zn and Cd) and nutrients (NH4^-, NO3^-, PO43^-, SiO32^-) were performed.Results indicate that concentrations of most of the heavy metals and nutrients in rainwater show clear seasonal variation, i.e. high level in winter and low level in summer. Regionally, concentrations are higher in the southern Yellow Sea than in the East China Sea, but the annual input of heavy metals into oceans by wet deposition is similar in both stations. However, the input of nutrients by wet deposition in the East China Sea is 2-3 times higher than that in the southern Yellow Sea. In individual, Pb and PO4^3- are input to the sea mainly by dry deposition; whereas Cu, Zn, Cd and N compounds are input dominantly by wet deposition, the N/P ratios in the rainwater from two stations are much higher than those in seawater, showing a significant impact of atmospheric wet deposition on marine production and biogeochemical circulation of nutrients in these sea regions.  相似文献   

19.
An N-shape thermal front in the western South Yellow Sea (YS) in winter was detected using Advanced Very High Resolution Radiation (AVHRR) Sea Surface Temperature data and in-situ observations with a merged front-detecting method. The front, which exists from late October through early March, consists of western and eastern wings extending roughly along the northeast-southwest isobaths with a southeastward middle segment across the 20–50 m isobaths. There are north and south inflexions connecting the middle segment with the western and eastern wings, respectively. The middle segment gradually moves southwestward from November through February with its length increasing from 62 km to 107 km and the southern inflexion moving from 36.2°N to 35.3°N. A cold tongue is found to coexist with the N-shape front, and is carried by the coastal jet penetrating southward from the tip of the Shandong Peninsula into the western South YS as revealed by a numerical simulation. After departing from the coast, the jet flows as an anti-cyclonic recirculation below 10 m depth, trapping warmer water originally carried by the compensating Yellow Sea Warm Current (YSWC). A northwestward flowing branch of the YSWC is also found on the lowest level south of the front. The N-shape front initially forms between the cold tongue and warm water involved in the subsurface anti-cyclonical recirculation and extends upwards to the surface through vertical advection and mixing. Correlation analyses reveal that northerly and easterly winds tend to be favorable to the formation and extension of the N-shape front probably through strengthening of the coastal jet and shifting the YSWC pathway eastward, respectively.  相似文献   

20.
The authors obtained the magnetostratigraphic division of Quaternary from the palaeomagnetic records of 7 cores taken from the northern plain of Jiangsu Province. The depositional characteristics of this area are now described. The core near the coastal region of the Yellow Sea showed the sedimentary rate was higher during Brunhes chron, but lower or nearly zero during Matuyama chron. The core located in the middle of the northern plain of Jiangsu Province showed the depositional formation was thin during Brunhes chron, but thicker in Matuyama. This depositional difference indicated obvious differences in the tectonic units, geological basement, and depositional environments of the two periods. This study provides information for the subdivision of Quaternary magnetostratigraphy. This paper was published in Chinese inOceanologia et Limnologia Sinica.18(2): 173–180.  相似文献   

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