摘要:Temporal and spatial characteristics of interdecadal SST variability of the North Pacific Ocean were investigated and its effect on ENSO was discussed. Interdecadal variability in SST obviously exists in both the tropical and north Pacific Ocean, while it is relatively weak in the equatorial Pacific and SST changes in the north Pacific possess lower frequencies. 1977 was a turning point for interdecadal SST variations (from cold to warm) in the equatorial Pacific as well as for the SST principal mode (EOF1) of the Pacific SST in terms of temporal change. But the north Pacific changed from warm to cold period from 1973, which is attributed mainly to the second mode. Both equatorial and north Pacific Ocean has turned to warm period since 1990. Revealed by the first mode, SST oscillation of the middle latitude North Pacific Ocean and its adjacent area are out of phase, while oscillation of the north Pacific was revealed by the second mode. Significant impact of interdecadal changes of equatorial SST on ENSO strength is shown. It seems that warm decadal background is a prerequisite condition for frequent and strong ENSO events.
关键词:sea surface temperature in the pacific,Interdecadal variability
摘要:Based on the NCEP-reanalyzed atmospheric data and COADS SST data for the recent 50 years, interdecadal oscillation of the atmospheric circulation over the North Pacific Ocean in winter and its related temporal and spatial variations of SST were examined. The results indicate significant interdecadal variability of the atmospheric circulation over the North Pacific Ocean with principal periods of 16-22 years. Before 1977, PNA indices were basically negative but positive after 1977, a turning point year of interdecadal variability. The temporal change revealed by the first mode (EOF1 of the interdecadal component of the atmospheric height over the Pacific Ocean in winter, showed that 1977 was the only turning point in the recent 50 years, while the spatial distribution is of typical NPDO structure-before/after 1977 the atmospheric potential height over the North Pacific Ocean was higher/lower. SST changes associated with interdecadal oscillation of atmospheric circulation over the North Pacific Ocean in winter to large extent are the SST interdecadal components themselves, i.e. air-sea interaction possesses selectivity in time scale.
摘要:The influence of Huanghe (Yellow) River Delta (HRD)changes on the tidal wave movement in its adjacent area was studied by using a 2D numerical model. Previous study (Le et al., 1995) showed that in modern times the HRD had silted up forward by 2530.4 km2 during the period 1855 to 1984. The changes of the Huanghe River Estuary (HRE) had significant influence on the tidal wave movement in the Bohai Sea. Due to the unceasing changes of the HRE in the past 100-odd years, some basic features of tidal wave movement have been varying with the HRD development. Although the tail of the Huanghe (Yellow) River (HR) has been relatively stable when the HR passes through the Qingshuigou Stream Outlet (QSO) since 1976, the HRD changes have influenced significantly the tidal wave movement. The main results from this study are as follows. (1) The regular diumal region off the HRD was the largest in 1855 and has been gradually decreasing since then. If the QSO keeps its tendency, it will probably vanish in the future. (2) The M2 and S2 amphidromic point locations and their corresponding amplitudes off St. Wuhaozhuang vary as the HRD develops. The locations of the M2 and S2 amphidromic points have been very close to the coast and their amplitudes have become bigger and bigger since 1855. The M2 amplitude at its amphidromic point location now is greater than 3 cm and the lacation slightly moved southeastward from 1976 to 1992. (3) The high speed region with probable maximum speed of > 120 cm/s varies with the development of the HRD from 1855 to 1976, but has not changed much since then. (4) It can be foreseen that if the QSO keeps on going its way for the coming decades, the amphidromic zones of constituents M2 and S2 will decrease gradually and even disappear. (5) It is noteworthy that the amplitued of diurnal constituent m1 along the northern coast of the HRD has slightly increased since the HR tail moved from the Diaokouhe Stream Outlet to the QSO in 1976.
关键词:tidal wave movement,Huanghe (Yellow) River Delta (HRD),Qingshuigou Stream Outlet
摘要:Sediment movement patterns control the stability of sandy seabed in three aspects: (ⅰ)the sediment edibility time and the thickness of the moving layer; (ⅱ)seabed accretion/erosion and their rate; and (ⅲ)seabed elevation changes in response to bedform (e.g. underwater dunes and tidal ridges) migration. These problems can be solved by the following procedures. Firstly, the sediment erodibility time and the rate of bed-load transport are calculated using an appropriate equation which takes into account the combined effect of waves and tidal currents. Secondly, the moving layer thickness and the accretion/erosion rate are estimated using the transport rate data. Finally, the information on the migration velocity of dunes/ridges and the resultant seabed elevation changes is obtained using the transport data and the geomorphic data of the bedform. As an example for its usage, we applied the method to the assessment of seabed stability over an area to the west of Hainan Island. The results show that the seabed material is highly mobile, with active sediment movement. The rate and amplitude of seabed elevation changes are both relatively large, in response to rapid bedform migration. These characteristics must be taken into account in the development of the natural resources of the region.
摘要:The origin of the Radial Sand Ridges in the southern Yellow Sea has been a controversial issue since they were discovered. The M2 tides and tidal currents over the Bohai Sea, Yellow Sea and East China Sea at present and at around 7000 a B. P., 6000 a B. P.,3800 a B. P., the 8th and 11th centuries A. D. were simulated with a two-dimensional tide model. The sediment transport field and sea bottom erosion-accretion pattern in the Paleo-Changjiang River Estuary and its adjacent area at the transgression maximum of Holocene were also calculated. The results showed that the radial tidal current field in the southern Yellow Sea has existed since at least the transgression maximum of Holocene, and is very stable. The formation and existence of the radial tidal current field has no relation to the local bottom topography and the Qianggang Bay outline. The radial tidal current field formed the Radial Sand Ridges in the southern Yellow Sea so they have tidal origin. At the transgression maximum of Holocene, sediment from the Paleo-Changjiang River filled the Paleo-Changjiang River Estuary, was the material source of the Changjiang Delta, and formed the primitive Radial Sand Ridges under the effects of tidal currents which transported sediments from sea to land. The formation of the Radial Sand Ridges in the southern Yellow Sea during the Holocene was mainly divided into five stages, and the inevitable result of the continental-oceanic interaction process in the area of the Changjiang Delta and northern Jiangsu littoral plain at a certain geological history stage.
摘要:The 1972, cutoff water flow in the lower course of the Huanghe river worsened day by day. In the 1970s, the time of the cut-off water flow was 8.6 days annually, in the 1980s, it was 10.5 days, in the first 6 years of the 1990s, it was 89.6 days, in 1977, it was 226 days, when the cut-off water flow was 704km. Large increase in the use of water volume for industry and agriculture in the Huanghe River basin was external cause for the cut-off water flow; However, deficient of water resources was basic reason or internal cause. In 1949, use of water for industry and agriculture is only 74 ×108 m3/a, but it increase to 300×108 m3/a in 1990s. The utilization ratio of the Huanghe River water resources is 60%, the first level in the world. 300×108 m3/a only account for 3.3% annual runoff in the Yantze River and 8.6% in the Pearl River but it is more than 1/2 of annual runoff in the Huanghe River. If preventive measures are not adopted, the situation of the cut-off water flow will worsen and be grimmer day by day. The situation of the cut-off water flow can be remedied by unified manage, proper allocate and conservation of the water resource in all basin, and adoption various cut-down water measures. However, allocation of water from the south to the north is the best method to resolve the problem of cut-off water flow and thus increase runoff o the sea and strengthen the construction of the ecological environment and enable sustainable use of the marine environment and resources in the Huanghe River estuary and adjacent sea area.
关键词:cutoff water flow;Huanghe River;large decrease of runoff
摘要:Excessive water drawn from a large number of dams and reservoirs built on the Huanghe Rivers main course caused cut-off of the water flow in lower course and decreased largely the discharged into the Bohai Sea. There are abundant wetlands and biological resources on the modem Huanghe River mouth delta. Marine biological resources are very rich in the Huanghe River estuary and adjacent sea area, The large decrease in the fluxes of water and sediment imputed into the sea and the cut-off of water flow will change greatly the marine ecological environment. For example, the delta coast will be strongly eroded by wave; the ecological environment of the wetland will degenerate; soil will change due to desertification; diluted water areas will disappear in the estuary; the influence of river water on the temperature of seawater will decrease greatly, nearcoast seawater will be characterized by high salinity, concentration of nutrients, such as phosphate, nitrate, silicate, in seawater will be decreased, etc. The balance of the ecological environment will be destroyed; and the tidal current distribution location of the amphidromic point of the M2 and high speed regions, etc. will change. All these affect greatly the sustainable use of the marine environment and resources in the Huanghe River delta and adjacent sea areas.
摘要:Input of huge quantities of sediment discharged to the sea and change of the lower course of the Huanghe River cause great changes in coastal and submarine geomorphology and sand movement. The sand spit on the Huanghe River mouth extended 40 km to seaward from 1976-1996. The sand spits extending velocity is 2.1 km/a at present, and its front is less than 50 km from the east and south coast of the Laizhou Bay. If it continuously extend for some ten years, this part of Laizhou bay will become a lagoon. By that time, the marine ecology environment will change largely and the Xiaoqinghe River mouth and adjacent harbor will be silted. Many ports have been built on the Huanghe River delta coast and adjacent areas. The continued extension of the river mouth spit, wrong choose of inlet position, untimely use of the rivers lower course, any and all of these will affect to construction of ports there. The Huanghe River changed its lower course and emptied into Laizhou Bay from the Qing 8 branch in Aug. 1996. When the lower course started to change, the inlets direction of the main axis was N81°30’E. However, two months later, it extended NW. Sandy sediment discharged from the Huanghe River transported along shore to NW and turbidity water with fine sediment reached the vicinity of Dongying Harbor. In order to decrease the influence of sediment discharged from the Huanghe River on coastal ports in the adjacent coast, it is necessary to scientifically choose the position of the inlet, correctly control the use time of the rivers lower course, and change the direction of inlet in due course.
摘要:A new concept, “Form of element in natural grain size sediments (FNG)”, was used studying the existence forms of phosphorous and silicon in five southern Bohai sea core sediments. FNG can yield the information which part of these biogenic matter contained in marine particulates can really participate in the cycling and what functions they have in the cycling, which ae two key issues dealt with in research on the cycling of marine biogenic elements. FNG provides a sound basis for research of transferable form biogenic elements contained in particulate matter.
In the studied southern Bohai Sea core sediments, P exists mainly in the form of organic matter, Si exists mainly in the form of carbonate-boned. Transferable phosphorus accounts for only 17.4% (about 1.7 μmol/g) of total phosphorus and transferable silicon accounts for 0.116% (about 11.9 μmol/g) total silicon in surface sediments, which show that only a small part of P and Si in sediments can participate in the biogeochemical processes. The transferable P and Si in natural grain size marine sediments are in leachable forms, different from previously known leachable P and Si obtained from total fine grain sediments.
The transferable forms of P and Si have clearly different characteristics because of rediagenesis in the total core sediments. In the deep layer of the core sediments, the stable forms can activate and become transferable forms. Therefore, the transferable P and Si in the deep layer are more than those in the shallow layers at some sites such as M9-5, M6-5, M9-12.
摘要:This paper reviews nitrogen cycling in marine sediments and consists of three parts:
1. Nitrogen Cycling Processes in Marine Sediments
(1) Nitrogen and primary production
Nitrogen regenerated from marine sediments can contribute largely to primary production. About 30%-80% of nitrogen consumed by phytoplankton is attributed to sediment mineralization and NH4+ (ammonium) is the preferred phase utilized. Benthic heterotrophic bacteria have a large impact on nitrogen cycling and can act as net N consumers sometimes.
(2) Early diagenesis and nutrients loss
Early diagenesis includes oxic and anoxic mineralization. Part of the regenerated NH4+ can be transformed into N2 by the nitrification-denitrification coupling, which leads to nutrient loss from the marine ecosystem. NH4+ adsorption in sediment is another pathway for nutrient loss.
(3) Nitrogen cycling and the controlling factors
NH4+ released from sediments can be assimilated by benthic organisms and diffuse to overlying water or be oxdized into NO3- (nitrate). The role of sediment as a source or sink for nitrogen in seawater is governed by the relative rates of ammonium, nitrate and N2 production. The nitrogen cycling process varies with time and space and the controlling factors includes: temperature, organic matter content, benthic bioturbation. etc.
(4) The formation and function of particulate nitrogen
PN (particulate nitrogen) is mainly formed biogenically. Amino acids account for 30%-60% of the organic nitrogen in particulates. PN can be mineralized or uptaken during sedimentation. The most attractive focus on PN is its function in the marine ecosystem food web.
(5) Nitrogen cycling and other biogenic element cyclings
Nitrogen cycling is in closely correlated with C and P cycling. The efficiency of N and P cycling increases with increased organic carbon loading in sediments. The atomic ratio of C, N, P in sediment deviates from the Redfield ratio of 106: 16: 1 and the former is a very important parameter in nitrogen cycling model construction.
2. Methods for nitrogen cycling research
Research on nitrogen cycling in marine sediments usually focuses on two aspects: nitrogen in sediment and nitrogen in porewater, on which much work has been done on the pore-water. The rates of mineralization, nitrification, denitrification and the exchange fluxes between sediment and overlying water can be measured. Acetylene (C2H2) inhibition technique and 15N tracer technique are most widely used. Analysis for sediment solid is not sufficient, only NH4+ adsorption concentration and total organic nitrogen can be measured.
3. Perspectives on nitrogen cycling research
It has been known that particulate size and organic matter composition in sediments can control nitrogen cycling significantly. So more attention should be paid to these two factors in further research.
Yan Xiaojun,Fan Xiao,Lou Qingxiang,Liu Xiaomei,Cui Yujun,Wu Zhenzhen,Lu Maosun
Vol. 8, Issue 43, (2001)
摘要:Carotenoids are one group of the most widespread and important pigments, and one of the major sources of natural carotenoids is seaweed. By chemical extraction, chromatography and spectroscopy, identification and quantification of carotenoids were carried out in various seaweeds, including Chlorophyta, Rhodophyta and Phaeophyta. It was demonstrated that carotenoid content in green algae is the highest, usually two or three times more than the other two. The structural analogs of carotenoids in green algae are also more variable than those in red and brown algae. The major carotenoids are zeaxanthin and lutein in green algae. zeaxanthin and violaxanthin in red algae, fucoxanthin and violaxanthin in brown algae. Among the seaweeds investigated, Codiumn fragile is the most potential resources for carotenoids with high content and structural variations. The chemical composition and contents of carotenoids could be used as possible markers of chemotaxonomy in marine algae.
关键词:marine algae;Carotenoids;solation and quantification
摘要:The ability of carotenoids to scavenge superoxide radicals in vitro was determined by pyrogallic acid autooxidation method. The results indicated that violaxanthin has the strongest superoxide radical scavenging activity, followed by β-carotene, β-cryptoxanthin, lutein and fucoxanthin. Combination experiments of carotenoids with vitamin E were also studied to show that β-carotene, zeaxanthin, or fucoxanthin could synergistically promote the superoxide radical scavenging activity of vitamin E.
By comparing the content and antioxidant activity of carotenoids, we hope to screen valuable species of seaweeds to further research on its physiological and pharmacological activities.
摘要:The research of marine anti-tumor drugs develops rapidly, and marine algae are kinds of unique potentially pharmaceutic materials and some of them can be cultivated. It is very important for exploiting and utilizing the resource of marine algae before studying marine drugs. This paper reviews the works on screening of anti-tumor substances in marine algae and the compounds with antitumor activities.
Different methods have been applied to evaluate the anti-neoplastic activities of marine algal extracts. Antitumor activities are determined by inhibiting KB human carcinoma cells, P388 lymphocytic leukemia or Ehrlich ascites tumor. They are also evaluated in a series of mechanism based anticancer screens, including protein kinase C (PKC), protein tyrosine kinase (PTK) and inosine monophosphate dehydrogenase (IMPDH).
About 70 compounds with anti-tumor activities from marine algae have been reviewed in this paper. Many of them are important, such as Halomon, which isolated from marine red alga Portieria hornemanni. More than 10 halomon-related anti-tumor monoterpenes have been identified and are useful in clinical experiment. Malynganide D is metabolites of Lyngbya majuscula, and it produces a highly cytotoxic profile against KB cells. Amphidinolid J is a cytotoxic macrolide from the marine dinoflagellate Amphiolonium sp. Other cytotoxic substances, such as okadaic acid, lyngbyatoxin A, debromoaplysiatoxin, hormothamnione, hormothamnin A, 15(28)-anhydrothysiferyl diacetate, 15-anhydrothysiferyl diacetate, magireol-A, magireol-B, magireol-C, caulilide, dexylapachol, dilopholide and caulerpenyne are also introduced.
摘要:Laminaria japonica was collected from the coast of Qingdao in April, 1995. Based on a first paper (determination of the content of organic iodine in seaweed, Acta Hydrobioloica Sinica,1999, 23(5): 489-493), the existing states and content of organic iodine in seaweed were investigated by paper chromatography and infrared spectrum. The result shows that iodine in Laminaria japonica occurs as organic iodo-compounds and inorganic iodine. The main organic iodo-compounds are amino-acids derivative and non-amino-acids derivative. 51% of total organic iodine compounds are iodo-amino acids and their main existing state is 3, 5-diiodotyrosine.
49%o of iodo-amino acids existed in free state amino acids and another 2% in combined state. Infra-spectrometry was used to confirm the structure groups of iodo-amino acids from fresh Laminaria japonica.
摘要:This article reports protection technology against damages to seawater refrigerating system and to seawater transporting pipeline, caused by seawater corrosion and marine biological filth. Two methods, seawater electrolysis method to prevent biological adhesion and applied current cathodic protection method to prevent corrosion by seawater, were cooperatively applied to the system under protection. These new technology and apparatus against corrosion by seawater and adhesion by biological filth were used to develop a monitoring, automatic corrosion control, and alarm system which not only solve the corrosion problem in the installation, transportation setup and seawater delivery pipe in the sea, but also provide monitoring, control and early warning alarm to the status of the protection system to ensure the safety of production. The principles and applications of the dual-protection system technology are also discussed.
摘要:Runoff from the Yellow River, the second largest in China, has historically nourished the fisheries resources in Laizhou Bay waters for a long time. However, a recent reduction in seasonal or annual outflow could lead to decline in nutrient flux and biological productivity. Our data from a series of comprehensive surveys in the above waters since 1982, showed that the 114 species of fish in the community were dominated by 66 warm-temperate species comprising 52.28% of total NED (Ecological Density of Number) and 57.06% of total BED (Ecological Density of Biomass). These fish averaging 14.48g, were much smaller than cold-temperate species. Therefore, the seasonal alteration in ecological density within the community could be differentiated into a November to next July cold group, characterized by abundant recruitment in estuarine waters, and an August to October warm group, characterized by congregation of maturing species for spawning. It was found that the spatial dynamics of e fish community in the studied area differed little among stations, and that numerical parameters were directly proportional to water depth. Although there were large seasonal variations in both species composition and ecological density in the fish community, japanese anchovy, Engraulis japonicus T. et. S, and hair-fin anchovy, Setipinna taty (V.) maintained and controlled the overall development of the nekton community in the waters.
摘要:The requirement for dietary lecithin for growth and survival in red sea bream (Pagrus major) larvae was tested using rotifers (Brachionus plicatilis) and Artemia with various levels of lecithin. Four treatments for rotifers and Artemia in the content of their lecithin were prepared by feeding them various oil emulsions respectively.
The results indicated that dietary lecithin significantly influence fish lecithin levels and are necessary for good growth and survival in red sea bream larvae. Under the experimental conditions, the optimal values of lecithin level in rotifers and Artemia were shown to be 324.19 mg/100g (wet weight) and 1048.75 mg/100g(wet weight) respectively for the best growth and survival in red sea bream larvae.
摘要:The specific activities of alkaline phosphatase in different digestive tissues in one-year-old pseudomale Paralichthys olivaceus were studied, and the enzyme activities in different stages were compared. The mean weights of the fish in Group I was 350±20g. The specific activities of alkaline phosphatase in foregut, midgut, hindgut, liver, and stomach were 0.097±0.015, 0.089±0.017, 0.068±0.011, 0.072±0.015, 0.037±0.0l6 (unit/(min?mg)).The mean weights of the fish in group was 460±30g. The specific activities of alkaline phosphatase in the foregut, midgut, hindgut, liver, stomach were 0.135±0.026, 0.128±0.019, 0.095±0.012, 0.101±0.017, 0.064±0.011 (unit/(min?mg)). From the results it can be concluded that the specific activities of alkaline phosphatase in different digestive tissues of pseudomale Paralichthys olivaceus are different. The specific activities of the alkaline phosphatase in the foregut and midgut are higher than those in other tissues, while the enzyme specific activity in the stomach is the lowest. Additionally, the enzyme activities in the liver and different parts of the gut of the fish in Group Ⅱ are higher than those in Group Ⅰ, while no significant difference was observed in the stomach.
摘要:The serum protein components of flounder, Paralichthys olivaceu were analyzed by capillary zone electrophoresis (CZE). Three kinds of proteins can be analyzed with current experimental conditions. Based on the time that these proteins appeared, they were named as Peak 2.59, Peak 1.60 and Peak 0.77. After storage at room temperature (25℃) for 24 hours, the protein Peak 2.59 remained stable, while the other two proteins were destroyed. Comparison of the results with those of the analysis of human beings serum, the protein Peak 2.59 is probably attributable to Albumin, the protein Peak 1.60 is probably attributable to Globulin-α, the protein Peak 0.77 is probably attributable to Globulin-β.
摘要:Electron microscopy examination of the ultrastructure of the peripheral blood cells of Paralichthys olivaceus showed that its blood cells were classifiable as erythrocytes (red cells) and leucocytes (white blood cells). The leucocytes were classifiable as lymphocytes, monocytes, thrombocytes and two types of granulocytes. A phagocyte-like leucocyte was observed in the peripheral blood too. The ultrastructure of these cells were described in details. According to the structure, no plasma cells were found in the peripheral blood.
摘要:12 Kinds of fishiries druges were tested to see the sonsitirity of the strain of hemorrhagic septicemia in Mugil So-iuy Basilewsky. The results showed that the efficiency of some kinds, such as norfloxacin, chloramphenicol and MZ+TMP. Were much stronger than those of others, the efficienty rates that 15-25 mg/kg and 20-30 mg/kg of norfloxacin separately prerented and controled the hemorrhagic septicemia in Mugic So-iuy, Basilewsky. Were all more than 80%, Norfloxacin's LD50 was 514.6 mg/kg in Mugil So-iuy, Basilewsky. The micronucleus test showed that norfloxacin didn't sharply cause the micronucleus rate of red celles. The efficienty rate of norfloxacin's controlling this disease was 89.5% and higher 42% on the testing pond than that of the control group of 47.5%
摘要:This study on the effect of 12L: 12D cycle and continuous light intensity (8000 lx, 4000 lx, 2000 lx 12h: 12h L D cycle and 4000 lx) on the total lipid content and fatty acid composition of three species of marine microalgae (Chlorella sp-2, Isochrysis galbana, and Amphidinium sp.) showed that the major fatty acids of Chlorella sp-2 were 16: 0, 16:1 (n-7) and 20:5 (n-3); those of Isochrysis galbana were 14:0, 16:0, 16:1(n-7), 18:4(n-3), and 22:6(n-3); and those of Amphidinium sp. Were 16:0, 18:1(n-9),18:4(n-3), 20:5 (n-3) and 22:6 (n-3). The total lipid contents of Chlorella sp-2 and Isochrysis galbana grown at higher light intensity were higher than those grown at lower light intensity. Generally, their percentage of the saturated and monounsaturated fatty acids increased with light intensity. The total polyunsaturated fatty acids decreased with increasing light intensity. EPA content decreased with increasing light intensity and the was no obvious changes in DHA as light intensity increased.
摘要:This is the second part of a study on Chinese Serpulidae. A total of 23 species, belonging to Pseudovermilia, Semivermilia, Serpula, Semiserpula, Spriobranchus and Vermiliopsis were reported. Among them 2 species are new to science, 7 species recorded for the first time from Chinese Waters, and one complex group. The type specimens of the new species are deposited in the Institute of Oceanology, CAS, Qingdao. A list of the species is given on page 1, in which those marked with an asterisk are recorded for the first time from China.
摘要:This is the third part of study on Chinese Serpulidae and Spirorbidae. A total of 24 species, belonging to Apomatus, Circiger, Ditrupa, Salmacina, Metavermilia, Pomatoleios, Pomatostegus and Protula of Serpulidae, and Circeis, Dexiospira, Duplicaria, Eulaeospira, Janua, Pileolaria and Simplicaria of Spirorbidae are identified. Among them 10 species are recorded for the first time from the Chinese Waters and 1 complex group Filograna/Salmacina dyster Huxley. A list of the species is given in which those marked with an asterisk are recorded for the first time from China.