Effect of organics (amino acids and fulvic acid) on the interaction between Cu(II) and clays in sea water

By the study of the effects of pH on the exchange ratio (%) of Cu(II) with clay(illite) in the presence of different concentrations of amino acids and fulvic acid, a new model of the mechanism of the effect of organics has been presented in this paper. Projects sponsored by the Natural Science Fund of the Chinese Academy of Sciences.     

Study on the isotherms of the interaction between suspended particles and Cu (II) in the Huanghe River

The isotherms of the interaction between the suspended particles and Cu²⁺, and the effects of lysine and asparaginic acid on the isotherms in the Huanghe (Yellow) River were studied by applying the theory and method of interfacial stepwise ion/coordination particle exchange. We obtained a new stepped river isotherm, formed by two curves joined together with a “plateau” in the middle. The adsorption equilibrium constantsK ₁ andK ₂ were calculated by using the isothermal equation of surface stepwise ion exchange. Amino acid in small amount promotes exchange adsorption of the suspended particles with Cu²⁺. The degree of promotive action relates to the isoelectric point of amino acid. The promotive effect of lysine is bigger than that of asparaginic acid. Project 29361001 supported by NSFC.     

The effect of amino acids on copper (II)-goethite ion exchange in seawater

In seawater, aside from metal elements and suspended particles, organic substances amount to about 500–2,000 ug carbon/l^[8], which is not neglegible in comparison with that of minor metal elements. But in the study of the interaction of the three constituents (metal elements, organics, and suspended particles), the effect of organics in seawater on the surface reaction of metal element—suspended particles has usually been neglected. Recent theoretical research^{[1, 11]} confirmed the importance of the effect of organics in seawater on the surface reaction of metal element—suspended particles. Generally, the effect of organics on the reaction of metal ions, especially Cu(II), on a solid surface is either promotive^[2] or inhibitive^{[7, 9]}. So far the fact that organics cannot affect the surface reaction of Cu(II) ions on solids has not been reported in literature. Our experimental results showed that none of the amino acids in seawater affect Cu(II)-goethite ion exchange under certain experimental condition (such as amino acid of lower concentration and lower pH). It was known that the metal ion-organics complex in a liquid competing with solids for metal ions may inhibit the surface reaction of metal ions on solids, but the mechanism of the complex reaction of metal ions competing with solids is not known yet. In fact, the decrease of surface site-exchanging due to the surface reaction of organics on solids is also inhibitive. It is also explained by the ion exchange isotherm of the “amino acid-Cu(II)-geothite” system. This result further demonstrates that the theory of interfacial stepwise ion exchange is applicable to the metal ion exchange isotherm with the presence of organic substances in the system. Projects supported by the Science Fund of the Chinese Academy of Sciences     

Investigation on the interaction between trace metals and humic acid in seawater

The interactions between trace metals and humic acid in seawater influence the metal species distribution and the various geochemical pathways. An approach for investigating these interactions based on stripping polarography is proposed. The basic principle is that the half-wave potentials of the stripping polarogram shift negatively with the increase of concentrations of humic acid. From the results of calculation, it may be concluded that the species of Pb-HA complex is less than 5% of total lead in seawater but has significant percentage in estuary, and that Pb-HA complex exists mainly as 1∶1 form. Contribution No. 1509 from the Institute of Oceanology, Academia Sinica     

Effect of water depth on wind-wave frequency spectrum II. Verification and comparison

The spectrum derived in Part I of the present paper is here systematically verified with field data and compared at some length with that obtained by multiplying the deep-water spectrum with the Kitaigorodskii factor. Project supported by the National Natural Science Foundation of China.     

Development of fatty acid biomarkers for the identification of wild and aquacultured sea cucumber (Apostichopus japonicus)

In this study,the fatty acids(FAs) of the organs and tissues of sea cucumber(Apostichopus japonicus) were profiled in order to compare the FA composition of sea cucumber collected from natural habitat(wild) and cages(cultured).The differences in FA contents in dermomuscular tube,peripharyngeal annulus,gonad and intestine(with or without content) between the wild and the cultured were determined.The main fatty acids in all organs and tissues were 20:5n-3,16:1n-7,20:4n-6,22:6n-3,18:0,and 18:1n-7.The basically different FAs of body wall and digestive tube were 16:1n-7,18:1n-9 and 20:1n-11.The ratio of saturated to mono-and polyunsaturated FAs in digestive tube was independent on inside content while there was a redistribution of the total amount of n-3 and n-6 fatty acids.The comparison of FA composition of the wild and the cultured sea cucumber showed that 20:5n-3,16:1n-7 and 18:1n-7 predominated the wild while 20:4n-6 predominated the cultured.The content of branched-chain fatty acids in the wild was 3%–4% and about 9% in the cultured.The possible FAs for identifying the wild and the cultured sea cucumbers were selected.It was suggested that the indexes such as the ratio of either(n-3:n-6) to(n-7:n-6) or(n-3) +(n-7) to(n-6) may serve as the biomarkers distinguishing the wild and the cultured sea cucumber.     

Controlling mechanisms for the trace metals, (Cu,Zn, Cd,Fe, Co and Ni) in anoxic sea water in Saanich Inlet,British Columbia,Canada

A study was conducted on Cu, Zn, Cd, Fe, Co and Ni levels in Saanich Inlet anoxic seawater. Data on the concentration of these trace metals and H₂S, and other oceanographic parameters were obtained in four cruises. Equilibrium models are presented together with in situ data. The results strongly support the assumption that the solubilities of Cu, Zn, Cd, Fe, Co and Ni are controlled by bisulfide and/or polysulfide complexes. The species of Cu, Zn, Cd and Ni are shown to be Cu(S₄) ₂ ³⁻ and Cu(Sn₄S₅)³⁻, Zn(HS) ₂ ⁰ and ZnHS ₂ ⁻ , Cd(HS) ₂ ⁰ and Ni(HS) ₂ ⁰ , respectively. The solid species controlling Fe²⁺ and Co²⁺ are respectively the pyrohotites FeS and CoS. The data illustrates that thermodynamic equilibrium has been established in the H₂S-controlled seawater of Saanich Inlet, and that equilibrium has not been established in the H₂S−O₂-coexisted seawater of Saanich Inlet. The lack of equilibrium in the H₂S−O₂-coexisted seawater is a result of the flushing or mixing of oxygenated seawater with anoxic water. The new species of trace metals are still in the processes of reduction and precipitation. Contribution No. 1428 from Institute of Oceanology, Academia Sinica     

Effect of shrimp (Litopenaeus vannamei) farming waste on the growth,digestion, ammonium-nitrogen excretion of sea cucumber (Stichopus monotuberculatus)

In this study, specific growth rate (SGR), ingestion rate (IR), food conversion ratio (FCR), apparent digestion ratio (ADR) and ammonium-nitrogen excretion were determined for sea cucumber (Stichopus m...     

Effect of Bacillus baekryungensis YD13 supplemented in diets on growth performance and immune response of sea cucumber (Apostichopus japonicus)

The effect of a potential probiotic on the growth performance and immune response of sea cucumber(Apostichopus japonicus) was investigated. Bacillus baekryungensis YD13 isolated from sea cucumber culturing ponds was added to sea cucumber basal feed as a probiotic in different doses(0, the control; 1×104(YD134), 1×106(YD136) and 1×108(YD138) CFU g-1 of diet), and administered orally to A. japonicus(initial mean wet weight 5.44 g ± 0.17 g). The sea cucumbers were fed in 20 aquaria, 5 each treatment, for 60 d. At the end of growth trial, 20 sea cucumbers from each treatment were challenged with Vibrio splendidus. A. japonicus in YD134 and YD136 exhibited significantly better growth performance than control(P 0.05). Five non-specific immune parameters including lysozyme, acid phosphatase, alkaline phosphatase, superoxide dismutase and catalase in coelomic fluid were measured to evaluate the immune response of A. japonicus to the probiotics. Results showed that all parameters were significantly improved when YD11 was supplemented in the dose of 1×106 CFU g-1(P 0.05). The cumulative incidence and mortality after the Vibrio splendidus challenge decreased significantly in sea cucumbers of YD136. Accordingly, 1×106 CFU g-1 of YD13 in diet was recommended for the growth promotion and immune enhancement of A. japonicus.     

Effect of n-3 HUFA levels in rotifers and Artemia on growth and survival of larval black sea bream （Sparus macrocephalus）

Requirement for dietary n-3 HUFA (n-3 highly unsaturated fatty acid) for growth and survival of black sea bream (Sparus macrocephalus) larvae was studied using rotifers and Artemia at various levels of n-3 HUFA. Five treatments with rotifers and Artemia differing in n-3 HUFA were prepared by enriching them with various oil emulsions. Results indicated that dietary n-3 HUFA significantly influence fish n-3 HUFA levels and are essential for growth and survival of black sea bream larvae. The results also indicated that the incorporation of n-3HUFA TG (triacylglycerols) into tissues of larval black sea bream was more effective from natural fish oil in comparison with n-3 HUFA fatty acid ethyl esters from ethyl-esterified oil.     

SIUDIES ON THE BIOCHEMICAL COMPOSITION,ENERGETICS AND ESSENTIAL AMINO ACIDS OF THREE MUDSKIPPERS IN XIAMEN HARBOUR

Measurements were made on the contents of protein,lipid,glycogen(PLG)and water,and on caloric values and amino acids,in muscle of three mudskippers periophthalmus cantonensis,Scarteiaosviridis and Boleophthalmus pectinirostris collected from Haicang,Xiamen.The essential amino acids(EAA)for these fishes were also studied with radioisotopic trace method.The results showed:(1)Thecontent of each component in tested fish muscles differed slightly,and protein was the most importantcomponent making up from 6.685% to 9.891% of the wet weight (about 44.21%-50.45% of dryweight);(2)Energy calculated from the sum of protein, lipid and glycogen in wet muscle was low (<4.3kJ/g) in these Fishes, especially in B. pectinirostris(<3.1 kJ/g), the ratios of energy to protein content (E/P) also were low(<39.873-45.535kJ/g), (3)Seventeen amino acids were determined in thesethree fishes.The content of the same amino acid(among the seventeen) tested in different species andsexes varied slightly.The amounts of methionine, phenyl     

Effect of high temperature on the balance between photosynthetic light absorption and energy utilization in Chlorella pyrenoidosa (Chlorophyceae)

Chlorella pyrenoidosa(Chlorophyceae) is widely cultured for production of health food and animal feed. In outdoors, mass cultivation of C. pyrenoidosa often suf fers from high temperature. A better understanding of the ef fects of high temperature on photosynthesis and photoprotection can help optimize the productivity of C. pyrenoidosa cultures. In this study, we investigated ef fect of high temperature(35, 38, or 41℃) on the balance between photosynthetic light absorption and energy utilization of C. pyrenoidosa. In contrast to 30℃, higher temperature of 35 or 38℃ did not inhibit the growth of C. pyrenoidosa. Treatment in 35℃ maintained the balance. Moreover, the PSI acceptor side in 38℃ was over-reduced and PSII reaction centers were over-excited under strong light, which destroyed the balance and generated active oxygen species(AOS). However, the activated antioxidant enzymes might remove completely the over-production of AOS, thereby protect C. pyrenoidosa cells from photodamage. It shows that this C. pyrenoidosa strain could tolerate as high as 38℃. Furthermore, treatment in 41℃ resulted in more lack of the balance than that in 38℃. However, the activities of antioxidant enzymes stopped increasing in 41℃, and were not strong enough to remove the excess AOS. Therefore, treatment in 41℃ could decrease the growth of C. pyrenoidosa. In addition, strong and longtime light exposure would cause serious photodamage to C. pyrenoidosa cells.     

Preliminary results on relationship between thermal diffusivity and porosity of sea ice in the Antarctic

The in situ sea-ice temperature, salinity and density observed from Chinese Antarctic Zhongshan Station have been applied to calculate the vertical profile of sea ice porosity. Based on numerical method, a number of schemes on sea-ice thermal diffusivity versus porosity have been accessed and one optimized scheme is identified by an optimal control model with an advanced distributing parameter system. For simplicity, the internal heating source item was neglected in the heat conduction equation during the identification procedure. In order to illustrate the applicability of this identified scheme, the vertical ice temperature profiles have been simulated and compared with measurements, respectively by using identified scheme and by classical thermodynamic formulae.The comparisons indicated that the scheme describing sea-ice thermal diffusivity and porosity is reasonable. In spite of a minor improvement of accuracy of results against in situ data, the identified scheme has a more physical meaning and could be used potentially in various applications.     

Studies on the phosphorus requirement and proper calcium/phosphorus ratio in the diet of the black sea bream (Sparus macrocephalus)

An expriment on the phosphorus requirement and the proper Ca/P ratio in the diet of the black sea bream using the phosphorus gradient method (with casein as basic diet, sodium dihydrogen phosphate as source of phosphorus, and calcium lactate as source of calcium) showed that growth was greatly affected by the diet's phosphorus content and Ca/P ratio. Inadequate phosphorus in the diet resulted in slow growth and poor food conversion ratio (FCR). Analyses of the fish body showed it contained a high level of lipid but a low level of moisture, ash, calcium and phosphorus. The optimal values of phosphorus and Ca/P ratio in the black sea bream diet are 0.68% and 1∶2 respectively. Phosphorus in excess of this optimum value resulted in slow growth or even death. The results of this experiment clearly indicated that phosphorus is the principal mineral additive affecting black sea bream growth. Contribution No. 1972 from the Institute of Oceanology, Academia Sinica.     

Effects of Pseudoalteromonas sp. BC228 on digestive enzyme activity and immune response of juvenile sea cucumber (Apostichopus japonicus)

A marine bacterium, Pseudoalteromonas sp. BC228 was supplemented to feed in a feeding experiment aiming to determine its ability of enhancing the digestive enzyme activity and immune response of juvenile Apostichopus japonicus. Sea cucumber individuals were fed with the diets containing 0(control), 105, 107 and 109 CFU g-1 diet of BC228 for 45 days. Results showed that intestinal trypsin and lipase activities were significantly enhanced by 107 and 109 CFU g-1 diet of BC228 in comparison with control(P 0.01). The phagocytic activity in the coelomocytes of sea cucumber fed the diet supplemented with 107 CFU g-1 diet of BC228 was significantly higher than that of those fed control diet(P 0.05). In addition, 105 and 107 CFU g-1 diet of BC228 significantly enhanced lysozyme and phenoloxidase activities in the coelomic fluid of sea cucumber, respectively, in comparison with other diets(P 0.01). Sea cucumbers, 10 each diet, were challenged with Vibrio splendidus NB13 after 45 days of feeding. It was found that the cumulative incidence and mortality of sea cucumber fed with BC228 containing diets were lower than those of animals fed control diet. Our findings evidenced that BC228 supplemented in diets improved the digestive enzyme activity of juvenile sea cucumber, stimulated its immune response and enhanced its resistance to the infection of V. splendidus.     

Effect of n?3 HUFA levels in rotifers and Artemia on growth and survival of larval black sea bream ( Sparus macrocephalus )

Requirement for dietary n−3 HUFA (n−3 highly unsaturated fatty acid) for growth and survival of black sea bream (Sparus macrocephalus) larvae was studied using rotifers andArtemia at various levels of n−3 HUFA. Five treatments with rotifers andArtemia differing in n−3 HUFA were prepared by enriching them with various oil emulsions. Results indicated that dietary n−3 HUFA significantly influence fish n−3 HUFA levels and are essential for growth and survival of black sea bream larvae. The results also indicated that the incorporation of n−3HUFA TG (triacylglycerols) into tissues of larval black sea bream was more effective from natural fish oil in comparison with n−3 HUFA fatty acid ethyl esters from ethyl-esterified oil. Project No. 39770588 supported by the NSFC.     

Studies on the optimum protein content and the ratio of animal to plant protein in the diet of the black sea bream (Sparus macrocephalus)

An experiment on the optimum dietary protein content for the black sea bream using semi-purified diets showed the optimum is 50.19% by weight as inferred from the growth rate and food consumption of the fish. Another experiment on the proper ratio of animal to plant protein in its diet using sandeel as the animal protein source and peanut cake meal as plant protein source showed that the ratio had great effect on its growth and should be 1.00: 0.89–0.96 as judged from the growth rate and food consumption of the fish. Contribution No. 1973 from the Institute of Oceanology, Chinese Academy of Sciences.     

EFFECT OF FUTURE SEA LEVEL RISE ON DISASTROUS FLOODS IN THE TAIHU LAKE LOWER REACH DEPRESSIONS AND COUNTERMEASURES

Use of numerical simulation of the tidal flow of the Changjiang River Estuary and the HuangpuRiver to forecast flood in the Taihu Lake lower reach drainage system for the case of future sea level riseof 0.4 m and 0.8 m,and floods preventing and reducing methods are discussed in this paper.     

温度对禾谷缢管蚜生长发育和繁殖的影响

在人工气候室不同温度下研究了禾谷缢管蚜（RhopqlosiphumPadi（Linnaeus））的生长发育和繁殖。结果表明在10～30℃范围内．随着温度的升高,禾谷缢管蚜的发育速率加快,到一定温度之后又随温度升高而减慢;在25．4℃时,rm值最大为0．4196;在25℃时的种群出生率最高。当种群达稳定状态后,若蚜的比例在25℃时最小,占73．5％,而成蚜的比例最大,达26．4％;随着温度的升高,禾谷缢管蚜的产仔期变短,产仔量减少．但产仔峰值加大,峰值来临时间提前。同时还对极端温度对禾谷缢管蚜存活的影响进行了系统测定。     

A numerical study on water diversion ratio of the Changjiang (Yangtze) estuary in dry season

We studied the flood, ebb and tidal averaged along (net) water diversion ratio (WDR) during dry season in the Changjiang (Yangtze) estuary, China, along with the effects of northerly wind, river discharge, tide and their interactions on WDR using the improved version of three-dimensional numerical model ECOM. Using data for annual mean wind speed and river discharge during January, we determined that the flood, ebb, net WDR values in the North Branch of the estuary were 3.48%, 1.68%, −4.06% during spring tide, and 4.82%, 2.34%, −2.79% during neap tide, respectively. Negative net WDR values denote the transport of water from the North Branch into the South Branch. Using the same data, the corresponding ratios were 50.09%, 50.92%, 54.97%, and 52.33%, 50.15%, 43.86% in the North Channel and 38.56%, 44.78%, 103.96%, and 36.92%, 43.17%, 60.97% in the North Passage, respectively. When northerly wind speed increased, landward Ekman transport was enhanced in the North Branch, increasing the flood WDR, while the ebb WDR declined and the net WDR exhibited a significant decrease. Similarly, in the North Channel, the flood WDR is increased, the ebb WDR reduced, and the net WDR showed a marked decrease. In the North Passage, the flood WDR also increased while the ebb and net WDR declined. As the river discharge increased, the flood and ebb WDR of the North Branch increased slightly and the net WDR increased markedly. In the North Channel the flood and ebb WDR changed very slightly, while the net WDR declined during spring tides and increased during neap tides. The WDR in the North Passage changed slightly during flood and ebb tides while the net WDR showed a marked increase. The WDR values of different bifurcations and the responses to northerly wind, river discharge, and tide are discussed in comparison with variations in river topography, horizontal wind-induced circulation, and tidal-induced residual current.