盐度、pH变化对凡纳滨对虾鳃丝Na+-K+-ATPase活力的影响

本文研究了盐度、pH变化对凡纳滨对虾(Litopenaeus vannamei)鳃丝Na -K -ATPase活力的影响.结果表明:盐度、pH变化对凡纳滨对虾鳃丝Na -K -ATPase活力的影响显著(F》F0.01).在盐度变化(30→5)3d内,各处理组鳃丝Na -K -ATPase活力随着处理时间的增加逐渐升高;至3～15d时,不同盐度下鳃丝Na -K -ATPase活力趋于稳定,与对照组相比酶活力明显升高(F》F0.05),而且盐度越低酶活力越大.在pH变化(7.0←8.0→9.5)3d内,各处理组鳃丝Na -K -ATPase活力随着处理时间的增加呈峰值变化,表现为向低pH和向高pH变化分别于9h和12h达到最大值,至3d时均恢复正常;在pH变化3～12d内,不同pH环境下鳃丝Na -K -ATPase活力无明显差异(F《F0.05).     

3种海洋赤潮微藻抗氧化酶活性对UV-B辐射增强的响应

利用生物化学的方法,研究了赤潮异弯藻、亚历山大藻和中肋骨条藻抗氧化酶活性对UV-B辐射增强的响应变化。结果表明:(1)不同赤潮微藻的抗氧化酶活性对UV-B辐射增强的响应变化是不同的。(2)不同的抗氧化酶活性对UV-B辐射增强的响应变化同样存在明显的差异。(3)与过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)相比,超氧化物歧化酶(SOD)活性对UV-B辐射增强的响应最敏感,谷胱甘肽过氧化物酶(GPX)活性的响应变化最不明显。3种赤潮微藻SOD活性的变化是指示UV-B辐射增强的优选生物学指标。     

氟苯尼考对菲律宾蛤仔抗氧化酶活性的影响

通过室内模拟实验研究了氟苯尼考对菲律宾蛤仔体内超氧化物歧化酶(SOD),过氧化氢酶(CAT),过氧化物酶(POD)和谷胱甘肽还原酶(GR)活性的影响.结果表明,培养7 d后,在氟苯尼考的作用下,菲律宾蛤仔内脏团和肌肉组织的SOD,CAT,POD和GR的活性都发生了变化.低质量比氟苯尼考对SOD,CAT和POD酶活性具有诱导作用,而在高质量比条件下则表现为抑制作用.不同质量比的氟苯尼考对菲律宾蛤仔内脏团和肌肉组织中的GR活性都有明显的抑制作用,且随着氟苯尼考质量比的增加抑制作用加强.     

塔玛亚历山大藻对罗非鱼肝及鳃组织ATP酶活性的影响

研究了罗非鱼(Tilapia mossambica)腹腔注射塔玛亚历山大藻(Alexandrium tamarense)毒素粗提液对鳃及肝组织的Na^ -K^ -ATPase活性的影响。结果显示低浓度毒素粗提液对罗非鱼鳃及肝组织Na^ -K^ -ATPase有激活作用,高浓度则有抑制作用。     

福建沿海米氏凯伦藻赤潮对皱纹盘鲍鳃组织抗氧化酶活性的影响研究

本文初步研究了在较低赤潮密度(低于107个/m L)下,一株米氏凯伦藻(Karenia mikimotoi)对皱纹盘鲍(Haliotis discus hannai)鳃内几种抗氧化酶,如超氧化物歧化酶(Superoxide dismutase,SOD)、过氧化氢酶(Catalase,CAT)、谷胱甘肽过氧化物酶(Glutathione peroxidase,GSH-Px)的毒性效应,以期分析米氏凯伦藻对鲍鱼生命活动可能的胁迫方式。研究表明,米氏凯伦藻对SOD、CAT酶活性均造成不利影响,并未对GSH-Px酶造成不利影响,其酶活性显著高于对照组。米氏凯伦藻对SOD酶活性的影响表现为"先诱导后抑制"效应,24 h内,各处理组(0.1个/m L,0.5个/m L,1.0×104个/m L)中,酶活性急剧增高,分别是对照组的1.2,1.3,1.3倍,之后酶活性迅速下降,分别是对照组的77%,77%,73%。SOD能够清除机体体内多余的自由基,其活力变化反映了机体抵制自由基损伤能力已受到明显抑制。此外,米氏凯伦藻处理组中,CAT酶活性则处于"被抑制"状态,48 h内酶活性持续下降,分别降低至对照组的58%,51%,37%。CAT可以清除SOD歧化超氧阴离子自由基产生的H2O2,其活力的下降也可能造成机体内过氧化物的累积及氧化损伤。结果表明,即使未达到较高赤潮密度(不超过107个/m L)时,米氏凯伦藻短时间内仍可对鲍鱼鳃内关键抗氧化酶活性造成显著抑制效应,这极有可能导致鲍鱼机体抗氧化系统遭受严重损伤。     

中肋骨条藻与微小亚历山大藻间的他感作用研究

在f/2全营养培养条件下,采用共培养以及滤液交叉培养的方法研究了中肋骨条藻(Skeletonema costatum)和微小亚历山大藻(Alexandrium minutum)之间的竞争作用,结果表明: 微小亚历山大藻指数生长后期的无藻细胞滤液对中肋骨条藻的生长没有抑制作用,但中肋骨条藻滤液明显抑制了微小亚历山大藻的生长,且抑制作用随着中肋骨条藻滤液比例的增大而增大,他感作用是影响这两种微藻间竞争的重要方式之一;通过向培养基中添加自他感物质标准品15S-hydroxy-5Z,8Z,11Z,13E,17Z-eicosapentaenoic acid (15(S)-HEPE)考察其对中肋骨条藻自身以及微小亚历山大藻生长的影响,发现15(S)-HEPE在中肋骨条藻滤液中并不是能够抑制微小亚历山大藻生长的他感物质,今后应进一步深入分析中肋骨条藻释放的抑制微小亚历山大藻生长的他感物质。     

不同粒径TiO_2颗粒对海洋微藻的毒性效应

本实验以新月菱形藻为受试生物,研究了低浓度不同粒径TiO2颗粒(21nm、60nm和400nm)对海洋微藻生长、抗氧化酶活性(超氧化物歧化酶SOD、过氧化氢酶CAT和过氧化物酶POD)、脂质过氧化产物(MDA)含量的影响,并测定了相应的活性氧自由基(ROS)的含量,初步探讨了TiO2颗粒对海洋微藻的作用机制。结果表明,1mg/L TiO2颗粒对新月菱形藻生长的抑制作用随着粒径的减小而逐渐增强,第48h、72h、96h呈现出显著的纳米效应。TiO2颗粒可以诱导藻细胞内ROS的含量增加,对藻细胞产生氧化胁迫,新月菱形藻的抗氧化酶活性发生应激响应,以清除过量的ROS,但剩余的ROS对藻细胞产生氧化损伤,导致MDA含量升高,并且纳米级TiO2颗粒对新月菱形藻的氧化损伤大于微米级颗粒。在不同粒径TiO2颗粒的胁迫下,藻细胞SOD和CAT活性的响应也存在差异。本研究将为开展人工纳米材料对海洋生态系统影响的潜在风险评估提供科学依据。     

不同氮源对微小亚历山大藻生长和毒素产生的影响

通过尿素、氯化铵、酵母浸出粉和硝酸钠等氮源对微小亚历山大藻(Alexandrium minutum)生长及毒素产生的影响研究,分析了微小亚历山大藻对不同氮源利用状况的差异.结果表明,在氮饥饿条件下,加入硝酸钠和酵母浸出粉能显著促进微小亚历山大藻的生长;高浓度的氯化铵在加入后对微小亚历山大藻有一定的毒性效应,表现为生长停滞,但毒性效应在5 d后消失,并得到与添加硝酸钠及酵母浸出粉相似的增长速率0.21 d-1;添加尿素对微小亚历山大藻的生长没有显著促进作用.在四种氮源中,尿素对微小亚历山大藻毒素产生的刺激作用也最弱,在稳定期每个细胞藻细胞毒素含量维持在6.00~8.00 fmol;添加硝酸钠、氯化铵和酵母浸出粉的藻细胞在稳定期毒素含量分别达到11.85,12.86和14.64 fmol.硝酸钠和氯化铵刺激藻毒素产生的效果比酵母浸出粉更为直接.四种含氮营养盐对微小亚历山大藻毒素组成的影响都很小.     

不同类型含磷营养物质对微小亚历山大藻(Alexandrium minutum)生长和毒素产生的影响

采用显微镜细胞计数和麻痹性贝毒的高效液相色谱分析方法,通过对比磷酸二氢钾、磷酸甘油和三磷酸腺苷（ATP）等含磷营养物质对微小亚历山大藻生长和毒素产生的影响,研究了微小亚历山大藻对不同类型含磷营养物质的利用情况.结果表明,在磷限制条件下,加入磷酸二氢钾、磷酸甘油和ATP均能促进微小亚历山大藻的生长,所获得的最大藻细胞密度分别为22700、28400和27800藻细胞/ml,对数期生长速率分别为0.12/d、0.14/d和0.15/d,溶解态有机磷对藻生长的促进作用稍好于溶解态无机磷.三种含磷营养物质对毒素产生的效应没有明显差别,稳定期藻细胞毒素含量分别为22.87、23.98和21.80fmol/cell.磷限制对毒素组成的影响很大,磷限制条件下膝沟藻毒素GTX1/4的含量占绝对优势,GTX2/3含量很少.在添加含磷营养物质后,GTX1/4所占比例降低,GTX2/3比例增加,说明磷限制显著改变了微小亚历山大藻的毒素组成.对藻体碱性磷酸酶活性分析的结果显示,磷限制组具有最高的碱性磷酸酶活性,添加有机磷化合物实验组的碱性磷酸酶活性显著高于添加无机磷化合物的实验组.研究结果表明,微小亚历山大藻可以利用实验中采用的无机磷化合物和有机磷化合物,但其利用溶解态有机磷化合物的机制尚不清楚,可能是通过诱导合成碱性磷酸酶来水解培养基中的溶解态含磷有机物,从而释放无机磷酸盐用于藻细胞的生长.     

改性粘土絮凝法对小球藻(Chlorella vulgaris)生理生化性质的影响

改性粘土治理赤潮生物的主要原理是絮凝作用,但水体中未被去除的微藻对改性粘土有怎样的生理生化响应尚不清楚。本文以小球藻(Chlorella vulgaris)为模式生物,考察了改性粘土絮凝后水体中残余小球藻生理生化性质的变化情况。研究发现,经改性粘土或原土絮凝后,残余小球藻的生长受到了明显抑制,其丙二醛(malondialdehyde,MDA)含量迅速上升,改性粘土组的MDA含量高于原土组。除了原土组过氧化氢酶(catalase,CAT)活性相比对照组没有明显变化外,改性粘土组和原土组超氧化物歧化酶(superoxide dismutase,SOD)、CAT、抗坏血酸过氧化物酶(ascorbate peroxidase,APX)和谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-PX)等酶活,均呈现先上升后下降、并稳定在较高水平的变化趋势。原土组各酶活普遍低于改性粘土组,但GSH-PX活性则相反。结果表明,改性粘土不仅能高效去除水体中的小球藻,而且能够刺激残余的藻细胞积累较多的O2-·和H2O2,从而对藻细胞造成过氧化伤害,抑制未被去除部分海洋微藻的正常生长。     

Model of the post-Cenozoic evolution of the cryolithozone of the shelf of the western part of the Laptev Sea

The analysis of the structure of the cryolithozone, facies, and thicknesses of the Quaternary sediments and the results of the physicochemical mathematical modeling of the modern shelf of the western part of the Laptev Sea support the influence of the Late Pleistocene glaciations on the heat conditions and the distribution of the permafrost in the area. A ～200-m thick glacier formed under aerial conditions from atmospheric precipitation represented the metamorphosed snow cover. According to the modeling, the long-living (from 60?50 to 10?4 ky) glacier reduced the thickness of the permafrost rocks in the reviewed shelf area for 280–360 m. The Holocene marine transgression additionally decreased the thickness from 50–140 m on the inner shelf to 220–350 m on the outer shelf. The modern submarine cryolithozone 450-0 m thick is wide-spread in the studied region from the coast to the shelf boundary (isobaths of 130–140 m), where it pinches out at a distance of ～380 km from the coast at a depth of ～250 m above the sea level.     

Investigation of the mechanism of the long-term evolution of the carbon cycle in the ecosystem of the Sevastopol bay

We analyze the components of the carbon system of the Sevastopol bay waters and the balance of main sediment-forming substances using the data of field investigations in 1998–2008. The interannual variations of total inorganic carbon and the equilibrium partial pressure of carbon dioxide in the bay water are noted. An increase in the flux of carbon dioxide into the bay and in the content of organic carbon in bottom sediments is revealed, and an explanation of this phenomenon is given. The priority accumulation of organic carbon in the sediments of the bay is established. We assess the interannual variation in the relative abundances of organic and inorganic carbon as an index of the carbon cycle stability.     

Contemporary state of the investigation of the influence of the discharge of rivers on the hydrologic structure of the Black Sea

We generalize and analyze the state of investigations of the influence of river waters on the hydrologic structure of the Black Sea. Specific features of the water, regime and hydrography of rivers flowing into the sea, data on the discharge of rivers, and intrayear and interyear variability of the discharge are presented. We discuss and analyze works studying the transformation of river waters, routes of desalinized sea waters, and their influence on the thermohaline structure and dynamic regime of the sea. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

Modelling of the ecosystem of the Black-Sea shelf zone near the estuary of the Danube

We analyze the results of numerical calculations performed according to the three-dimensional interdisciplinary model of an ecological system of the Black-Sea shelf zone near the estuary of the Danube. The complete system of equations of hydrothermodynamics is solved together with transport equations of the advection-diffusion-reaction type used to describe the transformation of a substance (nitrogen) between the components of the characteristic vectors of the ecosystem: plankton, detritus, and biogenic elements (nitrates). We describe the distinctive features of the circumcontinental distribution of components obtained as a result of numerical experiments and present arguments for the conclusion that the ecosystem of the Danube estuary water area plays the role of a buffer zone between the press of the Danubian biogenic pollutions and the neighbouring areas of the shelf zone and open sea. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

Dynamics of the ice cover and peculiarities of the ice transportation of the sediments at the tidal flats of the Kandalaksha Gulf of the White Sea

Ten years of semistationary studies of the interaction of the ice cover and the coastal relief of the Kandalakhsa Gulf in the White Sea allowed us to reveal the peculiarities of these processes in the warm and cold years and the mechanisms of the origination of ice forms, including ice tents, which govern the character of the tidal flats. Three dynamic fast ice zones are distinguished by their geomorphological location, morphology, and ice dynamics. The dependence of the mechanisms and volumes of the enrichment of the fast ice in the sediments on the coastal zone??s relief was established. At the coast of the Kindo Peninsula (Velikaya Salma Strait), the ice mostly contains fine-sandy sediments. Coarser sediments, including boulders, are occasional and frozen into the ice at the contact of the fast ice and the bottom. At the expense of the ice??s spreading by 4?C6 times in the warm years and 2?C4 times in the cold years, several thousand tons of sediments mostly from the tidal flat??s surface (100?C700 m³ from 1 km of coast in the wide tidal flats and <50 m³ on the steep coasts) are delivered to the water area.     

Relationship between the path of the Kuroshio in the south of Japan and the path of the Kuroshio Extension in the east

A relationship between paths of the Kuroshio and Kuroshio Extension (KE) is investigated, using the satellite-derived altimetry dataset of 1993–2008. When the Kuroshio takes the nearshore nonlarge meander path or typical large meander path and resultantly goes through the deeper channel (about 2500 m) of the Izu-Ogasawara Ridge, the KE path adopts a relatively stable state with the two quasi-stationary meanders. On the other hand, when the Kuroshio takes the offshore nonlarge meander path and then passes over the shallower part of the Ridge (about 1000 m), the KE path tends to be convoluted, i.e., an unstable state.     

Variability of the nutrient runoff of the rivers of the Arctic Basin

The spatiotemporal variability of the hydrochemical composition of the riverine runoff in nearmouth areas is presented using the example of selected rivers of the Arctic Basin. The temporal dynamics of the riverine nutrient runoff are mainly determined by the seasonal and interseasonal variations in the drainage basins. The spatial variations in the chemical composition of riverine waters in the near-mouth areas are mainly caused by the dynamics of the water flow and the river bed relief and, to a lesser degree, by biochemical processes. It is shown that the variations in the nutrient composition of the waters in near-mouth areas are comparable in magnitude to those at the river-sea geochemical barriers.     

Parameters of the sediments of the deep-water basin of the Black Sea

The methodology and the first results of the computations of the volumes, masses, and growth rates of the sedimentary body of the buried Black Sea basin are presented. Their temporal evolution reflects the regional paleogeodynamics, in particular, the reorientation of the vector of the relative movement of the Arabian and Eurasian lithospheric plates and the related intensification of their collision in the late Miocene-Pliocene.     

Modelling of the ecosystem on the shelf of the Republic of Guinea

Three mathematical models are considered: a two-dimensional model for calculating the concentration fields of the ecosystem components on the shelf of the Republic of Guinea, a pointwise model for the annual variation of the components, and a two predators-prey model. These models are used to study the effect of hydrodynamic conditions on the state of the shelf ecosystem and for research into the causes which distort the balance between marketable and unmarketable fish.Translated by Mikhail M. Trufanov.     

Evolution of the slope of the buried depression of the Black Sea

The first data on the temporal evolution of the slope of the buried depression of the Black Sea are obtained. The sharp change in the rate of the decrease in the slope steepness that occurred in the Late Miocene-Pliocene time reflects a reorientation of the vector of mutual movement and a related intensification of the collision between the Arabian and Eurasian lithospheric plates.