山东田横岛海域长牡蛎性腺发育及生化成分周年变化

为了阐明青岛近海长牡蛎(Crassostrea gigas)性腺发育周期及生化成分周年变化,于2019年4月—2020年3月,对青岛田横岛海区长牡蛎的性腺发育周期、生化成分(糖原、脂肪、蛋白质)的周年变化与环境因子(温度、盐度、叶绿素a)关系进行研究。研究显示,调查区长牡蛎性腺发育周期分为两个阶段:休止期(10—12月)和配子发生期(1—9月)。少部分长牡蛎配子发生于温度较低的1月(5.4℃),随着温度升高配子逐渐发育成熟,在6月温度较高(20℃)和叶绿素a浓度较大(1.67μg·L^-1)情况下,配子进入排放期。在配子发生期间,随着配子的成熟,条件指数和卵径在5月达到最大值,在配子排放后降低。生化成分含量为:在冬末春初浮游植物繁殖期间糖原含量储存在长牡蛎各组织中,随着性腺发育,各组织的糖原含量逐渐下降,为配子发育提供能量,这表明贮藏在各组织的糖原是配子发生期间的主要能源物质;性腺-内脏团的脂肪和蛋白质含量随着卵径增加呈上升趋势,产卵后其含量显著下降,表明脂肪和蛋白质与配子发育密切相关。研究结果表明,田横岛海域长牡蛎配子的发育方式为保守种模式。     

黄河三角洲青蛤的繁殖生物学研究

以我国沿海重要的经济贝类青蛤为研究对象,自2007年4月~2008年3月对黄河三角洲海区环境因子(温度,盐度,叶绿素a含量)和青蛤的繁殖周期进行了研究。环境因子的分析结果表明温度和叶绿素a含量存在明显的季节变化,而盐度则无明显变化。组织学研究表明配子发生开始于低温期1月;大部分卵子在6、7月成熟,此期条件指数的值为全年最高峰;产卵排精开始于水温和叶绿素a含量分别为全年最高的夏末秋初,伴随着条件指数的急剧下降;9月大部分成熟精卵都已排放,此时水温为21℃适于幼虫的生长,浮游植物含量最多有助于提高幼虫的成活率。本实验结果对于黄河三角洲青蛤种质资源的管理保护、养殖开发与可持续利用具有重要的应用意义。     

长牡蛎繁殖周期、生化成分的季节变化与环境因子的关系

为了阐明长牡蛎的繁殖策略,自2004年3月—2005年2月对乳山湾养殖海区的环境因子(水温、盐度、叶绿素a含量)、长牡蛎繁殖周期及其生化成分(糖原、脂肪、蛋白质、RNA/DNA比值)的季节变化进行研究。结果显示,水温在一年中呈现显著变化,夏季水温最高,最高值为29.5℃(8月),冬季水温最低,最低值为1.8℃(1月);盐度在夏季雨水较多的时候略有降低;叶绿素a含量在夏末秋初(8月和9月)和春季(4月)有2个峰值,冬季最低。长牡蛎的繁殖周期分为冬季的休止期和从春季到夏季的繁殖期,在长牡蛎的繁殖期,条件指数逐渐下降到最低值,表明繁殖期长牡蛎生长变慢。在长牡蛎的配子发生过程中软体部蛋白质和脂肪含量略有上升,而糖原含量显著下降,表明长牡蛎配子的发生需要储存的糖原提供能量;RNA/DNA比值在配子发生过程中逐渐升高,显示RNA/DNA比值可以作为一个指标来指示长牡蛎的性成熟。配子发生过程中,长牡蛎的灰分含量逐渐升高,表明长牡蛎通过分解自身的贮能物质提供能量,使体内有机物含量减少,从而导致灰分含量上升。实验结果表明长牡蛎的配子发生类型为保守种。     

青蛤软体部重量和生化组分含量的季节变化

本文研究青蛤Cyclina sinensis软体部重量和三种生化组分含量的季节变化。结果表明:6-9月,随着性腺的发育,青蛤标准动物(壳长34mm±0.4)软体部干重、蛋白质和脂类含量逐渐增大。8月,软体部干重和含脂量达一年中最高值,雌、雄个体含脂量分别为75.7mg和74.6mg。而软体部蛋白质含量最高值出现在产卵前的9月份,雌、雄个体蛋白质含量分别为226.6mg和303.7mg。雌性个体碳水化合物含量在这期间无显著变化,雄性个体则升高。从10月上旬开始,随着配子的排放,软体部干重、蛋白质、脂类和碳水化合物含量急剧下降至一年最低值。11月后又逐渐恢复至初春水平。软体部碳水化合物含量在12—1月较高,出现一年的第二个高峰。作者认为,碳水化合物是冬季青蛤代谢的主要能源。     

日本蟳的性腺发育和生殖周期

对日本蟳(Charybdis japonica)的性腺发育、生殖周期、繁殖习性和性比等进行了研究。根据其性腺的组织学和外部形态特征,将卵巢发育分为6个发育期:形成期、小生长期、大生长期、成熟期、排放期和恢复期;将精巢发育分为5个发育期:形成期、生长期、成熟期、排放期和恢复期。根据成熟系数的周年变化规律并结合性腺组织切片的观察结果,认为在连云港海区的日本蟳性腺发育为1年1个周期,繁殖期为5～9月,交配产卵盛期在5月中旬～6月下旬(水温17.5～23.5℃)。日本蟳为分批产卵类型,但第二批卵的数量远少于第一批卵。雌、雄性腺发育基本同步,雄性发育略快,雌雄比约为1∶1。     

中国蛤蜊繁殖生物学的初步研究

结合土池育苗的试验,对中国蛤蜊的繁殖习性和胚胎发育过程进行了研究。中国蛤蜊在山东省海阳市丁字湾海区的繁殖期为6~8月,7月下旬至8月上旬为产卵盛期。鲜出肉率的变化与性腺发育具有明显的相关性,产卵前达到最大,为45.3%。水温在20℃以上时性腺发育速度明显加快,23~24℃肥满度最大。可用阴干、流水或降低盐度等方法诱导其排放精卵,也可进行解剖受精。中国蛤蜊雌雄异体,个别雌雄同体。胚胎发育可在盐度18~30,温度20~28℃条件下进行,超过30℃则引起幼虫大量死亡。     

镉和汞两种重金属离子对四角蛤蜊的急性毒性

采用毒理学实验方法,比较研究了Cd~(2+)和Hg~(2+)对四角蛤蜊(Mactra veneriformis Reeve)急性毒性效应的差异,以期为进一步评价重金属离子对四角蛤蜊的毒性效应和作用机理等提供理论依据.死亡概率单位和实验液浓度对数的线性回归分析表明,Cd~(2+)对四角蛤蜊在24、48和96 h的半致死浓度(LC_(50))分别为15.961、5.149和2.383 mg/L,Hg~(2+)的LC_(50)分别为3.714、0.607和0.207 mg/L;Cd~(2+) 和Hg~(2+) 对四角蛤蜊的安全质量浓度分别为0.023 8 mg/L和0.002 1 mg/L,分别是我国渔业水质标准(GB11607-89)限定量的4.76倍和4.02倍.     

胶州湾大沽河口潮间带沉积物中叶绿素和有机质含量的季节变化

为了解胶州湾大沽河口潮间带沉积物中底栖微藻和有机质含量的季节变化,于2010年4月至2011年2月,分4次(春、夏、秋、冬)测定分析了沉积物中的叶绿素含量和有机质含量,并分析了沉积物的粒度组成及现场温度。结果表明,表层(0～2cm)沉积物叶绿素a含量为0.42～6.06mg/kg,有机质含量为0.48%～3.71%;次表层(2～5cm)叶绿素a含量为0.13～3.53mg/kg,有机碳质量为0.31%～3.78%;深层(5～8cm)叶绿素a含量为0.14～1.95mg/kg,有机质含量为0.47%～3.72%。经统计检验和Pearson相关性分析得出,胶州湾大沽河口沉积物中的叶绿素a含量春冬两季最高,夏季和秋季最低;叶绿素a含量与深度和温度呈负相关;与所处潮带、有机质含量、粉砂黏土含量在本实验中均无显著的相关性;有机质含量与季节关系不大,高潮带最高,其含量与粉砂黏土含量呈正相关,与叶绿素含量、深度和温度关系不明显。     

台湾海峡及其邻近海域表层水叶绿素a含量时空变化特征

从物理过程和营养输送方面讨论了2006～2007年台湾海峡及其邻近海域表层水叶绿素a含量的时空变化特征及其调控因素.结果表明,台湾海峡表层水体从南至北叶绿素a含量的季节变化存在着明显差异.在北部海区叶绿素a含量平均值以春季居高,冬季最低;中部海区以秋季最高,夏季最低;南部较反常,以冬季最高,夏季最低.浙闽沿岸流、海峡暖流及上升流所造成的营养盐输入方式的差异可能是决定海峡叶绿素a含量季节分布南北差异的关键因素.分析结果还表明,春、夏季叶绿素a含量的分布在南部和北部海域均主要受营养盐限制,秋季叶绿素a含量在南部和北部海域分别主要受到磷酸盐含量和水温的影响,冬季叶绿素a含量在南部和北部海域分别主要受到硝酸盐含量和水温的影响.     

福州沿海龟足的繁殖附着与生长

叙述了龟足[Pollicipesmitella(Linnaeus,1758)]的繁殖期与繁殖特点、性腺发育与分期、生长。繁殖期为5月中旬～9月中下旬,约130天,水温19.5～27.2℃,其中7～9月为盛期。最小繁殖个体峰吻径长为9.5mm,生长期为2年。成体1年中有多次产卵,一次产卵量平均为24360个。性未成熟个体年生长率为峰吻径长5mm/a,成熟个体2mm/a,终生生长。腺介幼虫附着期为6～11月。     

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.