5种微藻对4种滩涂贝类稚贝生长的影响

在室内可控条件下,比较和分析了青岛大扁藻Tetrasemis helgolandica、球等鞭金藻Isochrysis galbana、角毛藻Chaetoceros calcitrans、微绿球藻Nannochloropsis oculata和绿色巴夫藻Pavlovaviridis5种微藻对泥蚶Tegillarca granosa、缢蛏Sinonovacula constricta、青蛤Cyclina sinensis和彩虹明樱蛤Moerella iridescens4种滩涂贝类稚贝生长的影响。结果显示,在培养初期(5~6 d),投喂不同微藻的稚贝实验样品生长速度差异并不明显,但培养9~10 d后,各实验组稚贝实验样品的生长速度开始出现明显差异:投喂角毛藻、球等鞭金藻的泥蚶和缢蛏稚贝实验样品及投喂角毛藻、青岛大扁藻的青蛤和彩虹明樱蛤稚贝实验样品,运动能力强,生长迅速、整齐,经过15~18 d的培养,成活率达85%以上;投喂微绿球藻的4种稚贝实验样品,运动能力弱,生长缓慢、不整齐,成活率低于20%。投喂角毛藻的泥蚶、缢蛏和青蛤稚贝实验样品的生长速度最快;投喂青岛大扁藻的彩虹明樱蛤稚贝实验样品的生长速度最快,而投喂角毛藻的彩虹明樱蛤稚贝实验样品的生长速度与之非常接近。角毛藻对泥蚶、缢蛏和彩虹明樱蛤稚贝实验样品的饵料效果最好,球等鞭金藻次之;青岛大扁藻对青蛤和彩虹明樱蛤稚贝实验样品的饵料效果与角毛藻非常接近,而青岛大扁藻对泥蚶和缢蛏稚贝实验样品的饵料效果较差;绿色巴夫藻的饵料效果与球等鞭金藻类似但均比球等鞭金藻差;微绿球藻的饵料效果最差。用颗粒粒度计数分析仪分析泥蚶和青蛤稚贝实验样品对5种微藻的选择性滤食后发现,最先被泥蚶稚贝实验样品滤食干净的是角毛藻,其后是球等鞭金藻;泥蚶稚贝实验样品开始滤食青岛大扁藻时的速度较慢,但当角毛藻和球等鞭金藻被滤尽后,青岛大扁藻也被迅速滤食,泥蚶稚贝实验样品滤食微绿球藻的速度最慢;最先被青蛤稚贝实验样品滤净的也是角毛藻,其后是青岛大扁藻,在角毛藻和青岛大扁藻被滤尽后,球等鞭金藻也迅速被滤食干净,微绿球藻同样是最慢被滤食的。可见,贝类稚贝总是优先滤食饵料效果好的微藻,饵料效果最差的微藻被贝类稚贝滤食的速度最慢。     

CO_2加富对魁蚶稚贝潜沙能力和3种酶活性的影响

贝类的生长和代谢过程可能会受到高CO2浓度的影响。潜沙行为和酶活性是贝类响应环境变化的重要指标,但其对海水CO2浓度升高响应的研究鲜有报道。本文采用CO2加富培养实验的方法,研究了高CO2浓度条件对魁蚶(Scapharca broughtonii)稚贝潜沙能力和超氧化物歧化酶(Superoxide dismutase,SOD)、过氧化氢酶(Catalase,CAT)和乙酰胆碱酯酶(Acetylcholinesterase,AChE)3种酶活性的影响。结果表明,CO2组(1 000μatm)培养水体中DIC浓度显著高于对照组,魁蚶稚贝初次潜沙时间((5.73±0.51)min)相比对照组((7.80±1.27)min)明显缩短,潜沙率((69.67±5.13)%)相比对照组((61.33±3.21)%)明显升高。实验开始时魁蚶稚贝壳长为(17.20±0.03)mm,实验结束时CO2组魁蚶稚贝壳未出现明显生长((17.24±0.02)mm),显著低于对照组魁蚶稚贝壳长(17.37±0.07)mm。CO2组魁蚶稚贝SOD活性在培养第2和第4天时显著高于对照组(P0.01),之后出现下降并与对照组无显著差异;CO2组和对照组魁蚶稚贝CAT活性在前4天均上升,之后CO2组魁蚶稚贝CAT活性基本不变,而对照组出现下降;两实验组魁蚶稚贝AChE活性在培养过程中无明显差异。高CO2浓度条件下魁蚶稚贝壳的生长受到影响,潜沙过程受到促进,3种酶活性在培养过程中的变化趋势存在差异,未来海洋酸化可能会影响魁蚶的养殖。     

小刀蛏室内人工育苗技术研究

本文研究了小刀蛏(Cultellus attenuatus)室内人工育苗技术。在繁殖季节选择壳长7.5cm亲贝,采用铺泥沙蓄养培育,以阴干+维生素浸泡刺激法获得精、卵,幼虫培育中人工控制幼虫密度,D形幼虫到壳顶幼虫前期为5~6个/mL,壳顶幼虫后期为1~2个/mL。进行了不同运输方式和不同底质亲贝蓄养比较试验、不同底质附着基采苗方法试验以及稚贝无底质上升流培育和不同盐度培育试验。研究表明,采用铺细沙加冰的运输方法亲贝成活率最高,干露9h成活率可达90%;以纯海泥底质蓄养的亲贝肥满度和成活率最高;无底质采苗和铺泥采苗对幼虫变态率的影响没有差异;无底质采苗的稚贝,其生长速度明显慢于铺泥采苗;小刀蛏稚贝不宜用上升流进行培育,宜采用铺泥培育的方法;盐度为15时,稚贝培养效果最好,生长速度快、成活率高,盐度为35时培养效果最差。采用上述技术,成功培育出3mm以上的商品苗2000万粒,育苗效果显著。     

魁蚶生产性间断升温育苗技术的研究

本文介绍魁蚶间断升温育苗方法，从改善亲贝蓄养条件入后，促使亲贝快速成熟自然产卵，并进行洗卵。在幼虫培育时，加强营养，加大换水，及时筛选不同大小的幼虫分池培养。严格海上中间培养管理，使每立方水体出苗量达３１万个，取得了明显的经济效益。     

大型藻酶解单细胞用于贝类育苗的研究

用海藻工具酶将紫菜和裙带菜解离成单细胞作为饵料对海湾扇贝亲贝和幼体、魁蚶亲贝和皱纹盘鲍稚鲍进行了研究。结果表明：(1)海湾扇贝亲贝全喂紫菜细胞其效果与喂全微藻的效果相近，亲贝都能成熟，排放精卵和正常胚胎发育。微藻与紫菜细胞混合投喂可加速性腺发育，性腺指数较高。全喂紫菜细胞能够满足幼体的生长发育和变态。但变态率、生长率较全喂微藻和混合投喂的低。(2)紫菜细胞和微藻分别或混合投喂魁蚶亲贝，都能满足亲贝的性腺发育，进行正常受精、孵化和变为D形幼体。(3)用裙带菜细胞投喂稚鲍与人工配合饵料比较，能显著提高稚鲍的存活率。研究表明。由大型藻生产单细胞饵料，在海产动物育苗中具有广阔的应用前景。     

魁蚶生产性间断升温育苗技术的研究

本文介绍魁蚶间断升温育苗方法，从改善亲贝蓄养条件入手，促使亲贝快速成熟自然产卵，并进行洗卵。在幼虫培育时，加强营养，加大换水，及时筛选不同大小的幼虫分池培养。严格海上中间培育管理，使每立方水体出苗量达31万个（大小0．5cm），取得了明显的经济效益。     

海水温度和盐度对泥蚶幼虫和稚贝生长及存活的影响

1996～1997和1999年在浙江省乐清市东发水产育苗场和福建省宁德市四海水产育苗场分别研究了海水温度和盐度对泥蚶浮游幼虫和稚贝生长及存活的影响,结果表明,泥蚶浮游幼虫的适宜温度为25～33℃,最适生长温度为28～30℃.稚贝的适宜温度为15～35℃,最适生长温度为25～30℃.浮游幼虫的适宜盐度为16.54～30.02,最适生长盐度为1654～23.38;稚贝的适宜盐度为10.01～30.02,最适生长盐度为10.01～23.38.泥蚶幼虫和稚贝对高温和低盐海水有较强的适应能力,这与它们夏季的繁殖期和自然分布于内湾河口区是相适应的.     

海水中某些化学因子对魁蚶幼虫、稚贝及成体的影响

本文报道了S‰,NH_3-N,pH及O_2对魁蚶幼虫、稚贝及成体影响的初步研究结果,求得魁蚶幼虫、稚贝及成体对S‰,NH_3-N,pH和O_2的适应浓度范围和最适范围。结果表明:魁蚶随年龄的增长,对S‰的适应能力逐渐减弱;对NH_3-N,pH及O_2的适应能力则逐渐增强。     

泥蚶苗种的增殖研究

１９９１－１９９２年在青岛市黄岛区薛家镇唐岛湾进行了泥蚶苗种增殖试验。研究结果表明，泥蚶天然苗种增殖的主要技术措施有：首先要留足亲贝，保证了１．８个／ｍ２亲贝；其次是准确预报泥蚶产卵及幼虫附着期，然后及时采取平畦、挑沟、撒砂等措施人工改造滩涂环境，可使泥蚶附苗率增加达（１７～５６）×１０＾２。     

泥蚶苗种的增殖研究

１９９１～１９９２年在青岛市黄岛区薛家岛镇唐岛湾进行了泥蚶苗种增殖试验。研究结果表明，泥蚶天然苗种增殖的主要技术措施有：首先要留足亲贝，保证１．８个／ｍ２亲贝；其次是准确预报泥蚶产卵及幼虫附着期，然后及时采取平畦、挑沟、撒砂等措施人工改造滩涂环境，可使泥蚶附苗率增加达（７～５６）×１０－２。     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。     

Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans

A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level.     

Estimation of Sediment Properties during Benthic Impact Experiments

Sediment properties, such as water content and density, have been used to estimate the dry and wet weights, as well as the volume of sediment recovered and discharged, during benthic impact experiments conducted in the Pacific and Indian Oceans. The estimates show that the weights of dry (355-1332 t) and wet sediment (1651-4888 t) recovered during the experiments, are not only a function of the total duration and distance covered during the experiment, but also depend on water content and density of the sediment. Estimation of dry sediment and its volumetric ratio in the discharge, are key parameters for calculating the discharged volume. The estimated volume of wet sediment recovered (1427-4049 m 3 ) as well as discharged (2693-6951 m 3 ) during the experiments, provide important inputs to evaluate the sediment resettlement and migration. Using these estimates, the average depth of excavation on the seafloor, can also been calculated. However, the stages of sediment recovery and discharge are expressed differently in some of the experiments. In order to standardize these, different stages have been identified, and definitions of certain terms have been suggested, for use in the future. The methods of calculating different properties, as well as weight and volume of discharged sediment are described in the paper for use in other applications concerning deep-sea discharges.     

A Tidal Flow Model for the Gulf of Kachchh, India

A vertically integrated model has been used to study the tidal circulation and currents in the Gulf of Kachchh along the west coast of India. The model is fully nonlinear and uses a semiexplicit finite difference scheme to solve the basic hydrodynamic equations on a staggered grid. The model is forced by prescribing the tides along the open boundary of the model domain. The flow is simulated both with and without the presence of the proposed tidal barrage across the Hansthal Creek in the Gulf of Kachchh. The results show a considerable change in the behavior of the tidal flow in the presence of the barrage.     

利用中国GF-3卫星SAR和HY-2A卫星微波散射计的首次台风联合定量观测

<正>The typhoon,as a mature tropical cyclone that develops in the western part of the North Pacific Ocean with high wind speed and heavy rainfall,is one of the most lethal and costly of natural disasters for the densely populated countries of East Asia.It can be easily detected by space-borne sensors operated at microwave,visible or infrared bands(Liu et al.,2014).Synthetic Aperture Radar(SAR)is     

离子交换—原子吸收光谱法测定海水中痕量铜、铅、锌、镉、铁、锰

本文介绍了用国产D401型螯合树脂分离富集海水中铜、铅、锌、镉、铁、锰等痕量元素,并用原子吸收光谱仪测定其含量的方法。讨论了各元素的分离条件选择及干扰元素的影响,并与溶剂萃取法的结果作了比较。各元素检测的定量下限为:铜0.5μg/L、铅0.1μg/L、锌1.0μg/L、镉0.01μg/L、铁2.0μg/L、锰2.0μg/L。方法精密度在4—8％之间,回收率为90—102％。     

Biogeochemistry of Mangrove Soil Organic Matter: a Comparison BetweenRhizophoraandAvicenniaSoils in South-eastern Brazil

Soil core samples fromRhizophora mangleL. andAvicennia schauerianaStapf & Leech forests from south-eastern Brazil were analysed for their total organic matter content and their sugars, amino acid and amino sugars composition. Organic carbon and nitrogen contents were higher inAvicenniathan inRhizophorasoils. The contribution of sugars and amino acids to the total organic carbon pool was constant with depth inRhizophorasoils whereas inAvicenniasoils it increased. Spectral distribution of sugars and amino acids showed a dominance of Ca-affine monomers, particularly acidic amino acids, and the sugar arabinose. Biogeochemical indicators derived from ratios of individual sugar and amino acid monomers confirm previous studies which showed that organic matter in both soils is mainly of mangrove origin. The results further suggest accumulation of organic matter inRhizophorasoils and a continuing degradation of organic matter inAvicenniasoils. The latter may thus release more nutrients to adjacent ecosystems thanRhizophorasoils.     

A review of orange roughy Hoplostethus atlanticus fisheries,estimation methods,biology and stock structure

Orange roughy Hoplostethus atlanticus are unusual fish. They form dense aggregations that have fuelled lucrative fisheries at great depths (600–1 400 m), especially off Namibia, New Zealand and Australia. They are thought to be very long-lived (>100 years, maturity at 22 – 40 years), and to have exceptionally low natural mortality (M = 0.045–0.064 year^?1) and slow growth rates (K = 0.055–0.070 year^?1). In addition, they spawn large eggs and have low fecundity. These factors combine to make orange roughy highly susceptible to overfishing; most stocks are below 30% of pristine levels. Assessments are obtained from indices of catch rate and trawl, acoustic and egg surveys. Acoustic estimates are the most direct, but are confounded by the species' low target strength (?50 to ?53 dB)–attributable to the wax-filled swim bladder. Extracellular wax esters are stored in abundance and comprise mostly mono-unsaturated fatty acids, with low concentrations of the ω-3 fatty acid family. This unusual composition (resultant from the species' diet) ensures neutral buoyancy. Stock separation has been inferred mainly from biological studies, but genetic studies have also found differences among stocks within New Zealand and Australia. Deep-water habitat may be damaged by trawling operations and may take many years to recover, so in some quarters there is a call for a portion of suitable habitat to be set aside for preservation. Although Namibian orange roughy are shallower, smaller and younger than those in other stocks, the Namibian fishery sustained high catches for only a few years before quotas were reduced, from 12 000 to 1 875 tons. Three management lessons are suggested for developing orange roughy fisheries based on the Namibian experience: (1) imposition of catch limits during exploratory fishing; (2) starting the acoustic surveys earlier in the fishery, if possible; (3) greater reliance on trends in catch rate until a survey series has been established.