对虾池混养滤食性动物对浮游生物的影响

于１９９７年５～８月在山东海阳养虾场运用陆基围隔实验生态学方法,研究了罗非鱼—对虾、海湾扇贝—对虾、缢蛏—对虾、罗非鱼—缢蛏—对虾４种混养系统中滤食性动物对浮游生物群落的影响。结果表明：滤食性动物的滤食作用降低了浮游植物生物量和甲藻在浮游植物中的比例;混养罗非鱼和扇贝使浮游植物群落的多样性增加,而混养缢蛏却使它下降;罗非鱼优先滤食大型桡足类,使小型浮游动物增加,从而提高了浮游动物的总生物量,而扇贝则优先滤食浮游动物的小型种类;由于罗非鱼和缢蛏生态灶的互补性,罗非鱼—缢蛏—对虾混养能更全面、有效地利用浮游生物资源,促进生态平稳     

对虾养殖生态系不同粒级浮游生物呼吸率和初级生产率测定

1997年6～8月于山东省海阳市黄海集团公司养虾场,用5个实验围隔研究了对虾池不同粒级浮游生物的呼吸率和初级生产率.结果表明:(1)小型、微型及超微型浮游生物的呼吸率平均分别为0.07,0.38及0.31mg/(dm3·d),占各粒级浮游生物总呼吸率的9%,50%及41%.小型、微型及超微型浮游植物的生产率平均分别为0.04,1.26及0.15mg/(dm3·d),占相应粒级浮游植物总生产率的3%,87%及10%.各粒级浮游生物呼吸率占相应粒级浮游植物生产率的比例为:小型浮游生物175%;微型浮游生物30%;超微型浮游生物207%.(2)小型浮游动物、超微型浮游动物(含细菌)的呼吸率显著高于相应粒级浮游植物呼吸率,微型浮游植物的呼吸率明显高于微型浮游动物呼吸率.不同粒级浮游植物呼吸率的大小顺序为微型、超微型、小型,不同粒级浮游动物呼吸率顺序为超微型(含细菌)、微型、小型.     

中肋骨条藻-裸甲藻-双毛纺锤水蚤营养传递的级联效应

中型浮游动物因摄食微型浮游动物,释放了微型浮游动物对浮游植物的摄食压力,这种营养级联效应会增加浮游植物丰度和降低中型浮游动物对浮游植物的摄食率,从而弱化浮游生物网营养传递过程中的下行控制作用。本研究在实验室模拟了食物链中肋骨条藻-裸甲藻-双毛纺锤水蚤的营养传递过程,发现在中肋骨条藻低生物量时,双毛纺锤水蚤偏好于选择摄食裸甲藻;高生物量时,双毛纺锤水蚤偏好选择摄食中肋骨条藻。营养传递过程中存在正的级联效应(0.018~0.12 d^-1),级联效应的大小与裸甲藻的摄食率和双毛纺锤水蚤对裸甲藻的摄食选择指数呈现显著的正相关关系。双毛纺锤水蚤对中肋骨条藻的直接摄食死亡率大于营养级联效应,从而导致中肋骨条藻生物量的降低。因此,营养级联效应对中型浮游动物摄食浮游植物的影响要弱于中型浮游动物的直接摄食作用。     

东太湖不同水域浮游生物周年变化及鲢、鳙食性的研究

2012 年2～11 月对东太湖不同水域浮游生物组成、数量、水质情况及水生植物密度进行了调查, 并对9 月份太湖鲢、鳙的食性进行了研究。结果表明: 浮游动物和浮游植物多样性指数均为保护区＞余山＞老鼠山＞漫山岛。水体浮游生物数量和综合营养状态指数均为漫山岛＞老鼠山＞余山＞保护区。浮游植物总数量与蓝藻总数量、浮游动物总数量、富营养化因子呈正相关, 与水生植物密度呈负相关。9 月份太湖鲢、鳙的肠内含物中浮游植物和浮游动物分别占食物数量的89.1%、70.6%和10.9%、29.4%,其中蓝藻分别占74.5%、56%, 枝角类和轮虫分别占3.7%、13.4%和1.5%、11.5%; 鲢、鳙对蓝藻的选择性指数分别为1.42 和1.07, 对轮虫和原生动物的选择性指数分别为0.13、1.27 和1.30、0.40。本研究结果对揭示影响太湖浮游生物周年变化的环境因素以及通过鲢、鳙控制蓝藻具有一定的理论价值和指导意义。     

大亚湾中型浮游动物群落结构和植食性

本文以中型浮游动物成体为研究对象,通过在大亚湾实验站附近一个采样点连续两年的野外调查和现场摄食实验,分析大亚湾近岸富营养化海域中型浮游动物的群落特征,及其对浮游植物的选择摄食特性。结果表明:2015—2017年实验站附近中型浮游动物的总丰度在冬季达到最高,其次为春、秋和夏季;其优势种大多是滤食性桡足类,如锥形宽水蚤(Temora turbinata)、中华哲水蚤(Calanus sinicus)等,中型浮游动物的摄食特性与优势种摄食行为有很大的相关性。中型浮游动物群落更偏好于粒径较大的小型浮游植物(20—200μm),而对微型(2—20μm)或超微型浮游植物(0.7—2μm)的摄食影响较小,甚至会因为选择性摄食对这两种类型的浮游植物的生长有间接促进作用。且中型浮游动物的摄食选择性具有明显的季节性,除每个季节均倾向于摄食甲藻和青绿藻。除此之外,在春季偏好于定鞭藻和隐藻,夏季偏好于定鞭藻和绿藻,秋季偏好于硅藻、隐藻和聚球藻。尽管硅藻的生物量在调查期间平均约占总浮游植物类群的50%,但是中型浮游动物并不主动摄食硅藻,而更偏爱生物量低但营养较高的甲藻。总体上,中型浮游动物虽然对浮游植物有一定的摄食,但其植食性较弱,不能对浮游植物的生物量进行有效控制。     

缢蛏对对虾池浮游生物群落结构的影响

１９９６年５～９月在山东省海阳黄海水产集团公司养虾场,结合缢蛏和中国对虾混养实验,探讨了缢蛏对浮游生物群落结构的影响。结果表明：缢蛏主要滤食２～５μｍ的无鞭毛藻类,从而使隐藻等鞭毛藻类成为浮游植物优势类群;缢蛏滤食原生动物、轮虫等小型浮游动物和大型浮游动物的幼体,并且通过食物竞争来影响大型浮游动物,使浮游动物群落以捕食性和繁殖力强的剑水蚤及其无节幼体为主要成分。     

亚热带和热带环境下夜光藻的摄食压力

2015年以广西三娘湾海域为亚热带海区,三亚海域为热带海区,利用稀释法开展了现场培养实验,测定热带和亚热带海区夜光藻对浮游植物、微型浮游动物对浮游植物的摄食压力,研究了夜光藻对不同粒径的浮游生物的摄食作用.结果表明:两个海区都有比较高的生长率和摄食率,其中细菌有最高的生长率和摄食死亡率;夜光藻的摄食率,从总浮游植物、微微型浮游植物到聚球藻、细菌逐渐增高.亚热带海区与热带海区相比,微型浮游动物的摄食压力更小,表明低温影响了浮游动物的摄食活性;而营养盐是引起亚热带海区高生长率的主要因素.     

围隔实验研究台湾海峡2005年夏季小型浮游动物对硅藻水华的摄食

为了研究小型浮游动物对近岸浮游植物藻华的摄食调控作用,于2005年7月,应用"稀释法"并结合高效液相色谱(HPLC)光合色素分析技术,研究了台湾海峡船基围隔实验条件下浮游植物生长率及小型浮游动物摄食率的日变动。结果表明:由于营养盐添加的影响,迅速形成了以尖刺伪菱形藻(Pseudo-nitzschia pungens)为优势种的藻华,生物量(叶绿素a)从实验初始7月6日的1.45μg/dm3迅速增加到7月8日的29.80μg/dm3,随后消退。镜检和光合色素分析的结果显示,实验期间一直以此硅藻占绝对优势。浮游植物的生长率在藻华峰值(7月8日)前保持了较高的生长速率(>1.0/d)且大于小型浮游动物的摄食率;小型浮游动物的摄食率也逐渐增加,7月7日时达到0.86/d,显示有57%以上的浮游植物现存量被摄食。7月8日后,水华迅速消退,摄食率除13日外,均大于浮游植物的生长率。小型浮游动物主要由急游虫(Strombidium spp.)、侠盗虫(Strobilidium spp.)等无壳纤毛虫、异养甲藻-螺旋环沟藻(Gyrodinium spirale)及砂壳纤毛虫等组成,其对浮游植物的生长迅速作出了反应,各类群的丰度在水华峰值后的7月9日均几达最大值,水华后期(11日)大型的无壳纤毛虫达最大值。小型浮游动物的这种组成及变动特点是其保持较高摄食率及一定程度上控制和促进藻华消退的原因之一。     

草鱼-鲢-鲤混养生态系统的EwE模型分析

采用EwE模型软件,构建了一个具有14个生物功能组的草鱼、鲢和鲤混养生态系统EwE模型,对草鱼、鲢和鲤混养生态系统的结构和功能进行综合量化分析。研究表明,草鱼、鲢和鲤混养生态系统主要由3个营养级构成。从营养物质流量看,营养级Ⅰ流量最大,占系统总流量(TST)的56.90%;营养级Ⅱ、Ⅲ、Ⅳ、Ⅴ的流量随营养级的增加而递减,分别占总流量的34.45%、8.20%、0.44%和0.003%。食物网和营养级之间营养流动分析表明,系统营养流通的主要途径为从浮游植物开始的牧食链、从碎屑开始的腐食链和从饲料开始的饲料链。从生态营养学效率(EE值)看,除螺类的EE值为零外,大部分功能组的EE值都较高,表明系统中大部分功能组都得到了较好的利用。碎屑在草鱼、鲢和鲤混养生态系统中具有十分重要的作用,其主要来源是细菌、原生动物和浮游植物,且碎屑的EE值较高(水中为0.903,底泥为0.551),表明大部分碎屑重新进入食物链循环,碎屑得到了再利用。研究结果表明,草鱼、鲢和鲤混养的模式可以进一步优化,建议增加放养鱼类的密度,同时引进一些其他鱼类(如青鱼和鳙鱼),以提高系统的综合效益。     

海南清澜港水母暴发期间浮游生物生态特征研究

自2010年12月-2011年5月,调查研究了海南清澜港海域的浮游生物群落特征,重点跟踪监测了2011年5月黄斑海蜇(Rhopilema hispidum)暴发期间海水营养盐水平及浮游生物群落结构变化。通过样品分析,共鉴定出浮游植物111种(变种和变型),细胞密度范围为(2.25×104)-(8.19×108)cells/L,浮游动物36种,丰度范围为19.39-25798.74ind/L,其中浮游动物以桡足类为优势种群,浮游植物以硅藻为主要优势种。在水母暴发期间浮游植物以热带骨条藻(Skeletonema tropicum)为主,浮游动物以桡足类为主。清澜港养殖区为水母水螅体提供生长发育的环境和水母暴发前期浮游植物大量增殖,为浮游动物提供充足的食物,在一定程度上促进了水母的暴发。     

东海陆架表层水体有机与无机悬浮体的季节分布特征

利用2011年春季(5-6月)、2009年夏季(8月)、2010年秋季(11-12月)和2009 年冬季(12月一次年1月)4个航次实测的悬浮体质量浓度资料,分析了东海陆架表层水体总悬浮体、有机悬浮体和无机悬浮体质量浓度的季节分布特征。结果表明,东海陆架表层水体总悬浮体质量浓度冬半年高于夏半年,等值线基本平行于岸线,在浙江沿岸29°N附近有一浑水舌向东南方向延伸,常年存在2个高值中心和2个次高值中心。有机悬浮体质量浓度则为夏半年高于冬半年,存在2个高值中心和2个次高值中心,季节变化显著。无机悬浮体质量浓度分布趋势相似于总悬浮体质量浓度,但整体轮廓线向近岸收缩约0.5°,常年存在2个高值中心和1个次高值中心。有机悬浮体占总悬浮体百分比按季节从高到低依次为春季、夏季、冬季和秋季,其中长江口、杭州湾外近海海域和黑潮区为东海有机悬浮体百分含量高值区。     

污水与海水混合后海水颗粒物对磷的吸附-释放实验

本文模拟研究了厦门污水与海水混合后,海水颗粒物对磷的吸附-解吸过程,结果表明:颗粒物对磷的吸附只在混合后的1d内进行,之后即产生颗粒磷的释放,并表现为颗粒磷→溶解磷→溶解无机磷的转移过程。溶解无机磷是水体中磷的重要存在形式,其浓度的增加速率基本符合一级动力学模式。颗粒磷的释放过程可用交换吸附动力学模式(t/X)=(t/X_(eq))+B′处理。     

海洋悬浮颗粒物中氮同位素的 EA-IRMS法测定

本测定方法利用元素分析 同位素质谱 (EA IRMS)分析系统 ,设计改装了一套适用于大气氮标定钢瓶氮同位素的封闭分析系统 ,并建立了测定悬浮颗粒物中氮同位素的分析方法 .将海水样品经 45 0℃预燃烧过的玻璃纤维滤膜过滤 ,获得悬浮颗粒物 .设定大气δ1 5N值为零 ,连续进样 12次 ,测定大气氮的δ1 5Nair 值为 ( 0 .0 2±0 .0 3)‰ ;并对参考气高纯钢瓶氮进行了标定 ,其δ1 5Nair值为 ( -0 .0 9± 0 .0 2 )‰ ;其离子强度在 0 .5 0～ 6 .0V之间具有良好的线性 ,样品分析精度优于 0 .15‰ .采用该方法实测 5 8份海水悬浮颗粒物 ,获得1 5N天然丰度平均值为 0 .36 7% .     

Chemical determination of particulate nitrogen in San Francisco Bay. A comparison of two estimates

Particulate nitrogen was measured by both the ultra-violet light-catalyzed peroxide method and the high temperature combustion method. The difference between values obtained with the two methods (combustion minus UV) was found to be linearly correlated with the concentration of total suspended particulate matter (SPM) in the sample. The slope of this correlation was taken to be the concentration of refractory nitrogen associated with the suspended matter, which may be ammonium ions fixed in lattices of clay minerals or organic nitrogen compounds did not vary significantly with SPM, location, water depth or salinity. Refractory nitrogen concentration were possibly related to concentrations of chlorophyll a and to cruise date, but in neither case was the evidence conclusive. Based on the indirect evidence presented, the UV method appears to provide a good measure of biologically reactive nitrogen in this system.     

海洋雾状层的成因及其对海洋碳循环过程的影响

海洋雾状层既是陆源物质进入海底的输送通道,又是海洋水体中沉降颗粒及底部再悬浮颗粒物的停留场所。雾状层物质来源主要有陆源、生源以及海底表层沉积物的再悬浮,不同海区、不同层位的雾状层的物质来源有所差异;雾状层的成因具有复杂性,既有物理作用,又有生物及化学作用,大量研究表明,海底洋流、内波(潮)等物理作用是雾状层形成的主要控制因素。雾状层中碳的存在形态主要有颗粒有机碳(POC)、溶解有机碳(DOC)、胶体有机碳(COC)以及无机碳,雾状层与其上下海水之间、雾状层与海底表层沉积物之间不同形态碳在生物-化学-物理动力系统作用下不断发生物质交换与迁移,对海洋碳循环生物地球化学过程起重要的控制作用,是整个海洋碳循环的一个不可忽视的环节。     

海洋有机质的光谱分析方法评述

海洋有机质的光谱分析已成为海洋碳循环的研究热点之一。本文从天然有机质吸收光谱和荧光光谱分析的基本原理入手,系统梳理了有机质光谱分析中容易被忽视的基本概念,讨论了过滤与保存方式、p H值、荧光内滤效应等对有机质光谱分析的影响。结合色氨酸、酪氨酸、腐殖酸及大量现场样品的实验结果,对吸收光谱和三维荧光光谱的不同解析方法进行了系统的分析与对比。基于在南海、西菲律宾海获取的现场调查数据,对于文献中常用的荧光指数(FI)、腐殖化指数(HIX)、自生源指数(BIX)等光谱参数的内在含义及其在海洋环境中的适用性进行了评述。此外,还归纳和总结了胶体有机质和颗粒有机质荧光分析的最新进展,并对今后在光谱分析与观测领域有待完善和突破的一些关键领域进行了展望。     

Fluxes of organic carbon in a fjord on the west coast of Ireland

The supply of particulate organic carbon (POC) via freshwater influx, and its exchange with the open sea, were estimated for a fjord-like coastal inlet (Killary Harbour, Ireland) during 1981. Biological production and destruction of organic matter within the inlet were also studied. POC levels in rivers feeding the system were correlated with rainfall. C : N ratios suggested an increased proportion of POC of terrestrial origin at stations influenced by freshwater inflow, and throughout the fjord in the non-productive season.A tentative annual carbon budget is presented.     

The decomposition rate of the organic carbon content of suspended particulate matter in the tropical seagrass meadows

In terms of downward transport, suspended particulate matter(SPM) from marine or terrigenous sources is an essential contributor to the carbon cycle. Within mesoscale environments such as seagrass ecosystems, SPM flux is an essential part of the total carbon budget that is transported within the ecosystem. By assessing the total SPM transport from water column to sediment, potential carbon burial can be estimated. However, SPM may decompose or reforming aggregate during transport, so estimating the vertical flux without knowing the decomposition rate will lead to over-or underestimation of the total carbon budget. Here this paper presents the potential decomposition rate of the SPM in seagrass ecosystems in an attempt to elucidate the carbon dynamics of SPM. SPM was collected from the seagrass ecosystems located at Sikka and Sorong in Indonesia. In situ experiments using SPM traps were conducted to assess the vertical downward flux and decomposition rate of SPM. The isotopic profile of SPM was measured together with organic carbon and total nitrogen content. The results show that SPM was transported to the bottom of the seagrass ecosystem at a rate of up to(129.45±53.79)mg/(m~2·h)(according to carbon). Considering the whole period of inundation of seagrass meadows, SPM downward flux reached a maximum of 3 096 mg/(m~2·d)(according to carbon). The decomposition rate was estimated at from 5.9 μg/(mg·d)(according to carbon) to 26.6 μg/(mg·d)(according to carbon). Considering the total downward flux of SPM in the study site, the maximum decomposed SPM was estimated 39.9 mg/(m~2·d)(according to carbon) and 82.6 mg/(m~2·d)(according to carbon) for study site at Sorong and Sikka, respectively.The decomposed SPM can be 0.6%–2.7% of the total SPM flux, indicating that it is a small proportion of the total flux. The seagrass ecosystems of Sorong and Sikka SPM show an autochthonous tendency with the primary composition of marine-end materials.     

Vertical Patterns of Suspended Matter Characteristics Along a Coastal-basin Transect in the Western Baltic Sea

Suspended particulate matter samples were collected from the water column, the bottom nepheloid layer and the ‘ fluffy layer ’ from four stations along a coastal-basin transect in the Pomeranian Bight, western Baltic Sea. Sampling was performed nine times between October 1996 and December 1998 for various analyses, including electron probe x-ray micro analysis for detailed mineralogical investigations.Specific vertical patterns of clay mineral distributions were found. Suspended particulate matter (SPM) in the bottom nepheloid layer and the ‘ fluffy layer ’ overlying sediments was enriched in organic carbon and hydrated three layer clay minerals, whereas the non-aggregated SPM was dominated by quartz and biogenic opal. It appears that separation effects operate during aggregation of mineral particles and organic matter in repeated cycles of resuspension and settling. No clear seasonal variations in the composition of the SPM were found, in spite of high spatial and temporal variability of biological and physical variables. The results suggest that preferential incorporation, possibly aided by microbiological colonization, of hydrated three layer silicates into the organic flocs is a process that occurs under a wide range of conditions. Because aggregates sink faster than individual particles, aggregate formation led to a relative enrichment of illite and smectite in the near-bottom layers. Considering the affinity of organic contaminants and heavy metals to organic matter, the selective removal of aggregated organic matter and hydrated three-layer clay minerals from the water column and enhanced transport in the near-bottom fluffy layer may be a natural cleansing mechanism operating in the shallow waters of the bight.     

Limited nutritional benefit to the seagrass Halophila ovalis, in culture, following sediment organic matter enrichment

Essential nutrients for seagrass growth may be derived from benthic decomposition of organic matter. To test this idea, cores of Halophila ovalis (seagrass-vegetated) and unvegetated sediment (control) were amended with either particulate organic matter (POM) or dissolved organic matter (DOM) to test whether a positive feed-back loop exists, where increased organic matter results in increased seagrass nutrients. POM was added in the form of seagrass wrack (0, 1, 5, 12 g core⁻¹) and DOM was added with sucrose diffusion tubes at the root zone (0, 0.8, 2.4, 5.2 g core⁻¹). Cores were incubated under saturating light conditions (12 h light/12 h dark) at 18 °C, for 4 weeks. Results suggest a complex balance between positive and negative effects of organic matter enrichment. Whilst leaf molar concentrations of N and P of H. ovalis increased (by 15 and 30% respectively), plant growth declined (up to 50% relative to control) for both DOM and POM enrichments. Phosphate was removed from sediment porewater following POM addition and most likely translocated to the leaves. Stressors other than nutrient limitation (e.g. biogeochemical constraints) reduce growth and affect the nutrient dynamics of the seagrass and should be the focus of future work.