主养凡纳滨对虾池塘水体理化因子及浮游生物变化特征

选取3个主养凡纳滨对虾的鱼虾混养池塘,在养殖季节(5—10月)每月对池塘水体理化性质和浮游生物进行监测。通过定期监测,研究了该类型池塘水体理化性质和浮游生物的时空变化特点。结果表明:在整个养殖过程中,p H随养殖时间延长略有上升,但是变化较小;化学需氧量和亚硝态氮呈上升趋势;总氮、总磷、锌离子、总碱度浓度呈先下降后上升趋势;氨氮浓度在养殖前期最高,随养殖时间延长逐渐下降,养殖后期趋于稳定;硝态氮浓度呈波浪形变化,但整个养殖过程浓度都比较低;活性磷浓度呈下降趋势;铜离子和悬浮物浓度呈先下降后上升再下降的趋势;盐度总体趋势平稳;总硬度呈先上升后下降趋势。养殖过程中共检测到7门38种藻类,养殖池塘浮游植物主要以绿藻门和蓝藻门为主;共检测到5类18种浮游动物,浮游动物组成主要以轮虫类和枝角类为主。综合浮游植物和浮游动物的调查结果,由Shannon-Wiener指数分级评分标准可知养殖前期的水质较差,浮游生物丰富度较低。     

The influence of ocean climate on coastal plankton and fish production

This study evaluates the influence of oceanic variability on plankton and fish production in a coastal upwelling system off southern Vancouver Island, British Columbia, Canada. A trophodynamics model is used to hind-cast plankton and fish production as estimated by empirical seasonal patterns in upwelling, sea surface temperature, solar radiation, and by biomasses of Pacific hake (Merluccius productus) and Pacific herring (Clupea pallasi). Simulation results indicate that interannual and longer-term variability in coastal plankton production occurs, and that the patterns are primarily determined by the dynamics in the initiation and intensity of coastal upwelling. Fish properties are greatly influenced by zooplankton, with simulated hake production being correlated with summer euphausiid production, and measured herring condition being correlated with autumn zooplankton production. An evaluation of transfer efficiencies indicates that interannual variability in the diatom-to-fish transfer is high (CV = 78%), with the majority of this variability occurring in the diatom-to-zooplankton component of the transfer. Seasonal dynamics of the diatom-to-zooplankton transfer result from the effects of upwelling on diatom production, and subsequent trophodynamic phasing with copepods and euphausiids.     

河口区斑节对虾淡化养殖塘浮游生物状况

初步研究了 1998年河口区斑节对虾淡化养殖塘生态系中的浮游生物状况。各塘浮游植物生物量变幅较大 ,平均含量为 36 .33± 2 8.4 0mg/L ;浮游植物总密度均值为 3.0 5± 2 .18× 10 8cells/L ,水体已呈富营养化状态。浮游植物的生物量及种类数均以蓝藻占优势 ,其次是绿藻和硅藻 ,这与我国传统家鱼高产池塘的浮游植物群落结构显著不同。各塘浮游动物丰度与组成变化较大 ,不如浮游植物稳定。浮游植物与浮游动物生物量之比平均为 0 .90 3:1,斑节对虾塘尚有进一步开发的潜力     

2018年巢湖水生生物资源调查研究

通过巢湖2018年水质与水生生物资源调查,对水质状况,浮游生物、底栖动物、鱼类种类组成,密度与生物量、优势种类等情况进行了分析。[结果]巢湖2018年夏季浮游植物为118种(含变种),隶属5门26科60属,细胞丰度与生物生物量平均值分别为3.1×107 cells/L,平均生物量为5.7 mg/L;浮游动物140种(含属),其中枝角类、桡足类各9种,轮虫24种,纤毛虫98种(含属),平均丰度1898.9 ind./L,生物量为4.4mg/L;底栖动物为16种(含属),平均密度为495.5 ind./m2,平均生物量为42.04 g/m2;鱼类47种,隶属于8目15科,优势鱼类为刀鲚Coilia ectenes、鳙Aristichthys nobilis、鲫Carassius auratus、鲤Cyprinus carpio、翘嘴鲌Culter alburnus、太湖新银鱼 Neosalanx taihuensis等,各样点浮游生物与底栖动物有明显差异。在巢湖流域未来管理中,综合运用食物链调控技术、提高污水排放标准等生态修复工程,以提升巢湖生态环境质量。     

冬、春季黄海不同粒级浮游生物的脂肪酸组成

比较分析了2015年冬季1月和春末5月黄海不同粒级浮游生物的脂肪酸组成,旨在对不同粒级网采浮游生物营养价值进行评价,为海洋鱼类营养补充研究提供基础资料。结果显示,冬、春两季,ω3多不饱合脂肪酸(ω3PUFA)、二十碳五稀酸(EPA)、二十二碳六稀酸(DHA)、20:1+22:1的相对含量以较大粒级浮游生物(500~2000μm)较高;而16:0、18:0不饱和脂肪酸的相对含量以500μm粒级浮游生物较高。冬季各粒级浮游生物的总饱和脂肪酸(SFA)相对含量均高于春季相应值,但MUFA、PUFA、16:1ω7、EPA、DHA、20:1+22:1的相对含量却低于春季。多元对应分析显示,环境因子中海水温度与100~1000μm粒级浮游生物的不饱和脂肪酸MUFA和PUFA含量呈显著的正相关关系(P0.05)。对比冬、春季浮游生物脂肪酸组成与黄海主要经济鱼类的脂肪酸营养组成,初步认为,在冬季,可为鱼类生长提供足够营养的浮游生物的粒级范围相对较窄,主要是500μm粒级的较大型的浮游生物,而在春季,该类浮游生物的粒级范围较广,100~2000μm的浮游动物都可作为鱼类早期生长的有效饵料来源。由此初步推论,浮游生物食性仔稚鱼食物来源的粒级范围在春季比冬季更为广泛。     

船舶压载水浮游植物采样技术的比较

通过模拟实验,比较了夏季和冬季2个季节条件下4种采样方法(采水器法、隔膜泵法、潜水泵法和管道法)和4种采样体积(1 L、10 L、100 L和1 000 L)对船舶压载水浮游植物采样效果的影响。夏季4种采样方法采集到的浮游植物密度分别为1 180.00±20、971.00±20、964.00±20和676.00±20 cells/L,冬季为152.00±20、120.00±20、80.00±20和200.00±20 cells/L。夏季4种采样体积下采集到的浮游植物密度为1 000.00±50、288.40±20、45.24±10和0.05±0.01 cells/L,冬季为168.00±20、25.20±10、3.32±1和0.05±0.01 cells/L。结果显示不论夏季还是冬季,不同的采样方法和采样体积下采集到的船舶压载水浮游植物数量差异显著,因而采样方法和采样体积影响着船舶压载水浮游植物的采样效果,亟需在国际层面推动通过系统的科学研究,建立起统一准确的船舶压载水采样方法,为压载水港口国检测提供技术支撑,保护港口和海洋生态环境。     

Towards a more balanced view of marine ecosystems

Frank et al. (Nature, 477 , 2011, 86) hypothesize that the slow recovery of the Scotian Shelf ecosystem to its structure prior to the early 1990s is a result of the oscillatory, runaway consumption dynamics of the forage fish complex. Their hypothesis is based on the underlying assumptions that this ecosystem's dynamics are governed by top‐down forcing, predator–prey role reversals, and a trophic cascade extending from demersal predatory fish, especially cod, down to the level of nutrients (Science, 308 , 2005, 1621; Nature, 477 , 2011, 86). Greene and Pershing (Science, 315 , 2007, 1084) called into question the underlying assumption of an extended trophic cascade. They argued that while top‐down forcing can be important at higher trophic levels in many Northwest Atlantic Shelf ecosystems, its impacts on zooplankton, phytoplankton, and nutrients are minor or nonexistent. Instead, they argued that lower trophic‐level dynamics in these ecosystems are governed by climate‐associated, bottom‐up forcing. Observations over the past three decades (Greene et al. Ecology, 89 , (Suppl 11), 2008, S24; MERCINA Oceanography, 25 , 2012, 208.) are consistent with predictions from the climate‐forcing hypothesis proposed by Greene and Pershing (Science, 315 , 2007, 1084), while those from the past decade (MERCINA, Oceanography, 25 , 2012, 208) demonstrate that the trophic cascade hypothesis as proposed by Frank et al. (Science, 308 , 2005, 1621) should be rejected. A closer examination of these observations also calls into question the hypothesis of ecosystem recovery in the Northwest Atlantic being governed by the oscillatory, runaway consumption dynamics of the forage fish complex.     

Diatom derived polyunsaturated aldehydes do not structure the planktonic microbial community in a mesocosm study

Several marine and freshwater diatoms produce polyunsaturated aldehydes (PUA) in wound-activated processes. These metabolites are also released by intact diatom cells during algal blooms. Due to their activity in laboratory experiments, PUA are considered as potential mediators of diatom-bacteria interactions. Here, we tested the hypothesis that PUA mediate such processes in a close-to-field mesocosm experiment. Natural plankton communities enriched with Skeletonema marinoi strains that differ in their PUA production, a plankton control, and a plankton control supplemented with PUA at natural and elevated concentrations were observed. We monitored bacterial and viral abundance as well as bacterial community composition and did not observe any influence of PUA on these parameters even at elevated concentrations. We rather detected an alternation of the bacterial diversity over time and differences between the two S. marinoi strains, indicating unique dynamic bacterial communities in these algal blooms. These results suggest that factors other than PUA are of significance for interactions between diatoms and bacteria.     

投喂芽孢杆菌对鳜及饵料鱼养殖池塘水质和浮游生物的影响

采用一种芽孢杆菌制剂(Bacillus)对鳜(Siniperca chuatsi)及饵料鱼池塘进行水质调控。通过测定池塘水体的氨氮、亚硝酸盐、透明度及pH值等水质指标和池塘中浮游生物量,评价芽孢杆菌制剂对鳜及饵料鱼池塘水质和浮游生物的影响。结果表明,该芽孢杆菌制剂能够提高水质透明度,降解水体中氨氮和亚硝酸盐的含量,其中,亚硝酸盐的最大降解率为77.5%。投喂芽孢杆菌后,实验池塘和对照池塘浮游生物组成均变化不大,表明该制剂对池塘的浮游生物组成没有影响。