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1.
为了清晰了解温排水入海后的时空输移路径和温升范围,及其对海洋环境的影响,以湛江湾内的某电厂为例,应用ECOMSED海洋模式计算其温排水的时空输移路径及温升范围,并结合野外生态调查结果评价其对湛江湾内海洋生态环境的影响.结果表明：某电厂温排水导致湛江湾水体温升大于4℃、2℃、1℃的面积分别为0.110、0.480、1.629 km2,相对于约190 km2的湛江湾海域,影响面积很小;夏季浮游植物丰度随温度升高的变化率分别为-8.534%、-3.573%、-1.613%,浮游动物丰度随温度升高的变化率分别为-4.964%、-1.896%、-0.802%,温排水对浮游动、植物的影响夏季较冬季显著.某电厂温排水对湛江湾内海洋生态环境的影响即使在高温季节也不明显.  相似文献   

2.
The plankton community entrained in seawater used for cooling at Koeberg Nuclear Power Station was studied to determine the effects of short-term exposure to heat, chlorine and physical stress on plankton survival and productivity. Field-based studies conducted between September 1985 and February 1988 revealed that phytoplankton biomass, measured as chlorophyll a, was reduced by an average of 55,33 per cent following entrainment, and average productivity was depressed by 38,29 per cent, mainly as a result of chlorination. Zooplankton mortality averaged 17,48 per cent for all species and 21,88 per cent for copepods, the dominant group. Plankton entrainment at Koeberg was not considered to be particularly detrimental to the marine environment because of the localized area affected, the rapid dispersion of heat and chlorine, the rapid regeneration times of phytoplankton and some zooplankton, the low abundance of commercially important species, and the potential for recruitment from the surrounding productive Benguela upwelling region. A review of entrainment effects at overseas power stations is incorporated in the discussion.  相似文献   

3.
于2019年12月使用4种不同型号网具采集了珠江口浮游动物, 进行形态学鉴定和DNA分子鉴定, 分析珠江口浮游动物的群落结构特征, 并比较不同调查方法对浮游动物丰度和生物量结果的影响。形态学镜检鉴定浮游动物36种(类), 其中浮游幼虫6类。浅水I型浮游生物网采集的浮游动物平均丰度为115±96ind.·m-3, 平均生物量为0.21±0.14g·m-3; 浅水Ⅱ型浮游生物网采集的浮游动物平均丰度为3536±2444ind.·m-3, 平均生物量为0.56±0.33g·m-3; 浅水Ⅲ型浮游生物网采集的浮游动物平均丰度为4314±4172ind.·m-3, 平均生物量为0.50±0.25g·m-3; 25#浮游生物网采集的浮游动物平均丰度为6741±3826ind.·m-3, 平均生物量为4.33±3.42g·m-3。研究结果表明网具孔径大小对浮游动物研究结果具有重要影响, 三个站点水体DNA样品注释出15种浮游动物; 使用浅水Ⅱ型网采集的DNA样品注释出19种浮游动物; 镜检样品鉴定浮游动物17种。水体DNA样品能检测出更多的微型浮游动物如原生动物等; 网采样品能过滤更多的水样, 有利于采集更多的大中型浮游动物, 更能充分反映优势类群如桡足类的种类和数量。研究结果表明, 水体DNA可检出浮游幼虫和原生动物等较难镜检鉴别的种类, 采用不同型号网具采集浮游动物可以更全面地反映研究海域浮游动物的群落结构特征。多种调查方法的结合有助于全面了解研究海域的生态环境状况。  相似文献   

4.
象山港冬季浮游动物的分布   总被引：2，自引：0，他引：2  
对2002年12月象山港海区的浮游动物种类组成和数量分布特征及其与环境的关系进行了研究。结果表明,象山港海区出现浮游动物44种,可以划分为4个生态类群,其中近岸低盐性类群的种类较多,其优势种有真刺唇角水蚤Labidoceraeuchaeta、驼背隆哲水蚤Acro-calanusgibber、中华哲水蚤Calanussinicus、中华假磷虾Pseudeuphausiasinica和拿卡箭虫Sagittanagae等,半咸水河口类群、暖水性外海类群和广盐暖水性类群的种数均较少。浮游动物生物量的分布趋势与丰度的一致。湾顶部水域浮游动物的生物量和丰度都出现最高值,从湾顶部往湾口方向,浮游动物的生物量和丰度均呈逐渐降低的趋势。象山港海区周日连续站观测的结果显示,夜间半日潮时浮游动物的生物量和丰度均高于白昼半日潮时,低平潮时浮游动物的生物量与丰度均出现了最高值。  相似文献   

5.
基于2020年8月至11月在南海北部获取的声学多普勒流速剖面仪观测数据,利用后向散射强度数据估算得到相对体积散射强度并用其表征浮游动物生物量的相对大小,对相对体积散射强度的半月变化与具有半月周期的潮流动能进行相关性分析,进而分析天文大潮对声学估算的浮游动物生物量的影响。结果表明：半月周期的相对体积散射强度与潮流动能之间呈负相关关系,即天文大潮时,潮流动能较强,水体相对体积散射强度较低,浮游动物生物量则较小,天文小潮时则情况相反。初步推测其原因为：天文大潮时,强潮流一方面导致浮游动物生存环境恶化,使其生物量下降,另一方面也改变了浮游动物垂直迁移特性,浮游动物迁移到近海底处使其难以被观测。  相似文献   

6.
本研究于2015年在黑龙江省镜泊湖选取7个典型采样点,对镜泊湖春、夏两季间浮游生物群落结构的演替及其与环境因子关系进行分析。在调查期间共鉴定浮游植物152个分类单位,浮游动物38个分类单位,种类组成上浮游植物主要以绿藻门和硅藻门藻类为主,浮游动物以轮虫和原生动物为主。研究期间浮游生物优势种主要包括:河生集星藻(Actinastrumfluviatile(Schroed.)Fott)、梅尼小环藻(Cyclotella meneghiniana Kütz.)、谷皮菱形藻(Nitzschia palea (Kütz.) W.Smith)、前节晶囊轮虫(Asplanchna priodonta)、螺形龟甲轮虫(Keratella cochlearis)和瓶砂壳虫(Difflugia urceolata)。在研究期间水温、pH、电导率、和总氮在春、夏两季之间变化明显(P0.05或P0.01)。春、夏两季的浮游生物丰度呈现明显下降趋势(P0.05)。Spearman相关分析揭示镜泊湖水体浮游生物丰度与水温和电导率极其显著相关(P0.01)。冗余分析(RDA)表明,水温和电导率是驱动镜泊湖水体浮游生物群落生态分布的主要环境因子。与近10余年间镜泊湖相关研究对比发现,镜泊湖水体浮游植物群落结构较为稳定,浮游动物优势类群略有改变。综合营养状态指数评价表明镜泊湖水体为中营养状态,与前期研究结果相似,说明水体目前无进一步恶化的趋势。  相似文献   

7.
对虾池混养滤食性动物对浮游生物的影响   总被引：3，自引：0，他引：3  
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  相似文献   

8.
依据2011—2020年(2016年中断)黄河调水调沙工程实施前、后黄河口海域18个站位野外调查数据, 研究浮游动物种类组成和丰度变化及优势种更替, 以查明黄河口海域浮游动物的年间变动规律及调水调沙工程的影响。结果显示: 共记录浮游动物82种类(包括浮游幼体16类), 其中刺胞动物种类数最多, 共记录26种, 其次是桡足类出现23种。浮游动物种类组成的年间变化差异显著(P < 0.05), 2017年(未进行调水调沙)最低; 调水调沙前、后分别记录浮游动物69种和75种, 调水调沙前后种类数呈正相关(r=0.684, P=0.042); 调水调沙前后优势种更替率较高; 浮游动物丰度在2011—2015年较高, 2017—2020年相对较低, 调水调沙后浮游动物丰度年间变化达极显著水平(P < 0.01), 而调水调沙前后没有显著差异; 浮游动物丰度水平分布总体呈现从黄河口近岸到离岸递减趋势, 密集区位于黄河口北部近岸海域, 调水调沙后密集中心较调水调沙前向离岸海域略有推移。冗余分析表明, 对黄河口浮游动物年间变化影响较大的因子是叶绿素a浓度、溶解氧浓度和水温。研究表明: 2011—2020年调水调沙期间黄河口海域浮游动物丰度年间变动大于调水调沙前后变动, 调水调沙实施对浮游动物影响持续时间较短。  相似文献   

9.
The IMECOCAL Program began in 1997, with the objective of sampling plankton systematically in the Mexican region of the California Current. We present results of chlorophyll a concentrations and zooplankton displacement volumes for the eight cruises from September 1997 to October 1999. The abundance of 22 zooplankton groups was also analyzed for the first four cruises. The response of plankton to the 1997–1998 El Niño was atypical. From September 1997 to January 1998, chlorophyll a and zooplankton volume were at typical values (median integrated chlorophyll was 27 mg/m2 and zooplankton 100 ml/1000 m3 in 9801/02). After the peak of El Niño, the system shifted to cooler conditions. Integrated chlorophyll gradually increased to a median of 77 mg/m2 in April 1999. In contrast, zooplankton volumes decreased from October 1998 onward, despite favorable phytoplankton availability in 1999. Zooplankton structure was dominated by copepods and chaetognaths through the ENSO cycle, but interannual changes were evident. In the fall of 1997 there was a higher proportion of copepods, chaetognaths, and other minor groups, while the fall of 1998 zooplankton was richer in salps and ostracods. Historical data from previous Baja California CalCOFI cruises indicated that zooplankton volumes measured during the IMECOCAL cruises were above the long-term mean for the period 1951–1984. This suggests a differential response of plankton to the El Niño of 1997–1998 compared to the El Niño of 1957–1959. Regional differences in zooplankton volumes were also found, with central Baja California having 41% higher biomass than northern Baja California. Volumes from both regions were larger than those recorded by CalCOFI off southern California during 1997–1998, but the situation was reversed in 1999. The higher biomasses in the 1997–1998 El Niño can be attributed to high abundance of salps, which showed an affinity with warm, saline water.  相似文献   

10.
Research on New Zealand lakes over the past 25 years has focused mainly on eutrophication, measures of water quality, patterns, processes and production in plankton communities, and the spread and growth of submerged adventive macrophytes. Compared with most northern temperate lakes many New Zealand lakes show: low levels of inorganic nitrogen (N) and frequent N‐limitation of phyto‐plankton growth; diffuse, rather than point source, nutrient inflows; a great diversity of optical properties; unusual and often variable timing of plankton growth (attributed to the pervasive influence of New Zealand's oceanic climate); low productivity and biomass of zooplankton, which appear to be limited by food rather than predators; and sensitivity to invasion by adventive macrophytes. Notable research develop‐ments include improved methods of measuring nutrients, empirical predictive models that relate indices of eutrophication to nutrient loading, and significant advancements in methods of quantifying and measuring water colour and clarity.  相似文献   

11.
2009-08对乐清湾进行了生物调查。共鉴定浮游动物66种,浮游幼虫15类,分为半咸水河口类群、近海暖温带类群、近海暖水类群和大洋广布类群,其中近海暖水类群占主导地位。Ⅰ型网主要优势种有针刺拟哲水蚤、汤氏长足水蚤、太平洋纺锤水蚤、刺尾纺锤水蚤等;Ⅱ型网主要优势种有针刺拟哲水蚤、强额拟哲水蚤、太平洋纺锤水蚤、刺尾纺锤水蚤、短角长腹剑水蚤、简长腹剑水蚤、小长腹剑水蚤等。浮游动物优势种分布有明显差别,太平洋纺锤水蚤分布仅限于湾顶海区,小长腹剑水蚤密集区也在此区域,其它优势种则分布于乐清湾中部和湾口海区。浮游动物平均生物量为125.05mg/m3,平均丰度为234.00个/m3,数量分布呈现出从湾顶向湾口逐渐降低的趋势。  相似文献   

12.
The physical and chemical variability of the water column at subtidal station of an estuary in the Seto Inland Sea, Japan, was studied over a 24-hour period during a spring tide (tidal range ca. 2 m) in May 1995. Surface water and several depths through the water column were monitored every one and two hours, respectively. At each occasion, water temperature, salinity and dissolved oxygen concentration were measured and water samples were collected for the determination of nutrients and suspended particulate matter (SPM). Disruptive changes in the physical and chemical characteristics of the water was produced by the tidal cycle and the mixing of water masses of different origin. These changes were highly significant both spatially and temporally, yet with varying effects on physical parameters, nutrients and the different components of SPM. Significant differences in nutrient concentrations were also observed when the data-set was divided into ebb and flood components, irrespective of the depth. Nitrate and nitrite rose to 1.8 times higher during the flood. Spatial differences of SPM were less marked than those of nutrients, only particulate organic carbon (POC) being significantly higher at the surface than in the intermediate and the lower layer. Both POC and pheopigment concentrations increased markedly through the water column, being highest shortly before the lower low tide. In contrast, suspended solid (SS) content increased sharply after the lower low tide (>40 mg l−1) and this coincided with a marked decrease of the C/SS content (<20 mg g−1). The lagtime between POC and SS tidal transport was caused by particle resuspension from the exposed intertidal sediments as the tidal level rose, and particle transport selection in relation to the tidal state. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

13.
崇明东滩潮沟浮游动物数量分布与变动   总被引：3，自引：0，他引：3  
根据2008年4-12月对上海市崇明岛东滩潮沟进行4个季节的浮游动物调查资料,研究了崇明东滩潮沟浮游动物的数量分布及变动。结果表明,调查区浮游动物总丰度较高,四季变化明显。受潮汐作用的影响,夏、秋、冬三季落潮时丰度大于涨潮时,春季涨潮时丰度则大于落潮时。浮游动物在6条潮沟的平面分布不均匀,春季东旺沙边滩区和北八边滩区的数量明显多于近团结沙边滩区,夏、秋季分别以东旺沙边滩区和北八滧边滩区的数量最多,冬季则以近团结沙边滩区的数量最多。主要优势种细巧华哲水蚤(Sinocalanus tenellus)、中华华哲水蚤(Sinocalanus sinensis)、火腿许水蚤(Schmackeria poplesia)、四刺窄腹剑水蚤(Limnoithona etraspina)和四刺破足猛水蚤(Mesochra quadrispinosa)等数量的季节、潮汐变化及各时期的空间分布格局差异明显,其数量分布情况决定了浮游动物总数量的分布。盐度是影响冬、春季涨潮时浮游动物总丰度分布的主要因子,水温则是影响夏、秋季涨潮时总丰度分布的主要因子。此外,径流及潮流等动力因素对潮沟浮游动物数量的时空分布也产生重要影响。  相似文献   

14.
In September 2004, an extensive survey of a cold-core eddy in the Canada Basin, western Arctic was carried out with high-horizontal-resolution physical and chemical sampling and lower-horizontal-resolution biological sampling. The eddy was located over the continental slope north of the Chukchi Shelf and had a radius of ∼8 km. Its core was centered at a depth of ∼160 m. Water mass characteristics and the presence of copepods from the North Pacific Ocean (Neocalanus flemingeri and Metridia pacifica) demonstrated that the core contained water of Pacific origin. Vertical distributions of zooplankton were associated with the physical structure of the water column. For most taxa, concentrations in the eddy core were elevated compared with those in similar density water in the surrounding Basin. Based on tracer-age estimates and previous observations of eddy formation, the eddy is believed to have been formed during the previous spring/summer from the Chukchi shelfbreak jet. Surprisingly, the eddy also contained elevated abundances of Arctic-origin copepods (Metridia longa and Calanus glacialis). Analysis of a shelf–basin transect occupied in the region in August 2004 showed that these species were present in high abundances in relatively shallow water (50 m) inshore of the shelfbreak due to upwelling of deeper basin water, and copepods, onto the shelf in response to easterly winds. If the formation of the observed eddy occurred during, or shortly after, a period of such winds, upwelled Arctic-origin copepods on the shelf might have been entrained into the feature. Our observations suggest that formation and subsequent migration of such eddies may provide a mechanism for transporting zooplankton from the Chukchi Shelf into the interior Canada Basin. The periodic input of high abundances of zooplankton from productive shelf areas could affect food webs in the less productive basin.  相似文献   

15.
The monthly distribution of zooplankton communities in Han River estuary was investigated at two stations from July 1998 to June 1999. Monthly mean abundance of total zooplankton varied remarkably, with the range from 20 indiv.·m-3 to 19,600 indiv.·m-3. During the study period, dominant species of zooplankton community were dinoflagellateNoctiluca scintillans, copepodsParacalanus indicus, Paracaanus crassirostris, Acartia hongi, Acartia ohtsukai, and meroplanton cirriped larvae. According to tidal states, relative high abundance occurred at high tide without regard to season. The temporal distribution of abundance implied that the reduced salinity probably limited the zooplankton populations and the fluctuations of salinity were an important factor in the variation of abundance. However, the results of salinity tolerance test shows that the variations in salinity do not directly influence the decrease of abundance. This study shows that the relatively high abundance of zooplankton near high tide seems to be related with the expansion of abundant zooplankton inhabiting Incheon coastal waters through tidal currents.  相似文献   

16.
A comparison of the qualitative and quantitative characteristics of zooplankton caught by five different types of plankton nets was performed on the basis of the data of plankton surveys in various high production zones of the Pacific Ocean (392 zooplankton samples) in order to determine conversion coefficients for a more adequate quantitative estimation of plankton. In epipelagic zones, both the abundance and biomass of zooplankton caught by a Juday net were practically everywhere higher as compared to those estimated with the use of JuOM and Norpak nets but lower than the values obtained with Bongo nets. For the sake of the comparison of the quantitative estimations with different nets, we suggest coefficients equal to the ratios of the zooplankton biomass from a Juday net to the biomasses from other nets: from 0.4 to 1.5 for the total biomass values and from 0.3 to 2.3 for individual groups of zooplankton. The coefficients applied at the TINRO to account for the plankton underhauling with big Juday nets are reasonable and reliable for most of the dominating groups except for chaetognats, which are twice overestimated.  相似文献   

17.
The distribution of plankton across a warm-core eddy system in the California Current 400 km off Point Conception, California was studied in January 1981. The eddy system, about 150 km in diameter at the 7°C isotherm, was made up of a 75 m thick surface layer, a cold-core region extending from 75 m to about 200 m, and a warm-core eddy below 200 m extending to at least 1450 m. Casts for the vertical distribution of chlorophyll/phaeophytin and integrating zooplankton net tows were taken at 37 stations located about 20 km apart on two orthogonal transects across the eddy system. Vertical distributions of microplankton were determined on one section from the eddy center to beyond the eastern edge. Integrated chlorophyll/phaeophytin values were highest to the north and east of the eddy system; across the system itself, there was only a small increase of values near the center. Asymmetrical distributions of maximum concen Current water was being entrained into the center of the eddy system from the northeast. Dinoflagellates were numerically the most important member of the microplankton, especially in the deep chlorophyll maximum. Zooplankton distributions indicated the intermingling of warm and cool water species throughout at least the upper 200 m of the eddy system. Some cold water species were as abundant inside the system as outside to the north and east; their numbers were much reduced in a band surrounding the system where warm water species were most abundant. The presence of species characteristic of different water types throughout the region of the eddy system provides an indication of the mixing that had occurred since the system originally formed. The biological data, together with the physical and chemical results, indicate the importance of frontal boundary processes and lateral entrainment of surrounding water into the eddy system in determining the character and productivity of such systems.  相似文献   

18.
Models and laboratory experiments show that zooplankton may locate food more easily in turbulent waters, but whether plankton seek or avoid turbulence in the ocean is an open question. It is difficult to measure turbulence and plankton simultaneously and with the necessary spatial resolution using traditional methods (nets and airfoil shear sensors). Acoustics is commonly used to survey zooplankton abundance and recent studies have shown that stratified turbulence can also be a significant source of sound scatter. This may seem like more of a complication than a boon for those aiming to use acoustics to observe plankton in turbulence. We present acoustic data, however, that show that zooplankton and turbulence can be observed simultaneously with a single 307 kHz sounder. The different natures of the two targets (discrete targets versus a volume effect) allow them to be distinguished. The key is sampling the same targets at multiple ranges. The volume scattering strength of a discrete target will increase as the target nears the sounder, because the volume sampled decreases. Turbulence, as a volume scattering effect, has little range dependence to its volume scattering strength.  相似文献   

19.
春季水库浮游生物与鲢鳙生长的关系   总被引：1，自引：0，他引：1  
通过 2 0 0 0年春季对辽宁三座大中型山谷型水库的浮游生物和鲢鳙渔获物的 4、5月二次调查发现 :( 1) . 4月 ,各水库浮游植物生物量与其鲢鳙年平均渔获量正相关 ( p<0 .10 ) ,同时发现浮游植物在各水库的空间分布与环境因子无显著关系 ,浮游植物与浮游动物之间只有在产量较低的碧流河水库有极其显著的正相关关系 ( p<0 .0 1) ;但此时三水库浮游动物生物量的空间分布都与水温或流速相关显著 ( p<0 .0 5 ) ;( 2 ) . 5月 ,这种现象消失 ,而发现浮游植物多样性指数较 4月的比值与渔获量存在极显著的负相关关系 ( p<0 .0 1) ,浮游植物量空间分布的变异性与渔获量存在极显著的负相关关系 ( p<0 .0 2 ) ,浮游动物空间分布变异性与 4月的比值与渔获量存在显著负相关关系 ( p<0 .0 7) ;而且只有在鱼产量最低的碧流河水库显示了浮游动物生物量的空间分布与环境因子 (水温 )相关 ( p<0 .10 ) ;( 3) .鲢鳙肥满度和增重率显示与上述结果相对应 ,即浮游生物空间分布越不均匀 ,浮游植物的多样性指数随着温度的升高幅度越大的水库 ,鲢鳙的生长速度越快。认为 :1.鲢鳙的摄食 ,导致浮游生物的空间分布更均匀 ,而且使浮游植物的多样性受到限制 ;2 .用浮游生物空间分布的不均匀程度以及多样性指数的变化 ,可以用来评价和指导  相似文献   

20.
Many studies have been conducted in northern Norwegian shelf regions to assess distributions and abundances of zooplankton in the last decade using towed Scanfish-conductivity, temperature and depth sensors (CTD)–optical plankton counter (OPC), and plankton nets. Significant progresses have been made in understanding dominant species, life histories and behavior, and in using size-structured data to identify dominant species in a certain size range. Using these Scanfish–CTD–OPC data, the analysis of zooplankton community size structures, compositions and their relationships with water types is made along the shelf region from Lofoten, North Cape to Varangerfjorden. From the relationships between the water types and zooplankton communities, the transports and exchanges of zooplankton communities between the Norwegian Coastal and Norwegian Atlantic Waters in regions near Malangsgrunnen and Nordvestbanken are examined. The biovolume (biomass) spectra are further analyzed for the productivity, trophic levels and seasonality of communities in these regions, indicating a steeper slope of the biovolume spectrum for a community dominated by herbivorous species in spring and a flatter slope for a community dominated by carnivorous–omnivorous species in winter. The comparison with the zooplankton biovolume spectra obtained in areas west of Antarctic Peninsula is made to examine and understand the differences in the zooplankton biovolume spectra, their trophic dynamics and potential human impacts between different regions.  相似文献   

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