共查询到20条相似文献，搜索用时 436 毫秒
1.
ENSO现象与台湾海峡西部海区浮游生物的关系——台湾海峡西部海区ENSO渔场 总被引：3，自引：0，他引：3
本文探讨了台湾海峡西部海区ＥＮＳＯ现象与浮游生物及海洋环境的关系,得出结论：在ＥＮ１年春季（包括ＥＮ２年次年）海洋环境为优或较优,浮游生物数量大或较大;反之,在非ＥＮ年春季则否。同样在非ＥＮ年夏季,海洋环境则为优或较优,浮游生物数量大或较大;反之,在ＥＮＲ上夏季则否。 相似文献
2.
3.
台湾海峡西部海域糠虾类的分布 总被引：3，自引：0，他引：3
本文利用1984年5月—1985年2月台湾海峡西部海域海洋综合调查所获的浮游生物样品,分析研究了该海域糠虾的数量分布和季节变化。 相似文献
4.
埃尔尼诺现象与东海黑潮区及其邻近海域水文结构和环流的变异──东海黑潮区及其邻近海区ENSO渔场学问题之一 总被引：2，自引：0，他引：2
本文阐明ENSO现象与台湾岛东北部冷涡关系,在EN年（包括EN2年次年）夏季仅能出现东北型及该型双涡Ⅰ型,而非EN年和EN年（除夏季外）则出现东侧型和西侧型及双涡Ⅱ,Ⅲ型。此外还在前人研究基础上,给出东海东北部（非EN年和EN年除夏季外）环流图式和在EN年（包括EN2年次年）夏季环流图式。还对海洋锋等进行初步讨论。 相似文献
5.
乐清湾口海域春秋季甲壳动物的群落结构特征研究 总被引：3，自引：1，他引：2
根据2012年春季和10月在乐清湾口海域开展渔业资源调查所获甲壳动物资料,对乐清湾口海域的甲壳动物的种类组成、优势种、物种数量分布、生物多样性和群落结构相似性等群落结构特征及其影响因素进行了研究。结果表明,调查海域共鉴定出34种甲壳动物,隶属于2目17科23属,春季优势种仅有三疣梭子蟹1种,秋季为日本、口虾蛄、中华管鞭虾、三疣梭子蟹4种,两季优势种更替较显著;秋季物种数较春季丰富,调查水域中心区域物种数较多;秋季甲壳动物生物多样性指数高于春季;甲壳动物群落结构与海洋环境密切相关。乐清湾口海域的甲壳动物以季节性的广温低盐种类为主,该海域位于河口,受瓯江径流影响较大;春季受瓯江径流淡水水团影响,物种较少,而秋季受交汇水团影响,物种丰富;春秋季组内并无明显规律,地形、水深和水系等外部因素对甲壳动物群落结构影响较大。 相似文献
6.
春季冷水团的强度,取决于冷水区的最低水温及面积。本文取该二指标的多年距平绝对值的平均值之半作为标准,划分1960—1980年四、五月北黄海西部冷水团的强度(表1)。 冷水团强度与去年冬季的气候条件有密切相关关系。去冬水温较低,则气温的负逐日累计值越大,北风也越多,今春冷水则强;反之则否。 本文认为,使用依上述因子建立的回归方程预报冷水强度,会得到较好的结果。 相似文献
7.
《热带海洋学报》2016,(3)
依据2009年冬季、2010年春季和夏季在南日列岛西南部海区3个航次的渔业资源综合调查资料,通过对南日列岛西南部海区鱼类资源密度及分布特征、体长、体重、幼体比、优势种、相对重要性指数以及优势种对鱼类总数量的贡献,讨论了南日列岛西南部海区鱼类数量变化及其与水团变化之间的关系。结果表明:春、夏、冬3季鱼类重量密度分别为601.26kg·km~(-2)、2599.60kg·km~(-2)和730.36kg·km~(-2);尾数密度分别为17.3×10~3尾·km~(-2)、255.00×10~3尾·km~(-2)和22.6×10~3尾·km~(-2);平均体长、体重和幼体比分别在春季、冬季和夏季为最高,分别为14.95cm、49.76g和81.72%。春季主要由产卵群体组成,多为规格较大的成鱼;夏季由索饵群体组成,多为规格较小的幼鱼。鱼类数量的平面分布与福建近海不同季节水团的变化有关,春季鱼类聚集在闽浙沿岸水和海峡暖水交汇的外侧海域,夏季鱼类多聚集在营养盐丰富,沿岸流控制的近海海域。各季节鱼类数量分布特征与优势种分布基本一致。 相似文献
8.
ENSO现象在夏季对台湾海峡南部浮游桡足类分布的影响 总被引：3，自引：0，他引：3
EFFECTSOFENSOEVENTSONPELAGICALCOPEPODAINSOUTHERNTAIWANSTRAITINSUMMER浮游桡足类是浮游动物最重要的类群。它种类多,数量大,是海洋生态系中物质循环和能量流动一个重要环节,也是研究海洋生物地球化学过程一个组成部分。台湾海峡南部处于南海北部与海湾海峡一个接合部,该处水系十分复杂,是闽南渔场的所在地。方金钏等1979年,陈清潮1983年,费加祺等1991,1997年报道了该区域有关浮游动物方面的研究,但有关该区域浮游桡足类年变化的研究未见报道,特别是1997年5月～1998年春季,发生了本世纪以来最强… 相似文献
9.
《中国海洋大学学报(自然科学版)》2020,(Z1)
海洋浮游生物是一个复杂而庞大的生物群落,种类繁多、数量庞大,对海洋环境、生态、渔业及海洋基础科学研究具有重要的科研价值与现实意义。为实现对海洋浮游生物和颗粒物的实时原位,高分辨率,非侵入式成像,研发了OUC-HoloCam~(200)水下原位同轴数字全息浮游生物探测系统。OUC-HoloCam~(200)基于同轴数字全息技术,具有高精度、大景深的优点,仪器结构紧凑、集成度高,易于安装在各种水下观测平台上。该仪器可在海洋生物学、海洋光学、海洋环境监测等领域发挥一定的作用。OUC-HoloCam~(200)已在南海近岸地区进行了浅海测试,并已连续工作超过48 h,在海试期间,已记录超过5.4万张高质量的原位全息图。 相似文献
10.
11.
Robert C. Thunell 《Deep Sea Research Part I: Oceanographic Research Papers》1998,45(12):2059-2083
A six-year time series of sediment trap samples is used to document seasonal and interannual changes in particle fluxes in Guaymas Basin, Gulf of California. Sedimentation in this region of the Gulf of California is dominated by two seasonally varying components: biogenic silica during the late fall–spring and lithogenic material during the summer. This variability in sediment fluxes is a direct response to the seasonally reversing monsoon climate in this region. In addition, this seasonal variability in particle flux to the seafloor combined with the lack of bioturbation results in the formation of sediment laminae or varves in Guaymas Basin. Observed interannual differences in the magnitude of sediment fluxes appear to be related to ENSO. These findings indicate that biogenic sediment fluxes, and hence primary productivity, are higher during non-ENSO years in the central Gulf of California. A decrease in the carbonate: opal flux ratio from 1991 to 1996 indicates that diatoms became an increasingly important component of the plankton during this period and further supports our findings that productivity in Guaymas Basin is higher during non-ENSO years. 相似文献
12.
《Deep Sea Research Part II: Topical Studies in Oceanography》2009,56(24):2487-2502
Six research cruises were conducted off the west coast of Vancouver Island between April and October of 1997 and 1998 as part of the Canadian GLOBEC project to compare nutrient and phytoplankton dynamics between ENSO (1997) and non-ENSO (1998) years. Limited sampling also was conducted during three cruises in 1999. During the 1997 ENSO period, there was a shallow thermocline (∼10 m) that resulted in a shallower mixed layer, lower salinity and density, and stronger summer stratification. In general on the shelf, the 1997 growing season was characterized by higher nitrate (7.5 μM) and silicic acid (17 μM) concentrations, lower total chlorophyll (∼76 mg m−2), lower phytoplankton carbon biomass (0.2 mg C L−1), and lower diatom abundance and biomass than in 1998. Phytoplankton assemblages were dominated by nanoplankton in 1997 and by diatoms in 1998. These results suggest that the 1997 ENSO was responsible for a reduction in the growth and biomass of larger phytoplankton cells. In mid-1998, the hydrographic characteristics off the west coast of Vancouver Island changed suddenly. The 1997 poleward transport of warm water reversed to an equatorward transport of coastal water in July 1998, which was accompanied by normal summer upwelling. During 1998, a large diatom bloom (mainly dominated by Chaetoceros debilis, Leptocylindrus danicus and to a lesser extent by Skeletomema and Pseudo-nitzschia sp.) was observed in July over the continental shelf. This large bloom resulted in chlorophyll concentrations of up to 400 mg m−2, primary productivity of up to 11 g C m−2 d−1, and near undetectable dissolved nitrogen concentrations at some of the shelf stations in 1998. In contrast, during 1997, the sub-tropical waters that were advected over the slope, resulted in low chlorophyll a and primary productivity (generally <1 g C m−2 d−1). Therefore, there was a sharp contrast between the very high primary productivity on the shelf in July 1998, due to normal nutrient replenishment from summer upwelling and outflow from the Strait of Juan de Fuca, and the lower primary productivity during the 1997 ENSO year. During 1998, non-ENSO conditions resulted in phytoplankton biomass that was twice as high on the shelf as that measured in regions beyond the continental shelf of the west coast of Vancouver Island. 相似文献
13.
Fishery along the west coast of India largely depends on pelagic fish such as oil sardines, which are dominant during the south‐west monsoon. However, the response of sardine population to the warming caused by the climatic events such as El Niño/Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) is poorly studied. Here, we hypothesize that the ENSO‐related changes in biogeochemistry can adversely affect the oil sardines. We have used biogeochemical data collected along the Kerala coast during September 2015 (ENSO year) and September 2017 (a normal year) supported by catch per unit effort (CPUE) and fishery landing data to show the ENSO‐related bio‐physical dynamics and its impact on the oil sardine population along the south‐west coast of India. During the 2015 ENSO year, upwelling velocity decreased minimizing cooling of surface waters and resulted with an increase in sea surface temperature (SST) (~1.8°C). Consequent decrease in nutrient levels favoured nano‐phytoplankton and pico‐phytoplankton. On the other hand, during September 2017 when the ENSO effect was nullified, the decreased SST and availability of nutrients in the euphotic zone resulted in the dominance of micro‐phytoplankton. The hydrographic conditions (reduction in upwelling intensity), and reduction in micro‐phytoplankton abundance and zooplankton density in turn perhaps affected the fishery potential of the region. Oil sardines population (along the west coast) collapsed from 1.55 lakh tones (2014) to 0.46 lakh tones during 2015–2016 ENSO event, while in 2017 the conditions become favorable and their population was back to normal (1.27 lakh tones). Our results are in close agreement with our hypothesis and suggest that ENSO events could reduce phytoplankton productivity and disrupt the food chain, which in turn can affect the oil sardine population along the west coast of India. 相似文献
14.
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
15.
The statistical technique of functional data analysis (FDA) is applied to a time series analysis of plankton monitoring data. The analysis is focused on revealing patterns in the seasonal cycle to assess interannual variability of several different taxonomic groups of plankton. Cell concentrations of diatom, dinoflagellate and zooplankton abundances from the Bay of Fundy, Canada provide the observations for analysis. FDA was performed on the log-transformed abundance data as a new approach for treating such types of sparse and noisy data. Differences in the seasonal progression were seen, with peak numbers, timings and abundance levels varying for the three groups as determined by curve registration and higher order derivatives using the objectively fit FDA curves. Nonmetric multidimensional scaling was used to capture seasonal variation among years. These results were further assessed in terms of dominant species and the relationships between groups for different seasons and years. It is anticipated that the easy to use, general and flexible technique of FDA could be applied to a wide variety of marine ecological data that are characterized by missing values and non-Gaussian distributions. 相似文献
16.
夜光藻是全球广泛分布的藻华种之一, 其摄食作用对浮游生物的群落结构有着重要影响。利用环境DNA技术和Spearman相关性分析, 文章研究了2021年1月中旬大亚湾夜光藻高丰度站位浮游生物的群落结构与生物相关性。结果显示, 夜光藻高丰度站位的海水温盐条件为温度 14.4~18.3℃、盐度 32.52‰~33.14‰。夜光藻丰度较高的站位中, 卡顿藻科、海链藻科等浮游植物类群的相对丰度均值为2.41%和2.23%, 明显高于其他站位的0.75%和0.62%; 同时拟哲水蚤科与长腹剑水蚤科等类群的相对丰度均值为8.22%和4.46%, 明显低于其他站位的64.13%和11.12%。结合Spearman相关性分析表明, 夜光藻丰度增加可能导致其对拟哲水蚤科等类群摄食压力增加, 拟哲水蚤科类群丰度减少降低了卡顿藻科、海链藻科、原甲藻科、隐芽藻科等浮游植物类群的摄食压力, 使其生物丰度增加; 同时夜光藻摄食压力增加使得裸甲藻科、圆筛藻科等浮游植物丰度下降。因此, 夜光藻丰度增加影响了水域中真核浮游生物群落结构。综上结果表明, 环境DNA技术有助于认识夜光藻在浮游生物群落中的生态地位, 可用于浮游生物各类群之间的关系分析。 相似文献
17.
18.
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
19.
The impact of the scyphomedusa Aurelia sp. on planktonic assemblages was experimentally studied in enclosures incubated in situ in the sea lake of Mljet Island (Big Lake, Southern Adriatic), where jellyfish are present throughout the year. In situ feeding experiments using plankton at natural densities indicated a reduction in abundance for small calanoid and cyclopoid copepods, copepodites, nauplii and ciliates in the presence of Aurelia sp. In addition to direct predatory pressure, Aurelia sp. exerted an indirect cascading effect on autotrophic and heterotrophic microbial plankton. Phytoplankton biomass increases of up to 0.5 μg C·l?1·h?1 were mainly related to 19′‐hexanoyloxyfucoxanthin‐ and 19′‐butanoyloxyfucoxanthin‐containing phytoplankton. Bacterial production was about twice as high in the presence of Aurelia sp. and biomass was also consistently higher. It appears that the top‐down effect of predation along with material release by Aurelia sp. results in increases in microbial biomass and production. 相似文献
20.
Pacific Basin climate variability and patterns of Northeast Pacific marine fish production 总被引：1，自引：0，他引：1
A review of oceanographic and climate data from the North Pacific and Bering Sea has revealed climate events that occur on two principal time scales: a) 2–7 years (i.e. El Niño Southern Oscillation, ENSO), and b) inter-decadal (i.e. Pacific Decadal Oscillation, PDO). The timing of ENSO events and of related oceanic changes at higher latitudes were examined. The frequency of ENSO was high in the 1980s. Evidence of ENSO forcing on ocean conditions in the North Pacific (Niño North conditions) showed ENSO events were more frequently observed along the West Coast than in the western Gulf of Alaska (GOA) and Eastern Bering Sea (EBS). Time series of catches for 30 region/species groups of salmon, and recruitment data for 29 groundfish and 5 non-salmonid pelagic species, were examined for evidence of a statistical relationship with any of the time scales associated with Niño North conditions or the PDO. Some flatfish stocks exhibited high autocorrelation in recruitment coupled with a significant step in recruitment in 1977 suggesting a relationship between PDO forcing and recruitment success. Five of the dominant gadid stocks (EBS and GOA Pacific cod, Pacific hake and EBS and GOA walleye pollock) exhibited low autocorrelation in recruitment. Of these, Pacific hake, GOA walleye pollock and GOA Pacific cod exhibited significantly higher incidence of strong year classes in years associated with Niño North conditions. These findings suggest that the PDO and ENSO may play an important role in governing year-class strength of several Northeast Pacific marine fish stocks. 相似文献