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1.
荣成湾毗邻海域浮游动物群落季节分布特征 总被引：2，自引：0，他引：2
利用2009年度4个季度月的现场调查资料研究了荣成湾毗邻海域浮游动物群落的季节分布特征。研究表明, 在荣成湾毗邻海域出现的浮游动物共59个种类, 秋季、夏季和春季浮游动物均为30种以上(依次为38种、35种和32种), 而冬季种类数相对较少(22种)。浮游动物优势种主要为强壮箭虫(Aidanosagitta crassa)、中华哲水蚤(Calanus sinicus)、小拟哲水蚤(Paracalanus parvus)和拟长腹剑水蚤(Oithona similis)等种类, 其个体丰度的空间和季节分布特征差异较大。浮游动物湿重生物量冬季最高(433.8 mg/m3), 春季(220.7 mg/m3)和秋季(162.4 mg/m3)次之, 而夏季(52.5 mg/m3)相对较低。浮游动物群落物种多样性指数H′年平均值为2.50, 均匀性指数J′年平均值为0.65, 季节比较上, 夏季浮游动物多样性和均匀度均较高, 而春季多样性和均匀性平均值为低值, 且最大值和最小值之间波动范围较大。进一步分析显示, 湾内的筏架养殖对浮游动物群落的分布有显著影响。 相似文献
2.
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
3.
Zooplankton diel vertical migration is evident on the mixed isothermal side of the western Irish Sea frontal system but is often influenced by large tides and persistent geostrophic currents. On the stratified side of the front, temperature acts as a controlling factor with most of the zooplankton occurring above the thermocline and carrying out pronounced vertical migration when chlorophyll a levels are low and diffuse. At higher chlorophyll levels, when discrete chlorophyll a maxima form, zooplankton vertical movement may be greatly modified with a large number of species and stages concentrating within these maxima at all times of the diel light cycle. 相似文献
4.
《Deep Sea Research Part II: Topical Studies in Oceanography》2009,56(25):2656-2670
Zooplankton metabolic rates, determined from electron transfer system (ETS) activity, were studied at two seamounts (Seine: 34°N, 14°W, summit depth ∼170 m; Sedlo: 40°N, 27°W, summit depth ∼750 m) in the northeast (NE) Atlantic during three cruises in November 2003, April 2004 and July 2004. ETS activity and respiratory carbon demand were measured for samples taken at seamount and open-ocean locations in order to probe the hypothesis of locally enhanced seamount productivity. ETS activity and biomass revealed no consistent diel patterns of feeding activity and vertical migration at Seine and Sedlo Seamounts. Spatial differences of biomass-specific ETS activity were observed at both seamounts and coincided with differences in food abundance and quality. At Seine Seamount in April 2004, biomass-specific ETS activity was on average higher at the seamount locations compared to the open ocean, though the enhancement was of a lower magnitude than spatial and temporal variability and had no apparent influence on zooplankton respiratory carbon demand or biomass. A persistent pattern of reduced zooplankton biomass above the summit location at Seine Seamount in April 2004 and July 2004 resulted in a local reduction of respiratory carbon demand. At Sedlo Seamount in November 2003, large spatial differences in biomass-specific ETS activity observed at the seamount locations resulted in a large range of respiratory carbon demand at the seamount, but were not reflected in zooplankton biomass. The depth-integrated (0–150 m) median respiratory carbon demand of the zooplankton community estimated from day and night hauls was 2.1 mg C m−2 d−1 at Seine Seamount (range: 0.3–6.3) and 2.9 mg C m−2 d−1 at Sedlo Seamount (range: 1.6–12.0). The sporadic nature and low magnitude of locally higher zooplankton respiration rates at the seamounts, which did not result in locally higher zooplankton standing stock biomass, lead us to reject the hypothesis that locally enhanced seamount productivity provides an autochthonous food supply to the resident faunas at Seine and Sedlo Seamounts. Instead, we conclude that the faunas at both seamounts are more likely supported by advection of food from the surrounding ocean. 相似文献
5.
Boris Cisewski Volker H. Strass Monika Rhein Sören Krägefsky 《Deep Sea Research Part I: Oceanographic Research Papers》2010,57(1):78-94
Ten-month time series of mean volume backscattering strength (MVBS) and vertical velocity obtained from three moored acoustic Doppler current profilers (ADCPs) deployed from February until December 2005 at 64°S, 66.5°S and 69°S along the Greenwich Meridian were used to analyse the diel vertical zooplankton migration (DVM) and its seasonality and regional variability in the Lazarev Sea. The estimated MVBS exhibited distinct patterns of DVM at all three mooring sites. Between February and October, the timing of the DVM and the residence time of zooplankton at depth were clearly governed by the day–night rhythm. Mean daily cycles of the ADCP-derived vertical velocity were calculated for successive months and showed maximum ascent and descent velocities of 16 and –15 mm s?1. However, a change of the MVBS pattern occurred in late spring/early austral summer (October/November), when the zooplankton communities ceased their synchronous vertical migration at all three mooring sites. Elevated MVBS values were then concentrated in the uppermost layers (<50 m) at 66.5°S. This period coincided with the decay of sea ice coverage at 64°S and 66.5°S between early November and mid-December. Elevated chlorophyll concentrations, which were measured at the end of the deployment, extended from 67°S to 65°S and indicated a phytoplankton bloom in the upper 50 m. Thus, we propose that the increased food supply associated with an ice edge bloom caused the zooplankton communities to cease their DVM in favour of feeding. 相似文献
6.
基于声学仪器与粒径分析仪研究东海浮游动物昼夜垂直迁移过程 总被引：1，自引：0，他引：1
浮游动物的昼夜迁移活动与其种群变动和摄食节律紧密联系,浮游动物昼夜移动的研究已经成为种群动力学研究的一个重要组成部分。2013年夏季在浙江东部近海,结合声学多普勒流速剖面仪(ADCP)和激光粒径分析仪(LISST-100)等仪器进行了一次定点周日连续观测。通过声学反演方法,得到后向散射强度剖面的时间变化,结合LISST-100得到的水体悬浮物粒径谱,研究了浮游动物垂直迁移及其习性。分析发现了可能是精致真刺水蚤的一次昼夜垂直迁移过程,其在夜间进入跃层附近进食,白天蛰伏于底层低温高盐的台湾暖流水中,垂向迁移速度达到了0.05 m/s。LISST-100观测还发现在夜间跃层边界处大粒径颗粒聚集和100～150 μm大小的颗粒物的减少,水体中不同粒径的悬浮颗粒物有明显的昼夜变化节律,推测水体中不同层次生物群落结构存在昼夜差异。 相似文献
7.
《Deep Sea Research Part I: Oceanographic Research Papers》2000,47(1):137-158
The least known component of the “biological pump” is the active transport of carbon and nutrients by diel vertical migration of zooplankton. We measured CO2 respiration and dissolved organic carbon (DOC) excretion by individual species of common vertically migrating zooplankton at the US JGOFS Bermuda Atlantic Time-series Study (BATS) station. The inclusion of DOC excretion in this study builds on published research on active transport by respiration of inorganic carbon and allows a direct assessment of the role of zooplankton in the production of dissolved organic matter used in midwater microbial processes. On average, excretion of DOC makes up 24% (range=5–42%) of the total C metabolized (excreted+respired) and could represent a significant augmentation to the vertical flux that has already been documented for respiratory CO2 flux by migrant zooplankton. Migratory fluxes were compared to other transport processes at BATS. Estimates of combined active transport of CO2 and DOC by migrators at BATS averaged 7.8% and reached 38.6% of mean sinking POC flux at 150 m, and reached 71.4% of mean sinking POC flux at 300 m. DOC export by migrator excretion averaged 1.9% and reached 13.3% of annual DOC export by physical mixing at this site. During most of the year when deep mixing does not occur, diel migration by zooplankton could provide a supply of DOC to the deeper layers that is available for use by the microbial community. A carbon budget comparing migrant zooplankton transport to the balance of fluxes in the 300–600 m depth strata at BATS shows on average that the total migrant flux supplies 37% of the organic carbon remineralized in this layer, and that migrant DOC flux is more than 3 times the DOC flux gradient by diapycnal mixing. New estimates of active transport of both organic and inorganic carbon by migrants may help resolve observed imbalances in the C budget at BATS, but the magnitude is highly dependent on the biomass of the migrating community. 相似文献
8.
《Estuarine, Coastal and Shelf Science》2005,62(1-2):205-215
Plankton samples collected in November 2002, February, May and August 2003 were used to examine seasonal variation in tidal exchange of zooplankton biomass, abundance and species composition between Lough Hyne Marine Nature Reserve and the adjacent Atlantic coast. Micro- to mesozooplankton were collected by pump over 24-h sampling periods during spring and neap tides from the narrow channel connecting the semi-enclosed water body to the Atlantic. Sample biomass (dry weight) and total zooplankton abundance peaked in the summer and were lowest in winter, showing a positive relationship with temperature. Zooplankton biomass, total abundance and numbers of holo- and meroplankton revealed import during some diel cycles and export in others. However, the tidal import of these planktonic components was generally dominant, especially during May. The greatest import of numbers of holoplankters and meroplanktonic larvae occurred during May and August, respectively. There was no significant variation in sample biomass between periods of light and dark, but some variation in zooplankton abundance could be explained by this diel periodicity. Significant differences in sample assemblage composition between flood and ebb tide samples were always observed, except during winter neap tides. There was a net import of the copepods Temora longicornis and Oithona helgolandica and the larval stages of Mytilus edulis during spring and summer. Proceraea cornuta and Capitellid trochophores were imported during winter, and a hydrozoan of the genus Obelia during the spring spring tides. Seasonal export from the lough was shown by Pseudopolydora pulchra larvae (autumn and spring), Serpulid trochophores (autumn) and veligers of the bivalve Anomia ephippium (summer). It is suggested that the direction of tidal exchange of meroplanktonic taxa is related to the distribution of the adult populations. Copepod naupliar stages dominated the assemblages except during May spring tides when the copepod Pseudocalanus elongatus made up over 22% of the abundance. The general import of micro- to mesozooplankton may, in part, explain the higher densities of this size-class of zooplankton within the semi-enclosed system of Lough Hyne. 相似文献
9.
Myctophids are among the most abundant fishes in the world׳s ocean and occupy a key position in marine pelagic food webs. Through their significant diel vertical migrations and metabolism they also have the potential to be a significant contributor to carbon export. We investigated the feeding ecology and contribution to organic carbon export by three myctophid species, Benthosema glaciale, Protomyctophum arcticum, and Hygophum hygomii, from a structurally and ecologically unique ecosystem- the Mid-Atlantic Ridge (MAR). Similar to the results of previous studies, the diet of these fishes was primarily copepods and euphausiids, however, gelatinous zooplankton was identified in the diet of B. glaciale for the first time. Ridge section and time of day were significant explanatory variables in the diet of B. glaciale as determined by canonical correspondence analysis, while depth was the only significant explanatory variable in the diet of P. arcticum. Daily consumption by MAR myctophids was less than 1% of dry body weight per day and resulted in the removal of less than 1% of zooplankton biomass daily. Although lower than previous estimates of carbon transport by myctophids and zooplankton in other areas, MAR myctophid active transport by diel vertical migration was equivalent to up to 8% of sinking particulate organic carbon in the North Atlantic. While highly abundant, myctophids do not impart significant predation pressure on MAR zooplankton, and play a modest role in the active transport of carbon from surface waters. 相似文献
10.
基于声学方法的南黄海浮游动物垂直迁移季节变化研究 总被引：2，自引：1，他引：1
为研究南黄海浮游动物垂直迁移的季节变化, 分析了2006 年至2007 年4 个季节布放潜标中声学测流仪的观测数据。结果是: 声学测流仪测量的后向散射强度呈现显著的日变化特征, 这是由浮游动物垂直迁移造成的; 在4 个季节中都出现这一凌晨向下、黄昏向上的垂直迁移, 但是垂直迁移发生的时间有季节变化。利用南黄海辐射通量的直接观测数据, 讨论了垂直迁移发生时间与光照的关系,结果表明垂直迁移的季节变化主要受光照的影响。这对于研究浮游动物垂直迁移机制有一定意义。 相似文献
11.
Victor S. Kuwahara Grace Chang Xiaobing Zheng Tommy D. Dickey Songnian Jiang 《Journal of Oceanography》2008,64(5):691-703
Buoy-mooring platforms are advantageous for time-series validation and vicarious calibration of ocean color satellites because
of their high temporal resolution and ability to perform under adverse weather conditions. Bio-optical data collected on the
Bermuda Testbed Mooring (BTM) were used for comparison with satellite ocean color data in an effort to further standardize
sampling and data processing methods for high quality satellite-mooring comparisons. Average percentage differences between
satellite-measured and mooring-derived water leaving radiances were about 20% at the blue wavelengths, decreasing to as low
as 11% in the blue-green to green wavebands. Based on a series of data processing methods and analyses, recommendations concerning
rigor of quality control for collected data, optimal averaging of high-frequency data, sensor self-shading wind corrections,
and instrumentation placement requirements are given for the design and application of optical moorings for ocean color satellite
validation. Although buoy-mooring platforms are considered to be among the very best methods to validate ocean color satellite
measurements, match-up discrepancies due to water column variability and atmospheric corrections remain important issues. 相似文献
12.
Acoustic volume backscattering strength data were collected and Conductivity Temperature Depth (CTD) measur e m e n t s were
conducted in the southern Yellow Sea in summer 2005 and 2006. The high temporal and vertical resolution acoustic data measured
with a 307 kHz Acoustic Doppler Current Profiler (ADCP) and a 250 kHz acoustic Doppler profile (ADP) had dominant diel variation,
which resulted from vertical migration of sound scatterers. Some scatterers congregating in the bottom layer in the daytime
migrated upward at dusk, and migrated downward into the bottom layer at dawn. The migration speeds were estimated. More than
33 days data show that the diel migration varies with time. The feature of migration measured with ADCP and ADP is consistent
to some extent with what is described in the study on vertical migration of zooplankton in the southern Yellow Sea with conventional
net samples. 相似文献
13.
Michio J. Kishi Hitoshi Motono Makoto Kashiwai Atsushi Tsuda 《Journal of Oceanography》2001,57(5):499-507
A vertical one-dimensional ecosystem model with vertical migration of zooplankton was constructed and applied to Station A-7
off Sanriku district of Japan in the northwest Pacific Ocean. The model consists of an eight-compartment ecosystem model coupled
with a physical model of the oceanic mixed layer. The transition of phytoplankton species responsible for the spring bloom
is well reproduced by this model with vertical migration of zooplankton but is not simulated by the model without vertical
migration. This new model also simulates an observed inter-annual variability of the spring bloom, with the timing and intensity
of the simulated bloom in a given year depending upon the strength of mixing during the preceding winter.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
14.
《Deep Sea Research Part II: Topical Studies in Oceanography》2009,56(25):2671-2682
During different seasons of the years 2003–2005 in the NE Atlantic, zooplankton were sampled with a MOCNESS (multiple opening/closing net and environmental sensing system, mesh size 333 μm) above the slopes and summits of Seine, Sedlo and Ampère seamounts and at remote reference sites outside the influence of the seamounts (far field). Wet weights of different zooplankton size classes (<0.5, 0.5–2, >2 cm) were measured. Night and day hauls were analysed in order to detect diel vertical migrations of the zooplankton, as well as a possible trapping effect due to the shallow topography.Biomass concentrations, independent of daytime, season and summit height, were reduced above the summits at all three seamounts compared to the slope and far-field sites. No trapping effect or retention of biomass was apparent above the seamounts. The vertical distribution patterns of the size class <0.5 cm did not differ between night and day hauls at most sites, but indications of diel vertical migrations were found in the larger size fractions. With the exception of gelatinous organisms, zooplankton >0.5 cm were nearly absent above the summits of Seine and Ampère seamounts, but considerable numbers were found above the slopes and at the far-field sites. Possible explanations for the observed distribution patterns of zooplankton biomass and size classes are discussed, including retention and lateral advection due to the hydrography at the seamounts, as well as predation by resident seamount fish. 相似文献
15.
利用深海潜标所搭载的声学多普勒流速剖面仪(acoustic doppler current profiler,ADCP)得到的后向散射强度Sv,研究了黑潮-亲潮混合区浮游动物的垂向分布、其昼夜垂直迁移(diel vertical migration;DVM)的基本特征、多时间尺度变化及对反气旋式中尺度暖涡的响应.结果表... 相似文献
16.
《Deep Sea Research Part I: Oceanographic Research Papers》2003,50(10-11):1157-1187
Considerable attention has recently been focused on the role of eddies in affecting biogeochemical fluxes and budgets of the Sargasso Sea. In late November 1996, the Bermuda Testbed Mooring (BTM) and Bermuda Atlantic Time Series (BATS) shipboard sampling evidenced a fall phytoplankton bloom at the Bermuda time-series site which was strongly forced by the interplay between seasonal mixed layer destratification and perturbation of mixed layer dynamics due to passage of a warm mesoscale feature. The feature was characterized by clockwise current vector rotation from near the surface to about 200 m and a thick, warm, low salinity isothermal layer >180 m in depth. Nutrients, chlorophyll fluorescence and pigment profiles indicated high primary production stimulated by enhancement of nutrient entrainment and intermittent deep mixing down to the base of the feature's isothermal layer. Nearly coincident with the arrival of this productive feature at the BTM site, the Oceanic Flux Program (OFP) sediment traps recorded an abrupt, factor of 2.5 increase in mass flux at 3200 m depth. Even more dramatic was the observed increase in flux of labile bioreactive organic matter. Fluxes of primary phytoplankton-derived compounds increased by factors of 7–30, bacteria-derived compounds by 6–9, and early degradation products of sterols by a factor of 10. The covariation of early degradation products and bacteria-derived compounds with phytoplankton-derived compounds indicated that the settling phytoplankton bloom material contained elevated bacterial populations and was undergoing active degradation when it entered the 3200 m trap cup.The increase in the flux of bulk components, especially the residual silicate fraction, and refractory organic compounds clearly preceded the main pulse of the labile, surface-derived phytoplankton organic material. The coincident increase in the flux of refractory and zooplankton-derived compounds suggests that in the initial stage of the deep flux event, the mass flux increased largely as a result of an increase in the flux of refractory materials scavenged from the water column and repackaged into sinking particles and increased zooplankton inputs. These results imply that biological reprocessing of flux material within the water column acts to enhance the coupling between the surface and deep ocean environments.Our results show that transient, upper ocean forcing associated with variable upper ocean physical structure—which includes but is not limited to eddies—and variable meteorological forcing can have an enormous effect on the export flux of bioreactive organic material. The importance of pulsed fluxes of bioreactive material arising from transient physical forcing to the long-term average is not presently known. However, the occurrence of episodic high flux events throughout the OFP time-series record (also inferred from BTM time-series) suggests that such forcing, regardless of specific dynamics, may be responsible for a significant fraction of the total export flux of bioreactive carbon and associated elements to the deep oligotrophic ocean. 相似文献
17.
《Deep Sea Research Part I: Oceanographic Research Papers》2002,49(3):437-462
Integrated assessment of the euphausiid Nematoscelis difficilis (Crustacea; Euphausiacea) and the zooplankton assemblage of the California Current was designed to investigate individual, population, and community responses to mesoscale variability in biological and physical characters of the ocean. Zooplankton samples and observational data were collected along a cross-shelf transect of the California Current in association with the California Cooperative Fisheries Investigations (CalCOFI) Survey during October 1996. The transect crossed three domains defined by temperature and salinity: nearshore, mid-Current, and offshore. Individual N. difficilis differed in physiological condition along the transect, with higher size-corrected concentrations of four central metabolic enzymes (citrate synthetase, hexokinase, lactate dehydrogenase (LDH), and phosphoglucose isomerase (PGI)) for euphausiids collected in nearshore waters than in mid-Current and offshore waters. There was little variation in the DNA sequences of the genes encoding PGI and LDH (all DNA changes were either silent or heterozygous base substitutions), suggesting that differences in enzyme concentration did not result from underlying molecular genetic variation. The population genetic makeup of N. difficilis varied from sample to sample based on haplotype frequencies of mitochondrial cytochrome oxidase I (mtCOI; P=0.029). There were significant differences between pooled nearshore and offshore samples, based on allele frequencies at two sites of common substitutions in the mtCOI sequence (P=0.020 and 0.026). Silhouette and bioacoustical backscattering measurements of the zooplankton assemblage of the top 100 m showed marked diel vertical migration of the scattering layer, of which euphausiids were a small but significant fraction. The biochemical and molecular assays are used as indices of complex physiological (i.e., growth and condition) and genetic (i.e., mortality) processes; the bioacoustical observations provide insight into the ecosystem context for the single-species measurements. All data are intended for integration into predictive models of secondary production and biomass concentration in the ocean. 相似文献
18.
《Deep Sea Research Part I: Oceanographic Research Papers》2006,53(3):547-560
We report results from the first deployment of a buoy-mounted aerosol sampler on the Bermuda Testbed Mooring (BTM) in the Sargasso Sea, in which a time-series of 21 aerosol samples were collected over the period May 5–September 29, 2004. These aerosol samples were analyzed for iron and soluble sodium (as a proxy for sea salt). Also analyzed was a time-series of 22 aerosol samples collected over the same period at the Tudor Hill atmospheric sampling tower on Bermuda. The buoy sampler worked as intended and successfully collected a time-series of aerosol samples, thus demonstrating that moored buoys can be used as oceanic observatories to provide information on the temporal (weekly, monthly and seasonal) variability in the concentration of aerosol iron (and other trace elements) over the surface ocean. The magnitude and time variation of aerosol Fe concentrations calculated from the BTM buoy samples are in close agreement with the corresponding aerosol Fe record from the Tudor Hill tower, which is located approximately 80 km northwest of the mooring site. Both the BTM and Tudor Hill samples record periods of high aerosol iron loadings in late June and late July 2004, reflecting the transport of soil dust from North Africa, with the highest concentration of aerosol iron at the BTM site (0.83 μg m−3) measured in late June. Concentrations of sea-salt aerosol calculated from the BTM samples are comparable to values measured over the Sargasso Sea and for samples collected at the Tudor Hill tower. Sea-salt aerosols do not appear to impede the collection of mineral aerosols by the buoy-mounted sampler. 相似文献
19.
There have been a lot of papers on the diel vertical migration of marine copepoda published at home and abroad. But so far, no report on the diel vertical migration of the larvae of Clanus sinicus has been seen. The present paper discusses this problem and the result obtained will provide useful reference for further researches on this subject. Moreover, exploring the law of diel vertical migration of the secondary productivity in the ocean will help the development of marieulture and fishing in a scientific way. 相似文献
20.
On the basis of the data of oceanographic survey in the East China Sea in four seasons during 1997～2000 (23°30′～33°00′N,118°30′～ 128°E), the variation of total biomass and diet biomass of zooplankton and their spatial-temporal distribution and relationship with the fishing ground of Engraulis japonicus are approached and analyzed. The results show that the average biomass is 65.32 mg/m3 in four seasons, autumn (86.18 mg/m3) being greater than summer (69.18 mg/m3) greater than spring (55.67 mg/m3) greater than winter (50.33 mg/m3). The average value of diet zooplankton hiomass is 40.9 mg/m3.The trends of horizontal distribution both in the total biomass and the diet biomass of zooplankton are similar. The high biomass region (250～500 mg/m3) is very limited, only accounting for 1% of the investigation area. Seasonal variation of the biomass is very remarkable in the west and north parts of East China Sea coastal waters (29°30'N,125°E). The horizontal distribution of diet zooplankton depends on the abundance distribution of crustacean. The distribution of diet zooplankton is related to the fishing ground of Engraulis japonicus and the high-density area of young fish and larval. In spring, the central fishing ground of Engraulis japonicus (>100 kg/h) and the high-density area of young fish and larval (>100 individuals per net) are located at the same place of high-density (100～250 mg/m3)area of diet zooplankton in the middle-southern part of East China Sea or the edge of its waters. 相似文献