The Yellow Sea(YS)and East China Sea(ECS)are highly dynamic marginal seas of the northwestern Pacific Ocean.To gain an in-depth understanding of zooplankton community structure,zooplankton abundance,biovolume,and size...The Yellow Sea(YS)and East China Sea(ECS)are highly dynamic marginal seas of the northwestern Pacific Ocean.To gain an in-depth understanding of zooplankton community structure,zooplankton abundance,biovolume,and size structure in summer 2017 in the YS and ECS were assessed using ZooScan imaging analysis.Zooplankton abundance and biovolume ranged 2.94–1187.14 inds./m^(3)and 3.13–3438.51 mm^(3)/m^(3),respectively.Based on the biovolume data of the categorized size classes of 26 identified taxonomic groups,the zooplankton community was classified into five groups,and each group was coupled with distinctive oceanographic features.Under the influence of the Yellow Sea Cold Water Mass,the Yellow Sea offshore group featured the lowest bottom temperature(10.84±3.42℃)and the most abundant Calanoids(mainly in the 2–3 mm size class).In the Yellow Sea inshore group,Hydrozoans showed the largest biovolume and dominated in the 3–4-mm and>5-mm size classes.The East China Sea offshore group,which was affected by the Kuroshio Branch Current,featured high temperature and salinity,and the lowest bottom dissolved oxygen(2.58±0.5 mg/L).The lowest values of zooplankton abundance and biovolume in the East China Sea offshore group might be attributed to the bottom dissolved oxygen contents.The East China Sea inshore group,which was mainly influenced by the Zhejiang-Fujian Coastal Current and Changjiang Diluted Water,was characterized by high chlorophyll a and the largest biovolume of carnivorous Siphonophores(280.82±303.37 mm^(3)/m^(3)).The Changjiang River estuary offshore group showed the most abundant Cyclopoids,which might be associated with the less turbid water mass in this region.Seawater temperature was considered the most important factor in shaping the size compositions of Calanoids in different groups.展开更多
The estuarine areas are under frequent influence from freshwater intrusion and ocean currents,in which zooplankton species are diversified and variable as they are sensitive to physio-chemical variations in water.Ther...The estuarine areas are under frequent influence from freshwater intrusion and ocean currents,in which zooplankton species are diversified and variable as they are sensitive to physio-chemical variations in water.Therefore,understanding the relationships between zooplankton and environmental factors help us know the water quality.To achieve co-existence with species in similar ecological group or habit,they could inevitably alter themselves to fit the ecology and adjust the function according to the competitive exclusion in ecological theory.However,information of the co-existence of dominant species in the Changjiang(Yangtze)River estuary(CRE)and adjacent waters remains scarce.We explored the relationships between dominant zooplankton and environmental factors in the study region in spring-summer from 2016 to 2020,involving particularly the composition of dominant species,ecological groups,their relationships with environmental factors,and co-existence of important species,using the non-multidimensional scale analysis(nMDS)method and redundancy analysis.Results show that Labidocera euchaeta and Tortanus vermiculus were dominant species in the study scope.The turnover rate of dominant zooplankton was greater(>50%)in spring while the species number was higher in summer.The dominant species were estuarine,offshore,and eurytopic based on the adaptation to salinity.In spring,the ecological groups were dominated by estuarine species,while in summer by estuarine and offshore species.In addition,the nMDS showed that the dominant species in the same ecological group were more dispersed and not prominently clustered;the dominant species were staggered among different ecological groups.The temperature,salinity,pH,dissolved oxygen,and chlorophyll a were the main environmental factors on the distribution of the dominant species in spring,while in summer were dissolved oxygen,temperature,salinity,and pH.The domination of medusae of Nemopsis bachei and Pleurobrachia globosa in zooplankton community in spring,and the continuous decrease in abundance of L.euchaeta reflected the effects of local climate change.The temperature and salinity changes in different years and the subsequent response of zooplankton reflected the influence of freshwater intrusion and/or ocean currents.Zooplankton in similar ecological habits exhibited the competitive exclusion in terms of co-existence.展开更多
Zooplankton are important linkages in the food web and can respond nonlinearly to environmental changes.Marine organisms thrive from spring to summer.Thus,it is crucial to understand how ecological functions of zoopla...Zooplankton are important linkages in the food web and can respond nonlinearly to environmental changes.Marine organisms thrive from spring to summer.Thus,it is crucial to understand how ecological functions of zooplankton communities may shift under seasonal environmental changes during this period.Samples were collected from May to August(May,June-Ⅰ,June-Ⅱ,July-Ⅰ,July-Ⅱ,and August)in 2018 in Haizhou Bay,Jiangsu,East China for zooplankton and environmental variables.Crustaceans accounted for 75 out of 134 zooplankton taxa and 91.8%of total zooplankton abundance.The average abundance of crustacean varied between 2824.6±635.4 inds./m3 in July-Ⅱand 6502.7±1008.8 inds./m3 in June-Ⅱ.Multivariate analyses results showed that the dissimilarity of community increased gradually in the time series.Body length,feeding type,trophic group,and reproduction mode were used to investigate crustacean community functions.Trait-based functional groups contained species with similar ecological roles.Functional diversity fused the differences of species and trait.The proportion of large-sized species(2-5 mm)decreased with the increasing proportion of medium-sized species(1-2 mm).The proportion of current feeders increased with the drop in the proportion of mixed feeders.Parthenogenesis species increased with decreasing free spawners,and omnivores-carnivores increased with decreasing omnivoresherbivores.Generalized additive models suggested that temperature was the main driver of variations in crustacean zooplankton function.Seven identified functional groups varied with increasing temperature.Omnivorous-herbivorous copepods declined(90.0%-68.0%),whereas the parthenogenetic cladocerans increased(0-24.1%).The small egg-brooding ambush copepods fluctuated(6.5%-9.3%)with increasing water temperature.The other functional groups changed slightly.Functional diversity also varied according to temperature changes.The community structure and ecological function of crustacean zooplankton community showed gradual changes with increasing temperature from spring to summer.展开更多
The long-term data(1996-2021)on the summer abundances of the dominant zooplankton species(copepod Arctodiaptomus salinus(Daday,1885),rotifers Brachionus plicatilis(Müller,1786)and Hexarthra sp.)in saline Lake Shi...The long-term data(1996-2021)on the summer abundances of the dominant zooplankton species(copepod Arctodiaptomus salinus(Daday,1885),rotifers Brachionus plicatilis(Müller,1786)and Hexarthra sp.)in saline Lake Shira were used to analyze the response of zooplankton to air temperature and a change in the circulation regime of the lake:breakdown and reestablishment of meromixis.All groups of zooplankton responded to prolonged summer elevated temperatures by increasing their abundance.During the breakdown of the stable stratification of Lake Shira(2015-2016),zooplankton abundance increased on average by a factor of two and amounted to 9×10^(5)inds./m^(2)in the water column for copepods.That increase coincided with similar responses of other components of the lake’s mixolimnion ecosystem,whose biomasses increased approximately two-fold during that period.After the reestablishment of the meromixis,the abundance of zooplankton decreased to previous values.Thus,the abundance of zooplankton is largely determined by weather(the effect of temperature)and ecological factors(mixing regime).展开更多
Spatial and temporal distribution of abundance,community structure and succession,and mortality of zooplankton were examined in a subtropical bay—the Qinzhou Bay,Guangxi,South China,to evaluate the impact of oyster c...Spatial and temporal distribution of abundance,community structure and succession,and mortality of zooplankton were examined in a subtropical bay—the Qinzhou Bay,Guangxi,South China,to evaluate the impact of oyster culture on zooplankton.Data on zooplankton abundance,phytoplankton biomass,and environmental parameters were collected in 12 routine samplings at four sites in the Qinzhou Bay in 2018.Results show that the hydrological environment in the estuary affected the temporal variation of zooplankton of the Qinzhou Bay.However,the oyster culture affected the spatial distributions of zooplankton.The abundance of zooplankton outside the oyster farm was higher than that inside,whereas the mortality outside the oyster farm,on the contrary,was lower than that inside.Oyster culture in the Qinzhou Bay had built a significant impact on the abundance and community composition of zooplankton,and the food shortage caused by the ingestion of oyster might exacerbate the mortality of zooplankton in the Qinzhou Bay.In addition,the large-scale oyster culture increased the spatial heterogeneity of the community structure of zooplankton inside and outside the oyster farms.Findings of this study provide a reference for future policy-making in aquaculture management.展开更多
Zooplankton are critical components of the Southern Ocean ecosystems,acting as trophic links between phytoplankton and higher-level species.The composition,abundance,carbon biomass,and community structure of zooplankt...Zooplankton are critical components of the Southern Ocean ecosystems,acting as trophic links between phytoplankton and higher-level species.The composition,abundance,carbon biomass,and community structure of zooplankton were studied based on samples collected with a Norpac net(330-μm mesh,0.5-m^(2) net mouth)during the austral summers of 2017/2018.Three communities in a latitudinal gradient were identified based on both a zooplankton abundance dataset and a biomass dataset.Zooplankton were mainly dominated by small copepods(e.g.,Oithona similis and Ctenocalanus citer)in terms of abundance,while the total zooplankton biomass was dominated by krill(Euphausia superba and Thysanoessa macrura)and large copepods(e.g.,Calanoides acutus,Calanus propinquus,and Metridia gerlachei).Redundancy analysis demonstrated that environmental factors(e.g.,temperature,nitrate,dissolved oxygen,ammonium)accounted for more than 40%of the variance in zooplankton abundance/biomass.This indicates that physical processes significantly affect the zooplankton community.Meanwhile,a significant positive correlation was found between the abundance/biomass of zooplankton and that of dominant phytoplankton and ciliates,which suggests trophic links among various plankton functional groups.Our results reveal that both physical processes and biological factors shape the community structure of zooplankton in the Amundsen Sea.展开更多
Based on oceanographic survey data in June 2012 in the Lembeh Strait, the zooplankton ecological characteristics such as species composition, individual abundance, dominant species and distribution were analyzed. The ...Based on oceanographic survey data in June 2012 in the Lembeh Strait, the zooplankton ecological characteristics such as species composition, individual abundance, dominant species and distribution were analyzed. The results showed that 183 species(including 4 sp.) had been recognized, most of them belonged to copepoda.Cnidaria followed with 43 species(including 1 sp.) were identified. The average abundance of zooplankton was(150.47±58.91) ind./m^3. As to the horizontal distribution, the abundance of the zooplankton was higher in the southern waters than in the northern waters. The dominant species in the study area were Lensia subtiloides,Sagitta enflata, Lucifer intermedius, Oikopleura rufescens, Diphyes chamissoni, Creseis acicula, Subeucalanus subcrassus, Temora discaudata, Aglaura hemistoma, Doliolum denticulatum, Canthocalanus pauper, Oikopleura longicauda and Nanomia bijuga. Zooplankton biodiversity indexes were higher in study area than previous study in the other regions. The findings from this study provide important baseline information for future research and monitoring programs.展开更多
Understanding the relationship between the zooplankton distribution and salinity may provide key information to understand ecosystem function under the condition of a global mean sea level rise caused by global climat...Understanding the relationship between the zooplankton distribution and salinity may provide key information to understand ecosystem function under the condition of a global mean sea level rise caused by global climate change.However,little is known about how increasing salinity level will affect the entire zooplankton community on a large scale.Here we completed 1 year of field investigations on the Pearl River Estuary and analyzed the distribution and structure of the zooplankton community.A total of 68 zooplankton species were identified during the survey.The number and diversity(richness,evenness,Shannon index,and Simpson’s index)of the zooplankton species decreased as salinity increased from 0.10 to 21.26.Salinity negatively affected the abundances of rotifers,cladocerans,and total zooplankton,while it had little effect on copepod abundance.Some salt-tolerant species,such as Keratella tropica,Polyarthra vulgaris,and Paracalanus crassirostris,survived at high-salinity sites.A pattern was observed at all sites:the peak in copepod abundance always occurred when rotifers were abundant(sites S1 and S2)or after rotifer abundance reached a maximum level(sites S3,S4,and S5).In general,salinity was the most important environmental factor shaping zooplankton biodiversity and abundance.This study provides insight into potential biodiversity and structure of the zooplankton community in response to salinity change.展开更多
This study compares the structure of the zooplankton community in the Bay of Bengal(BoB) and South China Sea(SCS) during the period of spring inter-monsoon, 2010. A total of 215 species of zooplankton were identified,...This study compares the structure of the zooplankton community in the Bay of Bengal(BoB) and South China Sea(SCS) during the period of spring inter-monsoon, 2010. A total of 215 species of zooplankton were identified, of which 187 species were present in the BoB and 119 in the SCS. Of the taxonomic groups recorded, Copepoda was the most diverse group in all samples followed by pelagic Tunicata, Siphonophorae and Chaetognatha. Flaccisagitta enflata, Cosmocalanus darwinii, Euchaeta larva, Macrura larva and Candacia truncata were predominant both in the BoB and SCS. Moreover, the distribution of some dominant species differed regionally, such as Cypridina dentata, Pleuromamma robusta and Mesosagitta decipiens only in the BoB, and Pleuromamma gracilis, Neocalanus gracilis and Eudoxoides spiralis in the SCS. The average zooplankton abundance was 33.37 ± 7.19 ind. m^(-3) in the BoB and 35.08 ± 2.07 ind. m-3 in the SCS. Copepoda was one of the most abundant groups in the Bo B and SCS. Based on multivariate analysis, it was possible to distinguish the zooplankton in the BoB and SCS communities at the similarity level of approximately 55%, and the dissimilarity was mainly due to C. dentata, P. robusta, M. decipiens, C. darwinii, N. gracilis and P. gracilis. The relationships between zooplankton and temperature, salinity and chlorophyll a were not statistically significant. Zooplankton community structure in the BoB and SCS was observed to be generally similar in terms of species composition and abundance, but the differences observed may be the result of species-specific geographical distribution and local hydrographic conditions.展开更多
Nansi Lake and Hongze Lake are both water storage lakes along the East Route of the South-to-North Water Transfer project(ESNT).Frequent changes in hydrologic properties are responsible factors for controlling the zoo...Nansi Lake and Hongze Lake are both water storage lakes along the East Route of the South-to-North Water Transfer project(ESNT).Frequent changes in hydrologic properties are responsible factors for controlling the zooplankton community assemblages in both lakes,so we studied the possible influence of water transfer and environmental factors on zooplankton community structure and abundance.Zooplankton assemblages were investigated seasonally for one year in both lakes;a total of 133 and 122 zooplankton taxa were identified in Nansi Lake and Hongze Lake,respectively.The most dominant rotifer species were littoral,e.g.,Keratella tecta,Keratella valga and Lecane lunaris in Nansi Lake and Brachionus angularis,Brachionus forficula and Polyarthra vulgaris in Hongze Lake.Comparatively,Nansi Lake had a higher Shannon-Wiener diversity index value(5.13),while Hongze Lake had a higher species richness index(4.21).The average number of zooplankton across seasons in Nansi Lake(protozoa:774±63 ind./L,rotifers:4817±212 ind./L,cladocerans:896±14 ind./L,copepod:435±42 ind./L)was comparatively lower than Hongze Lake(protozoa:1238±63 ind./L,rotifers:6576±112 ind./L,cladocerans:1013±20 ind./L,copepod:534±25 ind./L).Canonical correspondence analysis identified differing environmental gradients that were most responsible for influencing zooplankton communities in the two lakes(Hongze Lake:NH4-N,total nitrogen,transparency and pH;Nansi:pH,temperature and total phosphorus).Frequent changes related to water transfer in lakes favoured the diversity of rotifers and protozoa communities.Zooplankton habitat preference,changes in community structure and opportunistic peaks and extinction of certain taxa were also observed in the study lakes.展开更多
Zooplankton was major indicator species of the environment. To explore the effect of marine environment on zooplankton distribution in the coast of China, the zooplankton samples from stations in Guanhe Estuary(GE), C...Zooplankton was major indicator species of the environment. To explore the effect of marine environment on zooplankton distribution in the coast of China, the zooplankton samples from stations in Guanhe Estuary(GE), Changjiang(Yangtze River) Estuary(CE), Oujiang Estuary(OE), Jiulongjiang Estuary(JE) and Beilun Estuary(BE)(covering 14 latitudes) in spring were surveyed and the variation of zooplankton ecological group was researched. According to the adaptability temperature, the zooplankton was divided into two ecological groups: warm-temperate species and subtropical species. The warm-temperate species was the main dominant species and subtropical species was only dominant species in BE. Calanus sinicus, a warm-temperate species, was the only dominant species in all five estuaries. From north to south, the proportion of warm-temperate species in the five estuaries gradually decreased depends on the number, were 83.33%, 48.39%, 45.00%, 43.75% and 30.43%, respectively. In contrary, the proportion of subtropical species was gradually increased. The warm-temperate species predominated over the total abundance and the percentage was whopping high in the north estuaries, including GE(96.16%), CE(95.57%), OE(97.83%) and JE(95.53%). The abundance percentage of subtropical species have remarkably higher(82.39%) in BE. Five estuaries zooplankton community was subdivided into three zooplankton groups, which were the northern warm temperate zooplankton group, the southern subtropical zooplankton group and the estuarine brackish-water group. The water temperature and coastal current of China Sea are recognized as the main factors determining the distribution and community structure of estuarine zooplankton in spring.展开更多
To explore the size-dependent responses of zooplankton to submerged macrophyte restoration, we collected macrophyte, zooplankton and water quality samples seasonally from a subtropical shallow lake from 2010 to 2012. ...To explore the size-dependent responses of zooplankton to submerged macrophyte restoration, we collected macrophyte, zooplankton and water quality samples seasonally from a subtropical shallow lake from 2010 to 2012. Special attention was given to changes in rotifers and crustaceans(cladocerans and copepods). The rotifers were grouped into three size classes(<200 μm, 200 μm–400 μm, >400 μm) to explore their size-related responses to macrophyte restoration. The results showed that during the restoration, the annual mean biomass and macrophyte coverage increased significantly from 0 to 637 g/m^2 and 0 to 27%, respectively. In response, the density and biomass of crustaceans and the crustacean-to-rotifer ratio increased significantly, while the rotifer density decreased significantly. Moreover, rotifers showed significant sizedependent responses to macrophyte restoration. Specially, rotifers <400 μm were significantly suppressed, while those ≥400 μm were significantly encouraged. Overall, the population of large-sized zooplankton tended to boom, while that of small rotifers was inhibited during macrophyte restoration. Redundancy analysis(RDA) revealed positive correlations between macrophytes and crustaceans, rotifers and COD or Chl-a, but negative correlations between macrophytes and COD or Chl-a, and between crustaceans and Chl-a. Moreover, the results indicate that increased predation on phytoplankton by large-sized zooplankton might be an important mechanism for macrophyte restoration during development of aquatic ecosystems, and that this mechanism played a very important role in promoting the formation of a clear-water state in subtropical shallow lakes.展开更多
An extreme persistent cold anomaly was prevailing in the South China Sea in February 2008. In order to understand the effect of the cold anomaly on zooplankton community, the zooplankton composition, abundance and bio...An extreme persistent cold anomaly was prevailing in the South China Sea in February 2008. In order to understand the effect of the cold anomaly on zooplankton community, the zooplankton composition, abundance and biomass were analyzed in the northern South China Sea in August 2007 and August 2008. A total of 467 zooplankton species representing 16 groups were identified, with 275 species in August 2007 and 351 in August2008. Copepods were the most dominant zooplankton group in the study area. Compared with 2007, a dramatic decline was observed in the abundance of four dominant copepod species: Subeucalanus subcrassus, Temora discaudata, Nannocalanus minor and Temora turbinata in 2008. Moreover, zooplankton abundance declined from 133.37 ind./m^3 in August 2007 to 75.49 ind./m^3 in August 2008. In contrast, the abundance of medusa, such as Diphyes chamissonis, and tunicate, such as Doliolum denticulatum and Dolioletta gegenbauri, increased during the same season. Cluster analysis showed that there was a difference in zooplankton community structure between the two years. These variations in zooplankton communities were indicative of an anomalous oceanographic condition along with the extreme cold event in 2008.展开更多
The response of zooplankton to the ecological environment in Daya Bay is unclear under the influence of both climate changes and anthropogenic activities on a seasonal to inter-annual scale.Based on monthly surveys an...The response of zooplankton to the ecological environment in Daya Bay is unclear under the influence of both climate changes and anthropogenic activities on a seasonal to inter-annual scale.Based on monthly surveys and historical data,we found the zooplankton community had changed temporally and spatially.A total of 134 species was recorded during the study,and copepods dominated numerically in terms of diversity and abundance.Both copepods and cladocerans were the main contributors to zooplankton abundance.The community structure of zooplankton was temporally classified into the warm and cold groups,and spatially into the three groups located in the marine cage-culture area(MCCA),the outflow of nuclear power plants(ONPP)and unpolluted waters(UPW).The zooplankton was characterized by low biomass(dry weight),high diversity and abundance in the warm period in contrast to that in the cold period.Compared with the other two groups,the MCCA group of zooplankton showed high abundance,low diversity and biomass.Variations in dominant species were closely related to temperature,salinity and chlorophyll a concentration.Species diversity and dry weight decreased in comparison with 30 years ago,while zooplankton abundance increased.The seasonal variation in zooplankton was affected mainly by temperature that was controlled by monsoon,while the spatial difference in the community structure was probably due to eutrophication in the MCCA and thermal water discharge from ONPP.The zooplankton community is undergoing great changes with the tendency of miniaturization and gelatinization in recent 30 years in Daya Bay.展开更多
To study effects of variations in climate-marine environment in the Arctic Ocean on ecology,based on the actual and reestablished data by biomarkers of algae in sediment in 1997,1999,2003,2008,and 2010,the interannual...To study effects of variations in climate-marine environment in the Arctic Ocean on ecology,based on the actual and reestablished data by biomarkers of algae in sediment in 1997,1999,2003,2008,and 2010,the interannual and spatial variations of phytoplankton,zooplankton and chlorophyll a concentration in the Chukchi Sea and the Bering Sea as well as their relations to El Nino-Southern Oscillation( ENSO) and Arctic Oscillation( AO) were analyzed. The results show that there were spatial and temporal anomalies in the phytoplankton community structure reestablished by biomarkers of algae in the Chukchi Sea and the Bering Sea in 1999 and 2010. The total content of biomarkers( brassicasterol,dinosterol,C37 alkenones and chlesterol) in sediment collected in 2010 was far lower than that in 1999,but brassicasterol was dominant in the two years,that is,diatom was dominant,which was consistent with the actual structure and distribution of phytoplankton community in 1999 and 2010; there were great changes in the dominant species of plankton in the two seas in 1999 and 2010,which could be regarded as the ecological response of the North Pole under the background of global warming. Chlorophyll a concentration in the water of the Bering Sea was 0. 720 μg/dm^3 at 0 m and 0. 765μg/dm^3 at 10 m in 1997 and 0. 723 μg/dm^3 at 0 m and 0. 731 μg/dm^3 at 10 m in 2003,and the concentration was very close to each other,which was affected by El Ni1 o and the negative phase of AO. It was 0. 395 μg/dm^3 at 0 m in 1999 and 0. 399 μg/dm^3 at 0 m and 0. 357 μg/dm^3 at 10 m in 2008,which was influenced by La Ni1 a and the positive phase of AO. The phases and intensity of AO and ENSO had various effects on the quantity and dominant species of phytoplankton and zooplankton in the Chukchi Sea and the Bering Sea. During the period of AO with positive or negative phase and El Ni1o( in 1997 and 2003),their combination was favorable to the growth of phytoplankton and zooplankton,while the combination of negative phase of AO and La Nina( in 2010) had adverse effects on the growth of phytoplankton. The combination of AO with positive phase and strong La Nina( in 1999 and 2008) had small effects on phytoplankton community.展开更多
Spatial survey of zooplankton community composition within the upper 10 m layer in Lake Kinneret was carried out. Samples were collected by plankton net (63 μ mesh size) and counted organisms were sorted by 2 groups:...Spatial survey of zooplankton community composition within the upper 10 m layer in Lake Kinneret was carried out. Samples were collected by plankton net (63 μ mesh size) and counted organisms were sorted by 2 groups: 1) Large-including Copepodite and adult Cyclopoid copepods and Cladocerans;2) Small nauplii and rotifers. It was found that in the northern part of the lake where turbidity is high, the density of small organisms is relatively lower, and in other parts of the lake where water is less turbid, large organisms are relatively less abundant. Speculative assumption about the impact of fish feeding behavior on that is presented.展开更多
The population explosion of jellyfish Aurelia coerulea occurred in Jiaozhou Bay,China in 2009.The potential predation impact of A.coerulea on zooplankton was investigated.Population clearance potential and residence t...The population explosion of jellyfish Aurelia coerulea occurred in Jiaozhou Bay,China in 2009.The potential predation impact of A.coerulea on zooplankton was investigated.Population clearance potential and residence time(t 1/2)for copepods were calculated from laboratory clearance rates and measurements of jellyfish size and abundance from May to August 2009 in Jiaozhou Bay.Clearance rates varied widely with prey organisms,but they were not significantly different among various prey concentrations.Medusae captured rotifers,fish larvae and hydromedusae more efficiently than fish eggs,copepods and chaetognaths.Ephyrae captured rotifers and hydromedusae more efficiently than fish larvae and copepods.Clearance rate linearly increased with the cross sectional area of A.coerulea(size from 0.3 to 7.1 cm).Water temperature also had a marked effect on clearance rate and this was related to the increased beat frequency as water temperature increased.In early May 2009,A.coerulea potentially cleared the volume of water in the Bay less than 0.001 times a day,but this value was estimated to be more than 0.3 times a day in July.The t 1/2 for copepods was less than 6 d in June and July.Abundances of copepods,hydromedusae and chaetognaths were extremely low in 2009 compared to 2008 and 2010(jellyfish non-bloom years).Large predation pressure by the A.coerulea population occurred to control zooplankton communities in Jiaozhou Bay.A.coerulea,when present at a high population level,can be a keystone species in Jiaozhou Bay and control the trophic structure here.展开更多
Understanding the effects of environmental heterogeneity on zooplankton communities has been a hot topic for several decades.However,relatively little is known about the responses of zooplankton communities to environ...Understanding the effects of environmental heterogeneity on zooplankton communities has been a hot topic for several decades.However,relatively little is known about the responses of zooplankton communities to environmental conditions at large scales from inshore waters to the open ocean.Here,we used the abundance,biovolume,taxa and size spectra of zooplankton col-lected from the surface waters of the western Pacific Ocean during the winter of 2014 to study the relationship between zooplankton community characteristics and environmental conditions using multiple linear regression(MLR)analysis and redundancy analysis(RDA).According to a hierarchical cluster analysis based on hydrographic conditions,the study area was classified into five water masses.Significant correlations were identified between the limited nutrients and the zooplankton abundance and biovolume from inshore waters to the open ocean.Non-metric multidimensional scaling(NMDS)revealed two distinct zooplankton assemblages.In the northern inshore,Copepoda and Euphausiacea were the dominant zooplankton taxa and in other water masses,Chaetognatha and gelatinous zooplankton were the dominant zooplankton taxa in addition to Copepoda.Our results suggested that,on a large scale from inshore waters to the open ocean in the western Pacific Ocean,the spatial distribution of zooplankton taxa was mainly influ-enced by environmental conditions,while in the inshore waters,it was due to the top-down effect of the dominant zooplankton taxa.Finally,the slope of the normalized biovolume size spectra(NBSS)was negatively correlated with chlorophyll-a(Chl-a)concentra-tion and PO_(4)^(3−)-P concentration in the inshore waters,which indicated that the higher the trophic level the dominant zooplankton taxa were,the steeper the NBSS slope was.展开更多
A summary of a long-term research of Lake Kinneret zooplankton distribution is presented. During 1969-2002 several prominent changes have been recorded in the Kinneret ecosystem. This paper is an attempt aimed at anal...A summary of a long-term research of Lake Kinneret zooplankton distribution is presented. During 1969-2002 several prominent changes have been recorded in the Kinneret ecosystem. This paper is an attempt aimed at analyzing the impact of these ecological changes on the zooplankton communities. The impacts of Phytoplankton, Bacteria, Protozoa, Temperature, Nutrient composition and fish predation on zooplankton dynamics are analyzed. It was found that periodical fluctuations of zooplankton density were mostly affected by fish predation as well as by temperature increase and food availability. Ecological conditions in Lake Kinneret have been modified since early 1990’s and the new conditions were consequently accompanied by zooplankton Homeostatic response. Moreover, as a result of the ecological changes fish intensified their pressure on zoo-plankton. The flexibility of food resource preference by zooplankton enabled its existence but fish predation predominantly controlled their density.展开更多
基金the International Science Partnership Program of the Chinese Academy of Sciences(No.133137KYSB20200002)the Laoshan Laboratory(No.LSKJ202204005)+3 种基金the State Key Program of National Natural Science of China(No.42130411)the International Science Partnership Program of the Chinese Academy of Sciences(No.121311KYSB20190029)the Aoshan Science and Technology Innovation Program(No.2016ASKJ02-4)the Taishan Scholars Project(to Song SUN)。
文摘The Yellow Sea(YS)and East China Sea(ECS)are highly dynamic marginal seas of the northwestern Pacific Ocean.To gain an in-depth understanding of zooplankton community structure,zooplankton abundance,biovolume,and size structure in summer 2017 in the YS and ECS were assessed using ZooScan imaging analysis.Zooplankton abundance and biovolume ranged 2.94–1187.14 inds./m^(3)and 3.13–3438.51 mm^(3)/m^(3),respectively.Based on the biovolume data of the categorized size classes of 26 identified taxonomic groups,the zooplankton community was classified into five groups,and each group was coupled with distinctive oceanographic features.Under the influence of the Yellow Sea Cold Water Mass,the Yellow Sea offshore group featured the lowest bottom temperature(10.84±3.42℃)and the most abundant Calanoids(mainly in the 2–3 mm size class).In the Yellow Sea inshore group,Hydrozoans showed the largest biovolume and dominated in the 3–4-mm and>5-mm size classes.The East China Sea offshore group,which was affected by the Kuroshio Branch Current,featured high temperature and salinity,and the lowest bottom dissolved oxygen(2.58±0.5 mg/L).The lowest values of zooplankton abundance and biovolume in the East China Sea offshore group might be attributed to the bottom dissolved oxygen contents.The East China Sea inshore group,which was mainly influenced by the Zhejiang-Fujian Coastal Current and Changjiang Diluted Water,was characterized by high chlorophyll a and the largest biovolume of carnivorous Siphonophores(280.82±303.37 mm^(3)/m^(3)).The Changjiang River estuary offshore group showed the most abundant Cyclopoids,which might be associated with the less turbid water mass in this region.Seawater temperature was considered the most important factor in shaping the size compositions of Calanoids in different groups.
基金Supported by the Innovation Team Project of Ecological Environment Monitoring and Restoration of Fishery Waters in the East China Sea of the Chinese Academy of Fishery Sciences(No.2020TD14)the National Basic Research Program of China(973 Program)(No.2010CB429005)。
文摘The estuarine areas are under frequent influence from freshwater intrusion and ocean currents,in which zooplankton species are diversified and variable as they are sensitive to physio-chemical variations in water.Therefore,understanding the relationships between zooplankton and environmental factors help us know the water quality.To achieve co-existence with species in similar ecological group or habit,they could inevitably alter themselves to fit the ecology and adjust the function according to the competitive exclusion in ecological theory.However,information of the co-existence of dominant species in the Changjiang(Yangtze)River estuary(CRE)and adjacent waters remains scarce.We explored the relationships between dominant zooplankton and environmental factors in the study region in spring-summer from 2016 to 2020,involving particularly the composition of dominant species,ecological groups,their relationships with environmental factors,and co-existence of important species,using the non-multidimensional scale analysis(nMDS)method and redundancy analysis.Results show that Labidocera euchaeta and Tortanus vermiculus were dominant species in the study scope.The turnover rate of dominant zooplankton was greater(>50%)in spring while the species number was higher in summer.The dominant species were estuarine,offshore,and eurytopic based on the adaptation to salinity.In spring,the ecological groups were dominated by estuarine species,while in summer by estuarine and offshore species.In addition,the nMDS showed that the dominant species in the same ecological group were more dispersed and not prominently clustered;the dominant species were staggered among different ecological groups.The temperature,salinity,pH,dissolved oxygen,and chlorophyll a were the main environmental factors on the distribution of the dominant species in spring,while in summer were dissolved oxygen,temperature,salinity,and pH.The domination of medusae of Nemopsis bachei and Pleurobrachia globosa in zooplankton community in spring,and the continuous decrease in abundance of L.euchaeta reflected the effects of local climate change.The temperature and salinity changes in different years and the subsequent response of zooplankton reflected the influence of freshwater intrusion and/or ocean currents.Zooplankton in similar ecological habits exhibited the competitive exclusion in terms of co-existence.
基金Supported by the National Natural Science Foundation of China(Nos.42076146,41876177,41930534)the Fundamental Research Funds for the Central Universities(No.201822027)。
文摘Zooplankton are important linkages in the food web and can respond nonlinearly to environmental changes.Marine organisms thrive from spring to summer.Thus,it is crucial to understand how ecological functions of zooplankton communities may shift under seasonal environmental changes during this period.Samples were collected from May to August(May,June-Ⅰ,June-Ⅱ,July-Ⅰ,July-Ⅱ,and August)in 2018 in Haizhou Bay,Jiangsu,East China for zooplankton and environmental variables.Crustaceans accounted for 75 out of 134 zooplankton taxa and 91.8%of total zooplankton abundance.The average abundance of crustacean varied between 2824.6±635.4 inds./m3 in July-Ⅱand 6502.7±1008.8 inds./m3 in June-Ⅱ.Multivariate analyses results showed that the dissimilarity of community increased gradually in the time series.Body length,feeding type,trophic group,and reproduction mode were used to investigate crustacean community functions.Trait-based functional groups contained species with similar ecological roles.Functional diversity fused the differences of species and trait.The proportion of large-sized species(2-5 mm)decreased with the increasing proportion of medium-sized species(1-2 mm).The proportion of current feeders increased with the drop in the proportion of mixed feeders.Parthenogenesis species increased with decreasing free spawners,and omnivores-carnivores increased with decreasing omnivoresherbivores.Generalized additive models suggested that temperature was the main driver of variations in crustacean zooplankton function.Seven identified functional groups varied with increasing temperature.Omnivorous-herbivorous copepods declined(90.0%-68.0%),whereas the parthenogenetic cladocerans increased(0-24.1%).The small egg-brooding ambush copepods fluctuated(6.5%-9.3%)with increasing water temperature.The other functional groups changed slightly.Functional diversity also varied according to temperature changes.The community structure and ecological function of crustacean zooplankton community showed gradual changes with increasing temperature from spring to summer.
基金Supported by the RFBR and Krasnoyarsk Krai Government and the Krasnoyarsk Regional Fund of Science(No.19-44-240002)supported by the State Assignment of the Ministry of Science and Higher Education of the RF(No.0287-2021-0019).
文摘The long-term data(1996-2021)on the summer abundances of the dominant zooplankton species(copepod Arctodiaptomus salinus(Daday,1885),rotifers Brachionus plicatilis(Müller,1786)and Hexarthra sp.)in saline Lake Shira were used to analyze the response of zooplankton to air temperature and a change in the circulation regime of the lake:breakdown and reestablishment of meromixis.All groups of zooplankton responded to prolonged summer elevated temperatures by increasing their abundance.During the breakdown of the stable stratification of Lake Shira(2015-2016),zooplankton abundance increased on average by a factor of two and amounted to 9×10^(5)inds./m^(2)in the water column for copepods.That increase coincided with similar responses of other components of the lake’s mixolimnion ecosystem,whose biomasses increased approximately two-fold during that period.After the reestablishment of the meromixis,the abundance of zooplankton decreased to previous values.Thus,the abundance of zooplankton is largely determined by weather(the effect of temperature)and ecological factors(mixing regime).
基金Supported by the Research Fund of the Science and Technology Project of Guangxi(Nos.Guike AB20297018,Guike AB20297037,Guike AB22035035,Guike AB22035065)the National Natural Science Foundation of China(No.41876112)。
文摘Spatial and temporal distribution of abundance,community structure and succession,and mortality of zooplankton were examined in a subtropical bay—the Qinzhou Bay,Guangxi,South China,to evaluate the impact of oyster culture on zooplankton.Data on zooplankton abundance,phytoplankton biomass,and environmental parameters were collected in 12 routine samplings at four sites in the Qinzhou Bay in 2018.Results show that the hydrological environment in the estuary affected the temporal variation of zooplankton of the Qinzhou Bay.However,the oyster culture affected the spatial distributions of zooplankton.The abundance of zooplankton outside the oyster farm was higher than that inside,whereas the mortality outside the oyster farm,on the contrary,was lower than that inside.Oyster culture in the Qinzhou Bay had built a significant impact on the abundance and community composition of zooplankton,and the food shortage caused by the ingestion of oyster might exacerbate the mortality of zooplankton in the Qinzhou Bay.In addition,the large-scale oyster culture increased the spatial heterogeneity of the community structure of zooplankton inside and outside the oyster farms.Findings of this study provide a reference for future policy-making in aquaculture management.
基金supported by the National Science Foundation of China(Grant nos.42276238,41876217)financially supported by National Polar Special Program“Impact and Response of Antarctic Seas to Climate Change”(Grant nos.IRASCC 01-02-01D,02-02,01-01-02A)the Taishan Scholars Program。
文摘Zooplankton are critical components of the Southern Ocean ecosystems,acting as trophic links between phytoplankton and higher-level species.The composition,abundance,carbon biomass,and community structure of zooplankton were studied based on samples collected with a Norpac net(330-μm mesh,0.5-m^(2) net mouth)during the austral summers of 2017/2018.Three communities in a latitudinal gradient were identified based on both a zooplankton abundance dataset and a biomass dataset.Zooplankton were mainly dominated by small copepods(e.g.,Oithona similis and Ctenocalanus citer)in terms of abundance,while the total zooplankton biomass was dominated by krill(Euphausia superba and Thysanoessa macrura)and large copepods(e.g.,Calanoides acutus,Calanus propinquus,and Metridia gerlachei).Redundancy analysis demonstrated that environmental factors(e.g.,temperature,nitrate,dissolved oxygen,ammonium)accounted for more than 40%of the variance in zooplankton abundance/biomass.This indicates that physical processes significantly affect the zooplankton community.Meanwhile,a significant positive correlation was found between the abundance/biomass of zooplankton and that of dominant phytoplankton and ciliates,which suggests trophic links among various plankton functional groups.Our results reveal that both physical processes and biological factors shape the community structure of zooplankton in the Amundsen Sea.
基金The China-Indonesia Maritime Cooperation Fund Project "China-Indonesia Bitung Ecological Station Establishment"the National Natural Science Foundation of China under contract No.41306204+1 种基金the Scientific Research Foundation of Third Institute of Oceanography,SOA under contract Nos 2017010,2015012 and 2016012the National Special Project on Gas Hydrate under contract No.GZH201100311
文摘Based on oceanographic survey data in June 2012 in the Lembeh Strait, the zooplankton ecological characteristics such as species composition, individual abundance, dominant species and distribution were analyzed. The results showed that 183 species(including 4 sp.) had been recognized, most of them belonged to copepoda.Cnidaria followed with 43 species(including 1 sp.) were identified. The average abundance of zooplankton was(150.47±58.91) ind./m^3. As to the horizontal distribution, the abundance of the zooplankton was higher in the southern waters than in the northern waters. The dominant species in the study area were Lensia subtiloides,Sagitta enflata, Lucifer intermedius, Oikopleura rufescens, Diphyes chamissoni, Creseis acicula, Subeucalanus subcrassus, Temora discaudata, Aglaura hemistoma, Doliolum denticulatum, Canthocalanus pauper, Oikopleura longicauda and Nanomia bijuga. Zooplankton biodiversity indexes were higher in study area than previous study in the other regions. The findings from this study provide important baseline information for future research and monitoring programs.
基金This research was financially supported by the National Natural Science Foundation of China(No.41673080)the China Postdoctoral Science Foundation(No.2020M672449).
文摘Understanding the relationship between the zooplankton distribution and salinity may provide key information to understand ecosystem function under the condition of a global mean sea level rise caused by global climate change.However,little is known about how increasing salinity level will affect the entire zooplankton community on a large scale.Here we completed 1 year of field investigations on the Pearl River Estuary and analyzed the distribution and structure of the zooplankton community.A total of 68 zooplankton species were identified during the survey.The number and diversity(richness,evenness,Shannon index,and Simpson’s index)of the zooplankton species decreased as salinity increased from 0.10 to 21.26.Salinity negatively affected the abundances of rotifers,cladocerans,and total zooplankton,while it had little effect on copepod abundance.Some salt-tolerant species,such as Keratella tropica,Polyarthra vulgaris,and Paracalanus crassirostris,survived at high-salinity sites.A pattern was observed at all sites:the peak in copepod abundance always occurred when rotifers were abundant(sites S1 and S2)or after rotifer abundance reached a maximum level(sites S3,S4,and S5).In general,salinity was the most important environmental factor shaping zooplankton biodiversity and abundance.This study provides insight into potential biodiversity and structure of the zooplankton community in response to salinity change.
基金found by the Natural Science Foundation of China (No.41576125)the National Project of Basic Sciences and Technology (No.2017FY201404)
文摘This study compares the structure of the zooplankton community in the Bay of Bengal(BoB) and South China Sea(SCS) during the period of spring inter-monsoon, 2010. A total of 215 species of zooplankton were identified, of which 187 species were present in the BoB and 119 in the SCS. Of the taxonomic groups recorded, Copepoda was the most diverse group in all samples followed by pelagic Tunicata, Siphonophorae and Chaetognatha. Flaccisagitta enflata, Cosmocalanus darwinii, Euchaeta larva, Macrura larva and Candacia truncata were predominant both in the BoB and SCS. Moreover, the distribution of some dominant species differed regionally, such as Cypridina dentata, Pleuromamma robusta and Mesosagitta decipiens only in the BoB, and Pleuromamma gracilis, Neocalanus gracilis and Eudoxoides spiralis in the SCS. The average zooplankton abundance was 33.37 ± 7.19 ind. m^(-3) in the BoB and 35.08 ± 2.07 ind. m-3 in the SCS. Copepoda was one of the most abundant groups in the Bo B and SCS. Based on multivariate analysis, it was possible to distinguish the zooplankton in the BoB and SCS communities at the similarity level of approximately 55%, and the dissimilarity was mainly due to C. dentata, P. robusta, M. decipiens, C. darwinii, N. gracilis and P. gracilis. The relationships between zooplankton and temperature, salinity and chlorophyll a were not statistically significant. Zooplankton community structure in the BoB and SCS was observed to be generally similar in terms of species composition and abundance, but the differences observed may be the result of species-specific geographical distribution and local hydrographic conditions.
基金Supported by the Service Project of Special Institute of Chinese Academy of Sciences(No.Y55Z06)the Key Project in Frontier Science of Chinese Academy of Sciences(No.QYZDB-SSW-SMC041)+1 种基金the National Science Foundation of Jiangsu Province,China(No.BK20141268)the National Natural Science Foundation of China(No.31400486a)。
文摘Nansi Lake and Hongze Lake are both water storage lakes along the East Route of the South-to-North Water Transfer project(ESNT).Frequent changes in hydrologic properties are responsible factors for controlling the zooplankton community assemblages in both lakes,so we studied the possible influence of water transfer and environmental factors on zooplankton community structure and abundance.Zooplankton assemblages were investigated seasonally for one year in both lakes;a total of 133 and 122 zooplankton taxa were identified in Nansi Lake and Hongze Lake,respectively.The most dominant rotifer species were littoral,e.g.,Keratella tecta,Keratella valga and Lecane lunaris in Nansi Lake and Brachionus angularis,Brachionus forficula and Polyarthra vulgaris in Hongze Lake.Comparatively,Nansi Lake had a higher Shannon-Wiener diversity index value(5.13),while Hongze Lake had a higher species richness index(4.21).The average number of zooplankton across seasons in Nansi Lake(protozoa:774±63 ind./L,rotifers:4817±212 ind./L,cladocerans:896±14 ind./L,copepod:435±42 ind./L)was comparatively lower than Hongze Lake(protozoa:1238±63 ind./L,rotifers:6576±112 ind./L,cladocerans:1013±20 ind./L,copepod:534±25 ind./L).Canonical correspondence analysis identified differing environmental gradients that were most responsible for influencing zooplankton communities in the two lakes(Hongze Lake:NH4-N,total nitrogen,transparency and pH;Nansi:pH,temperature and total phosphorus).Frequent changes related to water transfer in lakes favoured the diversity of rotifers and protozoa communities.Zooplankton habitat preference,changes in community structure and opportunistic peaks and extinction of certain taxa were also observed in the study lakes.
基金funded by the National Natural Science Foundation of China (No. G41176131)the National Marine Public Welfare Research Project of China (No. 201305027-8)the Young Ocean Science Fund of East China Sea branch of State Oceanic Administration (No. 201708)
文摘Zooplankton was major indicator species of the environment. To explore the effect of marine environment on zooplankton distribution in the coast of China, the zooplankton samples from stations in Guanhe Estuary(GE), Changjiang(Yangtze River) Estuary(CE), Oujiang Estuary(OE), Jiulongjiang Estuary(JE) and Beilun Estuary(BE)(covering 14 latitudes) in spring were surveyed and the variation of zooplankton ecological group was researched. According to the adaptability temperature, the zooplankton was divided into two ecological groups: warm-temperate species and subtropical species. The warm-temperate species was the main dominant species and subtropical species was only dominant species in BE. Calanus sinicus, a warm-temperate species, was the only dominant species in all five estuaries. From north to south, the proportion of warm-temperate species in the five estuaries gradually decreased depends on the number, were 83.33%, 48.39%, 45.00%, 43.75% and 30.43%, respectively. In contrary, the proportion of subtropical species was gradually increased. The warm-temperate species predominated over the total abundance and the percentage was whopping high in the north estuaries, including GE(96.16%), CE(95.57%), OE(97.83%) and JE(95.53%). The abundance percentage of subtropical species have remarkably higher(82.39%) in BE. Five estuaries zooplankton community was subdivided into three zooplankton groups, which were the northern warm temperate zooplankton group, the southern subtropical zooplankton group and the estuarine brackish-water group. The water temperature and coastal current of China Sea are recognized as the main factors determining the distribution and community structure of estuarine zooplankton in spring.
基金Supported by the Major Science and Technology Program for Water Pollution Control and Treatment of China 12th Five-Year Plan(No.2012ZX07101007-005)the National Natural Science Foundation of China(Nos.51178452,51208498,51308530)
文摘To explore the size-dependent responses of zooplankton to submerged macrophyte restoration, we collected macrophyte, zooplankton and water quality samples seasonally from a subtropical shallow lake from 2010 to 2012. Special attention was given to changes in rotifers and crustaceans(cladocerans and copepods). The rotifers were grouped into three size classes(<200 μm, 200 μm–400 μm, >400 μm) to explore their size-related responses to macrophyte restoration. The results showed that during the restoration, the annual mean biomass and macrophyte coverage increased significantly from 0 to 637 g/m^2 and 0 to 27%, respectively. In response, the density and biomass of crustaceans and the crustacean-to-rotifer ratio increased significantly, while the rotifer density decreased significantly. Moreover, rotifers showed significant sizedependent responses to macrophyte restoration. Specially, rotifers <400 μm were significantly suppressed, while those ≥400 μm were significantly encouraged. Overall, the population of large-sized zooplankton tended to boom, while that of small rotifers was inhibited during macrophyte restoration. Redundancy analysis(RDA) revealed positive correlations between macrophytes and crustaceans, rotifers and COD or Chl-a, but negative correlations between macrophytes and COD or Chl-a, and between crustaceans and Chl-a. Moreover, the results indicate that increased predation on phytoplankton by large-sized zooplankton might be an important mechanism for macrophyte restoration during development of aquatic ecosystems, and that this mechanism played a very important role in promoting the formation of a clear-water state in subtropical shallow lakes.
基金The National Natural Science Foundation of China under contract Nos 41506161 and 41276162the National Basic Research Program(973 Program)of China under contract No.2015CB452903+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences under contract No.XDA11020305the Special Fund for Agro-scientific Research in the Public Interest under contract No.201403008
文摘An extreme persistent cold anomaly was prevailing in the South China Sea in February 2008. In order to understand the effect of the cold anomaly on zooplankton community, the zooplankton composition, abundance and biomass were analyzed in the northern South China Sea in August 2007 and August 2008. A total of 467 zooplankton species representing 16 groups were identified, with 275 species in August 2007 and 351 in August2008. Copepods were the most dominant zooplankton group in the study area. Compared with 2007, a dramatic decline was observed in the abundance of four dominant copepod species: Subeucalanus subcrassus, Temora discaudata, Nannocalanus minor and Temora turbinata in 2008. Moreover, zooplankton abundance declined from 133.37 ind./m^3 in August 2007 to 75.49 ind./m^3 in August 2008. In contrast, the abundance of medusa, such as Diphyes chamissonis, and tunicate, such as Doliolum denticulatum and Dolioletta gegenbauri, increased during the same season. Cluster analysis showed that there was a difference in zooplankton community structure between the two years. These variations in zooplankton communities were indicative of an anomalous oceanographic condition along with the extreme cold event in 2008.
基金This work was supported by the National Natural Sci-ence Foundation of China(Nos.31971432,41976112)the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(Nos.GML2019ZD0401,GML 2019ZD0405)+1 种基金the Science and Technology Basic Re-sources Investigation Program of China(No.2017FY201404)the Science and Technology Planning Project of Guangdong Province,China(No.2020B1212060058).
文摘The response of zooplankton to the ecological environment in Daya Bay is unclear under the influence of both climate changes and anthropogenic activities on a seasonal to inter-annual scale.Based on monthly surveys and historical data,we found the zooplankton community had changed temporally and spatially.A total of 134 species was recorded during the study,and copepods dominated numerically in terms of diversity and abundance.Both copepods and cladocerans were the main contributors to zooplankton abundance.The community structure of zooplankton was temporally classified into the warm and cold groups,and spatially into the three groups located in the marine cage-culture area(MCCA),the outflow of nuclear power plants(ONPP)and unpolluted waters(UPW).The zooplankton was characterized by low biomass(dry weight),high diversity and abundance in the warm period in contrast to that in the cold period.Compared with the other two groups,the MCCA group of zooplankton showed high abundance,low diversity and biomass.Variations in dominant species were closely related to temperature,salinity and chlorophyll a concentration.Species diversity and dry weight decreased in comparison with 30 years ago,while zooplankton abundance increased.The seasonal variation in zooplankton was affected mainly by temperature that was controlled by monsoon,while the spatial difference in the community structure was probably due to eutrophication in the MCCA and thermal water discharge from ONPP.The zooplankton community is undergoing great changes with the tendency of miniaturization and gelatinization in recent 30 years in Daya Bay.
基金Supported by National Natural Science Foundation of China ( 41276199)Chinese Projects for Investigations and Assessments of the Arctic and Antarctic ( CHINARE 2012 - 2016 for 03-04 and 04-03)
文摘To study effects of variations in climate-marine environment in the Arctic Ocean on ecology,based on the actual and reestablished data by biomarkers of algae in sediment in 1997,1999,2003,2008,and 2010,the interannual and spatial variations of phytoplankton,zooplankton and chlorophyll a concentration in the Chukchi Sea and the Bering Sea as well as their relations to El Nino-Southern Oscillation( ENSO) and Arctic Oscillation( AO) were analyzed. The results show that there were spatial and temporal anomalies in the phytoplankton community structure reestablished by biomarkers of algae in the Chukchi Sea and the Bering Sea in 1999 and 2010. The total content of biomarkers( brassicasterol,dinosterol,C37 alkenones and chlesterol) in sediment collected in 2010 was far lower than that in 1999,but brassicasterol was dominant in the two years,that is,diatom was dominant,which was consistent with the actual structure and distribution of phytoplankton community in 1999 and 2010; there were great changes in the dominant species of plankton in the two seas in 1999 and 2010,which could be regarded as the ecological response of the North Pole under the background of global warming. Chlorophyll a concentration in the water of the Bering Sea was 0. 720 μg/dm^3 at 0 m and 0. 765μg/dm^3 at 10 m in 1997 and 0. 723 μg/dm^3 at 0 m and 0. 731 μg/dm^3 at 10 m in 2003,and the concentration was very close to each other,which was affected by El Ni1 o and the negative phase of AO. It was 0. 395 μg/dm^3 at 0 m in 1999 and 0. 399 μg/dm^3 at 0 m and 0. 357 μg/dm^3 at 10 m in 2008,which was influenced by La Ni1 a and the positive phase of AO. The phases and intensity of AO and ENSO had various effects on the quantity and dominant species of phytoplankton and zooplankton in the Chukchi Sea and the Bering Sea. During the period of AO with positive or negative phase and El Ni1o( in 1997 and 2003),their combination was favorable to the growth of phytoplankton and zooplankton,while the combination of negative phase of AO and La Nina( in 2010) had adverse effects on the growth of phytoplankton. The combination of AO with positive phase and strong La Nina( in 1999 and 2008) had small effects on phytoplankton community.
文摘Spatial survey of zooplankton community composition within the upper 10 m layer in Lake Kinneret was carried out. Samples were collected by plankton net (63 μ mesh size) and counted organisms were sorted by 2 groups: 1) Large-including Copepodite and adult Cyclopoid copepods and Cladocerans;2) Small nauplii and rotifers. It was found that in the northern part of the lake where turbidity is high, the density of small organisms is relatively lower, and in other parts of the lake where water is less turbid, large organisms are relatively less abundant. Speculative assumption about the impact of fish feeding behavior on that is presented.
基金the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2018SDKJ0504-3)the National Key Research and Development Program of China(No.2017YFC1404405)Mount Tai Scholar Climbing Plan to SUN Song。
文摘The population explosion of jellyfish Aurelia coerulea occurred in Jiaozhou Bay,China in 2009.The potential predation impact of A.coerulea on zooplankton was investigated.Population clearance potential and residence time(t 1/2)for copepods were calculated from laboratory clearance rates and measurements of jellyfish size and abundance from May to August 2009 in Jiaozhou Bay.Clearance rates varied widely with prey organisms,but they were not significantly different among various prey concentrations.Medusae captured rotifers,fish larvae and hydromedusae more efficiently than fish eggs,copepods and chaetognaths.Ephyrae captured rotifers and hydromedusae more efficiently than fish larvae and copepods.Clearance rate linearly increased with the cross sectional area of A.coerulea(size from 0.3 to 7.1 cm).Water temperature also had a marked effect on clearance rate and this was related to the increased beat frequency as water temperature increased.In early May 2009,A.coerulea potentially cleared the volume of water in the Bay less than 0.001 times a day,but this value was estimated to be more than 0.3 times a day in July.The t 1/2 for copepods was less than 6 d in June and July.Abundances of copepods,hydromedusae and chaetognaths were extremely low in 2009 compared to 2008 and 2010(jellyfish non-bloom years).Large predation pressure by the A.coerulea population occurred to control zooplankton communities in Jiaozhou Bay.A.coerulea,when present at a high population level,can be a keystone species in Jiaozhou Bay and control the trophic structure here.
基金This work was supported by the Key Research Pro-gram of Frontier Sciences of the Chinese Academy of Sciences(No.QYZDB-SSW-DQC02402)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB42030402)+2 种基金the Science&Technology Basic Resources Investigation Program of China(No.2017FY100803)the International Science Partnership Program of the Chinese Academy of Sciences(No.133137KYSB20200002)the National Natural Science Foundation of China(No.91751202).We are grateful to the captain and crew of R/V‘KE XUE’for their technical and logistical support.
文摘Understanding the effects of environmental heterogeneity on zooplankton communities has been a hot topic for several decades.However,relatively little is known about the responses of zooplankton communities to environmental conditions at large scales from inshore waters to the open ocean.Here,we used the abundance,biovolume,taxa and size spectra of zooplankton col-lected from the surface waters of the western Pacific Ocean during the winter of 2014 to study the relationship between zooplankton community characteristics and environmental conditions using multiple linear regression(MLR)analysis and redundancy analysis(RDA).According to a hierarchical cluster analysis based on hydrographic conditions,the study area was classified into five water masses.Significant correlations were identified between the limited nutrients and the zooplankton abundance and biovolume from inshore waters to the open ocean.Non-metric multidimensional scaling(NMDS)revealed two distinct zooplankton assemblages.In the northern inshore,Copepoda and Euphausiacea were the dominant zooplankton taxa and in other water masses,Chaetognatha and gelatinous zooplankton were the dominant zooplankton taxa in addition to Copepoda.Our results suggested that,on a large scale from inshore waters to the open ocean in the western Pacific Ocean,the spatial distribution of zooplankton taxa was mainly influ-enced by environmental conditions,while in the inshore waters,it was due to the top-down effect of the dominant zooplankton taxa.Finally,the slope of the normalized biovolume size spectra(NBSS)was negatively correlated with chlorophyll-a(Chl-a)concentra-tion and PO_(4)^(3−)-P concentration in the inshore waters,which indicated that the higher the trophic level the dominant zooplankton taxa were,the steeper the NBSS slope was.
文摘A summary of a long-term research of Lake Kinneret zooplankton distribution is presented. During 1969-2002 several prominent changes have been recorded in the Kinneret ecosystem. This paper is an attempt aimed at analyzing the impact of these ecological changes on the zooplankton communities. The impacts of Phytoplankton, Bacteria, Protozoa, Temperature, Nutrient composition and fish predation on zooplankton dynamics are analyzed. It was found that periodical fluctuations of zooplankton density were mostly affected by fish predation as well as by temperature increase and food availability. Ecological conditions in Lake Kinneret have been modified since early 1990’s and the new conditions were consequently accompanied by zooplankton Homeostatic response. Moreover, as a result of the ecological changes fish intensified their pressure on zoo-plankton. The flexibility of food resource preference by zooplankton enabled its existence but fish predation predominantly controlled their density.
