简介:ThespatialandtemporalcharacteristicsoftrophicstructureoffishcommunitiesinthesouthernHuanghaiSeawereexaminedbasedonthedatasampledfrombottomtrawlsurveysconductedduringtheautumnof2000andthespringof2001.HierarchicalagglomerativeclustermethodandbootstraprandomizationwereusedtoidentifysignificanttrophicgroupsforeachfishassemblageinthesouthernHuanghaiSea.Atotalofsixmajortrophicgroupswereidentifiedwithinthissystem,whichclassifiedpredatorsbaseduponlocationinthewatercolumnorpreysize(i.e.,benthictopelagicpredatorsorfishtosmallinvertebratepreypredators).Thesimilaritylevelusedtoidentifysignificanttrophicgroupsineachassemblagerangedfrom24%to34%.Althoughplanktivoreswerethedominanttrophicgroupineachassemblage(60%~79%),therewerespatialandtemporalvariationsinthetrophicstructure,whichreflectedthedifferencesintheabundanceandavailabilityofdominantpreys.Simplifiedfoodwebswereconstructedtoevaluatethemostimportanttrophicrelationshipsbetweenthedominantpreytaxaandthefishesineachassemblagewithinthissystem.Althoughthereweresomedifferencesinthekeypreyspeciesamongdifferentfoodwebs,pelagicpreyitems(mainlyeuphausiidsandcopepods)representthemostimportantenergeticlinkbetweenprimaryproducersandhighertrophiclevelpredators.Thetrophiclevelformostfisheswasbetween3and4,andtheweightedmeantrophiclevelforeachassemblagerangedfrom3.3to3.4.Comparedwithpreviousstudyinthemid-1980s,therewasanobviousdownwardtrendinthetrophiclevelformostfishspecies,whichresultedmainlyfromthefluctuationinkeypreyspeciesintheHuanghaiSea.ThedecreaseintheimportanceofJapaneseanchovyseemstobeoffsetbyotherabundantpreyspeciessuchasEuphausiapacificaandcopepods(mainlyCalanussinicus).
简介:Agridof22stations,givingabroadcoverageofthespawninggroundofanchovyinthesouthernHuanghaiSeawasselected.UndisturbedsedimentsweretakenfromsamplingstationsduringthecruiseinJune2003.Theaverageabundanceofmeiofaunais(1584±686)ind./10cm2,withcorrespondingbiomass(dwt)of(1086+425)μg/10cm2.Thepattemofabundanceofmeiofaunaissimilartothepatternofbiomass.Thereare65.88%meiofaunain0~2cmsediments,27.66%in2~5cmsedimentsand6.47%in5~8cmsediments.TheSpearmancorrelationanalysisbetweenmeiofaunaandenvironmentalfactorsshowsthatabundanceofmeiofauna,freelivingmarinenematodes,benthiccopepodshassignificantpositivecorrelationswithChl-a.AndtheabundanceofcopepodshassignificantpositivecorrelationswithseveralfactorssuchasChl-a,Pha-a,Chl-aplusPha-aandorganicmatter.Atotalof18meiofaunagroupsareidentified.Nematodeisthemostdominantgroup,averageabundance(1404±670)ind/10cm2,accountingfor88.65%,andthefollowinggroupsarealsoimportant:benthiccopepods(5.48%),kinorhyncha(1.26%),polychaeta(1.07%).Bybiomass,dominantgroupsarenematodes(51.72%),polychaeta(21.84%),copepods(14.87%),ostracoda(4.92%),kinorhyncha(3.67%).Atotalof90speciesofnematodesareidentified.Thespeciescompositionofnematodesislistedbasedonselectedtwostations7794(coastalarea)and10694(coldwatermassindeepwaters).
简介:Distributional characteristics of planktonic Amphipoda(Hyperiidea) in the South Huanghai Sea and East China SeaLinJinghongand...
简介:Thegrowingdemandofprawnproteinintheworldhasbeendemandinganincreasingcatchofprawnfromtheseawhich,however,failstomeettheneedsduetooverexploitation.Thiseasehasalwaysbeenakeensubjectamongusfisheryseientists.WiththesupportandguidanceoftheProvincialGovernmentofShandong,theShandongFisheryBureauhasbeencarryingoutaprojectof"theEx-
简介:InastudyofmeiofaunapolychaetefromtheHuanghaiSea,apreviouslyundescribedspeciesbelongingtoHesionurahasbeenfoundanddescribed.ThenewspeciesdiffersfromtheotherspeciesofthegenusHesinuramainlybythechaetation.