河口生态学Lecture_11Zooplankton, Nekton, and Macrobenth

Lecture11Zooplankton,Nekton,andMacrobenthosHoloplankton-permanentzooplanktonUsuallydominatedbycalanoidcopepods(Acartiasp.)Larvalstageisnauplius(muchmoreabundantthanadults),copepodites(developmentalstages),Adult(mature)Othermembersincludechaetognaths,mysids,carideans,cnidarians,ctenophores栉水母门•Meroplankton-temporaryzooplankton-larvalstagesofmanyspeciesShrimps(zoea),crabs(megalopae),molluscs(veliger),polychaetes(trocophore),fishlarvaeLarvalEcology-planktotrophyvs.lecithotrophy,dispersal,settlementMicroplankton-tinyzooplankton(200μm)-maybeVERYabundant-examplesincludeciliatesandheterotrophicnanoflagellatesZooplanktonCommonmembersofestuarinezooplanktonthebusinessendofachaetognathCopepodsandOstracodsFromHardy1956DecapodCrustaceanLarvaeFromHardy1956Jellyfish,MysidsandEuphausidsFromHardy1956MeroplanktonExamplesZooplanktonBiomassandAbundanceMaincontrolsaresalinity,temperature,foodsupply,andpredationSalinityeffectsandphysiologicaltolerances(osmoregulation)Seasonality-zooplanktonusually“track”phytoplanktonbloomsHavePATCHYdistributions(mayberesultofcirculationfeatures)-Hutchinson’sParadoxofthePlanktonVerticalmigrationandtransport,larvalretentionFromMiller2004FromRaymont1963ZooplanktonTrophicRelationshipsMostzooplanktonthoughttobeherbivoresfeedingonphytoplankton-recentevidencesuggestthisisnotalwaystrueMicrozooplanktonmaybeveryimportanttrophiclinkbetweenprimaryproductionandmacrozooplanktonMaybeseveraltrophiclevelswithinthezooplanktoncommunityZooplanktonGrazingrteCC12greCC12C1=phytoplanktonabundanceattime1C2=phytoplanktonabundanceattime2r=phytoplanktongrowthratet=timeg=grazingrateIfgr,zooplanktonwillgrazephytoplanktontoextinctionBenthicConsumers(Macrobenthos)Verydiversecommunities-SeveralFunctionalGroupsMacrofauna,infauna,meiofauna,microfauna,epifaunaSessilevs.motileBiomass/abundanceusuallyspace-limited(ascomparedtoresource-limitedinplankton)(Deepseaexcepted!)NematodesareVERYabundantEmphasizestandingstockvs.turnoverTurnoverTimes(peryear)200Bacteria(1-3μm)50-100Microbenthos(3-45μm)10Meiofauna(45-500μm)1-2Macrofauna(500μm)TheBipedalOctopusMacrobenthosFunctionalGroupsNameFunctionalCharacteristicsExamplesClassificationBasedonAdultSizeMacrobenthosFunctionalGroupsNameFunctionalCharacteristicsExamplesClassificationBasedonMicrohabitatMacrobenthosFunctionalGroupsNameFunctionalCharacteristicsExamplesClassificationBasedonFeedingTypeDon’tforgettoexerciseyourshrimp!MacrobenthosFunctionalGroupsNameFunctionalCharacteristicsExamplesClassificationBasedonFeedingTypeMacrobenthosFunctionalGroupsNameFunctionalCharacteristicsExamplesClassificationBasedonSedimentPreferencea)Maldanidpolychaeteb)seacucumber(holothurian)c)gastropodd)Nuculidbivalvee)polychaetef)Tellinidbivalve(Macoma)樱蛤科g)Nuculidbivalve(Yoldia)胡桃蛤科h)anemone海葵FromMann2000BioturbationSedimentreworkingbyfaunaProcessisimportantforsedimentresuspensionandnutrientcyclingMacrobenthosBioturbation5FunctionalGroupsFromAlleretal.2001TheBenthicBoundaryLayer(BBL)ViscousSublayer–molecularviscosityisdominantDiffusiveBoundaryLayer(DBL)–moleculardiffusionisdominantFromBoudreau&Jorgensen2001TheBenthicBoundaryLayer(BBL)FromBoudreau&Jorgensen2001EffectsofwaterflowontheDBLandfluxThethicknessoftheDBLdependsuponwaterflowoverthesedimentsurfaceTheBenthicBoundaryLayer(BBL)ThethicknessoftheDBLdependsuponwaterflowandtopographicfeaturesofthesedimentsurfaceOrganism-SedimentRelationsSedimentcharacteristicsmaydeterminespeciesassemblagesMetabolismandnutrientrecyclingin-situMediationofenergyflowProcessing/filteringwater–removalofparticulatesNutrientregenerationandexchangewithoverlyingwatersMacrobenthosImpactsofConsumersinBenthicFoodWebsFeedingPreferencescanstructurecommunitiesHerbivoregrazingcanaltercompetitivehierarchiesCoralreefs,oystersreefs,andseagrassbedsarecomplexbenthiccommunitieswithhighlydevelopedfoodwebsandfeedbackloopsMacrobenthicBiomassandPrimaryProductivityofshallow,well-mixedsystemsNotethe10%relationship!From:McLusky&Elliott2004Activelyswimmingpelagicorganisms-majorgroupsarefish(ichthyofauna),crustaceans,marinemammalsFunctionalClassificationPelagic-swimfreeinthewatercolumnUsuallyincludesschoolingfishes,planktivores,andplanktivorepredatorsHighactivityresultsinhighmetabolismandrequiresanabundantfoodsupplyDemersal(orEpibenthic)-associatedwiththebottomHighspeciesdiversityandspecializationSedentarynatureleadstolowermetabolicratesSomespeciesareverticalmigratorsNektonFrom:Kennish2001Nearlyone-halfoftheknownfishspeciesoccurinestuarineandcoastalhabitatsNektonNektona)Shallowwaterfishesb)Pelagicfishesc)benthicflatfishSomeCommonEstuarineFishSpeciesNektonSomeCommonEstuarineFishSpeciesd)Benthicdemersale)Benthicomnivoref)Pelagicbottomfeederg)BenthiccarnivoreEstuarineFishesLessthan15speciesaccountformorethan90%oftotalfishbiomassinmostestuariesFishabundanceandbiomassishigh,diversityislowrelativetootherecosystemsSecondaryproductioncanrangefrom1to60gm-2y-1(comparewithphytoplankton!)Onlyafewfishspeciesdominatethecommunity-butmaybeseasonalshiftsindominantspeciesTropical/Subtropicalestuariesareusuallymorediverse(wit