简介：ChemicalformsofphosphorusinthesedimentsoftheDayaBay,theZhujiangRiverestuary,andtheXiamenBayaremeasuredwithextractionsolutionsofMgCl2,NaOH,andHCl.TheiravailabilitiestoChlorellasp.andlsochrysisgalbanaareestimatedbyusingsedimentsasthesolesourceofPinthebioassays.Theresultsshowthatthecontentsoftotalphosphorus(TP)inthesesedimentsare449.3,650.1and643.9mg/kg,respectively.ThecontentsofnonapatiteinorganicP(NAIP)extractedwithMgCl2andNaOHfrom3sedimentsare168.8,146.6and118.1mg/kg,respectively,andaccountfor18.3%～32.6%ofTP.ThephosphorusextractedwithHClsolutionisgreaterthanthatextractedwithNaOHsolutionandthelowestextractedPisMgCl2-extractableP.ThegreatestrelativegrowthratesofChlorellasp.andIsochrysisgalbanaculturedwithsedimentsareintherangeof4.3%～26.9%.TheincreasingbiomassesofthesealgaecorrespondtoNAIPandAAPP(theestimatedalgal-availableparticulateP).AAPPaccountsfor42.4%～78.2%ofNAIP,21.1%～27.1%oftotalinorganicP,and11.8%～20.3%ofTP,respectively.

简介：ThestudiesonthedistributionandvaratiationofthespecificationofphosphorusinthesouthernpartoftheYellowSeaaremade.ThebiogeochemistryofphosphorusintheYellowSeaisdiscussed.ThephosphorusisslightlyhigherinthebottomthaninthesurfacewatersinthesouthernpartoftheYellowSeaandthedissolvedorganicphosphorusisthemainform.Thetransferpatternsbetweenvariousformsofparticulateanddissolvedphosphorusaredifferentinthebottomandsurface,probablyduetothecontributionofdissolvedorganicphosphorus.Thedistributionsofdissolvedinorganicphosphorusanddissolvedorganicphosphorusaremainlyaffectedbythebiologicalprocessesandcouldactasapredictionfactorfortheredtide.ThesupplyofNandPinmostoftheareasinthesouthernpartoftheYellowSeaissufficient,withoutapparentlimitationofNorP.

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简介：DetailedanalysesofthemonitoreddataprovidedbytheYantaiOceanAdministrationOfficebetween1989and1996showthat,thefluctuationregularitiesofcontentoftheinorganicphosphorusareasfollows:thecontentofinorganicphosphorusfluctuatedneartheclass-1standardlinebasicallyfrom1989to1993,tendedtoincreaserapidlyfrom1993,andincreasedcontinuously,causingwaterqualitytobedeterioratedfromtheclass-2toclass-3standardby19%.Causesforincrementofthecontentofinorganicphosphorusarealsoanalyzed.Theresultsshowthat,thefluxofphosphorusenteringYantainearshoreseaareaincreasesatanannualrateof16.5percent,inwhichtheincrementratesofthephosphoruscontainedinwashingpowderandinphosphatefertilizerare12.9and17.5percentrespectively.Bothofthemkeptapositiveinterrelationshipwiththeirfluxesintothesea.Inaddition,themigrationandregenerationmechanismofthephosphoruswithinthenearshoreareaalsoleadtotheinorganic

简介：Short-termuptakeexperimentsandlong-termsemicontinuouscultureexperimentswereperformedundertheconditionofphosphorus(P)limitationtoestimateandcomparethePuptakeandgrowthkineticsofthemicroalgaTetraselmissubcordiformisandthemacroalgaUlvapertusa.Twonewparameters,themaximumspecificuptakerate(Vspm)andthemaximalgrowthefficiency(β),areintroducedtoachieveuniformityforthecomparisonofnutrientuptakeandgrowthefficiencybetweenmicroalgaeandmacroalgae.T.subcordiformispossesses3timeslowerhalfsaturationuptakeconstant,4timeshighermaximalgrowthrateand20timeshighermaximumspecificuptakeratethanU.pertusa,whileU.pertusapossesses4timeshighermaximalgrowthefficiencythanT.subcordiformis.

简介：NitrogenandphosphoruscontentsareanalyzedintheoverlyingwatersandporewaterstakenfromtheChangjiangEstuaryandShanghaicoastaltidalflatsinthisstudy.Inaddition,thediffusionfluxesofnitrogenandphosphorusacrossthesediment-waterinterfaceintidalflatsareestimatedaccordingtothenutrientconcentrationgradientsattheinterface.Ithasbeenindicatedthattheconcentrationsofammonium,nitrite,nitrateanddissolvedphosphorusinoverlyingwatersrangefrom0.0082～2.56,0.03～0.58,0.69～5.38and0.035～0.53mg/L,respectively,while0.0025～1.35mg/LforNH4+-N,0.0055～0.20mg/LforNO2--N,0.61～1.14mg/LforNO3--Nand0.11～0.53mg/LforDPinsurfaceporewaters.Thefindingshaverevealedthatammonium,nitrite,nitrateanddissolvedphosphorusdiffusionfluxesacrossthesediment-waterinterfacearebetween-0.024～0.99,-0.39～-0.0019,-3.09～thesourceofphosphorusandanimportantsinkfornitrogeninthewaters.

简介：SurfacesedimentsamplestakenfromtheEastChinaSeaofftheChangjiangestuaryareusedasrawmaterialsforphosphorusreleasingexperiment.Itisfoundthatafterbeingthoroughlymixedwithseawaterforabout10minutes,phosphorusreleasedfromthesedimentsreachesitsmaximumvalue.AdsorptionkineticscanbefittedwithbothElovichequationandtwo-constantrateequation.Thereleasingamountiscloselyrelatedtothecompositionofthesediments.Phosphorusreleasefromsiltyandmuddysedimentishigherthanfromthatdominatedbysandycomposition.Forthedesorptionreaction,iron-phosphorus(Fe-P)isthemostactiveone,withareleasingratiohigherthanotherphosphorusforms,followedbyabsorbed-phosphorus(Ad-P)andorganicboundphosphorus(OP).Allofthemcanbereferredtoasbio-availablephosphorus.Theresultsdemonstratethatphosphorusinsedimentscanbereleasedintoseawaterundersuitablehydrodynamicconditions,andhaveagreatimpactonthenutritionstateandprimaryproductivityofmarinebiosphere.

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