Plankton respiration and oceanic carbon flux

PlanktonRespirationand verticalCarbonFluxinthe Ocean By TedPackard GrupodeinvestigaciónenOceanografía biológica,ULPGC http://www.seos‐project.eu POC (Bacteria& Phytoplankton) CO2 O2 ATP& Growth MarineTintinnid http://www.icm.csic.es/bio/images/welcome/tintinnid.gif(LluisaCros) 4FacetsofRespiration 4FacetsofRespiration 1.POC&DOCConsumption(Organicmatter degradation,Decay) 2. CO2Production &KrebsCycleDecarboxylases& CO2removingdehydrogenases 3.O2Consumption&theRespiratoryElectron TransportSystem(ETS) 4.BiologicalEnergyFormation,theproductionof ATP duringOxidativePhosphorylation&Growth FacetsofCarbonFlux Burdetal.2010 Lateral advection Lateral advection 4FacetsofCarbonFlux 1.PassiveSedimentation(Sedimenttraps, respirationofmicroplankton&zooplankton) 2. ActiveFluxviazooplanktonverticalmigration (Day‐nightbiomass,gut‐contents,&respiration differences) 3.DOCentrainmentandmixing(downwelling, convergencezones,wintermixing) 4.Lateraladvection (Offshelftransport,turbidity flows) OriginofSinkingParticles MarineSnow OriginofSinkingParticles MarineSnow OriginofSinkingParticles Graciasa:RussHopcroft OriginofSinkingParticles Salpa:http://culturingscience.wordpress.com Signatureofcarbonflux:AlboranSeaStory HighRespirationincoreoftheAlboranOMZ. Carbonfluxinginfromwhere? CarbonFluxthrough Convergenceinthe AlboranGyre Packardetal,1988 Concentrationofsinkingorganic matterdecreaseswithdepth. Why? Caveat:POCcanbeproducedinsituvianitrificationandagglutinationreactions.Theyarenot quantifiedyet,butconsideredminor. BacktoCarbonFlux,Itself. WHY? Becausemicrobialactivity degradessinkingorganicmatter producingCO2viarespiration. Deepoceanrespirationisbased onadvectedorganicmatter Caviat:NearcoastshorrizontallyadvectedPOCisanadditional source(Walsh,Alonso‐González&Arístegui). If horizontalfluxesaresmallorcancel, Respiration≈Δverticalflux.(Burdetal(2010) arguestheyareminor.) Respiration≈Δverticalflux Verticalflux≈∫Respiration Sincerespirationissodifficulttomeasurein oceanwaters,ETSactivityismeasuredasa proxy.ThusETSprofilesofmicroplanktonor zooplanktonbecomemeasuresofcarbonflux. CO2 O2 MarineTintinnid http://www.icm.csic.es/bio/images/welcome/tintinnid.gif(LluisaCros) Microbialactivitydegradessinkingorganic matterproducingCO2viarespiration. Concept: CarbonFlux=∫(respiration) Cf CO2 CO2 CO2 CO2 OceanBottom Tocalculatethecarbonfluxfromzttoinfinity(F∞),we findthatinthelimitaszsgoestoinfinity,[Rt /((b+1)(zt)b)][(zsb+1)]goestozero.Thus ETSactivity(nmole‐min‐1L‐1)alongtheC‐Line (13‐20Sept1976) MicroplanktonPassiveFlux FromETSActivity GulfofMaine CarbonFlux (gCm‐2y‐1) 0 500 1000 1500 2000 2500 3000 040 80 120 160 Sargasso Pacific W.Med C&W.Med PACIFIC ATL Classic CarbonFluxat100m (mgCm‐2day‐1) •PeruCurrent(Sept) –Offshore85 –UpwellingEdge 544 •CentralPacific 263 •SargassoSea 101 •WesternMediterranean 93 •Note!Negativefluxesnotincludedhere. CanaryIslandMicroplanktonPassiveC‐ Flux ZooplanktonRespiration ZooplanktonPassiveFlux ActiveFlux(viaverticalmigration) 0 50 100 150 200 ‐300 306090 ZOOPLANKTONCARBONFLUX(mols Ch‐1m‐2) DEPTH(meters) NightCarbonFlux DayCarbonFlux ACTIVECARBONFLUX Zooplanktonverticalmigrationdailytransports carbonfromthesurfacetodepth HISTORY:Ketchumreferstothisitin1957. SinceJGOFSLonghurst,Dam,Steinberg, Hernández‐León,Morales,Putzeys,etal. havemeasuredit. Hernández‐León’sgroupatULPGC:firsttouse ETSinthecalculationsofcarbonflux. THISISAPREDICTIONOFNEGATIVEC‐FLUX! Theverticalvelocityofwaterwas muchgreaterthanthesinkingrates ofparticlesduringthe52dayperiod,so thatthenetverticaltransportof particleswascontrolledbythe verticalvelocityofthewater.– Smithetal.,1983 Phytoplanktonupwellwiththeseawater! Allmeasurementsassociatedwithocean carbonfluxareflawedandneedserious refinement. Carbonfluxprofilescanbecalculatedfrom ETSactivityprofiles. Carbonfluxcanbeprofiled,it canbestudiedintime‐series,and itsnegativevaluescanbe demonstratedusingETS‐based rrespirationoceanprofiles. Acknowledgements Indifferentwayseachofthesepeoplehelpedme inthisresearch:FARichards,C.Barnes,MLHealy,HJ Minas,LACodispoti,JPChristensen,ADevol,Q Dortch,MEstrada,PGCoble,FDKing,NRAnderson, BJZahuranec&MMGómez.Ithankthemall. Forfinancialsupport,IthankEXMARSE‐53910/17 (ProyectoEstructuranteenCienciasMarinas).