海洋生物-浮游生物

MarineBiologyPlanktonGeneralInfo:•PlanktoncomesfromtheGreekword“planktos”whichmeansdrifter.Movement•Mostorganismsmovewiththecurrent.Somehavetheabilitytomoveontheirown.Forexample,copepodsarethefastestanimalfortheirsize-theymovemorethan500bodylengthspersecond.TwoTypesofPlankton•Phytoplankton-whichareautotrophs(plank-like)•Zooplankton-whichareheterotrohs(animal-like)Location-Epipelagicregionoftheocean:•Thislocationisnearthesurfacewherethewateriswarmerandlighter.•Thedepthisfromthesurfaceto200mor650ft.•Itoftencorrespondswiththephoticzone,theistheregionwherelightpenetrates.Location:Epipelagicregionoftheocean(con’t)•Shallowestpartofthepelagicrealm•ThepelagicrealmisthevastopenoceanawayfromthebottomandtheshoreLocation:Epipelagicregionoftheocean(con’t)•Coastal/neritic:arewatersthatlieoverthecontinentalshelf(smallportionoftheepipelagic)•Oceanic:aresurfacewatersbeyondthecontinentalshelf.Location:Epipelagicregionoftheocean(con’t)•ThisarealacksdepositfeederssincethereisNObottom•SuspendedfeedersarethereforeABUNDANT•Noneofthesedepositfeeders!Allenergycomesfromthesun:•Nearlyallprimaryproducers(photosynthesis)fromtheoceanoccursintheepipelagiczone•Foodproducedsinksoriscarriedbythecurrentstootherpartsoftheocean.•Autotrophscarryoutphotosynthesisbytakingincarbondioxideandconvertingittoorganicfood(glucose)Planktonhavetroubleremainingafloat:•Organismsandtheirshellsaremoredensethanwaterandthereforeshouldsink•Copingstrategies:–Increasewaterresistance-thegreaterthesurfaceareathemoreresistance–Beingsmallishelpful–Flatshapealsoincreasessurfacearea,asdoprojectionsandspinesPlanktonhavetroubleremainingafloat(con’t):•Copingstrategies(con’t)–Increasebuoyancy•Somestorelipidsasvacuolesofoil(lessdensethanwater)•Someusepocketsofgaswhichislessdensethanwater–Regulatingtheamountofgascanmovetheorganismupanddownthewatercolumn•ExchangeheavyionsforlighteronesVerticalMigration•Predatorsaboundtheepipelagic.Therefore,somezooplanktonsinkwherethereislittlelightduringthedayandrisetofeedatnightRecentResearch•Newmethodstocountandidentifyphytoplanktonbiodiversity–Flowcytometryisopticaltechniquethatcanprocesshundredsofthousandsperminute•MITresearchersdiscoveredtinybutabundantnewspeciescalledprophlorophytes•DNAresearchtounderstandevolutionandrelationshipsamongplanktonPhytoplankton•PhotosyntheticAutotrophs–Greaterthan95%ofphotosynthesisintheocean–Producenearly50%oftheoxygeninouratmosphere–Primaryproducerintheepipelagic-WHY?•Goupedbysize–Picoplankton-toosmalltobecaughtinnets–Netplankton-(micro,meso,macro,nano),largeenoughtobecaughtinnetsPhytoplankton(con’t)•2MainTypes–Diatoms•KingdomProtista•Havecharacteristicsofbothplantsandanimals•Prefertemperate,polar,andnutrient-richwater•Theyareunicellular,althoughsomegatherinchainsorclusters•EnclosedinacellwallthatismadeoutofsilicondioxidePhytoplankton(con’t)–Diatoms(con’t)•Theyhaveaglasslikefrustuleswhichisashellwithtight-fittinghalves.Thereisawidevarietyofbeautifulfrustules!–Somefrustuleshaveperforationsandspinesthatallowlighttopassthroughandgassesandnutrientstoenterandleave–Frustulesfromdeaddiatomsaccumulateontheoceanbottomandarecalleddiatomaceousooze–Fossilizedsedimentsoftheoozefoundinlandareminedasdiatomaceousearthwhichisusedforpolishing(toothpaste),insulating,andfiltering(swimmingpools)Phytoplankton(con’t)–Diatoms(con’t)•Reproducerapidlywhenconditionsaregood.Otherspeciesaredependonthisanditinfluencesthesuccessofsomefishspecies.Phytoplankton(con’t)•Secondtype–Dinoflagellates•KingdomProtista•Mostabundantphytoplanktoninwarm,tropicalwaters•Unicellularwithacellwallmadeofcelluloseplates•Mostoutstandingcharacteristic:2unequalflagella–Onewrapsaroundthegrooveinthemiddleofthecell–Onetrailsfree–TheybothdirectmovementinpracticallyanydirectionPhytoplankton(con’t)–Dinoflagellates(con’t)•UniqueDNAremainscoiledinchromosomesthroughoutlife•Althoughautotrophictheyalsofeedonotherfoodparticles•Reproducebycelldivision–Hugesurgesofreproductionarecalledblooms–TheyproducedtheRedTideswhichactuallyturnedthewaterredtored-brownPhytoplankton(con’t)–Dinoflagellates(con’t)–2ProblemswithRedTidesProducetoxinswhichmaycausefishtodieoraccumulateinthetissuesofresistantorganismswhichcanresultinparalyticshellfishpoisoningwhichcanbefataltohumansAsthebloomdiesanddecomposes,thebacteriadepletethedissolvedoxygenformthewatercausingfishtodiePhytoplankton(con’t)–Dinoflagellates(con’t)•SomespeciesproducelightbyBioluminescencewhichcanbeseenatnightintheopenocean•Somespeciescelledzooanthellaeliveinsymbioticrelationshipswithothermarineorganismssuchascoral.Theyreleaseorganicmatterusedbythecoralandhelpintheformationofthecoralskeleton.Phytoplankton(con’t)•Nanoplankton–Verysmallandhardtocatch–Stillimportantinoceanprimaryproduction–Twotypes•Cyanobacteria•CoccolithophoridsPhytoplankton(con’t)•Nanoplankton(con’t)•Cyanobacteria–KingdomMonera,thereforeprokaryotic–Containchlorophyll(greenpigment)andphycocyanin(bluepigment)–Mostaremicroscopic,butcanformlongvisiblestrandsormats–LikelythefirstphotosyntheticorganismsonEarthandcontributedtotheaccumulationofoxygenintheatmosphere–Canal