Designation:D4135−82(Reapproved2012)StandardPracticeforSamplingPhytoplanktonWithDepth-IntegratingSamplers1ThisstandardisissuedunderthefixeddesignationD4135;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticecoverstheproceduresforobtainingquan-titativesamplesofaphytoplanktoncommunitybyuseofdepth-integratingsampler.Themethodissuitableforuseinflowingwaters.1.2Thisstandarddoesnotpurporttoaddressallofthesafetyproblems,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D4137PracticeforPreservingPhytoplanktonSamples3.SummaryofPractice3.1Adepth-integratedsampleiscollectedbymeansofasamplerthatintegratesstreamdischargeasafunctionofdepth.Thevelocityofflowinastream,aswellthedensityofphytoplankton,variesbothverticallyandhorizontally.Depthintegrationisusedtocollectasamplethatisweightedaccordingtothevelocityateachincrementofdepth.3Thephytoplanktonmaybepreservedasdictatedbytheobjectivesofthestudy.4.SignificanceandUse4.1Theadvantagesofthedepth-integratingsamplersareasfollows:4.1.1Thesamplersprovidetheonlymeansbywhicharepresentativesampleofphytoplanktoncanbeobtainedfromastream.4.1.2Thevarietyofsamplerdesignsresultintheavailabil-ityofasamplerthatcanbeusedinvirtuallyallvelocitiesofflow.4.1.3Samplesofknownvolumescanbeobtained.4.1.4Aquantitativesampleisobtained.Nanno-andultra-planktonarenotlostfromthesamplingdevice.4.1.5Someofthesamplerscanbeusedinwaterupto55mdeep.4.1.6Manyofthesamplersarelight-weightandcanbeusedwithoutauxiliaryequipment.4.2Thedisadvantagesofthedepth-integratingsamplersareasfollows:4.2.1Thesamplerscanbeusedonlyinflowingstreamshavingavelocitygreaterthan1.5ft3/s.4.2.2Someofthesam...
