Designation:D4348–84(Reapproved1995)StandardPracticeforCollectingBenthicMacroinvertebrateswithHolme(Scoop)GrabSampler1ThisstandardisissuedunderthefixeddesignationD4348;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticecoverstheproceduresforobtainingquali-tativeorquantitativebottomsamplesofmacroinvertebratesinhabitingsand,gravel,mud,clay,andsimilarsubstrates.1.2Thisdeviceisusedprimarilyinmarinewatersanddeeplakes.1.3Fortheadvantagesandlimitationsofgrabsamplingdevices,seeGuideD4387.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.Forspecifichazards,seeSection5.2.ReferencedDocument2.1ASTMStandards:D4387GuideforSelectingGrabSamplingDevicesforCollectingBenthicMacroinvertebrates23.SummaryofPractice3.1TheHolme(scoop)grabsamplerhasasemicylindricalscoopmountedonthebottomofaheavyframe,mustbepositionedproperlyonthebottomtotakeascoop,andretaindiscretesamplesofsedimentthrough180°.3.2Thedevicepenetratestoadepthofabout150mm.3.3Thesamplermaybemodifiedtoincludedoublescoopseachof0.05m2orlarger.4.SignificanceandUse4.1TheHolme(scoop)grabsamplerisusedtocollectqualitativeandquantitativesamplesfromdifferentaquatichabitatscontainingbenthicmacroinvertebrateslivingonorinvarioustypesofsubstrates.4.2Theorganismsinthesampleareusedtodefinemacro-invertebratecommunitycharacteristicsinwaterqualitystudiesandecologicalassessments.5.Hazards5.1Thissamplercannotbeusedunderadversewindandwaveconditions.6.Procedure6.1Slowlylowerthesampleronaverticalplanewiththescoopopeningdownwarduntilitfirmlycontactsthesubstrate.6.2Thetripmechanismisreleasedonlifting;thescoopforceablyrotates180°alongitsh...
