ASTM_D_4345_-_84_1998.pdf

Designation:D 4345 84(Reapproved 1998)Standard Practice forCollecting Benthic Macroinvertebrates with Van Veen GrabSampler1This standard is issued under the fixed designation D 4345;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers the procedures for obtaining quali-tative or quantitative samples of macroinvertebrates inhabitingsand,clay,mud,gravel,and similar substrates.1.2 This device is used in marine and estuarine waters andis adaptable for large rivers.1.3 For advantages and limitations for grab sampling de-vices,see Guide D 4387.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility or regulatory limitations prior to use.For specifichazards,see Section 5.2.Referenced Documents2.1 ASTM Standards:D 4387 Guide for Selecting Grab Sampling Devices forCollecting Benthic Macroinvertebrates23.Summary of Practice3.1 The Van Veen grab sampler has paired jaws that mustpenetrate the intended substrate without disturbing the watersurface boundary of the substrate,close by pincher-like actionof two long arms when positioned properly on the bottom,andretain discrete samples of sediment while it is brought to thesurface for processing.3.2 The Van Veen is basically an improved version of thePetersen grab in that long arms have been attached to the jawsto stabilize the grab on the bottom in the open sea just prior orduring closing the device.3.3 Additional weights can be applied to the jaws to effectgreater penetration in sediments.3.4 The long arms give added leverage for penetrating hardsediments.3.5 Larger versions of this grab can be constructed depend-ing upon the type of bottom to be sampled,and the type ofvessel available to deploy this sampler.4.Significance and Use4.1 The Van Veen grab sampler is used to collect qualitativeand quantitative samples from different aquatic habitats con-taining benthic macroinvertebrates living on or in various typesof substrates.4.2 The organisms in the sample are used to define macro-invertebrate community characteristics in water quality studiesand ecological assessments.5.Hazards5.1 At great ocean depths the sampler is sometimes difficultto operate as standing waves or swell at the surface or deeperdown will act upon the levers so as to close the grab longbefore it reaches the bottom sediment.5.2 As with the larger grabs,the Van Veen must be loweredfrom a stationary vessel or platform with boom and liftingcapabilities.6.Procedures6.1 The standard Van Veen is cocked with the long armsassuming the spread condition.6.2 The chains from the jaws are attached to the counterbalance mechanism,as are the slackened wires from the longarms.6.3 Tension is carefully applied to the triggering mechanismas the sampler is winched off its platform,and once the tensionis firmly changed from the jaws,the Van Veen is relativelystable in the cocked position.6.4 Exercise care in lowering the Van Veen through thesurface of the water as occasionally contact will produce slackin the chain that will trip the counter balance mechanism.6.5 The grab is lowered slowly to the bottom,and once itmakes contact with the bottom the grab shall be winched in,which initially closes the device and then raises it from thesediment.6.6 The grab is retrieved slowly to prevent washout andonce aboard the vessel,empty the grab into either a suitablecontainer or a sieving device directly for processing.6.7 Thoroughly wash or hose the device with water so thatall the sample is processed before a replicate sample is taken.1This practice is under the jurisdiction of ASTM Committee E-47 on BiologicalEffects and Environmental Fate and is the direct responsibility of SubcommitteeE47.08 on Biological Field Testing.Current edition approved Feb.24,1984.Published November 1984.2Annual Book of ASTM Standards,Vol 11.05.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Book of ASTM Standards.Copyright ASTMNOTICE:This standard has either been superceded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connectionwith any item mentioned in this standard.Users of this standard are expressly advised that determination of the validity of any suchpatent rights,and the risk of infringement of such rights,are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be revi