ASTM_D_4343_-_84_1998.pdf

Designation:D 4343 84(Reapproved 1998)Standard Practice forCollecting Benthic Macroinvertebrates with Ekman GrabSampler1This standard is issued under the fixed designation D 4343;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 inhabitingsoft sediments.1.2 This device is used in freshwater lakes,reservoirs,andusually small bodies of water.1.3 For the advantages and limitations of selecting grabsampling devices,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 of 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 Ekman grab sampler is a box-shaped device withtwo scoop-like jaws that must penetrate the intended substratewithout disturbing the water surface boundary of the substrate,close when positioned properly on the bottom,and retain adiscrete sample of sediment while it is brought to the surfacefor processing.3.2 Each half of the grab is covered with hinged doors toprevent washout upon sample lowering and retrieval.4.Significance and Use4.1 The Ekman 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 Inspect the device for mechanical defects prior to its use.5.2 This sampler is inefficient in deep waters,under adverseweather conditions,and in waters of moderate to strongcurrents or wave action.5.3 Exercise caution at all times once the grab is loaded orcocked because a safety lock is not part of the standard design.5.4 Operate the sampler from a boat with a winch and cable.6.Procedures6.1 The sampler is cocked by raising each jaw upward intothe cocked position using the attached cable and securing thecable to the catch pin located at the top of the sampler.6.2 Once cocked,lift the sampler overboard and lowerslowly but steadily to the bottom.6.3 Once on the bottom,indicated by a slack line,themessenger is sent down the line tripping the catch mechanism,causing the spring loaded jaws to close the bottom of thesampler,containing the sediment.6.4 Raise the sample at a slow but steady rate to preventsample loss or washout.6.5 Once the sample is on board,empty the sample intoeither a suitable container or a sieving device directly forprocessing.6.6 Thoroughly wash or hose the device with water so thatthe entire sample is processed before a replicate sample istaken.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 October 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 reviewed every five years andif not revised,either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee,which you may attend.If you feel that your comments have not received a fair hearing you should make yourviews known to the ASTM Committee on Standards,100 Barr Harbor Drive,West Conshohocken,PA 19428.D 43432NOTICE:This standard has either been superceded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.