ASTM_D_4344_-_84_1998.pdf

Designation:D 4344 84(Reapproved 1998)Standard Practice forCollecting Benthic-Macroinvertebrates with Smith-McIntyreGrab Sampler1This standard is issued under the fixed designation D 4344;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,gravel,mud,clay,and similar substrates.1.2 This device is used for collecting bottom samples fromestuarine and marine bodies of water and large rivers.1.3 This device is useful under adverse weather conditions.1.4 For advantages and limitations of grab sampling de-vices,see Guide D 4387.1.5 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 Smith-McIntyre grab sampler has paired jaws thatare forced to penetrate into the intended substrate by two“loaded”springs,must close when positioned properly on thebottom,and retain discrete samples of sediment while it isbrought to the surface for processing.3.2 The Smith-McIntyre grab sampler is fitted with gauzepanels or free swinging panels on the top to reduce the shockwave during descent.3.3 Larger Smith-McIntyre grabs can be constructed de-pending on the type of bottom to be sampled and additionalweights can be fitted to the frame of the grab sampler foradditional penetration into the sediment.4.Significance and Use4.1 The Smith-McIntyre grab sampler is used to collectqualitative and quantitative samples from different aquatichabitats containing benthic macroinvertebrates living on or invarious types of 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 The spring-loaded jaws of the Smith-McIntyre grabmust be considered a hazard and caution must be exercisedwhen using the device.5.2 Due to the weight and size,this device must be usedfrom a vessel with boom and lifting capabilities.5.3 Do not handle this device in the loaded mode except justprior to sampling.6.Procedures6.1 The Smith-McIntyre grab is“loaded”by compressingthe large coil springs mounted on the instrument using theloading bar.6.2 As soon as the spring is loaded,insert the safety pins toprevent the accidental triggering of the bottom plates.6.3 Once the device is overboard,just prior to being loweredto the bottom,remove the safety pins.6.4 Exercise caution to stand clear of the cocked jaws.6.5 The Smith-McIntyre is lowered slowly but at a steadyrate by cable until the trigger plates contact the bottom.6.6 Pressure on these plates releases the two coiled springsthat drive the buckets(jaws)into the sediment.6.7 Applying tension to the lifting cable completes theclosure of the jaws,and the sampler may then be returned tothe surface.6.8 Closure of the sampler is made at the side,rather than atthe bottom.6.9 After closure the sample is given optimum protectionfrom washout during return trip by the cylindrical configura-tion of the sampler.6.10 This device may be fitted with a hydraulic closuredevice that facilitates sampling in hard-packed bottoms,suchas clay.6.11 Once on deck,place the sampler on a stand;the samplebuckets can be disengaged from the rest of the device byreleasing two retaining latches at each end of the uppersemicylinder,and the sample is dumped into a large basin orwashtub and prepared for processing.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.6.12 Thoroughly wash or hose the grab buckets with waterso that all the sediment material is included in the sampleprocessing before a replicate sample is taken.6.13 After the sample has been removed,the springs maythen be loaded and the safety pins installed.The American Society for Testing and Materials takes no position respecting the validity of any patent righ