1、Designation: D 4134 82 (Reapproved 2004)Standard Practice forSampling Phytoplankton with a Clarke-Bumpus PlanktonSampler1This standard is issued under the fixed designation D 4134; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e 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 semi-quantitative samples of a phytoplankton community by
3、 use ofa Clarke-Bumpus plankton sampler.1.2 This standard does not purport to address all of thesafety problems, 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
4、limitations prior to use.2. Referenced Document2.1 ASTM Standards:2D 4137 Practice for Preserving Phytoplankton Samples3. Summary of Practice3.1 The sampler is towed from a moving boat at a specifieddepth. The sampler uses a net for the concentration oforganisms and, as such, may be considered to be
5、 a semiquan-titative sampler. It is quantitative in that the actual volume ofwater entering the sampler is measured by a calibrated flowmeter. The phytoplankton are preserved as dictated by theobjectives of the study.4. Significance and Use4.1 The advantages of the Clarke-Bumpus plankton samplerare
6、as follows:4.1.1 It will sample a discrete depth or multiple depths,depending upon the sampling design.4.1.2 It is a slow to medium speed sampler requiring atowing speed of 3 to 5 knots.4.1.3 The sample size can be easily controlled.4.1.4 The sampler is light-weight and can be used withoutauxiliary
7、equipment.4.1.5 It has a relatively high filtration efficiency factor of0.88.4.1.6 It is a versatile sampler and can be used in all but theshallowest waters.4.1.7 The flowmeter records the amount of water that passesinto the net.4.1.8 Overspill of water at the mouth of the net due toexcess speed of
8、towing is of minimal consequence.4.2 The disadvantages of the Clarke-Bumpus plankton sam-pler are as follows:4.2.1 The flowmeter requires frequent maintenance includ-ing calibration and lubrication.4.2.2 It is not suitable for use in very small areas or shallowwaters.4.2.3 Because of the use of a ne
9、t as a filtration material, thesample is semiquantitative.4.3 There are several special considerations that shall beobserved when using a Clarke-Bumpus sampler. They are asfollows:4.3.1 The flowmeter should be calibrated and servicedfrequently to ensure efficient and accurate operation.4.3.2 The sam
10、pler is relatively fragile, particularly theclosing device and flowmeter. This necessitates careful deploy-ment and recovery procedures.4.3.3 Following each collection, the net must be thoroughlywashed.4.3.4 Special attention must be given to the strength of thecable and its attachment to avoid loss
11、 of the sampler.4.3.5 The sampler should not be used in beds of macro-phytes, in waters containing submerged objects, or close to thebottom.4.3.6 The net should be inspected frequently for pin-sizeholes, tears, net deterioration, and other anomalies.4.3.7 Following use, the wet net should be suspend
12、ed fulllength in air and in subdued light and allowed to dry.5. Apparatus5.1 The Clarke-Bumpus plankton sampler, Fig. 1, consistsof a metal frame in which a plankton net is attached at themouth and at the cod end. The sampler is available in threesizes: 120 mm, 200 mm, and 300 mm. The most widely us
13、edsize is the 200-mm diameter net, which reportedly has more1This practice is under the jurisdiction of ASTM Committee E47 on BiologicalEffects and Environmental Fate and is the direct responsibility of SubcommitteeE47.01 on Aquatic Assessment and Toxicology.Current edition approved April 1, 2004. P
14、ublished April 2004. Originallyapproved in 1982. Last previous edition approved in 1998 as D 4134 82 (1998).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the stan
15、dards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.efficient trapping characteristics. A metal tube at the mouth ofthe net is fitted with a digital flowmeter from which the volumeof water f
16、iltered can be calculated. The mouth also contains ashutter device that effectively opens and closes the net permit-ting the collection of samples from discrete depths. The shutteris opened by a messenger, and closed by a second messenger.The sampler usually is attached to a towing cable and itshori
17、zontal orientation is maintained by positioning veins at-tached to the side of the sampler frame. Several samplers canbe strung on a single cable for simultaneous sampling atvarious depths. The frame generally is constructed of stainlesssteel and the entire sampler weighs about 14 kg.6. Procedure6.1
18、 Under steady forward movement, the depth (D)oftowcan be determined by the following equation:D 5 L cos a (1)where:L = length of the tow line from the surface of the waterto the sampler, andcos a = cosine of the cable angle.Once the prescribed depth is reached the duration of the towshould be determ
19、ined experimentally, and will be dependentupon the density of phytoplankton, depth of tow, and size ofnet. When the sampling depth and length or time of tow havebeen achieved, release the messenger to close the opening tothe net and retrieve the sample, being careful to wash phy-toplankton off the s
20、ides of the net into the sample collector.Preserve the plankton as described in Practice D 4137.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determin
21、ation of the validity of any such patent rights, and the riskof 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 wit
22、hdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that yo
23、ur comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (sin
24、gle or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).FIG. 1 Clarke-Bumpus Plankton Sampler (Illustration by J. W.Steiner and W. G. Hester, U.S. Geological Survey, Doraville, GA)D 4134 82 (2004)2
