1、BSI Standards PublicationBS EN 14407:2014Water quality Guidancefor the identification andenumeration of benthic diatomsamples from rivers and lakesBS EN 14407:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 14407:2014. Itsupersedes BS EN 14407:2004/BS 6068-
2、5.35:2004 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee EH/3/5, Biological Methods.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovision
3、s of a contract. Users are responsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 75640 5ICS 13.060.70Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published unde
4、r the authority of theStandards Policy and Strategy Committee on 30 April 2014.Amendments issued since publicationDate Text affectedBS EN 14407:2014EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 14407 March 2014 ICS 13.060.70 Supersedes EN 14407:2004English Version Water quality - Guidance for
5、 the identification and enumeration of benthic diatom samples from rivers and lakes Qualit de leau - Guide pour lidentification et le dnombrement des chantillons de diatomes benthiques de rivires et de lacs Wasserbeschaffenheit - Anleitung zur Bestimmung und Zhlung von benthischen Kieselalgen in Fli
6、egewssern und Seen This European Standard was approved by CEN on 20 December 2013. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and
7、 bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the r
8、esponsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav
9、 Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE
10、NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 14407:2014 EBS EN 14407:2014EN 14407:2014 (E) 2 Contents Page Forewo
11、rd 3 Introduction .4 1 Scope 5 2 Terms and definitions .5 3 Principle 6 4 Apparatus .6 5 Determining analytical strategy .7 5.1 Determining taxonomic criteria for analysis .7 5.2 Determining units for enumeration 7 5.3 Determining sample size .7 5.4 Determining approach to enumeration7 5.5 Treatment
12、 of broken and other unidentifiable diatoms .8 6 Analytical procedures .9 7 Archiving data, slides and samples 10 8 Quality assurance . 10 9 Data interpretation 10 9.1 Use of indices and scores . 10 9.2 Comparison with reference conditions 10 Annex A (informative) Example for quality assurance of di
13、atom analyses from the UK 11 Bibliography . 13 BS EN 14407:2014EN 14407:2014 (E) 3 Foreword This document (EN 14407:2014) has been prepared by Technical Committee CEN/TC 230 “Water analysis”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national stan
14、dard, either by publication of an identical text or by endorsement, at the latest by September 2014 and conflicting national standards shall be withdrawn at the latest by September 2014. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rig
15、hts. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 14407:2004. This document contains the following technical changes compared with the previous edition: This European Standard is now also applicable for the identification
16、, enumeration and interpretation of benthic diatoms in lakes, i.e. not only rivers. Informative Annex A “Example for quality assurance of diatom analyses from the UK” was added. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bou
17、nd to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portuga
18、l, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 14407:2014EN 14407:2014 (E) 4 Introduction Diatoms are an important component of aquatic ecosystems and constitute a water quality monitoring tool where the primary objective is either a measure of ecolo
19、gical status or the impact of specific components of water quality (e.g. eutrophication, acidification). The requirement for the monitoring of such processes is inherent in the Water Framework Directive (2000/60/EC) and Urban Waste Water Treatment Directive (91/217/EEC) in addition to other EU Direc
20、tives and international agreements. This European Standard covers aspects of identification and enumeration of the relative abundance of diatom taxa on prepared slides and of data interpretation relevant to assessment of water quality. The use of diatoms as indicators of river and lake quality is wi
21、dely accepted both in Europe and the USA. The methodology is based on the fact that all diatom species have tolerance limits and optima with respect to their preference for environmental conditions such as nutrients, organic pollution and acidity. Polluted waters will tend to support an increased ab
22、undance of those species whose optima correspond with the levels of the pollutant in question. Conversely, certain species are intolerant of elevated levels of one or more pollutants, whilst others can occur in a wide range of water qualities. Methods using diatoms to assess water quality have been
23、developed in several European countries (recent work is summarized in the proceedings of three symposia 4 to 6. The methodologies for evaluating the diatom data vary but the sampling and preparation processes are similar 1. According to the precise usage to which this European Standard is to be put
24、it is essential for specifiers and users to mutually agree on any necessary variations or optional procedural details prior to use. All numerical values given in this standard are approximate. WARNING Persons using this European Standard should be familiar with usual laboratory practice. This Europe
25、an Standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate health and safety practices and to ensure compliance with any national regulatory conditions. BS EN 14407:2014EN 14407:2014 (E) 5 1 Scope
26、 This European Standard specifies methods for the identification and enumeration of relative proportions of diatom taxa on prepared slides and of data interpretation relevant to assessments of water quality in rivers and lakes. It is suitable for use with indices and assessment methods based on the
27、relative abundance of taxa. The methods for identification and enumeration may also be applied to the study of benthic diatoms in other habitats provided that data interpretation methods appropriate to these habitats are used. 2 Terms and definitions For the purposes of this document, the following
28、terms and definitions apply. 2.1 benthic diatoms diatoms living on natural or artificial substrata, rather than suspended in the water column 2.2 ecological status measure of the structure and functioning of aquatic communities 2.3 expected natural assemblage assemblage present at a site when only n
29、atural stresses (e.g. floods) occur and man-made stress is not significant 2.4 eyepiece graticule measuring device, inserted into one eyepiece of a microscope, permitting measurements of the size of objects Note 1 to entry: The relationship between each division on the eyepiece graticule and the act
30、ual size of the object will depend upon the magnification of the microscope. 2.5 frustule cell wall of diatoms, composed of silica and consisting of two valves linked by two or more girdle bands 2.6 habitat specific environment in which an organism lives 2.7 prepared slide slide plus coverslip on wh
31、ich has been mounted a sub-sample of diatoms 2.8 stage micrometer special graticule in the form of a scale carried at natural size on a microscope slide which is used as an absolute standard of length for calibrating microscope measuring systems SOURCE: ISO 10934-1:2002, 2.96.1 2.9 taxon (pl. taxa)
32、taxonomic units, for example families, genera or species BS EN 14407:2014EN 14407:2014 (E) 6 2.10 unit either diatom valves or intact frustules Note 1 to entry: The use of the term is depending upon the conventions adopted in 5.2. 2.11 valve structural component of the diatom frustule 2.12 vernier s
33、cale measuring device associated with the mechanical stage of a microscope, permitting the relative transverse and longitudinal position of a slide to be noted with a typical precision of about 0,1 mm 3 Principle Benthic diatoms, cleaned of cell contents and mounted in a medium with a high refractiv
34、e index, are identified and counted using a high power light microscope until an appropriate sample size has been obtained. These data are then interpreted using one or more indices or other assessment methods. 4 Apparatus 4.1 Light microscope, equipped with a mechanical stage and high power (e.g. 1
35、00 magnification) oil-immersion lens. Use of a phase contrast or differential interference (Nomarski) condenser is recommended. The microscope should incorporate facilities for measurements (e.g. an eyepiece graticule) with a scale division of at least 1 m. Apparatus for photomicroscopy or video cap
36、ture are useful for documentation of difficult specimens and can also assist with measurement of striae density, etc. 4.2 Floras, identification guides and iconographs, appropriate to the habitats under consideration (see 5.1). 4.3 Immersion oil and dispenser 4.4 Lens tissue 4.5 Facility for recordi
37、ng data as they are collected. This may be a pro forma count sheet with a list of taxon names and space beside each on which the counts can be made or a laboratory notebook organized in such a way that taxon identities and numbers can be clearly recorded, or a computer program with facilities for di
38、rect entry of data. The design of the count sheets or programs should take into account the requirements of any Quality Assurance programmes that are in place. 4.6 Facility for verifying the identity of difficult specimens This can take several forms: drawings, high quality photomicrographs or captu
39、red video images may suffice. However, it is also useful to be able to relocate actual specimens. If taxonomic assistance is available “in house”, noting coordinates on the microscopes Vernier scale may be sufficient. If another microscope is likely to be used, then a facility to record the absolute
40、 position of the specimen may be necessary. BS EN 14407:2014EN 14407:2014 (E) 7 5 Determining analytical strategy 5.1 Determining taxonomic criteria for analysis Recent debates about the fundamentals of diatom taxonomy have led to the co-existence of parallel systems of nomenclature. It is important
41、, when using diatoms for water quality assessments to ensure that any scope for confusion about the correct name to apply to a diatom is eliminated. The minimum level of taxonomy that is acceptable for a study will be determined by the intended uses of the data. Most pollution indices require specie
42、s-level identification, although some can be used with genera, or a mixture of genera and species. Adopting the nomenclature of a comprehensive flora relevant to the study area is recommended; however, it is also possible to use a national or regional checklist of diatoms. When taxonomic conventions
43、 of the index and the checklist differ, the conventions of the index should be adjusted to those of the checklist. This should be done in advance and the correct nomenclature recorded in standard operating procedures. Taxonomic authorities along with the names of taxonomic reference works consulted
44、should be cited in all cases where there is any potential for nomenclatural confusion. 5.2 Determining units for enumeration Different conventions have evolved for enumeration of diatoms, either using valves or frustules as the basic unit, or not distinguishing between valves and frustules. It is im
45、portant that the convention is specified and documented in advance. Because of the distinct definition, the use of valves or frustules (two valves are the equivalent of one frustule) as basic units guarantees the universal comparability between studies and enables further analysis, e.g. the calculat
46、ion of biomass considering reference data. In the case of small diatoms, such as e.g. some Achnanthes and naviculoid species, it may not be possible to distinguish between intact frustules and isolated valves with certainty on all occasions. The effects of this uncertainty on the enumeration, the re
47、lative proportions of diatom taxa and further analysis is likely to be small. If other definitions which do not distinguishing between valves and frustules (e.g. “objects”), are used as basic units it is essential to define the treatment of colonies and only partly separated frustules precisely. The
48、 comparability of such method specific enumeration techniques to other studies may be limited. 5.3 Determining sample size The number of units necessary to compute diatom-based pollution indices will depend upon the uses to which the data are put. A typical count size is 300 units to 500 units, alth
49、ough lower or higher numbers may be appropriate for some purposes. Lower numbers may lack the statistical rigour necessary for some applications. The minimum and maximum number of units should be appropriate to the objectives of the study and should be specified in advance. Details of studies with a range of objectives may be found in references 4 to 7. 5.4 Determining approach to enumeration The eyepiece graticule, or other measuring equipment, should be calibrated against a stage micrometer regularly. The results of this calibration should be disp
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