EN ISO 16665:2005

SLOVENSKI STANDARD
01-december-2005
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PDNURIDYQHPHKNHJDGQD,62
Water quality - Guidelines for quantitative sampling and sample processing of marine
soft-bottom macrofauna (ISO 16665:2005)
Wasserbeschaffenheit - Anleitung für die quantitative Probenahme und
Probenbearbeitung mariner Weichboden-Makrofauna (ISO 16665:2005)
Qualité de l'eau - Lignes directrices pour l'échantillonnage quantitatif et le traitement
d'échantillons de la macrofaune marine des fonds meubles (ISO 16665:2005)
Ta slovenski standard je istoveten z: EN ISO 16665:2005
ICS:
13.060.10 Voda iz naravnih virov Water of natural resources
13.060.70 Preiskava bioloških lastnosti Examination of biological
vode properties of water
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 16665
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2005
ICS 13.060.70; 13.060.10
English Version
Water quality - Guidelines for quantitative sampling and sample
processing of marine soft-bottom macrofauna (ISO 16665:2005)
Qualité de l'eau - Lignes directrices pour l'échantillonnage Wasserbeschaffenheit - Anleitung für die quantitative
quantitatif et le traitement d'échantillons de la macrofaune Probenahme und Probenbearbeitung mariner Weichboden-
marine des fonds meubles (ISO 16665:2005) Makrofauna (ISO 16665:2005)
This European Standard was approved by CEN on 7 April 2005.
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 bibliographical references concerning such national
standards may be obtained on application to the Central Secretariat 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 responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16665:2005: E
worldwide for CEN national Members.

Foreword
This document (EN ISO 16665:2005) has been prepared by Technical Committee ISO/TC 147
"Water quality" in collaboration with 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 standard, either by publication of
an identical text or by endorsement, at the latest by April 2006, and conflicting national
standards shall be withdrawn at the latest by April 2006.

According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary,
Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

Endorsement notice
The text of ISO 16665:2005 has been approved by CEN as EN ISO 16665:2005 without any
modifications.
INTERNATIONAL ISO
STANDARD 16665
First edition
2005-10-15
Water quality — Guidelines for
quantitative sampling and sample
processing of marine soft-bottom
macrofauna
Qualité de l'eau — Lignes directrices pour l'échantillonnage quantitatif
et le traitement d'échantillons de la macrofaune marine des fonds
meubles
Reference number
ISO 16665:2005(E)
©
ISO 2005
ISO 16665:2005(E)
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ii © ISO 2005 – All rights reserved

ISO 16665:2005(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Terms and definitions. 2
3 Quality and safety. 3
3.1 Health and safety requirements . 3
3.2 Quality assurance and quality control. 4
4 Strategies and objectives for soft-bottom faunal surveys . 5
4.1 Sampling programme and plan . 5
4.2 Positioning of sampling stations . 5
4.3 Reference stations. 6
4.4 Types of surveys. 6
4.5 Change in sampling programme and intercalibration . 10
5 Sampling. 10
5.1 Documentation and field log . 10
5.2 Sampling and sample processing in the field . 11
5.3 Sample fixation . 15
5.4 Background environmental descriptors. 15
6 Sample processing in the laboratory. 18
6.1 Sorting . 18
6.2 Sample residue . 18
7 Taxon determination and quantification .19
7.1 Level of identification and taxon lists. 19
7.2 Quantification. 19
7.3 Reference collection (see also 7.7.8). 20
7.4 Biomass . 20
7.5 Data reporting . 20
7.6 Storage and archiving . 21
7.7 Analytical quality control and quality assurance . 21
Annex A (informative) Processing particularly large samples . 24
Annex B (informative) Sampling devices. 25
Annex C (informative) Biomass measurements. 27
Bibliography . 28

ISO 16665:2005(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 16665 was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 5, Biological
methods.
iv © ISO 2005 – All rights reserved

ISO 16665:2005(E)
Introduction
Analysis of macrofaunal communities in soft-bottom sediments is an integral part of marine environmental
assessment. The faunal composition, in terms of both the species present and their relative abundance,
reflects integrated environmental conditions in the survey area over a period of time. The composition and
structure of soft-bottom macrofaunal communities therefore can be used to characterise environmental
conditions and estimate the extent of environmental impact.
Characterisation of environmental conditions is usually based on quantitative methods, in this case by relating
the numbers of species and individuals captured to a known area of sea floor. For accurate data interpretation,
it is essential to add information on the geophysical/geochemical characteristics or properties of the water
masses and bottom sediments, including nutrients, oxygenation and redox state where appropriate.
For effective data utilisation and quality assurance of the work carried out, it is essential that surveys are
intercomparable temporally, spatially and between operators. This International Standard contributes to
on-going work on quality assurance of data from soft-bottom macrofaunal surveys. These guidelines primarily
aim assisting in standardising monitoring surveys carried out for commercial purposes or in connection with
the EU Water Framework Directive. For this reason, detailed specifications are given in areas of consequence
for data intercompatibility.
Where appropriate, cost-benefit issues have been taken into consideration, and accepted minimal
requirements for general environmental impact assessment have been given. The cited minimum
requirements for accuracy are not intended to satisfy research needs, or to provide a full ecological
understanding of the sampling area. Designers of programmes for research or other studies requiring a
detailed knowledge of soft-bottom macrofauna should consult the guidelines given in Reference [17] for
decisions of survey design and sampling frequency.
This International Standard applies to all areas of the sea floor where it is possible to collect faunal samples
by a grab or coring device. For practical reasons, this applies to animals retained on a mesh screen of 0,5 mm
or 1 mm aperture size.
The sensitivity of the method, here defined as detection of faunal disturbance, change in taxon composition or
faunal mapping, is dependent on the type of environmental influences present in the area and on the level of
competence/standardisation of the personnel.

INTERNATIONAL STANDARD ISO 16665:2005(E)

Water quality — Guidelines for quantitative sampling and
sample processing of marine soft-bottom macrofauna
1 Scope
This International Standard provides guidelines on the quantitative collection and processing of subtidal
soft-bottom macrofaunal samples in marine waters.
This International Standard encompasses:
 development of the sampling programme;
 requirements for sampling equipment;
 sampling and sample treatment in the field;
 sorting and species identification;
 storage of collected and processed material.
This International Standard does not specifically address the following, although some elements may be
applicable:
 bioassay sub-sampling;
 deep water (> 750 m) or offshore sampling;
 in situ faunal studies, e.g. recolonisation assays;
 nonbenthic organisms caught in the sampling device;
 estuarine sampling;
 intertidal sampling;
[3]
 meiofaunal sampling and analysis ;
 sampling by dredge and sledge;
 Self-Contained Underwater Breathing Apparatus (SCUBA) sampling;
 statistical design.
Accuracy of position fixing is determined by the geographical area, equipment used and survey objective.
ISO 16665:2005(E)
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
baseline survey
environmental impact assessment
survey with emphasis on characterisation and description of biotic and abiotic conditions in the survey area,
and which forms the basis for future monitoring and/or follow-up surveys
2.2
benthic
associated with the sea floor
2.3
benthic macrofauna
bottom-dwelling animals retained on a mesh screen of 0,5 mm or 1 mm aperture size
2.4
receiving water body
water body which receives an input of material, of either natural or anthropogenic origin
NOTE The term often appears in the context of anthropogenic input, for example, effluent from municipal waste-
water outlets or industrial processed water.
2.5
reference station
one or more sampling stations chosen to represent environmental conditions in a given area, i.e. free from
direct anthropogenic influences
2.6
replicate sample
series of samples taken in the same time frame, at the same sampling station, in the same manner for
statistical validity and comparison
NOTE Replicate samples may include sets of subsamples taken from a larger sample.
2.7
sampling station
precise location where samples are collected
NOTE A sampling station is defined by its geographical position (OS National Grid Reference, latitude, longitude), its
depth (relative to chart datum and normalised to mean low water as given in tide tables) and any other invariant or
physical conditions. The station is delineated using the given level of precision. In cases of doubt when revisiting sampling
stations, emphasis should be placed on landmarks and water depth.
2.8
soft-bottom
areas of sea floor consisting of loose deposited particles including clay, mud, sand and gravel, shells and
maerl, also including mixed substrata with gravels, small stones and pebbles scattered on a bed of finer
material, but excluding cobbles
2.9
soft-bottom fauna
animals living on or completely/partially buried in soft-bottom sediments
2.10
sublittoral
portion of the shore which is either totally immersed or only uncovered by the receding tide infrequently and
then for very short period (i.e. below the littoral zone)
2 © ISO 2005 – All rights reserved

ISO 16665:2005(E)
2.11
subsample
ideally representative portion removed from a sample, taken for separate analysis
NOTE See Annex A.
3 Quality and safety
3.1 Health and safety requirements
3.1.1 General
All phases of benthic sampling and sample processing should adhere strictly to national and international
health and safety regulations. The main points are listed below.
3.1.2 Laboratory safety facilities
A valid health and safety manual should be freely available in the institute or laboratory and the appropriate
first-aid supplies and emergency facilities (such as eyewash station and shower) should be installed. The
laboratory and storage areas should further be equipped with point-ventilation outlets and preferably have a
monitor for chemical levels in the air.
3.1.3 Vessel safety and operation of field equipment
Vessels used for sampling should be certificated for safety and equipped with experienced crews and onboard
machinery maintained and suited to the operating environment.
Many types of sediment samplers present a serious danger to personnel. All staff should be fully aware of the
appropriate procedures to operate safely around each sampler. Only trained operators, or personnel under
their supervision, should handle equipment on deck.
3.1.4 Behaviour and training
All personnel collecting and handling samples should be given training in the appropriate health and safety
procedures and, where in force, have attained certification status. Refresher training should be carried out
every three years or sooner. Staff should be trained in assessing risks to personnel or equipment and follow
any documented procedures.
3.1.5 Handling of chemicals
Chemicals used for fixing or preserving faunal samples should be stored and handled with the proper
precautions according to health and safety regulations, see 3.1.2 and 3.1.6. Non-drip dispensers should be
used for liquid chemicals.
Common chemicals used in benthic work include the fixative formalin or substitutes, the preservative ethanol
and biological stains such as rose Bengal or methyl green.
WARNING — Formalin is particularly hazardous to health, and prolonged or intense exposure can
cause long-term allergies. A number of less hazardous, but expensive, alternatives to formalin are
available and should be used where possible, especially when dealing with small sample volumes.
ISO 16665:2005(E)
3.1.6 Equipment and protective clothing
Appropriate protective clothing should be made available. These include:
 in the field: helmet, safety boots, coveralls, life-jacket/floating suit (depending on the type of vessel),
gloves;
 in the laboratory and store: aprons, gloves, goggles, gas-filters.
3.2 Quality assurance and quality control
Quality assurance and quality control measures should be incorporated during all stages of benthic sampling
and sample processing programmes. These principles help to guarantee that all data produced are of a
specified quality, and that all parts of the work are carried out in a standardised and intercomparable manner.
All procedures should therefore be clearly described and carried out openly, such that all of the laboratory’s
activities can be audited internally and externally at any time.
NOTE The overall aim is to assure traceability and full documentation of samples and equipment from beginning to
end from sampling, sample transport, offloading from survey vessel, placement within and retrieval from a sample store to
sample processing, reporting and final archiving.
National and/or international accreditation should be sought if appropriate, required for most commercially-
operative laboratories. Guidance from relevant accreditation bodies should be sought in developing specific
in-house quality systems, work procedures and protocols. It is recommended that laboratories participate in
intercomparative tests or learning schemes to develop expertise and maintain the appropriate skills. This
ensures continued standardisation and reproducibility of results.
Further recommendations on quality assurance practices are given in Reference [17].
EXAMPLE Some examples of national guideline and/or audit schemes for marine benthos are given below:
 Germany (http://www.umweltbundesamt.de/wasser/themen/q-blmp.htm);
 UK - National Marine Biological Analytical Quality Control Scheme (http://www.nmbaqcs.org/).
Further, within the International Council for the Exploration of the Sea (ICES) are also two relevant Steering
Groups on Quality Assurance of Biological Measurements in the Northeast Atlantic and Baltic Sea,
respectively (see http://www.ices.dk/iceswork/workinggroups.asp).
A quality assurance/quality control scheme should encompass the following:
 training and training records;
 traceability of work and samples;
 standardised practices throughout;
 calibration of sampling and sample processing equipment;
 in-house and external audit, also referred to as Analytical Quality Control schemes;
 literature updates;
 reference or voucher collections.
Specific details on analytical quality assurance and quality control are given in 7.7.
4 © ISO 2005 – All rights reserved

ISO 16665:2005(E)
4 Strategies and objectives for soft-bottom faunal surveys
4.1 Sampling programme and plan
The design of the sampling programme depends on the detailed aims of the survey and the required power of
the data. The programme should be developed with regard to local topographical and hydrographic conditions
in the survey area, information on local contamination sources and knowledge from previous surveys, if any.
The number of sampling stations, their positions and numbers of replicate samples to be taken at each
sampling station should be established prior to the initiation of the survey. The design of the programme has a
strong influence on the options for data treatment and statistical analyses. Prior considerations about data
treatment and reporting should therefore be made. Quality assurance procedures should be incorporated at
this stage.
Guidance and considerations for sampling and statistical design may be found in Reference [17].
4.2 Positioning of sampling stations
4.2.1 General
Sampling stations should be located to satisfy predefined requirements, bearing in mind the objectives of the
study and the likely scale of natural variability in the biota.
For monitoring purposes (except for biodiversity studies — see below), sampling stations should preferably be
positioned in areas of even sandy/muddy bottom sediments. Certain bottom types where it is difficult to obtain
good-quality samples, such as in sediments containing large amounts of stones, hard gravel, twigs and similar
objects, should be avoided. However it may be possible for a diver to sample pockets of sediment in such
areas. Alternatively, supplementary semiquantitative techniques may be used, e.g. underwater photography,
video, remotely operated vehicle (ROV), or benthic dredging. In special cases where habitats within the
sampling area vary strongly, different sampling techniques may be combined, but generally the same gear
should be used for all sampling in one survey.
For biodiversity studies, various bottom types should be included, as appropriate to the aims of the
programme.
Sampling stations can be positioned according to one, or combinations of, the following strategies:
 station network, see 4.2.2;
 randomly;
 stratified;
 transect;
 single-spot sampling, see 4.2.6.
4.2.2 Station network
Sampling stations are arranged in a regular grid-like pattern. This arrangement is appropriate for overview
surveys and for mapping of distribution of factors of interest, for instance zone of influence around point
source discharges. The survey area should be one of topographic homogeneity, but some adjustments can be
made according to local conditions, for instance in fjords and coastal waters with smaller variations in depth.
ISO 16665:2005(E)
4.2.3 Random or scattered sampling
In special circumstances, sampling stations may be positioned randomly or scattered. An example of this
might be when no previous knowledge of the area is available as a guide to appropriate stratification, or when
an unbiased value for a whole area is desired.
4.2.4 Stratified sampling
Sampling stations are arranged within locally homogeneous subdivisions of the survey area. The subdivisions
(strata) may be delineated according to depth, sediment types or other factors that vary across the survey
area. Stratification is appropriate in cases where habitat variability can confound patterns of interest. Within-
strata stations may be placed in a network, for instance for zone-of-influence mapping, or randomised for
description of “average” characteristics of the strata. Echo-sounders or appropriate ground discrimination tools
should be used.
4.2.5 Transect sampling
Sampling stations are arranged along linear transects. One approach is to place stations along a known or
anticipated gradient of a factor of interest in a sub-area of minimum habitat variability. This is applicable, for
instance, to trace effects of point-source discharges by establishing the transect in the main current direction
from the source. Another rather different approach is to place stations across possible habitat gradients when
it is not feasible or appropriate to work in strata.
4.2.6 Single-spot (station) sampling
This applies when a small number of stations are placed according to individual assessment. In cases of
known or suspected eutrophication or chemical contamination, sampling stations may be positioned in the
deepest parts of the survey area (depressions, basins), where the earliest signs of disturbance are often seen.
However no formal statistical comparison among areas is possible based on single stations. This is regarded
as an undesirable design, only to be used either when it is just the station in itself that is interesting, or when
the limitation of available resources makes it impossible to sample several stations.
4.3 Reference stations
For surveys carried out in contaminated areas, or those believed to be contaminated, one or more reference
stations should be chosen beyond the affected area. The reference stations should, as far as possible, be
representative of conditions unaffected by effluent sources and allow assessment of natural temporal and
spatial variations in the soft-bottom faunal communities. Reference stations should be used in surveys where
special circumstances demand direct comparison of the fauna with that beyond the disturbed or affected area,
or where knowledge of the extent of natural variation is required.
Reference stations should be located in conditions as similar as possible to those at the regular sampling
stations, i.e. similar depth and sediment type. Multiple reference stations are particularly important in
heterogeneous areas.
Statistical considerations and the required precision of results dictate the number of reference stations and
sample replicates required.
NOTE Some surveys demand a higher number of sample replicates at reference stations than at “ordinary” stations.
4.4 Types of survey
4.4.1 General
Surveys may be divided into three main categories (see Table 1) according to the objectives.
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ISO 16665:2005(E)
Precision of results refers to the expected accuracy of the data obtained, i.e. how representative the samples
are of the environmental conditions. Precision of results is less in heterogeneous relative to homogeneous
sediments or water depth across a sampling area. Therefore, to achieve the same precision, heterogeneous
sediments require higher numbers of sampling stations and/or replicate samples relative to homogeneous
sediments. In addition, precision varies depending on whether the samples are processed quantitatively or
semiquantitatively. The required precision and therefore the sampling and processing intensity is determined
by the individual aims of the survey.
Table 1 — Overview of main categories of survey type
Survey type Objectives User group Precision of results
Pilot survey Gives a general overview of bottom and Regulatory authorities and Low
faunal conditions. Used for simple rapid consultancies. Research
assessment or to give basic information use as precursor to larger
for designing more detailed sampling programme
programmes
Baseline survey/ Characterises conditions in a given area. Mainly regulatory Medium to high,
environmental impact Also maps or identifies the impact of authorities and depending on individual
assessment point-source discharges (spatial extent consultancies. Research requirements
and intensity). Faunal composition is use for mapping,
compared with specified assessment succession/ recolonisation
criteria or simply with other or gradient studies
representative areas
Temporal trend Describes changes in benthic fauna over Mainly regulatory Medium to high,
monitoring time, either for detecting change in authorities and depending on individual
biodiversity or as applied to consultancies. Research requirements
environmental conditions use for environmental and
biodiversity changes over
time (also applied to
climate monitoring)
Note that the different survey types may supplement each other. For example:
 a pilot survey may provide information needed to design a sampling programme for a baseline survey/
environmental impact assessment;
 any of the surveys when repeated in the same manner and at the same time of year may provide
temporal trend data.
4.4.2 Pilot survey
This is an initial assessment of faunal conditions in the bottom sediments in an area where the contamination
source is not known or where there are no existing data from the area. The survey allows a coarse
assessment of conditions and can provide the basis for development of a sampling programme for applied
surveys, such as baseline/environmental impact assessment surveys as well as long-term surveillance by
temporal trend monitoring. The requirements for equipment, sampling methodology and repeatability are
usually relatively simple, see Table 2.
Pilot surveys can have another important use, namely to help design the size and calculate statistical power
for future monitoring programmes. For this purpose, it is desirable to have the pilot study resemble the
planned monitoring programme as much as possible in terms of the spatial and temporal arrangement of
samples.
A pilot survey generally requires relatively few samples. For applied purposes, the sampling area is chosen in
accumulation areas rather than where net erosion takes place. Sampling stations may be positioned at
random or in a grid. If the objective is to assess the faunal assemblages across an area at large, samples
ISO 16665:2005(E)
should be taken in both deep and shallow water. The sampling area should cover as much of the survey area
as possible.
In addition to quantitative faunal sampling, dredging should be carried out to collect the rare, large and more
mobile taxa not adequately sampled by remote quantitative methods. Especially in regions with varying sea
floor topography and open to wind and currents, an ROV or sledge-mounted video reconnaissance is
recommended to determine the extent of sediment and faunal patchiness (can occur in areas of both coarse
and fine sediments). If appropriate, acoustic ground discrimination techniques may also be used to provide
additional information.
Strategy and design for pilot surveys are summarised in Table 2.
Table 2 — Strategy and design for pilot surveys
Sampling devices Usually grab or box corer, preferably supplemented by use of a benthic dredge. If
appropriate, also other semi-quantitative techniques may be used (such as underwater
photography, ROV, video or acoustic ground discrimination tools).
Strategy for sampling May be one or a combination of strategies outlined in 4.2.
stations
Minimum requirements for Minimum requirements depend on purpose of survey. If carried out to identify best sampling
faunal assessment stations for future programme, a minimum of semi-quantitative assessment of benthic fauna
should be done at all stations (at least presence and relative abundance of the major animal
taxa), preferably also identification of large, abundant or otherwise prominent organisms.
If pilot survey required to make firm statements about environmental disturbance,
quantitative sampling is recommended.
Optional sampling Additional samples from priority stations (as assessed by visual observations or
physico-chemical data obtained during sampling or other documented or anecdotal
information) may be retained for later quantitative processing.
Field documentation Field log of sampling conditions and sediment description (see 5.1.).
required
Reference station Should also be sampled, unless previous data exist to assess the status of reference areas.
requirements
4.4.3 Baseline survey/environmental impact assessment
This is a survey widely carried out for applied research or commercial surveys, generally either where a
known source of impact exists or before effluent discharge is established. Such surveys may also be carried
out for biodiversity research or where an area needs to be characterised biologically. The aim is to document
faunal conditions and/or map the spatial extent of biological impact. Such surveys can be carried out using
relatively simple methodology, but usually there are specified requirements for the methodology and
procedures to be used.
Where external reference or survey data exist, these should be used to help plan the survey programme and
to assess overall impact, where appropriate. See also 5.4 for comments on supplementary nonquantitative
sampling.
Strategy and design for baseline surveys/environmental impact assessment are summarised in Table 3.
8 © ISO 2005 – All rights reserved

ISO 16665:2005(E)
Table 3 — Strategy and design for baseline surveys/environmental impact assessment
Sampling devices Usually grab or box corer, preferably supplemented by a benthic dredge. If appropriate, also other
semiquantitative techniques may be used (such as underwater photography, ROV, video or
acoustic ground discrimination tools).
Strategy for Sampling stations positioned according to aims of survey.
sampling stations
Grid or transect sampling; stations positioned in relation to known discharge points if applicable.
Stratified random sampling may also be applied according to the knowledge of expected
distribution of impacts. Likely impact distribution can be determined by assessing the degree of
impact in relation to local hydrography and bottom topography.
If intended to detect diffuse effluent or to monitor environmental change, one station may be
placed in the deepest part of the survey area (where impacted conditions often first appear). In
some cases, a follow-up survey can be carried out using fewer sample replicates or sampling
stations than the initial thorough environmental description.
If the samples are used for legislative purpose, the required precision of results (or statistical
power) should be determined, and the number of replicate samples taken adjusted as appropriate.
If necessary, the number of replicate samples to be used for the analyses can be determined by
calculating taxon-area curves.
Minimum At least one, usually three or more, replicates are processed quantitatively, depending on
requirements for statistical requirements. Faunal assessment may focus on individual taxa, groups of taxa or
faunal assessment community-based assessment. For impact assessment, larger-scale effluents demand a more
extensive station network and statistical power than small-scale effluents.
Optional sampling Contingency replicates may be collected from priority stations (assessed as for pilot survey) to be
processed later if required.
Field documentation Field log of sampling conditions and sediment description (see 5.1.).
required
Reference station Reference station(s) should be established in cases where environmental impacts are expected.
requirements In areas of strong impact gradients, one reference station may be sufficient. Where there is much
natural variation in conditions (heterogeneous bottom) and/or only low to moderate impacts, two
or more reference stations are recommended. If the end-points of transects are demonstrated
outside the zone of impact, these may act as reference stations. Where standards of “pass/fail”
have already been established for the area, reference stations may not be required.
To assess possible overall impact in the area studied, external reference data across a wider area
are recommended (can encompass new or existing data).
4.4.4 Temporal trend monitoring
This is a survey of the benthos in response to temporal changes in the chemical and/or physical conditions in
the sediments to document either contamination or natural variation over time. The surveys should be carried
out using standardised methodology according to an established programme. Sediments that are physically
disturbed by human activities (e.g. trawling) are generally not suitable for retrospective trend monitoring
purposes.
Strategy and design for temporal trend monitoring surveys are summarised in Table 4.
ISO 16665:2005(E)
Table 4 — Strategy and design for temporal trend monitoring surveys
Sampling devices Usually grab or box corer, supplemented if appropriate by semi-quantitative assessment
techniques (such as benthic dredging, remote underwater photography, ROV, video or
acoustic ground discrimination tools).
Strategy for sampling Sampling stations positioned according to aims of survey, but positions fixed and resampled
stations at regular intervals. A high level of documentation and replicability is required.
Statistical power is assessed as for baseline survey/ environmental impact assessment.
Minimum requirements for As for baseline survey/ environmental impact assessment.
faunal assessment
Optional sampling As for baseline survey/ environmental impact assessment.
Field documentation Field log of sampling conditions and sediment description (see 5.1).
required
Reference station Reference station(s) appropriate only if monitoring effluent impact (in which case strategy as
requirements for zone of impact mapping).
Seasonal sampling can have an important influence on the results of temporal trend monitoring. Surveys
should always be carried out during the same season to ensure continuity. The minimum is one sampling per
survey year, but two or more samplings during the same year are advantageous. For monitoring surveys,
sampling during known recruitment periods (e.g. summer) generally is avoided, except where there is an
express interest in recruitment and production.
The timing of sampling varies geographically. In certain areas, winter sampling is not possible due to ice cover,
subzero temperatures or other unfavourable conditions (e.g. the Arctic and Baltic Sea). In these cases, spring
and/or autumn sampling are the only alternatives. Where climate is not an issue, the preference is usually for
winter sampling, with additional sampling in autumn, if appropriate.
4.5 Change in sampling programme and intercalibration
The issue of reproducibility should be given due concern. If changes or modifications are to be made in a
running sampling programme, care should be taken to ensure comparability of old and new data. In particular,
if the sampling gear in a long-term monitoring programme is to be changed, appropriate validation of the new
techniques should be carried out. Intercalibration should be conducted when comparisons between studies
carried out with different techniques are to be made.
5 Sampling
5.1 Documentation and field log
A field log should be kept for recording information pertaining to the sampling, sampling stations and the
individual samples.
A minimum of the following information concerning sampling and the sampling stations should be recorded in
the field log:
 person responsible for sampling;
 project or contract identification code;
 geographical co-ordinates for each sampling station (also for each replicate sample if required, e.g. in
case of boat drift during sampling, see 5.2.2);
 track-plot of stations sampled, if required by the relevant protocols;
10 © ISO 2005 – All rights reserved

ISO 16665:2005(E)
 water depth (in metres) and tidal state, especially coastal or shallow waters, at each sampling station and
for each replicate sample;
 sampling programme for each sampling station (number of replicate samples, sampling of background
parameters, et
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