ISO 5667-12:2017

INTERNATIONAL ISO
STANDARD 5667-12
Second edition
2017-07
Water quality — Sampling —
Part 12:
Guidance on sampling of bottom
sediments from rivers, lakes and
estuarine areas
Qualité de l’eau — Échantillonnage —
Partie 12: Recommandations concernant l’échantillonnage des
sédiments dans les rivières, les lacs et les estuaires
Reference number
©
ISO 2017
© ISO 2017, Published in Switzerland
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ii © ISO 2017 – All rights reserved

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Sampling strategy . 3
4.1 General . 3
4.2 Type of investigation . 3
4.2.1 General. 3
4.2.2 Chemical investigation . 3
4.2.3 Physical investigation . 3
4.2.4 Biological and microbiological investigation . 4
4.3 Choice of sampling site . 4
4.4 Choice of sampling point . 4
4.5 Choice of sampling method . 5
4.5.1 General. 5
4.5.2 Consolidated bottom sediment . 5
4.5.3 Unconsolidated bottom sediment . 6
4.6 Frequency and time of sampling . 6
4.7 Site conditions . 6
4.7.1 General. 6
4.7.2 Meteorological and climatic conditions . 6
4.7.3 Hydrological conditions . 7
5 Sampling equipment . 8
5.1 General . 8
5.2 Grab systems . 8
5.3 Corer systems .10
6 Sampling procedure .13
6.1 Sampling container materials and types .13
6.2 Composite samples.13
7 Storage, transport and stabilization of samples .14
8 Safety .15
9 Sample identification and records .15
Annex A (informative) Description of the scissor-grab system (van Veen type) .17
Annex B (informative) Description of the piston drill system .19
Annex C (informative) Description of the corer system involving a diver .21
Annex D (informative) Description of the Beeker sampler system .22
Annex E (informative) Description of the sealed core sampler system .25
Annex F (informative) Description of the wedge core or Vrijwit drill system .27
Annex G (informative) Description of the gravity corer system .29
Annex H (informative) Description of the Jenkins mud sampler system .31
Annex I (informative) Description of the Craib corer system .33
Annex J (informative) Description of a piston corer .35
Annex K (informative) Description of peat borers .38
Annex L (informative) Freeze coring .40
Annex M (informative) Description of sediment sampler with slicing mechanism .44
Bibliography .46
iv © ISO 2017 – All rights reserved

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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 6,
Sampling (general methods).
This second edition cancels and replaces the first edition (ISO 5667-12:1995), which has been technically
revised.
A list of all parts in the ISO 5667 series can be found on the ISO website.
Introduction
This document should be read in conjunction with ISO 5667-1 and ISO 5667-15.
The general terminology used is in accordance with the various parts of ISO 6107, and more particularly,
with the terminology on sampling given in ISO 6107-2.
vi © ISO 2017 – All rights reserved

INTERNATIONAL STANDARD ISO 5667-12:2017(E)
Water quality — Sampling —
Part 12:
Guidance on sampling of bottom sediments from rivers,
lakes and estuarine areas
1 Scope
This document provides guidance on the sampling of unconsolidated sediments for the determination
of their geological, physical and chemical properties, as well as the determination of biological,
microbiological and chemical properties at the water and sediment interface. Guidance on achieving
sediment cores is given specifically for the measurement of rates of deposition and detailed strata
delineation. The main emphasis of this document is to provide methods that achieve sediment samples.
The environments considered are
— limnic (rivers, streams and lakes, natural and man-made), and
— estuarine, including harbours.
Industrial and sewage works for sludges, paleolimnological sampling and sampling of open ocean
sediments are specifically excluded from this document (and are addressed in ISO 5667-15), although
some techniques may apply to these situations. Sampling of suspended solids is outside the scope of
this document and reference can be made to ISO 5667-17 for such guidance.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 5667-1, Water quality — Sampling — Part 1: Guidance on the design of sampling programmes and
sampling techniques
ISO 5667-15, Water quality — Sampling — Part 15: Guidance on the preservation and handling of sludge
and sediment samples
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
3.1
composite sample
two or more samples or subsamples mixed together in appropriate known proportions, from which the
average result of a designed characteristic may be obtained
Note 1 to entry: The individual portions may be derived from the same unit (stratum) or at the same sediment
depth below a certain interface. The use of subsamples from the same stratum is limited to situations where a
natural mixing of strata is unlikely to have occurred or where the depth of the sediment stratum is sufficient to
allow subsampling without artificial mixing during sample operations. Therefore, subsampling from different
strata is allowed in relation to the objective of the investigation.
3.2
pile-working core compression
blockage
phenomenon which occurs when the sample rising up the inside of a piston corer meets a resistance
due to its own friction, a blockage by a large piece of stone, or the tube being full
3.3
descriptive mapping
description of the sediment (3.5) present in terms of its nature, variation and extent
Note 1 to entry: The exercise is carried out by precise marking of sample location and general recording of site
conditions. Pre-established conditions may be a requirement of the exercise.
3.4
monitoring
establishment of variation of the sediment (3.5) characteristics with time and location
3.5
sediment
solid material, both mineral and organic, deposited in the bottom of a water body
3.6
sediment quality
chemical nature, as well as the physical properties of the sediment (3.5) being sampled, e.g. in relation
to assessment of harbour sediment due to be dredged to determine disposal process
3.7
sampling site
sampling station
well-delimited area, where sampling operations take place
3.8
sampling point
precise position within a sampling site (3.7) from which samples are taken
3.9
uncertainty arising from sampling
part of the total uncertainty of a measured value attributable to sampling
3.10
unconsolidated sediments
sediments (3.5) that are loose so that individual particles are able to move easily relative to each other
2 © ISO 2017 – All rights reserved

4 Sampling strategy
4.1 General
Sampling of sediments from estuarine and inland water bodies can be completed to address the
following:
— temporal and spatial monitoring of the environment;
— as part of environmental impact assessment informing future construction developments (e.g.
increasing of harbour depth so that vessels can access harbours, and installation of renewable
energy applications such as wind farms);
— sediment distribution mapping of an area to enable, for example, sediment transport or intrusion of
fine inorganic particles and organic material to be determined;
— examining the sediment quality (physical and chemical) so, for example, sediment disposal method
can be determined prior to dredging of harbours or rivers;
— spatial and temporal patterns of sediment-dwelling organisms;
— fundamental research.
4.2 Type of investigation
4.2.1 General
The sampling strategy will vary depending on the aims of the work being completed. Three common
types of investigation can be distinguished:
a) chemical investigation;
b) physical investigation;
c) biological and microbiological investigation.
4.2.2 Chemical investigation
In this type of investigation, the nature and amounts of the substances which are bound to the sediment
or are associated with pore water may be determined. Some chemical species become bonded in
preference to small mineral particles and organic matter while some are incorporated in residual pore
water. It should be noted that where the sampling device is made of metal then abrasion and chemical
action, for example from sulfides and phosphates, may lead to specific contamination. In cases where
sample equipment made from plastics are used, chemical residues may leach from the material into
the sample, for example dispersants, or chemicals from the sediment may adsorb into the plastics.
Quality control measures should be undertaken in full consultation with the receiving laboratory in
order to establish the degree of influence of such effects on the survey results. Some study parameters
(e.g. sulfides) may require to be maintained in an oxygen-free atmosphere. In such circumstances,
storage and handling under an inert gas atmosphere may be needed. If it is necessary to maintain
anaerobic conditions while handling samples, tools such as a glove box should be used. For samples
whose measurements can be affected by exposure to oxygen, analysis should be performed as quickly
as possible.
4.2.3 Physical investigation
In this type of investigation, the structure, texture, particle size and layer formation of the sediment
bed are determined and the strata delineation is important for geographical, morphological and, in
some cases, geotechnical investigations.
4.2.4 Biological and microbiological investigation
A biological investigation generally involves classifying the species and numbers of flora and/or fauna
present on and in the sediment bed. In many cases, sampling is carried out in the habitat layer, with most
species present in the top 10 cm. However, this might extend to several decimetres. For specific details
regarding biological investigations, references should be made to specific ISO standards already in
existence or under development, including ISO 16665 for methods involving quantitative sampling and
sample processing of marine sub-bottom macrofauna and ISO 10870 for selection of sampling methods
and devices for benthic macroinvertebrates in fresh waters. In some cases, microbial processes may also
be of interest, such as denitrification, phosphate release, methylation of metals such as mercury or tin.
4.3 Choice of sampling site
In choosing the exact point from which samples are required, two aspects are generally involved:
a) the selection of the sampling site (e.g. the location of the sampling cross-section on the base of the
seabed);
b) the identification of the precise point at the sampling site.
The purpose of sampling is often at a precisely defined sampling site (as is the case when studying
deposition from a particular discharge point), but sometimes the purpose is only to lead to a general
definition of the sampling site as in the characterization of the quality and type of material.
The choice of sampling sites for a single sampling station is usually relatively easy. For example,
a monitoring station for a baseline record of sediment quality may be chosen to permit the use of a
convenient bridge or to allow an upstream effluent discharge or tributary to be well mixed laterally
before the station.
Remote sensing methods, such as use of echosounders, including multibeam, or side scan sonars, should
be considered to assist in checking sediment bed status for rock, or other obstacles such as protected
wrecks and unexploded ordnance, prior to sampling. Refer to EN 16260 for advice regarding completion
of visual seabed surveys using remotely operated and/or towed observation gear for collection of
environmental data.
To establish locations for sediment sampling, and to register the exact sampling point locations, it is
recommended to use Global Positioning System (GPS) technology.
The criteria for sample site choice can include:
— the presence of good sedimentation conditions (e.g. reduced flow rate);
— ease of repeated access to the location, for example a tidal influence;
— seasonal accessibility;
— the influence of marine traffic;
— heterogeneity of the stream bed (roughness, particle size, etc.) across a river transect or within an
area of interest.
4.4 Choice of sampling point
This will be influenced by physical constraints such as boat size or water depth but the precise point
will largely depend upon the purpose of the investigation. For example, if descriptive sediment mapping
is the sole purpose then choice may be the function of flow and current conditions only, whereas if
chemical contamination is being studied, the sampling point will depend largely on the conditions
present at the sediment bed.
NOTE For instance, it would not be expected to find contamination caused by anthropogenic metal inputs in
a riffle area of a stream compared with a pool area.
4 © ISO 2017 – All rights reserved

Consideration of local conditions and features in the monitoring of harbours, such as proximity to
outfalls, the influence of stream mixing and other factors such as plant growth, may be important.
Further guidance is given in 4.7 and ISO 5667-1.
The choice of sampling point will be a desirable pre-qualification for the programme, but exact locations
will inevitably be revised in the field. The number of sampling points required needs to be statistically
representative relevant to address the purpose of the investigation. In rivers and estuaries, it needs to
be considered that the sediments are turned over in several deposition and re-suspension cycles. Thus,
the sediment layers may not be representative for historical deposition scenarios. In this case, age
determination by radiological or limnological analysis is recommended. Statistical guidance is given in
ISO 5667-1. Composite samples may be produced to reduce analysis costs and assist deriving average
regional concentrations as indicated in 6.2. Because of the often patchy distribution of organisms, for
biological samples, it could be necessary to choose multiple random sample sites or to conduct stratified
[23]
random sampling .
4.5 Choice of sampling method
4.5.1 General
The choice of sampling method will largely be restricted by the two following factors:
a) the requirement for a largely undisturbed sample for delineation and the preservation of water and
sediment interface (further details are given in Clause 5);
b) the acceptance of a disturbed sample taken near the bed surface for a general morphological or
chemical examination.
Certain types of chemical parameter may necessitate the use of inert liners in piston or tube type
recovery devices, for example polytetrafluoroethylene linings if low-level pesticides are being
examined. Reference should be made to ISO 5667-15 for guidance on the preservation and handling of
sediment samples.
The remaining factor affecting the choice of sampling method will be the applicability of the proposed
device to the sediment bed conditions. Ideally, consistent sampling methods are used throughout
the survey, although if sediment bed conditions vary within the area being sampled, this may not be
possible. Sampling regimes are summarized in Table 1. More detail about samplers is given in Clause 5.
Table 1 — Sediment type and recommended sampler
a
Sediment type Sampler
Gravel Grab systems; large particle size may require heavier grabs.
Sand Both grab and corer systems can be used. A sand bed can be hard to penetrate
and thus prove difficult for lightweight grabs and manually operated corer
systems. Grabs of larger mass and heavy mechanical corers may be required.
Clay It may be necessary to use a corer because grab systems often cannot
penetrate easily into the clay.
Mud Both grab and corer systems can be used but care should be taken to avoid
over penetration (see 4.5.3).
Peat A difficult medium to sample but it is sometimes possible to use a manually
operated corer system or a special peat borer.
a
Sampler type versus sediment type may have to be determined by experimentation.
4.5.2 Consolidated bottom sediment
For consolidated bottom sediment, both grab and corer systems can be used. If a grab is used, it may be
difficult to determine the penetration depth of the sampling.
4.5.3 Unconsolidated bottom sediment
For unconsolidated bottom sediment, grab systems are not suitable as they are prone to sinking through
the soft layer. Corer systems are better but, when a frame is used at greater depth, care is essential to
prevent the frame from sinking through the soft layer. More support can usually be given to prevent
this by adding large plates to the feet of the frame. Samplers which depend on the free-fall principle are
not suitable for this bed type.
4.6 Frequency and time of sampling
Results from a sampling programme need to provide data with an acceptable uncertainty defined in
the objectives of the programme. If the objectives do not include a definition of the tolerable error, a
statistically-based sampling programme is impossible. It should be remembered that changes with
time of sediment composition may require a much longer period of observation to detect than changes
observed for water. For example, diurnal variation in concentration of metals may be detected in
estuarine water but the respective sediments may only show fluctuation over a much longer sampling
period. When using systematic sampling, it is essential to ensure that the frequency of sampling does
not coincide with a natural cycle present in the system. In the case of sediments, this may be seasonal
variation, yet it should also be considered that flow extremes, especially flooding, result in bed transport
and altered sediment structure and lead to intrusion or washout of inorganic and organic fine material.
It may be necessary to increase the sampling frequency in order to observe any variation in some cases,
for example when monitoring pore water nutrients. The frequency of sediment sampling is only likely
to have a major influence on the interpretation of results when rapid deposition rates are expected,
for example weekly sampling of a river bed downstream of a discharge point is not likely to reveal
any data that is different from that demonstrated from sampling at half yearly intervals other than
the inherent variability of the sediment. The reasons for sampling are constrained by the needs of a
particular project which will themselves define the frequency of sampling. For details of the application
of statistics to sampling frequency, refer to ISO 5667-1.
4.7 Site conditions
4.7.1 General
Conditions at the sampling position are of vital importance to achieve correct sampling. A number of
these conditions will usually be known before sampling takes place and should be taken into account
when preparing the operation and also when choosing the apparatus to be employed.
The following conditions are important:
— meteorological and climatic (e.g. temperature, precipitation, solar radiation);
— hydrological (e.g. discharge, water depth, current, velocity);
— geological (e.g. characteristics/composition/stratification of sediments, erosion);
— nautical;
— biological (e.g. with reference to macrophyte accumulation).
4.7.2 Meteorological and climatic conditions
Temperature, wind direction and force can be restricting factors when carrying out sampling. For
example, if the sampling location is situated in an area which is strongly affected by wave movements,
then this should be taken into account when planning the operation and when using the apparatus. The
restrictions related to climates are covered specifically for each type of instrument in the annexes.
In countries with cold climates, it may be practical to work on ice surfaces of lakes. However, safety
should always be a priority and local regulations should apply. Equipment and samples can be protected
from freezing in heated tents.
6 © ISO 2017 – All rights reserved

The need for sampling should be judged against the safety factors influenced by climatic conditions.
In addition, storm conditions may disturb sediment beds so that sampling can become impractical or
meaningless.
4.7.3 Hydrological conditions
4.7.3.1 Tidal areas
In tidal areas, attention should be paid to variations in the depth of water, current speeds and directions.
Variable currents, in particular, are often a restrictive factor in the choice of apparatus to be used. Many
instruments cannot be used where fast currents are present. Sampling using these instruments should
be restricted, due to the effect on the sampling vessel, to periods of low flow rates.
Since the depth of water in tidal areas varies, it is often advisable to carry out sampling at low tide, for
example on dried-out sandbanks, where manual sampling using conventional spades and similar tools
is possible, giving due regard to relevant safety precautions. Each sampling occasion should be judged
against local conditions and experience of local tides. With a budget supported sufficiently onboard,
sampling at high tide could be considered at the expense of precise location and site observation in
order to guarantee the safe field operation. In this case, sampling equipment should be adjusted with
grab systems or a corer of heavier weight.
The sampling of tidal river beds and mud flats may be approached in a similar manner to that employed
for the sampling of soil. Refer to ISO 18400-102.
4.7.3.2 Rivers
Account should be taken of high flow rates in rivers. If the project allows, it may be advisable to restrict
sampling to periods of low water level with low flow rates, where sampling equipment is less likely to
be affected. Other local hydrographical conditions may occur, for example the operation of locks, which
will require investigation before sampling.
4.7.3.3 Standing bodies of water
In lakes, harbour areas and some sedimentation ponds, the currents are often negligible so that the
hydrographical conditions have very little effect on the choice of sampling equipment. When choosing
the equipment to be used, the water depth at the sampling point is important in all three water systems
mentioned here. If the depth is less than 4 m, then manually operated equipment is advisable. At depths
of greater than 4 m, sampling systems operated by lifting or guidance mechanisms are recommended
because of possible vessel disturbance of the sediment surface layer. In the case of the grab systems, the
size of the equipment will determine whether this can be manually operated or not. Further guidance
is given in Table 2.
4.7.3.4 Geological conditions
The general nature of the sediment layer is important when choosing the apparatus to be employed. If no
prior knowledge is available then it is advisable to carry out a preliminary investigation using geological
maps, coastal charts, visual investigations, as well as remote sensing techniques, or even an inspection
via diving, thus preventing many problems arising during the actual sampling. Recommendations
for various combinations of sampler type and sediment bed material are summarized in Table 2 and
Table 3.
4.7.3.5 Nautical conditions
Due to certain nautical conditions, it is not usually possible to carry out sediment sampling from an
anchored vessel in harbour entrances or busy waterways. In these cases, the sampling equipment
should be able to be used quickly to compensate for these conditions and hand-operated systems are
preferable. In all cases, compliance with local safety regulations is essential.
4.7.3.6 Biological conditions
The use of all types of sampling device may be severely hindered by heavy macrophyte growth; on-
site decisions will be constrained by the conditions found. Clearing an area with a dragline is worth
trying before sampling, but it is not successful for all types of plant growth and it limits the sample to
physical examination. Clearing stands of rooted macrophytes will cause disturbance of the sediment
and water interface as well as the upper centimetres of the sediment. This may influence, for example,
measurements of sediment pore water nutrient concentrations or sediment phosphorus fractions.
4.7.3.7 Statistical considerations
The design of sediment sampling programmes is project-specific and generalizations cannot be made.
Some guidance is given in ISO 5667-1 and it is essential to consider prior to completion of programme to
ensure results are robust and fit for purpose desired. The statistical interpretation of data obtained can
be dealt with using the principles detailed in ISO 2602 and ISO 2854.
5 Sampling equipment
5.1 General
Sampling of bottom sediments can be broadly split into two methods: grab devices (see Table 2) and
coring systems (see Table 3). Samplers presented focus on obtaining undisturbed sediment sample,
mainly in finer sediment types. In the case of small depths, where an operator can enter directly on foot
into the water, it is possible to use a scoop to collect sediment. If a scoop is used, care should be taken
not to mix different layers of sediment.
When a grab system is not used, the criteria for selection of sampling apparatus may also be required
to meet the following conditions:
— storage of the sediment in order to minimize changes from in situ conditions;
— allow the selection of a layer;
— allow sampling at the required water depth.
5.2 Grab systems
Many samples are collected using bed grabbers. The most well-known is the scissor grab, sometimes
known as the van Veen type grab sampler. There are, however, a large number of variations. In
general, grab systems consist of one or more hinged buckets which close as it is raised. During closing,
sediment is enclosed by the buckets providing disturbed samples, especially for the van Veen grabber
type. This can be avoided by using other grab systems, such as the Ekman type, which provides
relatively undisturbed samples compared with van Veen type. Probe depths vary from 5 cm to several
decimetres, depending upon the size and mass of the sampler and the structure of the bed material.
Due to the grab construction, there is a large chance of losing part of the finer fraction and/or the top
layer, although Ekman grab systems have shown to be less prone to such losses. Generally, grab systems
are not suitable for sampling peat, clays or gravel beds in fast-flowing areas. Grabs are available in a
variety of designs and examples are given in Table 2. Since generally all grab systems have the same
sampling characteristics, only the van Veen type is described in detail in Annex A. Detailed operating
instructions of grab systems are provided by the manufacturer.
8 © ISO 2017 – All rights reserved

Table 2 — Grab samplers
Sampler Pore Water
Accuracy Sediment type
Type Examples penetration water depth Nautical conditions
of sample (geological conditions)
depth sampling (guide)
Manually operated grab Hand-held van 0 cm to No 0 m to Need to make Unconsolidated sediments Both shallow and deep water
(smaller versions of bucket grabs) Veen grab, petite 10 cm 20 m sure sampler (muds and sands); petite and in areas of slow and fast
Ponar grab is sampling Ponar grab is good for currents. However, the
sampler, mini- perpendicular sampling coarse and construction and mass should
Shipek sampler, to the bed. consolidated bottom be adapted to suit the
Sediment snapper, Inaccuracies sediments. conditions. For mechanical
Telescopic arise because devices, it is recommended,
sample with of washing that a secondary line
stainless beaker away of fine carrying a marker float be
fractions. attached as a security
measure, in case the main line
Mechanical bucket grab – hinged bucket/s van Veen (scissor 0 cm to 5 m to Relatively Unconsolidated sediments
needs to be abandoned for
that shut together when reaching grab) – see 30 cm 200 m undisturbed (muds and sands); Ponar grab
safety reasons.
sediment surface Annex A, sediments. is good for sampling coarse
Clamshell, Day Inaccuracies and consolidated bottom
grab, Smith arise because sediments.
MacIntyre grab, of washing
Birge-Ekman away of fine
sampler, Ponar fractions.
grab, Lafond and
Deitz mud
snapper grab
Mechanical grab – bucket rotates under Shipek grab 0 cm to 5 m to Unconsolidated sediments
spring-loaded mechanism into the 10 cm 200 m (muds; sands and gravels).
sediment upon reaching the sediment Sensitive trigger mechanism –
surface never pull out trapped
particles directly.
NOTE  Additional equipment, which emulates or compliments the advantages of that discussed in this document, may also be available commercially. The scope for inclusion in future revisions will
be considered at the appropriate time.

5.3 Corer systems
Sampling using a corer system depends on the principle of driving a hollow tube into the bed so that
the sediment is pushed into it. A sample is obtained by pulling the tube out of the bed. This sampling
principle is used in many different ways and there are a great variety of corer systems available as
summarized in Table 3. It is possible to distinguish between systems in which the tube, where necessary
extended by rods, is pushed into a bed manually and systems in which the tube is inserted by means of
its weight or a vibration mechanism.
When using a boat, it is important that it remains stationary so that, when the core tube is pushed into
the sediment, the vessel is not pushed away. There is a possibility of the vessel being moved against the
rods by wind or currents. This should be prevented in order to avoid damage to the sampling equipment
and boat.
A core cutter can be used to aid penetration of the corer into the sediment bed. Core catchers can be
used to maintain retention of sediment when the core is retrieved from the sediment bed. However,
they can disturb the sediments during sediment collection as the sediment passes through it.
Pile-working core compression or blockage can occur with corer systems. The amount of compression
varies depending on factors such as the diameter of the tube, the composition of the bed and the
penetration speed. It is difficult to judge when this phenomenon is recurring, as each location is
different, and interpretations should be made with caution. The chance of “pile-working” is high in
consolidated silt. In this case, the penetration depth is greater than the compressed strata depth of
the sample in the core tube. This should be borne in mind during the sampling operation and when
interpreting the core.
Evidence can be found by observing distortions in the strata indicating compression at the centre of the
core and a lack of movement at the core periphery during sampling. In general, a concave appearance will
predominate from the bottom of the sample up. The consequences of this occurring vary depending on
the reason for occurrence and the end use of the sample. Stratification studies can be acutely hampered
by this phenomenon. It is possible that the only way to overcome the problem may be to use a different
technique, for example a core tube with a larger diameter. Lubrication of the inside of the sample tube
should only be used with the agreement of the laboratory carrying out subsequent testing.
A cored sediment sample frequently requires dimensionally accurate subsampling in order to take full
advantage of subsequent laboratory analysis and interpretation. Some sampling requirements may
mean that division by slicing a core is carried out on-site before storage. The subsampling procedure
should include the removal of the sediment proximal to the core barrel or liner. The extrusion device
can be a simple piston or a variety of fixtures using a stationary vertical piston over which the core
tube is placed; systems with a thread bar allow to slice a core more precisely. The extruded material
can be sectioned with a device, which can be put on the top of the sampling tube. The cored sediment
sample can be split longitudinally to show sediment horizons. The sample can be simply removed with
a spoon or, if the sediment is solid enough, a spatula. The material of the corer or sectioning devices
should be chosen so as not to conflict with any chemical analysis. Subsampling should target sediment
in the centre of the core, away from the edges, to avoid contamination. If there are clear sediment
horizons present, and these have been photographed and logged, it is possible to subsample each of
these horizons rather than at regular intervals down the core.
10 © ISO 2017 – All rights reserved

Table 3 — Corer samplers
Examples of Sampler Pore water Water Sediment type
Type sampling system penetration extraction depth Accuracy of sample (geological Nautical conditions
and type depth possible (guide) conditions)
Box corers Ekman box corer, 0 cm to 50 cm Yes 5 m to 200 m Sediment can be Soft sediments (muds, Hand-operated devices are prone to
Reineck box corer, Nioz subsampled by muddy sands, sands). nautical constraints such as fast flow
corer inserting core tubes Not gravelly or mixed or high winds in small boats.
into the sediment. sediments, especially
Mechanical devices can be used
Possible to collect if interested in pore
remotely from boats and are more
undisturbed sediment water sampling.
suitable for use in rough weather.
with overlying
They are not recommended for use
water for microcosm
from bankside or bridges.
experiments.
The large weight and size of some
of these corers require heavy-duty
cranes and experienced operators,
these corers are used on larger vessels.
Hand (push) Hand corers, corer 0 cm to 200 cm No 0 m to 20 m Relativel
...