tools used in water sampling are vessels or plankton traps (Crawford and Quinn
2017; Silva et al. 2018).
Some of the main factors that influence the sampling with nets and, therefore, the
results of each study are the mesh size used and the network area that acts as a filter.
According to the data collected in the literature, the nets usually have a length of
3–4.5 m, and most of the meshes are 300 μm size. It implies that not all microplastics
are collected in commonly used sampling techniques. In addition, other techniques
are occasionally used to evaluate microplastics in water. Particularly, the use of a
cascade of filters is a very promising technique developed by -4H-JENA engineering
GmbH, yet under development.
Sediment Samples
In the case of sediments, sampling is relatively easy. However, currently there is no
official procedure for the sampling in terms of sampling depth, amount of collected
sample, or location. Therefore, the comparison between data produced by different
authors is restricted. At present, sediments of beaches are more often studied.
Sampling work is performed on the whole beach. With respect to the location of
the sample on the beach, the applied sampling strategies include random sampling in
several sites, following perpendicular (vertically from the water edge) and parallel
(horizontally to the water) lines. Transects are a common approach when conducting
a beach sampling using quadrats of various sizes (Hanvey et al. 2017).
With regard to sampling depth, taking samples in the first 5 centimeters is the
most common technique, although sampling at a greater depth has also been found in
published works (Claessens et al. 2011). Authors as Hanvey et al. (2017) think that
Fig. 1.4 Diagram of the main sources of microplastic emissions and their distribution flow through
the marine environment; (1) microplastics from beaches; (2) and (3) microplastics from river
estuaries and from maritime human activities, respectively, and their possible ingestion by organisms; (4) microplastics emitted to the air (Source: Original production)
1 Microplastic Pollution in Water
7
2017; Silva et al. 2018).
Some of the main factors that influence the sampling with nets and, therefore, the
results of each study are the mesh size used and the network area that acts as a filter.
According to the data collected in the literature, the nets usually have a length of
3–4.5 m, and most of the meshes are 300 μm size. It implies that not all microplastics
are collected in commonly used sampling techniques. In addition, other techniques
are occasionally used to evaluate microplastics in water. Particularly, the use of a
cascade of filters is a very promising technique developed by -4H-JENA engineering
GmbH, yet under development.
Sediment Samples
In the case of sediments, sampling is relatively easy. However, currently there is no
official procedure for the sampling in terms of sampling depth, amount of collected
sample, or location. Therefore, the comparison between data produced by different
authors is restricted. At present, sediments of beaches are more often studied.
Sampling work is performed on the whole beach. With respect to the location of
the sample on the beach, the applied sampling strategies include random sampling in
several sites, following perpendicular (vertically from the water edge) and parallel
(horizontally to the water) lines. Transects are a common approach when conducting
a beach sampling using quadrats of various sizes (Hanvey et al. 2017).
With regard to sampling depth, taking samples in the first 5 centimeters is the
most common technique, although sampling at a greater depth has also been found in
published works (Claessens et al. 2011). Authors as Hanvey et al. (2017) think that
Fig. 1.4 Diagram of the main sources of microplastic emissions and their distribution flow through
the marine environment; (1) microplastics from beaches; (2) and (3) microplastics from river
estuaries and from maritime human activities, respectively, and their possible ingestion by organisms; (4) microplastics emitted to the air (Source: Original production)
1 Microplastic Pollution in Water
7