ISO/DIS 23040-2020 pdf free.Marine environment impact assessment (MEIA) – Specification for marine sediments in seabed areas – Sediment interstitial biota survey.
5 Survey of sediment
5.1 Methods summary
Methods primarily include analyses of sediment characteristics, sediment classification, physicochemical characteristics of the sediment, and sediment grain sizes in order to obtain information regarding the substrate environment for surveying the interstitial biology of sediments.
5.2 Technical requirements
The contents include the following:
a) Qualitative and quantitative analyses can be selected based on the survey task;
b) The samples must not be mixed or contaminated;
c) The characteristics surveyed are primarily the grain size, type and biological components of the
5.3 Collection and preservation of samples
Seafloor surface sediments, columnar cores, or undisturbed drill cores can be collected. A site description of the samples should be made and certain physicochemical factors of the samples can be measured on site. The samples can be then sealed for refrigeration- or cryo-preservation, depending on the survey task
When measuring the physicochemical characteristics and grain sizes, surface sediments and columnar or drill core samples can be collected from various strata at different depths. Each collected sample can be sealed in a polyethylene bag and related information including sampling site, sampling time and location coordinates can be marked on the bag. Parameters including pH, Eh, temperature and Fe3-to- Fe2 ratios can be measured at the sampling site. For the measurement of other physicochemical characteristics, the samples can be stored in a refrigerator at a temperature of-20 °C and transported to the laboratory for analysis.
5.4 Measurement of environmental factors
The environmental factor measured can include suspended particulate matters, moisture content (%). total organic carbon content (%), chlorophyll a (ChI a) and pheophytin a (Ph a) content, pH, Eh, temperature and the ratio of Fe3 to Feb. The items for measurement can increase or decrease according to the survey task Methods of measurement can refer to related projects in this standard and relevant clauses in EN 16503, EN 16260, EN 16161, ISO 16221 as necessary.
5.5 Measurement of the age of the sediments
As per the requirements of the survey, the sediments of columnar or drilling cores can be dated by the methods appropriate to each sample.
For sediments from columnar cores and the top of drilling cores, 2lOPb or 137Cs dating can be conducted in accordance with the requirements of task; for drilling cores, ‘C dating, optically stimulated luminescence (OSL) dating, and paleomagnetic chronology can be selectively conducted depending on the survey task.ISO/DIS 23040 pdf download.