This International Standard provides guidelines on the quantitative collection and processing of subtidal soft-bottom macrofaunal samples in marine waters.This International Standard encompasses:a) development of the sampling programme;b) requirements for sampling equipment;c) sampling and sample treatment in the field;d) sorting and species identification;e) 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. recolonization assays;— non-benthic organisms caught in the sampling device;— estuarine sampling;— intertidal sampling;— meiofaunal sampling and analysis (see Reference [9]);— 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.