Abstract

The STAR project’s extensive replicated sampling programmes have provided the first ever quantitative comparative studies of the susceptibility of a wide range of national macroinvertebrate sampling methods and taxonomic metrics to uncertainty resulting from the effects of field sampling variability and subsequent sub-sampling and laboratory (or bank-side) procedures and protocols. We summarise six STAR project papers examining various aspects of the potential sources of uncertainty in the observed fauna and observed metric values. The use of new simulation software STARBUGS (STAR Bioassessment Uncertainty Software System) to incorporate the effects of these potential errors into quantitative assessments of the uncertainty in assigning water bodies to WFD ecological status classes is discussed.