Macroinvertebrate frequency data for the RIVPACS III sites in Great Britain and their use in conservation evaluation

1. A total of 637 macroinvertebrate taxa were recorded from the 614 running‐water sites in the RIVPACS III data‐set for Great Britain, after the application of a standardization procedure to ensure that all samples were identified to the same taxonomic level. 2. The frequency of occurrence of the 637 taxa in the data‐set is presented and discussed. 3. The wide range of sites and taxa included in this study represents a valuable source of information on the occurrence of local species which complements the Red Data Book (RDB) and Notable (N) species designations in current use for conservation evaluations.