River classification using invertebrates: RIVPACS applications

Abstract

1. This paper sets out the need for and approach taken in developing the River InVertebrate Prediction And Classification System (RIVPACS). The merits and limitations of this approach are considered in relation to a number of other schemes, based on biotic and/or environmental attributes. 2. RIVPACS III includes 614 reference sites throughout Great Britain distributed between 35 classification groups and a further 70 sites in Northern Ireland in seven classification groups. The main features of the site classification for Great Britain are described and examples of changes in faunal composition across the major divisions of the classification are given. 3. The major use of RIVPACS III is for prediction of the macroinvertebrate fauna to be expected at a site in the absence of environmental stress. Predictions may be made at different taxonomic levels and for different seasons, according to the needs of the user. Procedures are available for comparing the fauna observed at the site with the expected fauna, based on presence/absence data (any taxonomic level) or log categories of abundance (family level only). 4. The value of the RIVPACS III classification as an additional framework for determining whether the full range of river types have been selected as Sites of Special Scientific Interest (SSSIs) is discussed. River SSSIs occur in a high proportion of RIVPACS III classification groups, but some small stream groups lack examples of SSSIs. 5. The 614 reference sites for Great Britain include 637 taxa. The number of taxa recorded at each site after the standard sampling period varies from 31 to 134, although approximately 85% of the sites hold between 50 and 100 taxa. The data-set includes a number of Red Data Book and Nationally Scarce taxa and provides valuable information on the status and geographical occurrence of river invertebrates which has application to conservation evaluation. 6. Finally, some opportunities for linking RIVPACS and River Habitat Survey (RHS) are reviewed. © 1998 John Wiley & Sons, Ltd.