Convergence of field survey protocols for SERCON (System for Evaluating Rivers for Conservation) and RHS (River Habitat Survey)

Abstract

1. SERCON is a technique for assessing the conservation value of rivers in terms of criteria such as naturalness, physical diversity and species richness. Part of the process involves gathering information on the physical features of rivers and their corridors, for which accurate survey data are essential. 2. SERCON has been developed in parallel with River Habitat Survey (RHS), a method for compiling an inventory of physical features and for classifying habitat quality based on surveys of discrete river reaches. 3. A study was carried out to compare SERCON scores derived from RHS data with those obtained from a tailor-made SERCON survey method. RHS surveys were carried out at 118 sites (each 0.5 km in length, one site every 4 km) on five rivers in Scotland. The whole length of each river was also surveyed using the SERCON survey method. Additional data comprising a complete RHS coverage of one river in NW England were used to assess the influence of survey site frequency on SERCON scores. 4. Scores derived from both methods were similar for some of the features evaluated. However, other features were either not recorded at all by RHS, or were recorded in a way that led to inaccurate scoring. A survey strategy of one RHS site every 2 km was found to represent the most cost-effective compromise between the ideal of contiguous survey and the reality of limited time and money. 5. A revised SERCON survey protocol has been devised consisting of a modified RHS together with an ‘inter-reach’ survey for assessing any major changes between survey sites. Further modifications to the way some features are scored in SERCON may be needed later to provide full integration with RHS. © 1998 John Wiley & Sons, Ltd.