Erratum to “An expert system to estimate the pesticide contamination of small streams using benthic macroinvertebrates

We developed an expert system (LIMPACT) to estimate the pesticide contamination of streams using macroinvertebrate indicators. Here, we present the database consisting of 157 data sets obtained from 1992 to 2000 through investigation of 104 small headwater streams with an agricultural catchment area. The contamination by pesticides (insecticides, fungicides and herbicides) during rainfall events varied greatly in both water and suspended-particle samples, occasionally reaching ecotoxicologically relevant levels. On the basis of standardised toxicities, the data sets were grouped into Not Detected (n = 55), Low (34), Moderate (42) and High (26) contamination with pesticides. Additionally, nine water-quality and morphological parameters were evaluated with regard to their influence on the fauna and are used to exclude unsuitable streams from LIMPACT. The benthic macroinvertebrate fauna data were divided into four time frames (March/April; May/June; July/August; September/October) and analysed regarding the abundance and the abundance dynamics of the 39 most common taxa. In contaminated streams, lower abundance for negative and higher for positive indicator taxa were observed. The number of taxa was significantly lower (unpaired t-test P < 0.015) in the most severely contaminated streams. Information abstracted from this empirical approach was used to create rules indicating or not indicating contamination and to build up the heuristic knowledge base of LIMPACT as shown in the Part 2 paper (M. Neumann, J. Baumeister, M. Liess, R. Schulz, An expert system to estimate the pesticide contamination of small streams using benthic macroinvertebrate as bioindicators. Part 2. The knowledge base of LIMPACT, Ecological Indicators, this issue). © 2002 Elsevier Science Ltd. All rights reserved.