Fish assemblage in European Western Highlands and Western Plains: a type-specific approach to assess ecological quality of running waters

After typological pre-classification of 398 calibration sites, fish-based metric models were used to predict the impact of human activities on river quality in European Western Highlands and Western Plains ecoregions. Calibration sites were grouped into six assemblage types and according to their geomorphology; test sites were assigned to their corresponding assemblage type. Five anthropogenic variables were used to describe the impact level of each site and stepwise discriminant analysis was performed to: (i) avoid redundancy between metrics; (ii) examine how selected metrics discriminated impact classes and (iii) predict ecological status for each site of the given fish type. Globally, this approach predicted the impact class correctly for 64% of sites. The difference between observed and predicted impact was more than one class for only 2.5% of the sites. When validating this approach with an independent data set, differences between observed and predicted impact values never exceeded 2 impact classes, but these differences varied in size among countries

Aanpassing KRW Visindex IJsselmeer

Allereerst wordt een overzicht gegeven van de verschillende vismonitoringsurveys, zowel actieve als passieve monitoring, die worden uitgevoerd in het IJsselmeer. Vervolgens worden enkele indicatoren geselecteerd om nader uit te werken