To compare methodologies for assessing ecological status and classifying water bodies on the basis of fish, an intercalibration exercise was carried out in the countries of the Alpine GIG, involving methodologies from Austria (ALFI; Austrian Lake Fish Index), Italy (I-LFI; Italian Lake Fish Index), Germany (DELaFI_SITE; National Fish Assessment Method for Southern German Alpine Lakes) and France (MMI; Multimetric Index Based on Fish Fauna for the Assessment of Subalpine Lakes). As we have not developed a method in Slovenia for assessing the ecological status of lakes based on fish, we examined the suitability of the methods developed in the Alpine GIG countries. Due to differences in fish communities between lakes in different regions or countries, we were unable to directly apply any existing fish-based lake typology; instead, we first defined a reference community for Lake Bohinj and Lake Bled. We used historical data and fish catch data. Of the methods used to assess the impact of all pressures, the values most consistent with the pressure index were obtained using the adapted Italian method, whilst those least consistent were obtained using the adapted Austrian method. To assess the ecological status of Alpine lakes in Slovenia, we propose the use of the adapted Italian method, which is based on the same metrics as the original Italian method and utilises the characteristic reference fish communities defined for Lake Bled and Lake Bohinj.
Lake Bohinj