Mikołaj Adamczyk, Paweł Prus
ABSTRACT. The paper presents the results of the State Monitoring Program for assessing river ecological status based on ichthyofauna in 2018. The project was led by experts from the Stanisław Sakowicz Inland Fisheries Institute in co-operation with several partner institutions. In total, 304 sites representative of river water bodies (RWB) were sampled with the electrofishing technique according to standard Polish monitoring procedures. In total, nearly 65,000 fishes representing 55 species, including 18 under various forms of protection and 11 foreign and invasive ones, were caught. The national EFI+IBI_PL assessment method and the complementary diadromous index D were used to assess the ecological status of 116 RWBs. As many as 64 RWBs were not classified because of the lack of fish, low fish numbers, or the occurrence of single species. Twenty-four percent of RWBs were assessed as least good ecological status, while 29% of highly modified and artificial RWBs were categorized as having good ecological potential. Generally, the results indicated that assessment with the IBI_PL index was stricter in comparison to that with the EFI+PL method. This phenomenon was also observed in previous years, and it is an argument for calibrating the literature-based IBI_PL class boundaries with available data from undisturbed, “close to natural” sites. The proposed improvement and changes in method were incorporated in the new classification ordinance issued in 2019.
Keywords: fish, rivers, ecological status 2018, EFI+, IBI, environment monitoring
Przyjęto po recenzji 17.02.2020 r.