Gavril, ArdeleanWilhelm, Sándor2021-06-282021-06-282007-04-11Acta Agraria Debreceniensis, No. 25 (2007): Pisces Hungarici I. (Supplement Issue) , 6-82416-1640https://hdl.handle.net/2437/316553Over the period 2003-2005 we made ichthyologic research in the basin of the Lapus river. During the sampling we noticed that in some area the water was polluted. In those areas fishweretotallyorpartiallymissing. The main pollution sources are those related to nonferrous metal extraction and processing, but there is also pollution from organic substances resulted from the communal residual waters, as well as the “tuica”(alcoholic drink) distilleries. Confronting the spots of the pollution sources with the results of the ichthyologic research.we noticed a significantcorrespondencebetween the qualitative and quantitative component of the ichthyofauna and the presence of these sources. We could, therefore prove the effect of the process of self-purificationofthewater,aswellastheexistenceofsomespeciesoffishshowing a great degree of tolerance towards pollution.application/pdfextraction of nonferrous-metalsLapos river basinpollutionfishfaunafolyóiratcikkOpen Accesshttps://doi.org/10.34101/actaagrar/25/3029Acta Agraria Debreceniensis25Acta agrar. Debr.