In 1975–2005, we utilized data on water quality (N-NH4+, O2, Cl-) and number of carp caught (CC) as environmental data, and sport fishery statistics as species data, fromthree fishing stretches of the Berounka River, Czech Republic. An indirect gradient analysis (DCA) for calculating the strongest gradient affecting the species data, and direct linear gradient analysis (RDA) were used for assessing the relationships among environmental and species data. All RDA models were significant and consecutively explained 45.5, 39.6, and 39.7% of the variability of species data. The strength of environmental variables was evaluated by partial RDA. In the first stretch below the City of Plzeň, with the poor water quality and low carp yields, all environmental variables were significant and the CC data alone explained 26.2% variability of species data. In the second stretch, with intermediate water quality and carps yields, only two environmental variables (O2 and Cl-) were significant and in the third stretch near the city of Prague, with the same water quality and exceptionally high yields, the environmental variables did not significantly influence the species data. These results indicate that sport fishery statistics can be used as at least one source of information for studies of fish assemblages in streams where other data is lacking.