EN
The study was completed on the basis of the results of commercial fish catches from lakes in Northeastern Poland. The number and status of the pikeperch lake habitats were determined in 14 river basins in this part of Poland, as recorded in 1951-1994. The river basins differed in the potential of the lakes inhabited by this predatory fish. The highest percentage of such lakes relative to all lakes larger than 10 ha was found in the river basins of the Liwa, Pasłęka and Osa. The status and distribution of pikeperch habitats were established at the beginning and in the final years of the time period analyzed. The total increase in the number of lakes settled by pikeperch was 209, with the aggregate area of pikeperch habitats rising by 41 365 ha. The dispersion of pikeperch was not connected directly with the fish stocking carried out during that time. In the Ełk and Pisa river basins, over 90% of new pikeperch habitats appeared owing to natural migration of this fish species.