EN
The aim of the study was to estimate the economic effectiveness of stocking conducted by Lake Enterprise, Ltd. (Gospodarstwo Jeziorowe Sp. z o.o.) in Ełk based on the analysis of the value of catches made with commercial fishing gear and recreational fishing and the value of released stocking material. Additionally, the effectiveness of the stocking performed by this company was compared with that in other Polish lakes. The study is based on the following materials and data from the literature: prices of commercial lake fish and stocking material used by lake fisheries enterprises in 2005 (Mickiewicz 2010); information on the size and species structure of lake fisheries catches; the quantity and type of stocking material introduced into the lakes; the value of fishing permits sold during the 1998-2005 period by Lake Enterprise, Ltd. in Ełk; and the size and species composition of recreational fishing catches from the 1998-2005 period drawn from questionnaires completed by recreational fishers. The results obtained permitted concluding that the coefficient of the economic effectiveness of the stocking programs conducted in Ełk lakes was higher in comparison to nation-wide data with regard to eel, pike, tench, Crucian carp and carp, while it was lower with regard to vendace, whitefish, pikeperch, and wels catfish. The discussion of the results indicated that the method applied for estimating the fisheries effectiveness of stocking Ełk lakes could have decidedly underestimated effectiveness.