EN
As a particularly significant species in terms of ecology and economics, eel determines the profitability of fishing facilities. The eel population in Poland has declined substantially in the last decade, and this has had a negative impact on the financial condition of fisheries facilities. This is confirmed by the analysis of commercial catches and stocking programs recorded in lake fisheries logs from the 1973-2004 period and by recreational catches recorded in catch reports and angler questionnaires from the 2004-2006 period. Analyses were conducted based on lakes in the four major river basins of the Vistula, Oder, Pregola, and coastal lakes. The analysis included 289 lakes with a surface area of 120,009 ha. The decrease in eel catches from the Vistula River basin was, on average, 3.46% annually during the 1973-2004 period. The mean, annual eel yield in the initial period (1973-1982) was 2.85 kg/ha, while in the 1995-2004 period it was 1.17 kg/ha. Eel stocking, especially of the glass form, also underwent substantial reduction from the maximum number released in the late 1970s to the discontinuation of eel stocking in 2000. Recreational catches of eel in the waters of the Vistula River basin are estimated to be 105 tons.