WHITEFISH, COREGONUS LAVARETUS (L.), IN THE FISHERIES MANAGEMENT OF LAKE GO£DOPIWO (NORTHEASTERN POLAND) FROM 1950 TO 2005

The aim of this study was to analyze the growth rate of whitefish, Coregonus lavaretus (L.), in Lake Go³dopiwo in the 1932-1999 period. The magnitudes of catches and stocking during the 1950-2005 period were also determined. Once the studied population reached the maximum density, the growth rate diminished distinctly but commercial catches remained at a very high level for the subsequent 21 years at an annual mean of 8181 kg, and 9.5 kg ha -1 . Throughout the entire study period, no significant relationship was noted between the magnitudes of catches and stocking. The cause of the collapse in whitefish exploitation in Lake Go³dopiwo must be sought for in disadvantageous changes in the environment and decreasing fisheries exploitation.