Fish stock assessment in dam reservoirs located in the upper Vistula and Warta river [Poland] catchment areas based on angling catch records

The regional departments of the Polish Anglers' Association (PAA) in the provinces of Bielsko-Biala, Czestochowa, and Katowice (Poland) stipulated that anglers keep records of catches in registers. On average, 35,682 registers were analysed annually from 2001 to 2005, which represents 57.4 percent of total PAA membership. Of the 22 fish species recorded in the catches, six comprised 91.6 percent of the total catch, as follows: common carp, Cyprinus carpio (L.), bream, Abramis brama (L.), roach, Rutilus rutilus (L.), pike, Esox lucius L., pikeperch, Sander lucioperca (L.), perch, Perca fluviatilis (L.). The share of cyprinids decreased from 73.5 percent in 2001 to 64.8 percent in 2005, whereas the share of predators increased from 18.1 to 26 percent, in the same time period. The results indicate that eutrophication and stocking are the main factors that determine the status of fish stocks in dam reservoirs located in the upper Vistula and Warta river catchment areas (Poland)