Factors affecting survival of asp (\kur{Aspius aspius}) and pikeperch (\kur{Sander lucioperca}) in a deep canyon-shaped reservoir

Changes in abundances of 0+, 1+ and 2+ age classes of the two most important piscivorous species - asp (Aspius aspius) and pikeperch (Sander lucioperca) in a deep canyon-shaped reservoir were investigated. A long-term fish sampling in the reservoir including fry trawling, fry and adult beach seining and gillneting was used to determine the factors affecting the recruitment. All data were used in a single linear model and the results obtained using different sampling methods were discussed.