| Popis: |
Pikeperch Sander lucioperca is an economically important fish which depleted populations need intensive management and supplemental stocking. We aimed to assess the relative influence of various pikeperch stocking strategies in Lake Balaton, Hungary, and tested 60 stocking set-ups (two seasons × three lake areas × shore vs. offshore release × five size groups) by releasing 3000 tagged yearlings. Anglers reported data of 522 recaptures within four years after stocking. Recapture rate was highest in stocking of the most productive lake area, increased with fish size, was higher in shore than offshore releases, but did not differed between stocking seasons. Fish stocked to oligotrophic areas travelled longer distances and dispersed more than those stocked to the mesotrophic area. Fish size had little effect, whereas season and method of stocking had no effect on dispersal of fish. To conclude, in pikeperch, autumn stocking with large yearlings released directly from the shore is recommended over other set-ups. Stocking quotas may be concentrated in space in low productivity areas, but should be dispersed between multiple sites in food rich areas to attain complete dispersal. This study provides a framework for testing fisheries management alternatives and behaviour of stocked fish in intensively utilized habitats. |
