Succession of fish communities in reservoirs of Central and Eastern Europe

Abstract

The fish communities of 84 Central and Eastern European reservoirs were sub-divided according to their species compositions into six fish faunal types that are identical with the successional stages of reservoir ichthyocenoses. The six types are: (1) Briefly existing fish faunas in which riverine species (especially salmonids) predominate. Found in 4% of reservoirs. (2) Faunas characteristic of the reservoir initial filling period and with extraordinarily high (15–70%) percentage occurrence of northern pike. Found in 6% of reservoirs. (3) Faunas in which perch (Perca fluviatilis) is predominant usually with one particular year class strongly represented (a ‘cycling’ population). Found in 9% of reservoirs. (4) A transient fish fauna which is dominated by perch plus cyprinid fish. Found in 8% of reservoirs, with 20–50% of the fauna being perch and the rest represented by the predominant cyprinid species of type 5. (5) A fauna dominated by cyprinids, usually by Rutilus rutilus, Abramis brama and/or Blicca bjoerkna together with a non-cycling perch population of less than 20%. This faunal type is the most frequently occurring one in Central and Eastern European reservoirs (61% of cases). (6) The remaining reservoirs (12%) contain fish faunas that are dominated by coregonids or Clupeonella or Carassius or Ctenopharyngodon or Hypophthalmichthys or Aristichthys or Cyprinus carpio or Pelecus cultratus.