Abstract

The Lake Berezno (Gdov District, Pskov Region) is a part of a joint water system of Lake Berezno, Lake Orlovo and a river connecting them. Before the 1960s this system was inhabited by a large population of Astacus astacus. In Lake Berezno crayfish were found until 1968. Historical data on the crayfish population in this water system and new data (1993-1997) on the hydrobiology and hydrochemistry of Lake Berezno are reviewed. The results of the crayfish introductions after 1985 are presented, including the initial crayfish stock, size classes, sex ratio, and male and female sizes. At present, the crayfish quantity is 0.4 specimens/m². To achieve a commercially exploitable population density of 4 specimens/m² it is necessary to introduce 413,250 animals. Therefore, the construction of a special pond-nursery using semi-intensive technology for production of crayfish juveniles is continuing at the lake’s bank. The juveniles and summerlings produced are to be stocked in the lakes Berezno and Orlovo to restore the crayfish stocks in these areas. Another objective of this work is to examine the ecological role of crayfish, their contribution to the processes of eutrophication, and the use of Astacus astacus for monitoring the quality of waterbodies.

Supplemental Documents

• There are no supplementary documents for this article

Cited By

Citations: