The Results of Introduction of the Pike-Perch, Sander lucioperca, into Lake Khanka

Аннотация

As reported in the 1930s, the level of the forage base in Lake Khanka could provide from 2600 to 17 000 t of fish. The low fish capacity of the lake was explained mainly by a high abundance of small non-commercial species. For the purpose of increasing the fish capacity, a proposal was made in 1961 to introduce the Pike-Perch into Lake Khanka. This fish was expected to provide 200–300 tons extra fish product a year and also increase the proportion of valuable fish species in the lake by “destroying harmful rough fish” within 10–12 years. The introduction of pike-perch into Lake Khanka was carried out in 1970–1978. An analysis of data on the current status of the pike-perch population in the lake shows that this species has formed a stable self-reproducing population, whose biomass is now comparable to the level of the native common predatory fishes (80–100 t). In preying mainly on the sharpbelly (genus Hemiculter) and other abundant rough fish, it does not compete with other predators. Nevertheless, the pike-perch provides 20 t of marketable product a year, being rated as the second or third most commercially valuable fish species in catches from the lake.