The history of huchen, Hucho hucho (L.), in Poland – distribution, restoration and conservation

摘要

The huchen, Hucho hucho (L.), became extinct in its autochthonous locations in the upper parts of the Czarna Orawa and Czadeczka systems in the early 1950s as a result of increased anthropogenic stress. It began to be introduced into the Dunajec River system in 1966. The quantity of stocking material released into the Dunajec and its tributaries during the first ten years was small, ranging from 8 to 30 thousand fry per year. In subsequent years, the production of stocking material at the ￡opuszna Fish Farm increased gradually, and in recent years it has been from 0.6 to 0.99 million fry per year. The stocking material produced in 1955-2012 included approximately 15.2 million fry and 4.6 million fall fingerlings. Increased stocking material production made it possible to stock more rivers in the 1972-1995 period including the Nysa K3odzka, San, So3a, Skawa, Raba, Bobr, and Gwda. Of the nine rivers into which it was introduced, the huchen only adapted successfully in the Poprad, Dunajec, and San, where it now occurs along a total of approximately 400-450 km. Only these rivers are regularly stocked because of their favorable environmental conditions. In Poland huchen was saved (ex situ) through active protection by translocating it outside of its natural distribution range, artificial breeding, and the regular stocking of selected montane rivers. The restoration of huchen in the Czarna Orawa began in 2002, but success was moderate. To preserve this species in Polish waters, the spawning stock kept by the PAA at ￡opuszna should be financed regularly by the Ministry of Environment, and systematic monitoring, licensing, and limiting of the size of recreational catches should be introduced.