In Austrian waters the biologic diversity has been decreasing for
years. Out of 74 endemic fish species 52 are regarded as
endangered respectively as already extinct. Most of these species
are small fish serving as food for larger fish species which are very
important for the ecologic balance. Their existence can only be
secured by contingent biotope protection measures.
Some endangered species are important for business or sport fishery
like the Great Lake Trout (Salmo trutta silvestris), the Grayling
(Thymallus thymallus), the Brook trout (Salmo trutta fario) and the
Char (Salvelinus umbla). Besides protection measures like catch
prohibitions or close seasons their numbers are increased by restocking with hatchlings or fertilised spawn of preferably autochthonous origin. Thus the singular genetics originating in the Alpine zone is protected. Analysis of DNA microsatellites is used to identify stocking with foreign material.
As in wild caught fish eggs and semen are not often available evenly deep frozen semen is used also. The Institute for Water Ecology, Fishery Biology and Lake Research works in co-operation with the Institute for Organic Farming and Biodiversity of Farm Animals in Thalheim to establish a fish gene bank.