Rearing and Stocking of Brown Trout as Perceived by Austrian Fish Culturists

In Austria, brown trout (Salmo trutta L.) is an intensively stocked species. A major concern on this activity is that stocking disrupts the genetic integrity of wild populations and may lead to a further decline of natural stocks. Understanding the current processes of artificial propagation is paramount for the development of sound and conservation-oriented stocking programs. These processes include the economic activity and relationships of brood operations, especially in the framework of privately managed fisheries. To gain insight into these processes, we carried out a survey of fish farmers in three of the nine provinces of Austria.  The particular aims of the study were to obtain information about the origin of stocking material, trading routes as well as quantitative and qualitative characteristics of rearing conditions. Furthermore, a network analysis of hatchery operators was conducted to describe the economic relations among the operators and to identify special positions of single elements within the social network.

The findings show that wild brown trout populations in Austria face severe ecological impacts from stocking of hatchery trout. One of the main threats derives from the predominant introduction of allochthonous brown trout strains, whereas 70 % of the produced eggs originate from broodstocks containing non-resident strains. Poor genetic diversity within the stocked strains and assumedly high rates of domestication in hatchery fish pose further threats. The willingness of the interviewed fish farmers to change their rearing methods towards more ecologically sound methods is limited, especially since the farmers do not see the necessity to apply changes. Next to the visualisation of these grievances, starting points for sound management strategies in the future were identified, whereby customers, state administrators and scientists play a central role. Furthermore, key players among the interviewed fish farmers were identified. Overall the study provides a comprehensive review of the current situation and points the way toward future participatory processes.