Nationalpark Hohe Tauern

Autochthonous brown trout

"Urforelle"

The brown trout (salmo trutta) is "endangered" in Europe. This statement may be surprising as this species is widely spread across Europe and West Asia and has been introduced to rivers in East Asia, Africa, North and Central America and Australia. In addition, the brown trout does not appear on the classic "red lists" of endangered species.

At the end of the last ice age approximately 10,000 years ago, brown trout lines with differing genetic make-up developed in the large river systems of Europe. The Danube-type indigenous to the waters of the national park is threatened with extinction as the fast-growing Atlantic-type trout has been used predominantly in the past 40 years as breeding material for stock purposes. As a result, the Danube brown trout has almost disappeared or has become genetically mixed with the Atlantic brown trout. This means valuable biological resources are disappearing at an alarming rate. Furthermore, studies have shown that brown trout were fished out of waters with brook trout in their stomage contents.

Monitoring Urforelle

Uniform minimum standards in all three national park provinces
Annual controlled fishing to collate the survival rate, recapture rate, philopatry, growth, fecundity and the number of hatching and young fish. The purpose of this is to monitor the naturally occurring numbers and conserving these numbers without having to intervene in stock levels. Sampling of genetics as part of controlled fishing measures (in 2013).
Recording of water temperature (data logger) and flood events

Restocking measures

The restocking measures of previous years have been sufficient and subsequently, the focus will be on inventory control and monitoring of reproduction. Other restocking measures only occur on the basis of the monitoring results.