MAINTAINING THE LEGACY OF ONE OF EUROPE’S MOST REMARKABLE FRESHWATER FISH
The Soča River in northwestern Slovenia belongs, rightfully, in discussions of the most beautiful rivers in Europe and is renowned within the flyfishing community for its mysterious resident: the marble trout. Originally evolved from brown trout, marble trout evolved within the unique confines of the Soča watershed and are known for their remarkable vermiculated color patterns, predatory behavior and an ability to reach large sizes. Yet, the marble trout as we know it would not inhabit the Soča River today if not for a dedicated group of scientists and local anglers that spent countless hours every winter over the last 25 years, fighting what could have been the slow death of this unique species.
Misguided attempts to improve fish stocks in the past led to the introduction of brown trout into marble trout waters; these fish reproduced with marble trout, producing fertile offspring that, if not curtailed, would have spelled the end of one of the most unique trout species on the planet. By 1996, the results of extensive scientific research showed that genetically pure marble trout had all but disappeared in the Soča River.
After searching numerous tributaries of the Soča between 1993 and 1996, eight genetically pure marble trout populations were found high in the mountains, isolated from the main Soča River system by waterfalls. In the following years, a group of scientists created the “ACTION PLAN for Marble Trout,” which outlined actions for saving the marble trout of the Soča.
full story published on: THE FLYFISH JOURNAL ISSUE 14.2
In 1993, scientists of the Fisheries Research Institute of Slovenia realized the imminent threat of extinction of the Marble Trout. Not because of the usual issues like overfishing, water pollution or loss of habitat, but genetic hybridization.