The marble trout (Salmo marmoratus) is a slow growing but long-lived freshwater species found in limited basins and rivers of the Adriatic basin. It is not a species well suited to aquaculture. The fish has pink colored, low-fat flesh that is suitable prepared as carpaccio and marinated with mild spices.
Local culture gives significant meaning to the trout with stories telling that a fish carries the world on his back, and by moving the tail he causes earthquakes. As such, in the 15th century this became part of folk tradition, reflected in prayer and in the frescoes in the local churches. In the past, wild marble trout could only be caught by those who owned the property where rivers and tributaries flowed. Once commercial fishing became allowed, the marinated marble trout would be found in markets in Gorizia and Trieste. However, commercial fishing has been outlawed, and today this product is made from fish caught exclusively for personal or family consumption.
Local fishery organizations are working to preserve this species, especially after it was threatened by interbreeding with brown trout. Production for the culinary market started in the mid-2010s, when fishermen managed to breed offspring of wild trout and at the same time keep all the necessary production of the first generation, which is aimed at preserving the marble trout in the wild. Water pollution, degradation of aquatic habitats and the appearance of non-native trout species have all caused the decline of marble trout populations. In the upper basin of the Soca River in Slovenia, ongoing work is part of a ten-year plan by fisheries organizations to keep the marble trout.