European Native Trout Challenge
Cast a line, make a change

Slovenian Native Slam.

The Slovenian Native Slam invites anglers to explore the diversity of Slovenia’s native salmonid species by catching them in their natural habitats. Slovenia may be a small country, but it holds exceptional freshwater diversity. Its rivers are divided into two major European drainages: The Adriatic basin (primarily the Soča system), flowing toward the Adriatic Sea and, the Danube basin, flowing toward the Black Sea Each basin hosts distinct native species and lineages, shaped by geological history and long-term isolation. This natural division makes Slovenia uniquely diverse and adds depth to the challenge. The Slam celebrates all five historically native species through its logo, even though only four are required for completion. Participating in the challenge means fishing responsibly, exploring extraordinary rivers, and actively contributing to conservation.

The Native Species.

Required for the challenge.

  • Marble Trout (Salmo marmoratus)
    Found exclusively in the Adriatic basin. Famous for its striking marbled pattern, this iconic species is one of Europe’s most unique trout.
  • Brown Trout (Salmo trutta, Danubian lineage)
    Distributed across Slovenian rivers in the Danube basin. Highly variable in form and colour depending on habitat and river system.
  • European Grayling (Thymallus thymallus, Western Balkan & Southern Alps lineages)
    Found in the Sava system (Western Balkan lineage) and Drava & Mura systems (Southern Alps lineage). Recognized for its sail-like dorsal fin and preference for clean, well-oxygenated rivers.

Optional.

  • Huchen / Danube Salmon (Hucho hucho)
    Present in the Sava basin and its tributaries. A legendary apex predator often referred to as the “fish of 1000 casts.” Typically targeted in winter and requiring specialized gear and techniques. Due to its seasonal nature and technical demands, Huchen is optional. Participants who successfully document Huchen will receive the title: Slovenian Native Slam – Hucho Master. This distinction will be reflected on the official certificate and completion listing.

Excluded.

  • Adriatic Grayling (Thymallus aeliani) – Historically found in the Adriatic basin, but now no longer present as a pure species. It is excluded from the challenge, but represented in the logo to honour Slovenia’s native diversity.

To complete the Slovenian Native Slam, participants must catch all required species listed above.

  • marble trout
  • brown trout
  • adriatic grayling
  • european grayling
  • huchen

Why Participate?

  • Adventure & Exploration: Discover Slovenia’s rivers, from alpine headwaters to classic grayling waters.
  • Skill Challenge: Test your fishing abilities by targeting multiple species in different habitats
  • Conservation Impact: Every entry helps fund projects that protect native species and restore freshwater habitats.
  • Recognition: Receive a round challenge magnet and an official certificate.
  • Purposeful Fishing: Celebrate Slovenia’s freshwater heritage while respecting and protecting it.

How It Works.

  1.  Enter the challenge – €15 per participant.
  2. Catch & document – Fish responsibly and take care of the fish’s health when photographing.
  3. Submit your catches – Send an email with a Word document for each species, containing:

Required information:

  • A sharp picture of the fish (above water, fish’s health in mind).
  • The date the fish was caught.
  • The river where the fish was caught.

Optional information:

  • Fishing rod type (spinning rod, fly rod, etc.)
  • Type of fishing (streamer, nymphing, dry fly, spinner, jerk bait, etc.)
  • Bait type/name
  • Fish weight
  • Fish length

4. Receive your rewards: A magnet button featuring the challenge logo and a certificate recognizing your achievement.

 Rules.

  1. Participants must register before starting the challenge. Read the information and rules, enjoy the process, and help conserve and restore native populations.
  2. Know and follow all fishing rules and regulations for the rivers you intend to fish.
  3. Only fish caught after 1-1-2025 can be counted for this challenge.
  4. Fish must be caught in their native watershed.
  5. Fish must be caught barbless and according to catch-and-release principles.
  6. There is no time limit to complete the challenge.
  7. All photos submitted may be used by the European Native Trout Challenge for content.