The Sottocastello Hatchery

The marble trout breeding programme of Bacino di Pesca N. 4

2023 — The beginning

2023 marked the start of activity at the Sottocastello hatchery, with the introduction of the first marble trout broodstock supplied by Regione Veneto and the Provincia di Belluno, as part of the restocking effort launched after Storm Vaia.

Much of the year was spent bringing a facility that had stood idle since the 1990s back into working order: every system in the hatchery was overhauled, with work carried out on the tanks and on the water and electrical systems. At the same time, the team began learning to manage the marble trout broodstock — no small task, since the Association had no prior experience running a breeding operation.

Thanks to guidance from provincial and regional biologists and support from veterinarians, management challenges were addressed in line with the technical guidelines set out by the Provincia di Belluno. Mortality stayed within normal ranges, mostly linked to fish transport and handling stress.

2024 — The first major results

2024 proved to be a particularly strong year, thanks to the high number of marble trout eggs (Piave strain) produced: the target of 500,000 fertilised eggs was reached.

The fry and fingerlings raised were released into various watercourses across the Province of Belluno, contributing to the recovery of fish populations affected by Storm Vaia. To build a new broodstock for the future, around 8,000 fingerlings were held back to grow on and be selected as future breeding females and males.

2025 — Steady progress and new milestones

2025 passed without major setbacks: the broodstock continued to grow steadily, and the fingerlings destined to become future breeders showed no health or management issues.

In November, 6,000 fingerlings measuring 15–18 cm were released on behalf of Veneto Acque into watercourses within fishing districts (bacini) 3, 5, 8 and 9. This was a particularly rewarding milestone, as these fish were born at the hatchery in 2024 from the first stripping of broodstock supplied by Veneto Acque.

The December 2025 stripping season, brought forward compared with the previous year, has already produced very encouraging results: 450,000 fertilised eggs. As not all females were mature yet, further stripping was carried out in early January 2026, with additional sessions planned before the end of the month.

The fry and fingerlings produced were used to restock stretches of the Piave river managed by Bacino di Pesca N. 4, while a portion was transferred to other concession holders along the Piave and its tributaries for restocking purposes.

During the year, the hatchery’s disease-free certification for viral haemorrhagic septicaemia (VHS) and infectious haematopoietic necrosis (IHN) was also renewed, allowing it to retain Category I disease-free status.

The Numbers Behind the Project

Looking Ahead

Based on the results achieved so far and the ongoing development of the broodstock, the hatchery is expected to reach a rearing capacity of between 600,000 and 700,000 fertilised eggs in the coming years, with scope for further growth in the medium term.

From a facility left idle for decades to a hatchery capable of regenerating the Piave’s marble trout: the Sottocastello hatchery is now the beating heart of fish conservation for Bacino di Pesca N. 4.

Heartfelt thanks go to all the volunteers and collaborators whose time and dedication make the hatchery’s work possible every day, in service of the project’s goals.