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The Modrej Hatchery

The hatchery gets its water from the spring Zapolje pri Vodivčku, which is drinking quality water with a stable temperature of 10 to 11°C. The hatchery uses up 7 liters per second.

In the hatchery there are 64m2 of breeding surfaces for half-year juveniles and 77m2 for raising and storing marble trout for breeding and year-old juveniles.


The hatcheries capacities currently allow hatching up to 500,000 fry and 200,000 half-year juvenile marble trout yearly, as well as 30,000 one-year grayling juveniles. Yearly we also breed as many trout juveniles and we’ve bred up to 25,000 grayling juveniles in a year.

Approximately half of the juvenile trout are introduced into breeding streams, while the other half is kept for one-year breeding on the Tolminka and partially at the Hatchery.


Fish Farm Tolminka

It stands by the river Tolminka in Tolmin itself. Together with the construction of the fish farm the small hydro-plant SENG Nova Gorica was also repaired. Both objects function together, the water from the Tolminka is used first for fish farming and then to produce electricity.

The Tolminka is a torrential river, which is why we have built a number of filtration stations to clear leaves and other debris from the water used in the fish farm. The temperature of the Tolminka varies from 5 to 13°C. At normal operational capacity 150 l/s of water run through the fish farm. The water is cleaned in our own treatment plant.

The fish farm has a total of 19 pools (230m2) for raising year-old trout and two canals 80m long and 3.5m to 4m wide for raising marble trout for breeding. We have sufficient capacity to breed 100,000 year-old trout, and in the breeding canals we have room for 500 adult marble trout under conditions which are very similar to those found in the wild.

The technology needed to breed marble trout is different from that used to breed other species of trout because of the marble trout’s special requirements. This is also the reason for the unusual appearance of the fish farm, as the pools and canals are covered.


The Marble trout tour will be organised on request for all those who are interested to have a look behind the screens how the fishing club of Tolmin managed the rebound of the pure Marble trout and Adriatic grayling 

population in our rivers. These tours will be given by an employee of RD Tolmin and will answer all of your questions. We strongly recommend for all fly fishing enthousiasts to take a look at the great job that was and is still done by the club and the members. 


To support the work of the club and the survival of the special Marble trouts we ask politely at the end of the tour in the fish farm and/or fish hatchery, for a donation of € 5,- per visitor. 

The full amount will be given to RD Tolmin for upcoming research works that will help to secure the future of the endemic species of the Soca river system.

Three years old juvenile from the Tolminka fish farm



Marble trout's fry.


Marble trout's eggs.


The brand new fish farm next to the Tolminka river


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