Research Projects

ABSTRACT

Brown trout is a salmonid species native to and widespread in Slovenia, inhabiting primarily cooler rivers and streams. It is an important fishing species that fishermen have been managing for a very long time, most likely since before the first written records mentioning fishing in Slovenia. In recent years it has represented about 10% of the catch of all trout species, and its presence has been documented in 127 fishing districts. Brown trout was included in the first attempts of farm raised fish. Currently there are 19 registered fish farms dedicated to raising brown trout for stocking them into open waters. An important part of raising brown trout is the co-natural method of raising fish in streams. During the 2006-2010 reporting period there were almost 750 streams designated as nursery streams for co-natural farming of brown trout. Over the last few decades fishery practices have been changing in the direction of intensified farming and increased fishing. Today, fishermen, fish and ecology experts, and geneticists all agree that a revision in managing brown trout is needed. New practices leading to sustainable management of their population should be introduced. This motivated our proposal Creation of a strategy for managing brown trout in Slovenia.

There are several reasons for the decline in brown trout in recent years: environmental changes such as the deterioration of habitats and increased average temperatures, as well as inappropriate management of the species. The main issue with the current management practices of brown trout is the introduction of the domesticated Atlantic fishery line of brown trout into open waters, where they cross-breed with the native population.
The goal of this project is to determine the conditions and define reasonable locations within which it will be managed, based on the analysis of the current status of the species, the existing conditions, and established management practices. The genetic purity of the population will need to be determined in order to designate management units. In addition, the rules of raising of brown trout in fisheries and streams will have to be established. When establishing management units, the changes in conditions due to degradation of the habitats, climate change, and resources available to the managers will also need to be considered. To ensure the long-term success of this strategy we also propose to develop a system for continuous monitoring of the purity of the genetic material used in raising brown trout.

The project is expected to last for 24 months, and result in a strategy for managing brown trout that introduces new approaches that will enable more sustainable use of natural resources, as well as help managers of fisheries with their work. For that purpose, we are including in our study fishing associations, fisheries, and experts in protection of species and habitats.     

THE PHASES OF THE PROJECT AND THEIR REALIZATION

1. Analysis of the state of the brown trout population in Slovenia; Month 15; BF, ZZRS
2. Analysis of brown trout management in Slovenia; Month 15; ZZRS
3. Assessment of the genetic purity of the reared and wild brown trout populations ; Month 18; BF
4. Determination of management areas and management units of the brown trout in Slovenia; Month 24; BF, ZZRS
5. Determination of the rules for the creation of breeding stocks and for sustainable breeding of brown trout in nursery streams; Month 24, BF, ZZRS
6. Proposal of continuous monitoring of brown trout genetic material for the purpose of its breeding and restocking; Month 24; BF, ZZRS
7. Project report including brown trout management strategy in Slovenia; Month 24; BF, ZZRS
8. Presentation of the results to the customer and the interested public; Month 24; BF, ZZRS

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