Olsztyn/ Scientists began research on a dying fish species

Danube salmon survival in Polish waters depends on stocking with material produced by the stocking centre in Łopuszna (Podhale), which has Poland’s only parent stock and breeding site of this species. Scientists want to determine the genetic condition of the stock. Protection programs based on fish breeding in captivity carry the risk of losing genetic diversity, leading to a decline in the effectiveness of stocking.

"This is pioneering research in Poland, because Danube salmon has not been genetically studied until now. So far, the centre in Łopuszna only carried out reproduction of these fish, and stocking material was introduced into the open waters. Because it is a fish threatened with extinction, we need to determine its ecological and genetic status" - told PAP scientific supervisor of the research team, Dr. Dorota Fopp-Bayat from the Faculty of Environmental Sciences, University of Warmia and Mazury in Olsztyn.

The study will allow to assess the need to enrich the gene pool of the parent stock, complementing it with fish imported from abroad. Genetic analyses will also allow to develop a breeding program based on proper selection of breeding pairs.

Researchers will also conduct a comparative analysis of wild populations of Danube salmon and the parent stock, to assess whether they are supplemented with genetically correct fry. This will be possible thanks to the cooperation with the Polish Angling Association. Anglers who catch Danube salmon - before releasing it back into the water - should take a fin portion. Such samples along with information about the catch location will be transferred to scientists from Olsztyn.

Head of the research project Marcin Kuciński told PAP that the research project scheduled for two years is made possible by a grant from the National Centre for Science in the competition Prelude for people starting a career in science.

Danube salmon is the largest fish from the salmon family occurring in Poland, it can reach up to 1.5 meters in length. The size of this species population in our waters is estimated at only 1.5-2 thousand adults.

In the early 1950s, Danube salmon populations began to disappear from their natural habitats, the rivers Czarna Orawa and Czadeczka belonging to the Danube Basin. Contributing factors included poaching, pollution and regulation of rivers and hydrotechnical constructions.

Active protection of this species began when it was on the verge of extinction. Breeding attempts under controlled conditions to produce stocking material were successful. Thanks to years of stocking of the largest mountain rivers and strict angling regulations, Danube salmon populations persist in the Dunajec, Poprad and San.

Danube salmon parent stock in the stocking centre in Łopuszna was founded in 1955 with virtually the last fish caught in their indigenous places of occurrence. Currently, the stock has 155 spawners, the oldest of which are 15 years old. The farm produces more than 0.5 million fry annually.

PAP - Science and Scholarship in Poland

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