Haplotype Diversity of Brown Trout (Salmo trutta L.) Populations from Una River Drainage Area in Bosnia and Herzegovina: Implications for Conservation and Fishery Management

Abstract

Data about the mitochondrial DNA haplotypes of brown trout (Salmo trutta L.) in the area of the Danube River Basin in Bosnia and Herzegovina have not been hitherto published. Brown trout from the drainage area of the Una River was assessed for the first time using the Control Region of the mitochondrial DNA. Anal fin clips of 43 brown trout specimens were sampled from four sites in the headwater section and in two tributaries joining the Una River in the middle section. In total, three CR haplotypes were recorded: Da2 and Da22 from the Danubian and At1 from the Atlantic brown trout lineage. Da22 haplotype was inferred the native one in the Una River drainage area owing to its most frequent and most upstream dispersal in the headwater section. The other two haplotypes were found with the native one only in one or two tributaries joining the Una River in the middle section. They are considered alien and were most likely introduced by stocking with hatchery reared brown trout fingerlings. Occurrence of several trout hatcheries in the area poses strong risk of introduction of alien haplotypes into the headwater section and consequential breakdown in local native brown trout.