Temporal changes in allele frequencies in a small marble trout Salmo marmoratus population threatened by extreme flood events

• Published in: Journal of fish biology Vol. 88; no. 3; pp. 1175 - 1190
• Main Authors: Pujolar, J. M., Vincenzi, S., Zane, L., Crivelli, A. J.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-03-2016; Wiley Subscription Services, Inc
• Subjects: Animal Migration; Animals; disturbance events; Floods; Gene Flow; Gene Frequency; genetic erosion; genetic events; Genetic Variation; Heterozygote; Population Density; recurring floods; resilience; Rivers; Salmonidae - genetics; salmonids; Slovenia; Trout - genetics; genetic erosion; genetic events; salmonids; recurring floods; resilience; disturbance events
• ISSN: 0022-1112; 1095-8649
• DOI: 10.1111/jfb.12897

The effect of extreme floods on the genetic composition of marble trout Salmo marmoratus living in Lipovscek, a tributary of the Soca River in Slovenia, which has been affected by multiple destructive flood events for centuries was investigated. By monitoring genetic variability during the period 2004–2011, apparent signatures of genetic erosion including a decline in observed and expected heterozygosities and allelic richness were observed. Contemporary effective population size was estimated between 11 and 55 individuals, which is congruent with census data. The data suggest asymmetric gene flow between the two sections of the river. The existence of substantial downstream migration (15–19%) was confirmed by paternity analysis. A small (1–3%) upstream migration was also suggested, which was confirmed by tagging data. Overall, low genetic diversity has not prevented the survival of the Lipovscek population, which might be a common feature of salmonid freshwater populations.