Re-evaluation of Salmo data by Gridelli (1936) - Description of stocking, hybridization and repopulation in the River Soča basin

Abstract

History of stocking in Salmo marmoratus habitat in the Adriatic region and its effects are poorly known due to data deficiency. Well-documented research from 1936 based on trout external morphological characters was compared with research of extant trout populations based on genetic markers in an attempt to clarify the impact of stocking in the River Soča basin. Application of multivariate statistical methods reveals a similar pattern of native and non-native trout distribution in 1936 and after a recently started S. marmoratus repopulation project. Remnants of initial stocking from 1906 were detected in one stream in the upper Soča basin. Gridelli's samples of S. dentex, one of the least researched trout species of the Adriatic region, were also re-analysed and were found to differ from all other trout populations used in the study.