Scientific publications

Populations of the European grayling in the Mologa and Suda river catchments are included in the Red Data Book of the Vologda Region with the status 3 (VU) - rare, vulnerable species. According to the analysis of the literature, archival materials, interviews and questionnaires, information from online fishermen's forums, and the author's own studies, collectively covering the period from 1855 to 2017, Thymallus thymallus has been reported from 103 rivers and 7 lakes of the Vologda Region. The article presents the list of rivers and lakes where the grayling has been recorded, as well as a schematic map of its distribution in the Vologda Region. In the region, grayling mostly inhabit rivers up to 100 km long (80 % of the total number of watercourses from which the species was reported). The presence of the species in lakes of the region is not confirmed by recent studies (with the exception of Lake Onego). This study demonstrates that the combination of standard research methods with questionnairing and online forums allows for a more efficient assessment of the distribution patterns of rare fish species in the region.