The research of salmonids migrations in the lower and estuarine parts of Onega River and Northern Dvina River (White Sea basin) with the use of hydroacoustic method ...

• Main Authors: Zelenkov, Vasilij M., Studenov, Igor I., Gerasimov, Yuri V., Lapshin, Oleg M.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: ASC 2004 - S - Theme session 2024
• Subjects: Fisheries and aquaculture; Ecosystem observation, processes and dynamics; dvina; White Sea
• Online Access: https://dx.doi.org/10.17895/ices.pub.25349797; https://ices-library.figshare.com/articles/conference_contribution/The_research_of_salmonids_migrations_in_the_lower_and_estuarine_parts_of_Onega_River_and_Northern_Dvina_River_White_Sea_basin_with_the_use_of_hydroacoustic_method/25349797

No abstracts are to be cited without prior reference to the author.Complicated hydrodynamic structure of the rivers, especially in the lower part if them, determined by rivers’ channel morphometry exerts significantly influences the fishes’ behaviour, which become apparent in distributional and displacement patterns of migratory fishes. Such factors as sharp changes of the depth and width of channel or in the degree of meandering alter the trajectories of fish movements causing the long delays before the obstacles and changes in velocity regime of migration. Presence of the survey set fishing gears in the river results in similar changes of migration behaviour that can be classified as “violations'. On the one hand, it brings the negative impact on the migration; on the other hand, it gives rise to some doubts about reliability of the data on abundance of the migrating fishes obtained by means of set fishing gears and may cause an increased level of elimination. The purpose of this work was to study the ...