Factors affecting the within-river spawning migration of Atlantic salmon, with emphasis on human impacts

• Main Author: Tor G. Heggberget
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Atlantic salmon
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.525.1470; http://www.lakseelver.no/Nyheter/2008/oktober/Thorstad et al migration review.pdf

Abstract We review factors affecting the within-river spawning migration of Atlantic salmon. With populations declining across the entire distribution range, it is important that spawners survive in the last phase of the spawning migration. Knowledge on the factors affecting migration is essential for the protection of populations, and to increase the success of reintroduction programmes. A number of studies have documented that the upstream migration may be delayed for many weeks at man-made obstacles such as power station outlets, residual flow stretches, dams, weirs and fishways. The fish may also be delayed at natural migration barriers. Often, the magnitude of delay is not predictable; fish may be considerably delayed at barriers that appear to