No indications of Atlantic salmon (Salmo salar) shoaling with kin in the Baltic Sea

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Authors: Palm, Stefan, Dannewitz, Johan, Järvi, Torbjörn, Koljonen, Marja-Liisa, Prestegaard, Tore, Olsén, K. Håkan
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 2008
• Subjects: Aquatic Science; Ecology, Evolution, Behavior and Systematics; Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1139/f08-088; http://www.nrcresearchpress.com/doi/full-xml/10.1139/F08-088; http://www.nrcresearchpress.com/doi/pdf/10.1139/F08-088

Several studies have shown that fish shoals may consist of closely related individuals. It has been found, for example, that released out-migrating salmon smolts tend to aggregate with kin, including when sibling groups have been reared separately. We used genetic microsatellite markers to test whether “shoals” of adult Atlantic salmon ( Salmo salar ) during the marine phase (i.e., aggregations of fish caught in drift nets at offshore feeding areas in the Baltic Sea) consisted of closely related individuals (full-siblings, half-siblings). We found no evidence of kin cohesiveness related to shoals, however. Despite a weak overall tendency for individuals assigned to the same population (river or stock) to occur together, estimates of genetic relatedness in combination with consistent heterozygote deficiencies, and results from mixed-stock analyses and assignment tests collectively indicated that shoals consisted of unrelated fish from multiple populations.