High prevalence of straying in a wild brown trout (Salmo trutta) population in a fjord system

Autor: Kristi Källo, Henrik Baktoft, Martin Lykke Kristensen, Kim Birnie-Gauvin, Kim Aarestrup
Rok vydání: 2022
Předmět:
Zdroj: ICES Journal of Marine Science. 79:1539-1547
ISSN: 1095-9289
1054-3139
DOI: 10.1093/icesjms/fsac079
Popis: Natal homing is a prevalent life-history strategy among salmonids. However, not all individuals return to their natal river, a behaviour known as straying. In this study, we investigated the prevalence of straying and its connection to different life-history characteristics in an anadromous brown trout (Salmo trutta) population. In total, 21 538 juvenile out-migrating brown trout were tagged with Passive Integrated Transponder (PIT) tags in two years. Individuals were grouped according to their developmental status (parr, pre-smolt, and smolt) at the time of out-migration to investigate the effect of such life-history characteristic on the likelihood of straying. High number of anadromous brown trout (36%) were detected in non-natal rivers. Individuals spending longer time at sea were less likely to stray. Additionally, the likelihood of straying was dependent on the developmental status during out-migration, with parr having lower likelihood to stray compared to pre-smolt and smolt. However, the latter is further dependent on length and timing of juvenile out-migration. These results indicate that straying is an inherent part of this anadromous brown trout population and it is influenced by several life-history characteristics at different life stages. This may have significant implications to genetic structure within and between populations and to population dynamics.
Databáze: OpenAIRE