Effects of release timing on migration behaviour and survival of hatchery‐reared Atlantic salmon smolts in a regulated river
Abstract In this study, 221 two‐year‐old hatchery‐reared salmon, S almo salar , smolts were tagged with radio transmitters over a period of three consecutive years and released in the river in groups of 20–21 fish in various dates between late A pril and early June. Tagged smolts were tracked during...
| Published in: | Ecology of Freshwater Fish |
|---|---|
| Main Authors: | , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Wiley
2013
|
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1111/eff.12097 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Feff.12097 https://onlinelibrary.wiley.com/doi/pdf/10.1111/eff.12097 |
| Summary: | Abstract In this study, 221 two‐year‐old hatchery‐reared salmon, S almo salar , smolts were tagged with radio transmitters over a period of three consecutive years and released in the river in groups of 20–21 fish in various dates between late A pril and early June. Tagged smolts were tracked during their downstream migration in the lower 36‐km stretch of the regulated R iver O ulujoki, with the focus on the effects of release date, water temperature and river flow on migration behaviour and survival. The results indicate that release timing and river temperature have profound effects on the initiation of migration, swimming speed and survival of released S . salar smolts. Smolts released early in the spring in cold waters ceased migration after brief downstream movement and were vulnerable to predation, whereas the migration speed and survival rates increased markedly for smolts released later in the spring. |
|---|