Vigren, Carl, 2018. Sexual dimorphism in the migratory dynamics of a land-locked population of brown trout (Salmo trutta) in central Sweden : a study at three temporal scales. Second cycle, A2E. Umeå: SLU, Dept. of Wildlife, Fish and Environmental Studies
|
PDF
1MB |
Abstract
In this study I use a 56 years long dataset to study the migratory behaviours of a land-locked population of Brown trout (Salmo trutta) in the river Dammån, positioned in central Sweden. I found that there was a mean female-to-male sex ratio in the spawning-run of approximately 2.31 with an average 50% run date on the 29th of July.
I principally investigated if there were any trends in 3 different temporal scales: diel, seasonal and interannual. The model investigating diel effect was not significant, likely due to the light summer nights at this latitude. I found that there was a seasonal trend, where the probability of an observation being female increased by 54.33% during the season, indicative of a protandric trait where males gain from an early arrival to the spawning-grounds. The interannual model displayed a decline of 13.85% in the proportion of females migrating over the 56 years investigated.
| Main title: | Sexual dimorphism in the migratory dynamics of a land-locked population of brown trout (Salmo trutta) in central Sweden |
|---|---|
| Subtitle: | a study at three temporal scales |
| Authors: | Vigren, Carl |
| Supervisor: | Hellström, Gustav and Leonardsson, Kjell |
| Examiner: | Alanärä, Anders |
| Series: | Examensarbete / SLU, Institutionen för vilt, fisk och miljö |
| Volume/Sequential designation: | 2018:17 |
| Year of Publication: | 2018 |
| Level and depth descriptor: | Second cycle, A2E |
| Student's programme affiliation: | SY001 Forest Science - Master's Programme 300 HEC |
| Supervising department: | (S) > Dept. of Wildlife, Fish and Environmental Studies |
| Keywords: | trout, salmonid, salmo, trutta, migration, upstream, Storsjon, Storsjön, Damman, Dammån, regulated, fish ladder, behaviour, protandry |
| URN:NBN: | urn:nbn:se:slu:epsilon-s-9918 |
| Permanent URL: | http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-s-9918 |
| Subject. Use of subject categories until 2023-04-30.: | Aquatic ecology |
| Language: | English |
| Deposited On: | 08 Nov 2018 14:24 |
| Metadata Last Modified: | 28 Feb 2019 08:15 |
Repository Staff Only: item control page
