Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2025
Erindi/veggspjald / Talk/poster E38
Höfundar / Authors: Anja K. Nickel, Michelle Valliant, Guðbjörg Ásta Ólafsdóttir
Starfsvettvangur / Affiliations: 1.-3. Háskóli Íslands, Rannsóknasetur á Vestfjörðum
Kynnir / Presenter: Anja K: Nickel
Nursery habitats play a key role in shaping growth, survival, and recruitment of juvenile fish. Their use is influenced not only by structural complexity and biotic interactions but also by water parameters, such as temperature. Fish cope with thermal challenges through two main strategies: physiological or plastic adjustments, and through behavioral shifts, such as by avoidance, habitat use or activity levels. Considerable between individual variation exists in both strategies, highlighting that population-level responses may mask important differences among individuals. We used acoustic telemetry to track juvenile Atlantic cod, Gadus morhua, (n = 52) and saithe, Pollachius virens, (n = 24) in Dýrafjörður from 2021 to 2024, recording depth, temperature, and horizontal position during summer. Analyses focused on horizontal and vertical movements within the fjord and on the timing of departure relative to previously experienced thermal conditions. Despite limited vertical variation in temperature within Dýrafjörður we found substantial variation in thermal exposure between and within species, suggesting that individuals employ a combination of strategies to cope with fluctuating thermal environments.