Anthropogenic activities are greatly altering the habitats of animals, whereby fish are already encountering several stressors simultaneously. The purpose of the current study was to investigate the capacity of fish to respond to two... more
Anthropogenic activities are greatly altering the habitats of animals, whereby fish are already encountering several stressors simultaneously. The purpose of the current study was to investigate the capacity of fish to respond to two different environmental stressors (high temperature and overnight hypoxia) separately and together. We found that acclimation to increased temperature (from 7.7±0.02°C to 14.9±0.05°C) and overnight hypoxia (daily changes from normoxia to 63-67% oxygen saturation), simulating climate change and eutrophication, had both antagonistic and synergistic effects on the capacity of fish to tolerate these stressors. Thermal tolerance of Arctic char (Salvelinus alpinus) and landlocked salmon (Salmo salar m. Sebago) increased with warm acclimation by 1.3°C and 2.2°C, respectively, but decreased when warm temperature was combined with overnight hypoxia (by 0.2°C and 0.4°C, respectively). In contrast, the combination of the stressors more than doubled hypoxia toleran...
Publication Date: Jan 31, 2015
Publication Name: The Journal of experimental biology
Standard metabolic rate (R(S)), specific growth rate (G) and aggressiveness were investigated in three Finnish populations of Atlantic salmon Salmo salar (Neva, Saimaa and Teno), which were reared in identical hatchery conditions. The... more
Standard metabolic rate (R(S)), specific growth rate (G) and aggressiveness were investigated in three Finnish populations of Atlantic salmon Salmo salar (Neva, Saimaa and Teno), which were reared in identical hatchery conditions. The populations differed in their geographical origin and native habitat. There was a significant difference between populations in R(S): the southernmost Neva population had higher values in R(S) than the northernmost Teno population. No difference was found in G or aggressiveness between the populations. G was found to have a significant positive association with aggressiveness and R(S) among the three populations, however, these results were not statistically significant after correction for multiple tests. There was no significant association between R(S) and aggressiveness. Higher metabolic rate of the most southern population Neva is suggested to be an adaptation to the more abundant food sources of the southern stream.
