Optimum temperature of a northern population of Arctic charr ( Salvelinus alpinus ) using heart rate Arrhenius breakpoint analysis

• Published in: Polar Biology
• Main Authors: Hansen, Aslak Kappel, Byriel, David Bille, R. Jensen, Mads, Steffensen, John Fleng, Svendsen, Morten Bo Søndergaard
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2017
• Subjects: Aerobic scope; Climate change; Heart rate; Optimum temperature; Oxygen transport; Salvelinus alpinus; Arctic; Arctic charr; Global warming; Greenland; Polar Biology; Qeqertarsuaq
• Online Access: https://curis.ku.dk/portal/da/publications/optimum-temperature-of-a-northern-population-of-arctic-charr-salvelinus-alpinus-using-heart-rate-arrhenius-breakpoint-analysis(197fa67b-e808-4df1-9219-a39919343330).html; https://doi.org/10.1007/s00300-016-2033-8

Assessment of maximum aerobic scope, as a proxy for scope of activity, in ectotherms can be instrumental in predicting distributional responses to e.g. global warming. The waters of the Arctic regions represent one of the most vulnerable ecosystems to climate change. In this study, we determine the optimum temperature (T opt ) of nine adult Arctic charr (Salvelinus alpinus) from Qeqertarsuaq, Greenland, using maximum heart rate (f Hmax ) for investigating the optimal temperatures for activity. The Arrhenius breakpoint of maximum heart rate measurements occurred between 5.9 and 8.3 °C (average = 7.5 °C ± 0.4). The Q 10 breakpoint occurred at an average of 7.1 °C ± 0.3. There was no significant difference between the breakpoint temperature found using Q 10 and Arrhenius [two-sample t test, df = 16; p > 0.1]. The highest f Hmax was found at 12.8 °C ± 1.0 reaching an average of 61.8 BPM ± 3.1. Arrhythmia occurred between 11 and 18 °C (average = 15.2 °C ± 0.9). The results obtained in this study suggest that the studied population of Arctic charr lives at summer temperatures (−0.6 to 9.1 °C) that are optimal for activity, but an increase in temperature expected with climate change, could have an impact on life cycle events and fitness-related tasks for this northern population.