TY - JOUR

T1 - Physiological effects of temperature on Greenland halibut Reinhardtius hippoglossoides shows high vulnerability of Arctic stenotherms to global warming

AU - Ruth, Andreas

AU - Svendsen, Morten Bo Søndergaard

AU - Nygaard, Rasmus

AU - Christensen, Emil Aputsiaq Flindt

AU - Bushnell, Peter G.

AU - Steffensen, John Fleng

N1 - Publisher Copyright: © 2023 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles.

PY - 2023

Y1 - 2023

N2 - Global warming affects the metabolism of ectothermic aquatic breathers forcing them to migrate and undergo high-latitudinal distribution shifts to circumvent the temperature-induced mismatch between increased metabolic demand and reduced water oxygen availability. Here the authors examined the effects of temperature on oxygen consumption rates in an Arctic stenotherm, the Greenland halibut Reinhardtius hippoglossoides, and calculated the optimal temperature for maximum aerobic scope, AS(Topt,AS), which was found to be 2.44°C. They also investigated cardiac performance as limiting the oxygen transport chain at high temperatures by measuring maximum heart rate (fHmax) over acute temperature increases and found various metrics related to fHmax to be at least 3.2°C higher than Topt,AS. The authors’ measured Topt,AS closely reflected in situ temperature occurrences of Greenland halibut from long-term tagging studies, showing that AS of the species is adapted to its habitat temperature, and is thus a good proxy for the species' sensitivity to environmental warming. The authors did not find a close connection between fHmax and Topt,AS, suggesting that cardiac performance is not limiting for the oxygen transport chain at high temperatures in this particular Arctic stenotherm. The authors’ estimate of the thermal envelope for AS of Greenland halibut was from −1.89 to 8.07°C, which is exceptionally narrow compared to most other species of fish. As ocean temperatures increase most rapidly in the Arctic in response to climate change, and species in these areas have limited possibility for further poleward-range shifts, these results suggest potential severe effects of global warming on Arctic stenotherms, such as the Greenland halibut. The considerable economic importance of the species raises concerns for future fisheries and species conservation of Arctic stenotherms in the Northern Hemisphere.

AB - Global warming affects the metabolism of ectothermic aquatic breathers forcing them to migrate and undergo high-latitudinal distribution shifts to circumvent the temperature-induced mismatch between increased metabolic demand and reduced water oxygen availability. Here the authors examined the effects of temperature on oxygen consumption rates in an Arctic stenotherm, the Greenland halibut Reinhardtius hippoglossoides, and calculated the optimal temperature for maximum aerobic scope, AS(Topt,AS), which was found to be 2.44°C. They also investigated cardiac performance as limiting the oxygen transport chain at high temperatures by measuring maximum heart rate (fHmax) over acute temperature increases and found various metrics related to fHmax to be at least 3.2°C higher than Topt,AS. The authors’ measured Topt,AS closely reflected in situ temperature occurrences of Greenland halibut from long-term tagging studies, showing that AS of the species is adapted to its habitat temperature, and is thus a good proxy for the species' sensitivity to environmental warming. The authors did not find a close connection between fHmax and Topt,AS, suggesting that cardiac performance is not limiting for the oxygen transport chain at high temperatures in this particular Arctic stenotherm. The authors’ estimate of the thermal envelope for AS of Greenland halibut was from −1.89 to 8.07°C, which is exceptionally narrow compared to most other species of fish. As ocean temperatures increase most rapidly in the Arctic in response to climate change, and species in these areas have limited possibility for further poleward-range shifts, these results suggest potential severe effects of global warming on Arctic stenotherms, such as the Greenland halibut. The considerable economic importance of the species raises concerns for future fisheries and species conservation of Arctic stenotherms in the Northern Hemisphere.

KW - aerobic scope

KW - Arrhenius breakpoint

KW - ectotherm

KW - heart rate

KW - optimum temperature

KW - thermal tolerance

U2 - 10.1111/jfb.15434

DO - 10.1111/jfb.15434

M3 - Journal article

C2 - 37170416

AN - SCOPUS:85164136674

VL - 103

SP - 675

EP - 683

JO - Journal of Fish Biology

JF - Journal of Fish Biology

SN - 0022-1112

IS - 3

ER -