title: Acclimation potential of Arctic cod (Boreogadus saida) from the rapidly warming Arctic Ocean.
abstract: As a consequence of the growing concern about warming of the Arctic Ocean, this study quantified the thermal acclimation responses of Boreogadus saida, a key Arctic food web fish. Physiological rates for cardio-respiratory functions as well as critical maximum temperature (Tc,max) for loss of equilibrium (LOE) were measured. The transition temperatures for these events (LOE, the rate of oxygen uptake and maximum heart rate) during acute warming were used to gauge phenotypic plasticity after thermal acclimation from 0.5°C up to 6.5°C for 1 month (respiratory and Tc,maxmeasurements) and 6 months (cardiac measurements). Tc,maxincreased significantly by 2.3°C from 14.9°C to 17.1°C with thermal acclimation, while the optimum temperature for absolute aerobic scope increased by 4.5°C over the same range of thermal acclimation. Warm acclimation reset the maximum heart rate to a statistically lower rate, but the first Arrhenius breakpoint temperature during acute warming was unchanged. The hierarchy of transition temperatures was quantified at three acclimation temperatures and was fitted inside a Fry temperature tolerance polygon to better define ecologically relevant thermal limits to performance of B. saida We conclude that B. saida can acclimate to 6.5°C water temperatures in the laboratory. However, at this acclimation temperature 50% of the fish were unable to recover from maximum swimming at the 8.5°C test temperature and their cardio-respiratory performance started to decline at water temperatures greater than 5.4°C. Such costs in performance may limit the ecological significance of B. saida acclimation potential.
authors.affiliation: Zoology Department, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z4 drost@zoology.ubc.ca.
authors.forename: H E
authors.identifier: 0000-0002-8818-227X
authors.initials: HE
authors.lastname: Drost
authors.affiliation: Zoology Department, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z4.
authors.forename: M
authors.initials: M
authors.lastname: Lo
authors.affiliation: Institute of Ocean Sciences, Fisheries and Oceans Canada, 9860 West Saanich Road, Sidney, British Columbia, Canada V8L 4B2.
authors.forename: E C
authors.initials: EC
authors.lastname: Carmack
authors.affiliation: Zoology Department, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z4 Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4.
authors.forename: A P
authors.initials: AP
authors.lastname: Farrell
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D000332:Aerobiosis; D000758:Anesthesia; D000818:Animals; D001110:Arctic Regions; D005399:Fishes / Q000502:physiology*; D057232:Global Warming; D006339:Heart Rate / Q000502:physiology; D010101:Oxygen Consumption; D012119:Respiration; D013696:Temperature
keywords: Arctic food web; Arrhenius plots; Cardio-respiratory performance; Climate change; Metabolic rate; Sea ice ecosystem