title: Elevated temperature causes metabolic trade-offs at the whole-organism level in the Antarctic fish Trematomus bernacchii.
abstract: As a response to ocean warming, shifts in fish species distribution and changes in production have been reported that have been partly attributed to temperature effects on the physiology of animals. The Southern Ocean hosts some of the most rapidly warming regions on earth and Antarctic organisms are reported to be especially temperature sensitive. While cellular and molecular organismic levels appear, at least partially, to compensate for elevated temperatures, the consequences of acclimation to elevated temperature for the whole organism are often less clear. Growth and reproduction are the driving factors for population structure and abundance. The aim of this study was to assess the effect of long-term acclimation to elevated temperature on energy budget parameters in the high-Antarctic fish Trematomus bernacchii. Our results show a complete temperature compensation for routine metabolic costs after 9 weeks of acclimation to 4°C. However, an up to 84% reduction in mass growth was measured at 2 and 4°C compared with the control group at 0°C, which is best explained by reduced food assimilation rates at warmer temperatures. With regard to a predicted temperature increase of up to 1.4°C in the Ross Sea by 2200, such a significant reduction in growth is likely to affect population structures in nature, for example by delaying sexual maturity and reducing production, with severe impacts on Antarctic fish communities and ecosystems.
authors.affiliation: Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Section Bentho-Pelagic Processes, Am Alten Hafen 26, 27568 Bremerhaven and University of Bremen, Germany tina.sandersfeld@awi.de.
authors.forename: Tina
authors.initials: T
authors.lastname: Sandersfeld
authors.affiliation: School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.
authors.forename: William
authors.initials: W
authors.lastname: Davison
authors.affiliation: Department of Marine Science, University of Otago, 30 Castle Street, Dunedin 9022, New Zealand.
authors.forename: Miles D
authors.initials: MD
authors.lastname: Lamare
authors.affiliation: Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Section Bentho-Pelagic Processes, Am Alten Hafen 26, 27568 Bremerhaven, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Knust
authors.affiliation: Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Section Bentho-Pelagic Processes, Am Alten Hafen 26, 27568 Bremerhaven and University of Bremen, Germany.
authors.forename: Claudio
authors.initials: C
authors.lastname: Richter
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D000818:Animals; D000864:Antarctic Regions; D001481:Basal Metabolism; D049628:Body Size; D001835:Body Weight; D057231:Climate Change; D004435:Eating / Q000502:physiology; D010473:Perciformes / Q000254:growth & development / Q000378:metabolism*; D013696:Temperature
keywords: Antarctica; Climate change; Energy budget; Growth; Production; Teleost; Thermal tolerance