Data from: First measurements of field metabolic rate in wild juvenile fishes show strong thermal sensitivity but variations between sympatric ecotypes ...

• Main Authors: Chung, Ming-Tsung, Jørgensen, Kris‐Emil Mose, Trueman, Clive N., Knutsen, Halvor, Jorde, Per Erik, Grønkjær, Peter
• Format: Dataset
• Language: English
• Published: Dryad 2020
• Subjects: metabolic range; Otolith; phenotypic performance; stable carbon isotope; stable oxygen isotope; Norway; atlantic cod
• Online Access: https://dx.doi.org/10.5061/dryad.ffbg79ct2; https://datadryad.org/stash/dataset/doi:10.5061/dryad.ffbg79ct2

The relationship between physiology and temperature has a large influence on population-level responses to climate change. In natural settings, direct thermal effects on metabolism may be exaggerated or offset by behavioural responses influencing individual energy balance. Drawing on a newly developed proxy, we provide the first estimates of the thermal performance curve of field metabolism in a wild fish. We investigate the thermal sensitivity of field metabolic rate in two sympatric, genetically distinct ecotypes of Atlantic cod from the Skagerrak coast of southern Norway. The combined ecotype median of field metabolic rate increased with increasing temperature until around 16°C, coincident with the thermal optimum for growth for juvenile Atlantic cod. Individual cod experienced temperatures in excess of the thermal optimum for field metabolic rate, indicating some degree of thermal limitation of field metabolism in a complex natural environment with the potential for thermal refugia. The two cod ecotypes ...