Fig. 3: Thermal performance curves for field metabolic rate (C_resp values) inferred from otolith stable isotope compositions.

Hexplots show the density of 100 iterations of Monte Carlo resampling from the full dataset of 4776 otoliths. Black lines show best fitting quadratic models, yellow lines show best fitting linear breakpoint analysis models, black dots indicate C_resp and temperature estimates from raw data based on single values for all uncertain variables. Circular plots show the temperature and C_resp values inferred without uncertainty, colours indicate the location in the first year of life, either known at capture (A, B) or assigned (C, D) to the Mediterranean (red) or Western North Atlantic (blue). A Fish caught at age 0 fish and B fish caught as yearlings (age 1). C Fish caught as adults, with the otolith sampled to reflect first 3 months of growth, D fish caught as adults with the otolith sampled over the first year and E distribution of z-scored averages of Monte Carlo estimates for preferred temperatures (blue curve), C_resp values (red curve) and inter-quartile range of C_resp values (green curve) for yearling bluefin tuna, identifying preferred (T_pref) and limiting (T_lim) temperatures. Data and code are available¹⁰³.