21We resurrect the metabolic life table (MLT), a combination of life table and energy budget that 22 quantifies how metabolic energy is acquired and allocated to survival, growth and reproduction 23 over the life cycle. To highlight its broad implications and utility, we apply this framework to 24 John Brett's classic data on sockeye salmon. In the life cycle of Skeena River sockeye, a pair of 25 breeders dies in fresh water after spawning, and the offspring move to the ocean where they 26 feed, grow and suffer mortality before returning to freshwater and migrating upstream to 27 spawn and die. Most of the accumulated biomass energy is transported into freshwater 28 ecosystems and expended on respiration for migration and breeding or is transferred to 29 2 consumers. Reanalyzing Brett's data in the context of a MLT has broad implications and 30 applications: i) for basic ecology, because of the unusual physiology, life history and ecosystem 31 impacts of wild salmon; and ii) for conservation and management, because of the enormous 32 economic importance of wild-caught and farmed salmon. Moreover, the MLT highlights the 33 intimate relationships between two universal biological processes: i) demography as a function 34 of age; and ii) metabolism-the balancing of uptake, transformation, and allocation of 35 metabolic energy over the life cycle. Linking these two universal processes provides a general 36 MLT framework that can be applied across the diversity of life. 37 38 45 have important implications for applied issues in science including conservation, management 46 and exploitation of animals for human use. 47 Canadian fisheries biologist John "Roly" Brett (1983, 1986) introduced the concept of a 48 "life table of energetics," which combines the demographic framework of a traditional life table 49 with the energy balance framework of physiological ecology. Brett illustrated the conceptual 50 approach and practical applications using data on sockeye salmon collected over decades of 51 3 field and laboratory research. Here, we resurrect Brett's seminal ideas in the context of recent 52 advances in metabolic scaling theory. We compile and reanalyze his data to address theoretical 53 and empirical, basic and applied problems. We show how updated metabolic life table (MLT) 54 analysis offers new insights into the fundamental general features of demography and 55 metabolic ecology that govern the diversity of life (Brown et al. 2018; Burger et al. 2019). 56 Sockeye salmon provide an exemplary model system for MLT analysis illuminating the keystone 57 energetic roles of salmon in ecosystems and human economies. 58 59 Figure 1. Life cycle of Babine Lake sockeye salmon after Brett (1983). The parts of the life cycle 60 spent in fresh water and the oceans are indicated by green and blue shading, respectively, but 61 not to scale; salmon spend nearly equal time, two years, in freshwater and marine 62 environments. Figure modified from 63 4 https://www.google.com/search?q=salmon+life+cycle&rlz=1C1CHFX_enUS555US...