Putting life to work: Metabolic labour and value production in the global bluefin tuna supply chain

Abstract

Drawing on ongoing multi-sited ethnographic research on the tuna trap fishery between Sardinia and Portugal, this article focuses on a tuna trap in Algarve, examining how bluefin tuna is transformed into a lively commodity within capture-based aquaculture. Moving beyond the question of whether animals work, it aims to investigate the value animals hold for capital by analysing the new forms of labour mobilized in the global tuna supply chain. The study traces the everyday practices of feeding, monitoring, and killing through which tuna vitality is sustained, managed, and ultimately extinguished for market purposes. It argues that value is generated not merely from the fish’s flesh but through the controlled exploitation of its biological capacity to grow: a process enabled by a quota system that converts biomass into surplus value. This process, which can be conceptualized as metabolic labour, represents a significant reconfiguration of work under contemporary capitalism and reveals the tuna as an active, though exploited, participant in its own valorisation. By focusing on the fragile interspecies relations and opaque metabolic processes involved, the article shows how this form of production, which depends on rendering life legible and controllable, ultimately requires that same vitality to be erased in a rapid, standardized death to preserve its commodity value.