CO₂ Emissions in the Canned Tuna Market: Insights from the Spanish Purse Seine Fleet and International Transport

Canned tuna represents a growing market and a key component of global food security. As the environmental cost of food systems becomes increasingly recognized, this study aims to investigate the carbon dioxide (CO₂) emissions associated with the main industrial fishery supplying raw material for canned tuna production (the tropical tuna purse seine fleet), as well as those linked to transport modes involved in international distribution. We focused on Spain as a case study due to its central role in the global tuna supply chain. Results indicate that the Spanish tropical tuna purse seine fleet generated greater emissions than the transport used in Spain’s global exports of canned tuna. The fleet emitted 148.9 ± 12.7 kt CO₂ per year, with the fishing vessels operating in the Indian Ocean being the major contributors. Meanwhile, international transport emitted 19.1 ± 1.5 kt CO₂ per year, dominated by road transport. In terms of efficiency, the fleet emitted 0.71 kt CO2 per kilotonne of tropical tuna landed, while 0.19 kt CO₂ was emitted per kilotonne of canned tuna exported. Overall, our findings contribute to a better understanding of greenhouse gas emissions related to the canned tuna market.