Spain’s seafood futures to 2050 under climate change and contrasting transition scenarios

This study presents an integrated assessment of Spain’s seafood system under contrasting climate and transition scenarios towards 2050. We analyze the current highly globalized, import-dependent baseline against two transition scenarios: Business as Usual (BAU) and Relocalised Seafood Transition (REST) model. Combining IPCC climate projections with detailed biomass flow, trade, and emission accounting, we quantify future environmental and nutritional outcomes. Results indicate the current system generates 17.2 TgCO₂eq annually, heavily reliant on distant-water catches and imports. The BAU pathway maintains this high-emission globalized structure, with emissions stable and nutritional overconsumption persisting (136% above EAT-Lancet recommendations). In contrast, the REST scenario—prioritizing domestic production, low-impact gears, and bivalve aquaculture, while drastically reducing imports— achieves an 85% reduction in emissions (2.6 TgCO₂eq) and aligns per capita consumption (30.3 g·cap⁻¹·day⁻¹) closely with healthy dietary guidelines. The REST transition simplifies supply chains, enhances resilience to global shocks, and reorients diets towards low-trophic species like pelagic fish and molluscs, which offer high nutritional value with lower environmental impact. This analysis highlights a critical trade-off: maintaining current consumption volumes undermines climate goals, while a relocalized, sufficiency-oriented model offers a viable pathway to integrate ecological integrity, nutritional health, and climate resilience within Spain’s seafood system.