Global capture fisheries are a vital global food provisioning to help end hunger and malnutrition. To ensure that global seafood supply sustainably supports a growing population, many initiatives within the UN Sustainable-Development-Goals seek to balance management with efficient resource use. Here we examine changes for 150 countries that represent over 98% of global catch for the 1950–2014 period by analysing multiple fleet outputs relative to inputs (such as vessel power) using data envelopment analysis. We show that country specific technical efficiency has declined at rates of −3% yr−1 for artisanal and industrial fleets in 44 and 49 countries respectively. Recent global artisanal fleet (2010–2014 average) declines of −0.2%yr−1 show losses that translates to ∼71400t posing serious implications for sustainable food security and vulnerable livelihoods in the face of climate change Financiado para publicación en acceso aberto: Universidade de Vigo/CISUG