Disentangling global supply chains: A systematic map of research on the biodiversity and social impacts of European blue food consumption

Abstract

Background : Seafood is a vital global resource, yet the rapid growth of aquaculture – which now supplies over half the world’s blue food – has introduced significant ecological and social challenges. As a major importer and consumer, Europe is central to these global supply chains. While the industry bolsters rural economies, it is frequently linked to nutrient pollution, habitat loss, disease, and labour exploitation. This systematic map evaluates the biodiversity and societal impacts of European blue food consumption, specifically regarding salmon, cod, sea bass, and sea bream. Methods : We searched 10 bibliographic databases/indexes and a suite of grey literature sources for evidence. Following a rigorous screening of over 28,000 results from bibliographic and grey literature sources, a random 60% subsample (210 studies) was analysed through metadata extraction and coding using a tried-and-tested form. Consistency checking prior to screening and data extraction ensured operationalisation and consistency. Results : The findings reveal a fragmented and deeply uneven evidence base. Research focus largely mirrors production volume; Atlantic salmon is the most studied species, with data concentrated in Norway, Chile, Canada, and the UK. While Mediterranean sea bass and sea bream are well-documented, evidence for cod remains negligible. A stark thematic imbalance exists between ecological and social research. Most studies prioritise ecological outcomes, such as benthic health, sea lice, and wild fish mortality. In contrast, social impacts are severely under-represented; critical issues like food security and labour conditions in producing or feed-extracting regions are almost entirely absent. Furthermore, the map highlights an under-representation of interdisciplinarity, with only one study integrating both social and ecological outcomes. The evidence also suffers from production stage bias. Most research focuses on the “grow-out” phase in offshore pens, leaving upstream activities like feed production and downstream stages like processing largely unexamined. Crucially, only six studies evaluated the effectiveness of mitigation measures, creating a significant barrier to evidence-based policy. Discussion : Ultimately, the current evidence base is insufficient for a holistic understanding of the implications of European blue food consumption. Research remains narrowly focused on specific species and production stages, overlooking cumulative and supply-chain-wide effects. To support the European Biodiversity Strategy for 2030 and foster equitable food systems, future research must prioritise the social dimensions of production and investigate mitigation strategies across the entire value chain.