Main actors in the Cephalopod Global Trade Network: a graph theory analysis

Abstract The global cephalopod trade is a multi-billion-dollar industry that involves fishing and captive breeding of a dozen species of high commercial value. It also contributes wholly or partly to the income and subsistence of thousands of families around the world. Despite its broad ecological, social, and economic importance, limited research has been conducted to describe the scope and scale of the global cephalopod trade. To date, there is no specific regulation, nor have tracking systems been implemented, to study the traceability of the global cephalopod trade at an international level. We provide, for the first time, a comprehensive description of the legal trade in cephalopods to understand who the key world players in the cephalopod seafood markets are. We analysed 20 years of records compiled by the United Nations COMTRADE database. The database contained 115,108 entries for squid and cuttlefish and 71,659 entries for octopus, including the product flow between traders (countries or territories) weighted by volume (kg) and monetary value (USD). Graph theoretic analysis was used to explore the emergent properties of this database through the analysis of different measures of centrality that provide insights on the key role of the traders in the network. Our findings show that most of the market movements between ca. 250 traders are led by three countries (China, Spain, and Japan), involving 11 clusters of traders based on the volume and value of cephalopod trade and number of transactions. The most important cluster, that dominates the cephalopod seafood market, is composed by 5 Asian countries (China, India, Republic of Korea, Thailand, and Vietnam), 2 European countries (the Netherlands and Spain) and the USA. This work identifies the traders that act as major exporters and/or importers, the modulators, intermediaries or accumulators, the best-connected traders, the principal flow routes and the weaknesses of the global cephalopod trade network. This network information is essential to advance towards a transparent and sustainable cephalopods world trade.