| Tuna and squid are important marine resources and occupy an important position in the international trade market.At the same time,they are also the most important and most productive fishing targets in my country’s distant water fishery.This paper uses the data in the UN Comtrade database to analyze the import and export trade of squid and tuna products in the world and China,including trade scale,product structure and market structure.In order to understand the structure of the global trade network and the changes in China’s pattern,this paper uses the trade data of global squid products and tuna products from 2002 to 2020,and based on their product forms,respectively constructs the live,fresh,or chilled squid trade network,elaborated squid trade network,fresh or chilled tuna trade network and elaborated tuna trade network,in 2002,2008,2014 and 2020.According to the directional characteristics of trade and the data requirements of different indicators in the social network analysis method,a directed unweighted(binary)trade network and a directed weighted trade network are respectively constructed.Firstly,use the indicators such as network density and trade links in the social network to measure its overall characteristics.Secondly,the characteristics of different nodes in the trade network are characterized by degree,betweenness centrality and strength,and then the core-periphery model is used to describe the relationship between countries(regions)participating in the trade of squid products and tuna products in the world.position in the trade network.And using the "circlize" package in the R language and Gephi 0.9.2 network visualization software,the overall pattern and evolution relationship of the trade network are displayed more clearly and intuitively.Finally,use the HM index to measure China’s dependence on the target export trading partner country(region).The results showed that:(1)Live,fresh or chilled squid products and elaborate squid products have low network density and obvious core-edge structure.Spain and France occupy a central position in the trade network of live,fresh or chilled squid products and have strong control capabilities,Spain is also the largest import market.In the network of elaborated squid products,Europe and East Asia are the regions with the closest trade connections of elaborate squid products.Spain,China,the United States,Thailand,India and other economies have always been at the core,and have absolute control and influence over the entire trade network of elaborated squid products.(2)The density of the trade network of tuna products is small,but its network density and trade links are generally increasing.Trade networks in both product forms exhibit a distinct core-periphery structure.In the fresh or chilled tuna trade network,the United States,Japan and some European countries occupy the core positions,and have strong control over trade.In the elaborated tuna trade network,Thailand is the most influential country,and China’s node degree and betweenness centrality and strength increased significantly,but the ranking of betweenness centrality was relatively low.(3)China mainly participates in the trade of elaborated squid products and occupies a central position in this network.The trade network for live,fresh or chilled squid products has always been a semi-peripheral country,and its influence and control in the network are not strong enough.China’s demand for live,fresh or chilled squid products is small,its import trade volume is gradually decreasing,while the export trade volume is increasing.Although China has the largest trading partner and the largest import and export trade volume in the trade network for elaborate squid products,it is not the largest " betweenness " in the network.China’s import and export value have increased year by year,and most of the time it is ranked first in the in-strength and out-strength of elaborated squid products,indicating that China has a large demand for squid in this product category,and the elaborated squid is exported to other markets after processing.(4)China’s participation in the global trade network for fresh or chilled tuna products is low and has always been on the periphery.The changing position of China can be clearly seen in the trade network for elaborated tuna products,which is becoming more and more important in the trade network.This is mainly due to the fact that China’s exports of elaborate tuna products have improved greatly,and China’s trading partners and trade volume have increased greatly.China’s role as an intermediary in the network has also been greatly improved,and it has a strong ability to control other participants in the network.(5)From 2002 to 2020,the main export markets of Chinese squid are concentrated,but the HM index of the main export markets is low,and the overall trend is downward,indicating that the dependence on China is not high.There is still a lot of room for development of squid trade cooperation between China and these economies.(6)Except for some countries(regions),the HM indexes of China’s main tuna export markets are all low and generally showing a downward trend.Among them,Thailand is the largest export market of China’s tuna,but the average proportion of tuna originating from China in its total imports Only 6.9%.There is still great potential for trade cooperation between China and major tuna importing countries(regions).Clarify the pattern and structural characteristics of the global squid and tuna trade network,ascertain China’s position and influence in the trade network,and calculate the dependence of China’s squid and tuna products on the target export market,which will help further optimize China’s Import and export trade structure of pelagic fishery aquatic products. |
