Research On The Relationship Between Marine Ship Movements And Invasive Species In Major Ports Of China

Invasion of alien organisms has gradually become a focus of discussion in people’s daily lives,and is one of the important reasons leading to the extinction of native species,the reduction of species diversity,and the loss of genetic diversity.Studies have found that many species enter a new environment mainly through the ballast water of the ship and the wooden packing box carried on the ship(SWPM),which leads to biological invasion.It is not uncommon for alien species to enter a new environment through the ocean.After entering the millennium,China’s economy has embarked on a track of rapid development.In order to strengthen cooperation and ties with other countries and regions,China has put forward the concept of "21st Century Maritime Silk Road".Following this,trade exchanges have become more frequent,and the number of biological invasions in China has gradually increased each year.However,there are very few studies on marine alien species.Under the above background,it is urgent to study the influence of marine ship movements worldwide on the biological invasion of China’s ports.By analyzing the relationship between the invading/arriving alien organisms in China’s ports and the laws of marine ship movements,we can find the ports in China’s coastal provinces.The characteristic factors of the ports most prone to biological invasion,provide early warning for the future quarantine work of China’s ports.Based on this,this research first analyzes China’s entry logs based on the statistics of the State General Administration of Customs on the intercepted pests at Chinese ports,and compares the log epidemic interception status of each port.On this basis,the comprehensive evaluation model is used to evaluate the possibility of biological invasion of major ports in China’s provinces,and find the factors that have the greatest impact on the occurrence of port pests.Then,using the Stata 15 software tool,the number of ships that arrived at China’s ports and intercepted harmful organisms from 2007 to 2017 was used as the research object,and 126 countries in the world were divided into 6 continents based on their geographic locations.Taking the trade gravity model as the prototype,the annual "population","GDP","geographical distance","exchange rate" of the year,"whether there is a common language","are adjacent to each other" of the trading country to which the ship belongs to China "and "is it a coastal country" and other factors as variable factors,establish a mathematical model and carry out relevant statistical analysis.The relationship between the number of ship movements and the frequency of marine invasions is clarified,and the results are analyzed for feasibility.The main conclusions are as follows:(1)The analysis of the epidemic situation of China’s imported logs showed that from 2007 to 2017,the number of pests intercepted by China’s major ports had increased rapidly and then the total amount had gradually stabilized in recent years.Among the wood packaging materials from six continents(except Antarctica),the largest amount of pests intercepted by Chinese ports is in Africa,and most of them are dry-boring pests.In 2017 alone,the number of pests intercepted in Africa was about 8 times that of the least in South America.(2)The results of the assessment of the possibility of biological invasion in major ports in 11 provinces in China showed that infrastructure conditions had a greater impact on biological invasion in ports.After further refining the indicators,the port temperature,port ship access and investment support would also have a greater impact.(3)From the perspective of trade source,the "total GDP" and "population" of each continent,the "exchange rate" of each country,"whether the same language is used","is the land bordered","is it a coastal city",etc.All factors have a great influence on the "number of ship movements intercepting harmful organisms" in trade.Among them,with a confidence level of 1%,China’s economic scale,"total population" and "number of ship movements intercepted by pests" are positively correlated,with coefficients of 0.630 and 0.618,respectively.With a confidence of 1%,the "distance" from each continent to China is negatively correlated with the "number of intercepted ships",with a coefficient of-0.359.