我国主要海港外来船舶引起的生物入侵风险分析

外来生物入侵是导致原生物种衰竭、物种多样性减少和遗传多样性丧失的重要原因。其中,有不少外来物种主要通过船只压舱水和随船木制包装箱携带这两种方式入侵新的环境。为了明确抵达我国的外来生物与海运船舶进港次数是否有关联,本文采用了Stata 15软件,选取126个与我国有贸易往来的国家,以2007年-2017年到达我国各港口并被截获出有害生物的船舶进港次数为研究对象,先证明了截获有害生物的船舶进港次数与我国的进口贸易量呈线性正相关,再以贸易引力模型为基本模型,将船舶所属的贸易国与我国每年的人口数量、国民生产总值(GDP)、地理距离、当年的汇率、是否有共同语言、是否相邻、是否是沿海国家等因素作为变量因子,建立模型并进行相关统计分析,阐明了两国间的“汇率”因素,在一定程度上能够十分显著地负向影响由海运产生的生物入侵发生频次和入侵的风险。其结果可为今后由海运产生的生物入侵预测和管理提供参考依据。

Risk analysis of biological invasion caused by foreign ships in major seaports in China

Invasion of alien species leads to failure of original species, the decrease of species diversity and the loss of genetic diversity. Many alien species invade the new enviroment mainly by ballast water and wooden packing boxes. In this study, we aimed to elucidate the factors that affect the movement of ships and the related entry of alien species into China. Stata 15 software was adopted and 126 countries that have trade relations with China were selected as research objects. We collected data of ship movements that had arrived at major ports in China and the intercepted harmful organisms from 2007 to 2017. It was proved that there was a linear positive correlation between the number of ships with intercepted pest and the import trade volume of China. With the trade gravity model as a prototype, using the annual population, total GDP, geographic distance, exchange rate of the year, availability of a common language, adjacency to China and being a coastal country or not as variable factors, a model was established, relevant statistical analysis was performed to clarify the relationship between the number of ship movements and the frequency of biological invasions, and a feasibility analysis was conducted on the results obtained. The results confirmed that the exchange rate had a significant negative effect on trade volume, reducing the number of ships crossing the border. Our findings provided a reference for future practical implications and research on prediction and management of marine biological invasion.