New patterns of global tuna fishing vessel dynamics in the post-pandemic era

The COVID-19 pandemic has led to a significant reduction in global maritime activities. As an important component of global marine fishing, the tuna fishery has been strongly affected by the pandemic. Despite the evident impacts, the full extent and lasting effects of the pandemic on global tuna fishing operations remain underexplored. In this study, we analyzed the spatiotemporal dynamics of global tuna fishing vessels before, during and after the pandemic based on approximately 36 million high-resolution AIS data by using artificial intelligence algorithms. Results indicated that the number, per capita traveling hours and distance of tuna fishing vessels were reduced during the pandemic, and recovered to higher levels afterward. The impacts of the pandemic on tuna fishing activities varied across different fleets and oceans; longline fleets experienced more severe disruptions than purse seine fleets, with the Indian Ocean showing the greatest impact, whereas the Pacific and Atlantic Oceans recovered the fastest and earliest, respectively. Moreover, the spatial distributions were significantly different before and after the pandemic, indicating emerging new patterns in global tuna fishing activity. In the post-pandemic era, the hotspots have not changed but become more prominent; the overall activity range has expanded, and the spatial center of gravity has shifted southeastward. Additionally, the spatiotemporal dynamics of catch and fishing effort revealed adaptive responses among fleets. Thus, longline fleets expanded their operational footprint and intensified fishing efforts to compensate for reduced efficiency, whereas purse seine fleets optimized their spatial aggregation through strategic adjustments. Our study highlighted systematic shifts in global tuna fishing activities following the pandemic, indicating the importance to consider pandemic impacts when assessing and managing tuna fisheries.