Far away or close, marine fisheries spatial coagglomeration and fisheries' economic benefits in coastal cities of China—Based on machine learning algorithm and fsQCA method

As the traditional cornerstone of the ocean's primary industries, the rationality of the spatial layout of marine fisheries holds immense significance for the construction of a modern marine industry system and the advancement of the fisheries' economic benefits. Based on this, the paper focuses on marine fisheries, with marine engineering equipment manufacturing and marine shipbuilding serving as auxiliary sectors. By leveraging an enhanced Sinkhorn algorithm to optimize the Wasserstein distance, it calculates coagglomeration indices through hypothesis testing and Monte Carlo simulations. FsQCA is then employed to assess whether coagglomeration enhances fisheries' economic benefits. Key findings include: (1) Marine fisheries exhibit lower coagglomeration with marine engineering equipment manufacturing and marine shipbuilding than between the latter two due to differing development models and needs. (2) Urban coagglomeration indices vary by region, influenced by policies, resources, and competition, with northern cities having lower indices in 2015 but higher in 2022 compared to the south. (3) Coagglomeration is not pivotal for high fisheries' economic benefits; instead, non-coagglomeration emerged as a key factor in 2022. Therefore, this study puts forward the following suggestions: Optimize the allocation of resources, promote regional coordinated development; Strengthen policy support to alleviate the current situation of industry competition; Optimize the spatial layout and promote high-quality coagglomeration of industry. The study aims to provide decision-making support for optimizing marine fisheries layout, promoting high-quality fisheries' economic development, and building a modern marine industry system.