A new exploration of the “Three Lines One Permit” policy: Marine zoning strategy based on land-sea coordination

Marine zoning has been widely used to effectively manage the relationship between economic development and marine environmental protection. However, it remains challenging for marine environmental management to integrate land–sea coordination and effectively implement spatially differentiated control under the existing technical framework. This study aims to explore the development and practice of marine zoning in China. This paper discusses the technical framework and key technical methods of marine zoning under the "Three Lines One Permit" policy. The main effectiveness and shortcomings of this strategy are described in the Hainan Free Trade Port case. The Hainan Free Trade Port has 276 marine control units, of which 36% are priority protection units and 6% are priority control units. These marine control units help improve the orderly development and utilization of land and sea resources and promote construction of an ecological security pattern of land–sea coordination. The marine zoning under the "Three Lines One Permit" policy complements and enhances the existing marine zoning system and promotes the potential for integrated coastal zone management. Suggestions are proposed to promote a more efficient marine zoning strategy towards land–sea integration and science-management integration.