Research progresses on estuarine fish ecological corridors

As an important part of the land-sea linkage ecological corridor, the estuarine fish ecological corridors play an irreplaceable role in maintaining biodiversity, safeguarding fishery resources and promoting ecosystem health. They also provide essential passages for fish to migrate, reproduce, feed, and survive, and are crucial for preserving the integrity and functionality of the “three fields and one corridor” (spawning grounds, nursery grounds, foraging grounds, and migration corridors) in estuarine aquatic ecosystems. However, research on estuarine fish ecological corridors faces challenges such as the difficulty in observing and tracking target species, the complexity of estuarine dimensions, and the high dynamics of habitat factors. Therefore, It is necessary to have a deeper understanding and study of the migratory behavior of estuarine fish and the main habitat types of ecological corridors. It is also necessary to adopt comprehensive, dynamic and adaptive methods for ecological corridor identification, assessment, protection, restoration and planning to ensure the long-term maintenance of its connectivity and ecological functions. In this paper, we summarize the diverse migration behaviors of estuarine fish and the complex habitat types in the ecological corridors and discuss technological advancements in identifying potential migration routes and key habitats in the life history cycle of estuarine fish. We also summarize assessment methods for estuarine fish ecological corridors both from the aspects of functional benefits and economic costs. Based on reviewing the recent progress in conservation measures and engineering restoration techniques for these corridors we propose a perspective on more effective planning and construction of estuarine fish ecological corridors by combining structural and functional connectivity. Looking forward, this article highlights the importance of multi-scale planning, ecological network integration, the adoption of novel habitat restoration technologies and the integration of ecosystem service functions. It also emphasizes the necessity of interdisciplinary cooperation, public participation and policy support to achieve long-term protection of estuarine fish ecological corridors and sustainable development of ecosystems.