Abstract: Typical marine ecosystems are ecosystems composed of unique habitats and organisms, such as coral reefs, mangroves and seagrass beds; these ecosystems are distributed in tropical and subtropical marine areas worldwide. It is characterized by high material cycling efficiency, unique ecological functions, rich biodiversity and extremely high productivity and has always been a key area of marine scientific research and resource utilization. Under the multiple pressures of human activities and global changes, its degradation trend has become increasingly prominent. How to restore the function of these typical ecosystems and maintain their sustainable development for the benefit of mankind has attracted increased amounts of attention from the academic community and the international community. In this paper, the distribution patterns, degradation trends and influencing factors of such typical marine ecosystems in the world are described, and the distribution patterns and biodiversity characteristics of coral reef, mangrove and seagrass bed ecosystems in China are analyzed. Focusing on coral reef ecosystems, this paper discusses the causes of degradation in the ecosystems and relevant action measures for restoration and protection in China. According to the global action plan for biodiversity conservation and the actual situation of China, countermeasures and suggestions for the restoration, reconstruction and protection of the typical marine ecosystems were proposed: 1) Establishment of a research center for typical ecosystems in the South China Sea, an intelligent monitoring system and database, and an expert think tank; 2) Establishing a demonstration zone for the restoration and protection of the typical marine ecosystems, and organizing experts from multiple disciplines to jointly carry out work on research-experimentation-demonstration-promotion; and 3) Improving policies and regulations, strengthening law enforcement and management, increasing efforts in science popularization and education, raising public awareness of environmental protection, and promoting conscious social actions. By doing this, this study aims to provide a reference for strengthening the conservation and management of typical marine ecosystems and biodiversity, maintaining their sustainable development and implementing international 30×30 goals.

Key words: typical ecosystem, distribution pattern, causes of degradation, restoration and reconstruction, conservation technology, coral reef, mangrove, seagrass bed