National restoration initiatives promote China’s marine ecosystem recovery

Rapid coastal development and climate change drive global coastal ecosystem degradation, prompting widespread cross-regional and multi-ecosystem marine restoration initiatives. However, the effectiveness of such initiatives remains difficult to assess nationally or globally due to the lack of scalable indicators and accessible data. Here, we present a marine ecological restoration effectiveness index as a framework for cross-regional, multi-ecosystem assessment, emphasizing data accessibility and multidimensional evaluation of restoration stability, ecological benefits, and economic benefits. Applying the index to 81 projects within 2016-2022 China’s Marine Eco-environmental Restoration Programme reveals high restoration stability, alongside significant gains in median natural coastline retention (38.62% to 79.44%), median fractional vegetation cover (36.58% to 55.29%), total carbon accumulation rate (37690.30 to 73438.87 Mg C year −1 ), and total ecosystem service value (5.73×10 9 to 8.12×10 9 Int$ year −1 ). Overall, this national application establishes a transferable tool and a state-led benchmark for assessing cross-regional, multi-ecosystem marine restoration efforts worldwide.