Assessing long-term restoration effectiveness in urban coastal ecosystems: Insights from Wuyuan Bay, China

Urban coastal restoration is essential for maintaining ecosystem health while meeting societal needs. However, evaluation of its multidimensional outcomes remains limited. This study assessed the long-term restoration effectiveness of Wuyuan Bay, one of China’s earliest urban coastal restoration initiatives, using a multidimensional framework tailored to its restoration objectives. This framework included ecological environmental quality, ecosystem process, and cultural ecosystem service. We quantified restoration effectiveness from 2000 to 2020, examined synergies among the three modules, and assessed spatial spillover effects. Recovery across indicators and modules was asynchronous. Seven of the eight indicators exhibited varying degrees of improvement. Nutrient‐related indicators and cultural ecosystem services improved rapidly, with an increase of 0.41–0.64. Meanwhile, dissolved oxygen and benthic species richness declined initially and recovered slowly. At the module level, the cultural ecosystem service exhibited the greatest improvement, followed by ecological environmental quality, and ecosystem process. The phased analysis of integrated effectiveness showed a pronounced lag effect. The integrated assessment score increased by 64.40% over the 20-year period with over 80% of this improvement occurred in the decade following restoration rather than immediately after restoration, which highlighted the necessity of long-term monitoring and assessment of restoration projects. Synergy analysis indicated the strongest coupling between ecological environmental quality and ecosystem process, with other module relationships evolving. Restoration-associated positive changes showed a spatial distance-decay pattern extending to approximately one km from the intervention sites. Overall, our study showed that different dimensions of coastal ecosystem restoration recovered at varying rates and exhibited dynamic interconnections, providing scientific evidence to support long-term assessment and adaptive management of urban coastal restoration.