Abstract:As a strategically emerging industry, the marine economy has become a focal point in the competition for national comprehensive strength. Systematic research on the spatiotemporal differentiation characteristics of China's marine "dual-chain" integration and its influencing factors holds significant theoretical value for formulating differentiated regional strategies, optimizing industrial layouts, guiding capital and technology flows, and enhancing the overall competitiveness of the marine economy. Apply the stickiness theory to gain a deep understanding of the connotations of the marine industry chain, the innovation chain, and their integration mechanisms, and establish a comprehensive evaluation index system accordingly. Employing an enhanced horizontal and vertical opening grade method alongside a stochastic frontier function model, this study examines the evolution characteristics and pathways of the spatial-temporal patterns of the marine "double chain" fusion across 11 coastal provinces in China from 2010 to 2020. The results indicate that the comprehensive index of the marine industry chain and the marine innovation chain across 11 coastal provinces exhibits a fluctuating upward trend. The overall level of the marine industry chain is higher than that of the marine innovation chain, with significant spatial differences observed. The fusion effect of the marine industry chain and the innovation chain follows an inverted "U" curve, initially rising before declining. The degree of fusion has significantly increased throughout the marine industry chain-driven innovation chain. Its index surpasses that of the marine innovation chain-driven industry chain, establishing the marine industry chain-driven innovation chain as a "double chain." In order to further accelerate the integration process of the "double chain" of the ocean, the agglomeration of the marine industry should be used to promote the strengthening of the marine industry chain, supplement the chain and extend the chain, and create a modern marine industry system with regional characteristics.