Structural evolution and formation mechanism of the innovation cooperation network in China’s fishery industry

Existing research on urban innovation networks has predominantly focused on high-tech and strategic emerging industries, leaving innovation networks in foundational industries—particularly fisheries—largely unexamined in terms of their structural dynamics and driving forces. This study aims to systematically examine the spatiotemporal evolution and mechanisms of formation of China’s fishery industry innovation cooperation network across three developmental stages. To this end, an inter-city innovation cooperation network is constructed based on cooperative patent data (2007–2024), and social network analysis, GIS spatial analysis, and an exponential random graph model (ERGM) are employed to analyze the network’s structural characteristics, spatiotemporal evolutionary patterns, and formation mechanisms. The results show that: (1) the network evolved from a single-core structure centered on the Yangtze River Delta to a multi-core configuration led by Beijing and Guangzhou, while network density fluctuated downward and the core-periphery structure continuously consolidated; (2) social proximity exerts the strongest and persistently increasing positive effect on network formation, followed by cognitive and institutional proximity, both exerting strong positive effects over time, while geographical proximity’s inhibiting effect gradually weakens; (3) the number of higher education institutions is a consistently positive driver, the promoting effect of primary industry added value emerges with a time lag, and cities preferentially attach to higher administrative-level cities; (4) weighted ties exhibit a predominantly significant negative effect reflecting high coordination costs, while star structure shows a consistently positive effect indicating preferential attachment dynamics that accelerate core-periphery differentiation. These findings reveal distinct stage heterogeneity and sectoral specificity in foundational industries, contributing new empirical evidence to innovation network theory and offering policy guidance for advancing China’s maritime strategy.