Vessel noise, ecological costs, and sustainable pathways for China's blue economy

Rapid expansion of maritime transport, offshore engineering, and coastal industrialization has positioned China's blue economy as a central pillar of national economic growth, yet it has simultaneously intensified underwater vessel noise as a pervasive and largely unpriced environmental externality. This study provides an integrated assessment of vessel-generated underwater noise, its ecological costs, and sustainable mitigation pathways within the context of China's blue economy development. Drawing on acoustic propagation theory, vessel traffic density analysis, and ecosystem-based impact assessment, the study synthesizes how chronic and acute noise exposures affect marine mammals, fish, and benthic communities through behavioral disruption, habitat displacement, impaired communication, and reduced reproductive success. Ecological costs are conceptualized using an extended ecosystem services framework that links noise-induced biological impacts to losses in fisheries productivity, biodiversity resilience, and coastal socio-economic welfare. Building on this analysis, the paper evaluates a portfolio of sustainable pathways, including quiet ship design, speed optimization, spatial planning of shipping lanes, seasonal traffic management, and market-based instruments such as green port incentives and differentiated harbor fees. The findings highlight that integrating underwater noise governance into marine spatial planning and blue finance mechanisms can significantly reduce ecological risks while maintaining the economic competitiveness of China's maritime sectors. By framing vessel noise as a measurable environmental cost rather than an unavoidable byproduct of growth, this study contributes a policy-relevant pathway for aligning marine ecological protection with the long-term sustainability objectives of China's blue economy.