Enhancing legal collaborative governance for cross-border marine pollution in the Guangdong-Hong Kong-Macau Greater Bay Area: aligning rules, transforming mechanisms, and coordinating institutions

Within the framework of “One Country, Two Systems and Three Legal Jurisdictions,” managing cross-regional marine pollution in the Guangdong-Hong Kong-Macau Greater Bay Area encounters significant legal obstacles, including inconsistent regulations, differing standards, and unclear liability determination. Current models of administrative agreements and soft law collaboration lack stability and universal binding force, hindering effective responses to the challenges posed by the transboundary nature of marine pollution. This study utilizes methodologies from legal hermeneutics, comparative law, and case analysis methodologies, focusing on two illustrative cases—the Yachong River in Zhuhai-Macau and Dapeng Bay in Shenzhen-Hong Kong. Through this analysis, we systematically explore key issues within the legal frameworks, governance mechanisms, liability assignment, and remediation measures across these three regions. The findings reveal that while existing collaborative mechanisms have enhanced standard alignment, governance efficiency, and information sharing, significant systemic issues remain in cost-sharing, stabilization of expectations, and clarification of liability. The study contributes by: comparing the effectiveness and limitations of administrative authorization versus soft law cooperation models; advancing the discourse on cross-border pollution governance from policy coordination towards normative legal analysis; establishing a rule-based collaborative framework that includes “regulatory alignment, mechanism transformation, and institutional synergy”; promoting legislative adaptation for interregional administrative agreements; optimizing Hong Kong and Macau’s dual licensing system for yacht operations; developing supporting mechanisms with fiscal and technical safeguards and dynamic evaluation systems; and proposing a governance pathway that blends theoretical rigor with practical applicability for managing transboundary marine pollution in the Greater Bay Area.