<p>Owing to the increasingly critical ecological security challenges of marine ranching, the government and marine ranching enterprises must collaborate effectively to address this issue. This study employs differential game theory to explore collaborative strategies for maintaining marine ranching ecological security. It considers the influence of marine environmental disaster factors and the effect of enterprises’ ecological security investment through advertising. Three collaborative modes are analyzed: No-cost-sharing, cost-sharing, and full collaborative cooperation. Results show that the increased intensity of marine environmental disasters reduces the optimal ecological security effort by the government and enterprises. Government subsidy initiatives can achieve Pareto improvements in total returns for the government, enterprises, and the system as a whole. In the fully cooperative mode, the collective income of the government, enterprises, and system achieves its highest value, reaching Pareto optimality. Introducing an income distribution mechanism can effectively sustain cooperative engagement between the government and enterprises.</p>