I think system dynamics methodology will be better for modeling and evaluating scenarios, strategies, and policies in complex situations such as marine environment
Strategic policy and planning in and around each country and all together among the countries may be the right solution to control Marine Environment. Further there should be universal dos and Donts for survival of the marine life. An umbrella with genuine rules will help our Universe to sustain especially related to marine life
Elinor Ostrom's work on common pool resources involving local participants and perhaps using games to articulate and, possibly, discover the rules needed to make the system sustainable.