Our oceans are in declining health. The Global Ocean Commission, a group including former heads of State, private sector leaders, and scientific and economic advisors, has identified five main drivers causing this decline: rising demand for resources; technological advances; decline of fish stocks; climate change, biodiversity and habitat loss, and weak high seas governance. Thirty-six percent of the world’s oceans lay within the sovereign territory and governance of coastal nation States. As physical boundaries and barriers do not exist between marine zones governed under various political regimes, what happens in one area has varying degrees of effect or ramifications in others. The International Law Commission (ILC) comments in its Articles on Prevention of Transboundary Harm (APTH): The ecological unity of the planet does not correspond to political boundaries. In carrying out lawful activities within their own territories, States have impacts on each other. These mutual impacts, so long as they have not reached the level of “significant”, are considered tolerable. Our knowledge of the extent and pervasiveness of detrimental effects caused by near-coast harm is less than complete. Therefore, protection of the global marine environment depends upon existence of strong, ecosystem-based laws, agreements, principles, and norms that focus on acts that protect, conserve, and sustainably use marine resources. However, without political will and legal ability to enforce those expectations, their directives and policies become little more than volumes of written good ideas and intentions. When transboundary harm is not demonstrable in the traditionally-defined material sense (sometimes even when it is), or when a negotiated agreement does not exist between States relative to marine conservation and/or protection, a gaping void exists for legal protection of the world’s oceans. This is the case within States’ sovereign waters (internal waters and territorial seas) and in waters where they enjoy sovereign rights (exclusive economic zones and on continental shelves). Even where a legal obligation does exist to protect and preserve the seas, as in the United Nations Convention on the Law of the Sea (UNCLOS), it is no secret that States are reluctant to invoke the jurisdiction of international tribunals to hold fellow States accountable for breaches of their international obligations on marine conservation. The glass house principle dictates State practice in this area, or the lack thereof, as evidenced by the dearth of judicial cases on point. For marine areas beyond the jurisdiction of States (the high seas), customary international law (CIL) provides an obligation to prevent harm; however, an effective enforcement regime is the missing link there. This thesis focuses on States’ failure to prevent harm to the marine waters under their sovereign jurisdiction. It searches for both an international obligation to prevent that harm, as well as a mechanism to invoke State responsibility when breach occurs
