This chapter begins the presentation of substantive regulation in international environmental law by focusing on the rules governing oceans, seas and freshwater.
These objects (the marine environment and freshwater), although separate from a regulatory standpoint, are closely related in that the main cause of marine pollution originates from land-based sources and is partly carried by rivers. In addition, both the law of the sea and that of watercourses, particularly regarding navigation, can be traced back very far in the history of international law, even though the regulation of environmental issues within those areas is relatively recent. Another common feature is the customary character of some of the rules governing these two objects. More generally, from an environmental perspective, these different regulatory regimes are all concerned with the ‘hydrosphere’ or the waterbodies of the planet. For these reasons, it is useful to examine oceans, seas and freshwater in the same chapter.
The first substantive section covers the regulation of the marine environment (4.2). Broadly speaking, the law of the sea protects the marine environment in two principal ways. On the one hand, it distributes the jurisdiction over vast marine areas (and therefore the primary responsibility for their protection) among different States. On the other hand, it introduces a set of duties to protect the marine environment, which are, in turn, specified by other instruments. These instruments are either concerned with specific issues (e.g. a source of marine pollution) or a particular marine area or object (e.g. the Regional Seas Conventions or the on-going negotiation on ‘biodiversity beyond national jurisdiction’ discussed in Chapter 6). Following this structure, we analyse, first, the distribution of jurisdiction under the United Nations Convention on the Law of the Sea (UNCLOS) (4.2.1) and then turn to the duties of States in the protection of the marine environment, both in general (4.2.2) and in connection with specific sources of pollution (4.2.3) or geographical areas (4.2.4).
The following section of this chapter examines the international regulation of freshwater (4.3). After presenting the overall structure of this body of law (4.3.1), we discuss the law governing international watercourses (4.3.2), groundwater (4.3.3) and freshwater locked in the form of ice (4.3.4). The question of access to water as a human right and its expression in environmental treaties, such as the Protocol on Water and Health, is left for Chapter 10.