The termsinternational waters ortransboundary waters apply where any of the following types of bodies of water (or theirdrainage basins) transcend international boundaries: oceans,large marine ecosystems, enclosed or semi-enclosed regional seas andestuaries, rivers, lakes,groundwater systems (aquifers), andwetlands.[1]
"International waters" is not a defined term in international law. It is an informal term, which sometimes refers to waters beyond the "territorial sea" of any country.[2] In other words, "international waters" is sometimes used as an informal synonym for the more formal term "high seas", which under the doctrine ofmare liberum (Latin for "freedom of the seas"), do not belong to any state's jurisdiction. As such, states have the right to fishing, navigation, overflight, laying cables and pipelines, as well as scientific research.
TheConvention on the High Seas, signed in 1958, which has 63 signatories, defined "high seas" to mean "all parts of the sea that are not included in theterritorial sea or in theinternal waters of a State" and where "no State may validly purport tosubject any part of them to its sovereignty."[3] The Convention on the High Seas was used as a foundation for theUnited Nations Convention on the Law of the Sea (UNCLOS), signed in 1982, which recognizedexclusive economic zones extending 200 nautical miles (230 mi; 370 km) from thebaseline, where coastal states have sovereign rights to the water column and sea floor as well as the natural resources found there.[4]
The high seas make up 50% of the surface area of the planet and cover over two-thirds of the ocean.[5]
UNCLOS also contains, in its part XII, special provisions for the protection of the marine environment, which, in certain cases, allowport States to exercise extraterritorial jurisdiction over foreign ships on the high seas if they violate international environmental rules (adopted by theIMO), such as theMARPOL Convention.[8]
When an underground water crosses international boundaries, the term transboundary aquifer applies. The term transboundariness can then be applied, which is a concept, measure and approach first introduced in 2017[9] when talking about underground transboundary waters.
The importance of this approach is that the physical properties of aquifers become merely additional variables within the broad spectrum of the transboundary nature of an aquifer: social (population); economic (groundwater efficiency); political (cross-border); existing research or data; water quality and quantity; other issues that drive the agenda (security, trade, immigration, etc.).
The criteria proposed through this approach attempt to encompass and quantify all potential variables that play a role in defining the transboundary nature and multidimensional boundaries of an underground transboundary water.
Several international treaties have establishedfreedom of navigation on semi-enclosed seas.
TheCopenhagen Convention of 1857 opened access to theBaltic Sea by abolishing theSound Dues and making theDanish straits an international waterway free to all commercial shipping. Separately, the Royal Ordinance of 1999 regulates the access of foreign warships to Danish waters.[10][11][12]
International Freshwater Treaties Database (freshwater only).[14]
The Yearbook of International Cooperation on Environment and Development profiles agreements regarding the Marine Environment, Marine Living Resources and Freshwater Resources.[15]
Addressing regional freshwater issues is the 1992Helsinki Convention on the Protection and Use of Transboundary Watercourses and International Lakes (UNECE/Helsinki Water Convention)[26]
^abThe term "international waters" technically includes the "Contiguous Zone" and "Exclusive Economic Zone," although the chart only uses this term where no national jurisdiction or special rights apply.
