5.2 The Continental Shelf and the High Seas: The
Superjacent Waters of the Continental Shelf Beyond
200 nm
One of the concerns most commonly shared by international lawyers regards the
possible threats posed by the delineation and management of the outer continental
shelf to the freedoms of other states on the high seas. It is uncontroversial that coastal
states enjoy sovereign rights over natural resources within 200 nm, be it in the air and
water column, seabed, or subsoil. In other words, where the continental shelf
coincides with the EEZ, states have rights over energy resources of the air column
(wind energy), fisheries, sedentary species and minerals (on the seafloor), hydrocarbons in the subsoil, among others. Yet, the same is not true to the area beyond
200 nm, where coastal states enjoy solely sovereign rights over the resources of the
shelf and subsoil,
17 leaving the superjacent waters and airspace under the regime of
the high seas and its respective freedoms to fish, navigate, conduct marine scientific
research, lay cables and pipelines, and to overflight.
18
In fact, UNCLOS Articles 86 ff. on the high seas provide a definition of the high
seas, as well as the principles and mechanisms governing the interaction with the
continental shelf regime, in order to prevent mutual violations or encroachments into
one another. Upfront, the Convention provides a negative definition of the high seas,
taken as those areas not included in the EEZ, territorial sea and internal waters of
coastal states. Then, Art. 87 UNCLOS crystalizes the famous freedom of the seas’
principle, while balancing it with the duty of flag states to have due regard respect the
interests and rights of other states in the high seas. On the one hand, it enunciates the
freedoms reigning on and in the high seas, i.e. of navigation, overflight, fishing, to
lay submarine cables and pipelines, to construct artificial islands and installations not
prohibited by international law, and to conduct scientific research. On the other, it
reinforces one of the most relevant provisions concerning the high seas, the obligation to have due regard to the interests of other states and to the provisions governing
the Area.
19 The core idea embedded in those provisions alludes to the mare liberum
principle, as famously defended by Grotius.
Since the creation of the continental shelf, however, geographical and functional
limitation of the principle of freedom of the seas followed suit. The high seas have
shifted from an area where freedoms may be exercised in an absolute manner to a
“managed common area”.
20 In fact, international developments have pushed for the
reappraisal of the traditional meaning of “freedoms” of the high seas, in order to
condition such freedoms to the respect of other states’ rights. An example, among
17 Art. 78, paragraph 1, UNCLOS.
18 A non-exhaustive list of freedoms of the high seas is to be found in Art. 87, UNCLOS.
19 Art. 87, paragraph 2, UNCLOS, on the obligation to exercise freedoms of the high seas with due
regard to the interests of other states and the rights applicable to activities in the Area.
20 This expression is used by Rothwell and Stephens (2016) chap. 7.
114
5 Jurisdictional Intersections Between the Continental Shelf and Other Maritime. . .
Superjacent Waters of the Continental Shelf Beyond
200 nm
One of the concerns most commonly shared by international lawyers regards the
possible threats posed by the delineation and management of the outer continental
shelf to the freedoms of other states on the high seas. It is uncontroversial that coastal
states enjoy sovereign rights over natural resources within 200 nm, be it in the air and
water column, seabed, or subsoil. In other words, where the continental shelf
coincides with the EEZ, states have rights over energy resources of the air column
(wind energy), fisheries, sedentary species and minerals (on the seafloor), hydrocarbons in the subsoil, among others. Yet, the same is not true to the area beyond
200 nm, where coastal states enjoy solely sovereign rights over the resources of the
shelf and subsoil,
17 leaving the superjacent waters and airspace under the regime of
the high seas and its respective freedoms to fish, navigate, conduct marine scientific
research, lay cables and pipelines, and to overflight.
18
In fact, UNCLOS Articles 86 ff. on the high seas provide a definition of the high
seas, as well as the principles and mechanisms governing the interaction with the
continental shelf regime, in order to prevent mutual violations or encroachments into
one another. Upfront, the Convention provides a negative definition of the high seas,
taken as those areas not included in the EEZ, territorial sea and internal waters of
coastal states. Then, Art. 87 UNCLOS crystalizes the famous freedom of the seas’
principle, while balancing it with the duty of flag states to have due regard respect the
interests and rights of other states in the high seas. On the one hand, it enunciates the
freedoms reigning on and in the high seas, i.e. of navigation, overflight, fishing, to
lay submarine cables and pipelines, to construct artificial islands and installations not
prohibited by international law, and to conduct scientific research. On the other, it
reinforces one of the most relevant provisions concerning the high seas, the obligation to have due regard to the interests of other states and to the provisions governing
the Area.
19 The core idea embedded in those provisions alludes to the mare liberum
principle, as famously defended by Grotius.
Since the creation of the continental shelf, however, geographical and functional
limitation of the principle of freedom of the seas followed suit. The high seas have
shifted from an area where freedoms may be exercised in an absolute manner to a
“managed common area”.
20 In fact, international developments have pushed for the
reappraisal of the traditional meaning of “freedoms” of the high seas, in order to
condition such freedoms to the respect of other states’ rights. An example, among
17 Art. 78, paragraph 1, UNCLOS.
18 A non-exhaustive list of freedoms of the high seas is to be found in Art. 87, UNCLOS.
19 Art. 87, paragraph 2, UNCLOS, on the obligation to exercise freedoms of the high seas with due
regard to the interests of other states and the rights applicable to activities in the Area.
20 This expression is used by Rothwell and Stephens (2016) chap. 7.
114
5 Jurisdictional Intersections Between the Continental Shelf and Other Maritime. . .