Australian Year Book of International Law
The exclusive economic zone (EEZ) has been asserted by States, in one form or another, for up to half a century. The continental shelf, as a concept in international law, is generally traced back to the Truman Proclamation of 1945. During the 50 years both zones of extended jurisdiction have existed, the relationship between the EEZ and the continental shelf has presented international lawyers with the knotty problem of how these zones of maritime jurisdiction are to be reconciled with each other. The simplest solution to the problem was considered at the Third United Nations Conference on the Law of the Sea (UNCLOS III), where delegates considered whether the regime of the continental shelf would be best served by being subsumed into the EEZ. This solution was rejected, and the continental shelf and EEZ continued to co-exist, now within the framework of the 1982 Law of the Sea Convention, as related but distinct maritime zones. Certainly as much was confirmed by the International Court of Justice (ICJ) in the Libya v Malta Continental Shelf case, indicating the shelf still has a separate identity.
The years since UNCLOS III have seen a number of jurists question the nature of the EEZ in its relationship with the continental shelf, specifically in the area of delimitation. In recent years, as States have sought to use more creative techniques to seek resolution to their boundary disputes, other questions concerning the relationship between the continental shelf and EEZ have been raised. These questions are no longer academic, as there is state practice concerning areas where jurisdiction is shared, exercised cooperatively, or where the boundary of the continental shelf has been separated from that of the EEZ. The Law of the Sea Convention gives little or no guidance as to how such practice can take place, or how jurisdiction is to be exercised where the continental shelf of one State overlaps with the EEZ of another. This examination firstly will seek to consider what issues arise from the separation of EEZ and continental shelf jurisdiction, and then turn to relevant state practice where jurisdiction has been separated.
The logical starting point for any examination of the relationship between the EEZ and the continental shelf must begin with the Law of the Sea Convention. While, as noted above, both maritime zones had some existence in international law before the conclusion of UNCLOS III, which in the case of the continental shelf included a specific convention, the provisions of the Law of the Sea Convention have come to codify the content of international law with respect to offshore jurisdiction. On this basis, it is appropriate to examine briefly the content of both regimes, and to note where conflict may potentially occur.
The continental shelf is dealt with in Part VI of the Law of the Sea Convention. The shelf is defined in Article 76 as being the seabed and subsoil adjacent to the coastal State to a distance of 200 nautical miles, and in limited circumstances beyond that distance. The coastal State’s rights over the continental shelf are spelled out through the remainder of Part VI and include sovereign rights to explore and exploit the natural resources of the continental shelf, rights to construct artificial islands, installations and structures, exclusive rights to authorise drilling, and for the coastal State to permit tunnelling through the subsoil.
The EEZ is dealt with in Part V of the Law of the Sea Convention. Article 56 (in part) defines the EEZ as the area where a coastal State has:
(a) sovereign rights for the purpose of exploring and exploiting, conserving and managing the natural resources, whether living or non-living, of the waters superadjacent to the seabed and of the sea-bed and its subsoil, and with regard to other activities for the economic exploitation and exploration of the zone, such as the production of energy from the water, currents and winds; (b) jurisdiction as provided for in the relevant provisions of this Convention with regard to:
(i) the establishment and use of artificial islands, installations and structures;
(ii) marine scientific research;
(iii ) the protection and preservation of the marine environment.
This is an impressive range of rights and jurisdictional responsibility, covering all aspects of the economic exploitation of the sea and seabed, and the activities necessary to support and protect these activities. Article 57 indicates that the EEZ is to operate beyond the territorial sea, to a distance of 200 nautical miles from the territorial sea baselines. Part V goes on to describe how these rights are to be exercised, and for the most part the limitations do not have relevance for the continental shelf regime. An exception is Article 68 dealing with sedentary species. It provides for an abdication of responsibility over the regulation of these species under the EEZ regime, leaving them regulated pursuant to the continental shelf provisions in Part VI. In doing so, it resolves one area of potential conflict, although, given the overlap extends to a far wider range of subjects, its resolution in this instance is somewhat curious.
What is clear is that both the EEZ and continental shelf regimes overlap in the context of the economic exploitation of the seabed and its subsoil. Both grant coastal States sovereign rights for the exploration and exploitation of the natural resources. The closest the Convention comes to resolving the overlap is in Articles 56(2) and 56(3). The former notes that where rights under Part V are exercised by a coastal State “due regard” will be had to the rights of other States, and that the coastal State will “act in a manner compatible” with the provisions of the Convention. The latter states that rights with respect to the seabed and subsoil shall be exercised in a manner consistent with Part VI.
These provisions are suggestive of some superiority of the shelf regime over that of the EEZ, and that in the event of conflict the rules of the continental shelf ought to prevail. This could be seen to be part of the “harmonisation” of the two regimes described by Attard, to ensure that they are consistent with each other. While this solution, if accepted, neatly resolves conflict in a coastal State’s choice of applicable international law, it does nothing to resolve the difficulty of differing coastal States having jurisdiction over continental shelf and EEZ in the same area. Certainly, it is not open to be argued that the EEZ rights of one State to the seabed are subservient to the rights of the continental shelf coastal State, as Article 56(2) requires only “due regard” be had to such rights. Giving due regard to another State’s rights would seem somewhat less onerous than surrendering rights or admitting that EEZ rights were necessarily inferior. Given the continental shelf grants exclusive rights to the seabed and subsoil, such an interpretation of due regard would necessarily mean extinguishment of EEZ rights over the seabed, which is not the tenor of the provision at all.
Consequently, the Law of the Sea Convention does not squarely face the problem of different coastal States exercising continental shelf rights and EEZ rights over the same area. It would seem that the problem was not foreseen by delegates to UNCLOS III, probably because both regimes were given the same criteria for calculation within 200 miles of the coast, leading to the assumption that the two could not fall to different States if calculated by the same method.
Logically, this direct inconsistency can only be resolved by limiting certain rights under one regime, to permit the exercise of rights with respect to the same subject matter under the other regime. Two propositions necessarily follow from any limitation: first, that it can only be achieved with the agreement of the affected States, and, secondly, that it must involve the limitation of rights pertaining to the EEZ. The first proposition is necessary because it is clear that nothing in the Law of the Sea Convention obliges a coastal State to limit the scope of its EEZ or continental shelf rights where they overlap with another State’s maritime zones, except by agreement, or by voluntary application of dispute resolution procedures. Secondly, given EEZ rights deal with the seabed and the water column, making such rights superior at the expense of shelf rights would leave a shelf coastal State with no rights apart from a right to harvest sedentary species guaranteed under Article 68. Therefore, to get a meaningful division, EEZ rights would need to be restricted to the water column, leaving rights over the seabed and subsoil to be determined solely by the continental shelf regime. In the two existing instances of agreements to separate shelf and EEZ jurisdiction, such a division has been implemented.
The difficulties are not so easily resolved. One area of potential concern is in the context of artificial islands, installations and structures under the Law of the Sea Convention. References to the construction of artificial islands and other man-made features in the Convention are found in the EEZ regime, and applied mutatis mutandis to the continental shelf. Article 60 gives the exclusive right to construct islands and other installations and structures to the coastal State. Further, it continues by providing that a coastal State also retains exclusive jurisdiction over such structures. Clearly, exclusive rights cannot be possessed by two coastal States over the same area over ocean-space or on the same installation, so the rights of both States must be circumscribed, or alternatively the rights of one extinguished. As might be expected, the Convention provides no clue as to how this might be done, but several points can be made. First, the construction of installations such as oil platforms are essential to the viable exploitation and exploration of the continental shelf. Logically, if a shelf State is to retain rights that are of any value, it must retain control over the construction of, and jurisdiction over such features. Second, any feature constructed on the seabed is entitled to the benefit of a safety zone of up to 500 metres, where navigation must respect. The construction of an installation by an EEZ State would therefore interfere with the enjoyment of the safety zone area by a shelf State, with the same consequent loss of enjoyment for the EEZ State where the shelf State constructs an installation. Finally, if EEZ rights are limited to the water column, then it makes it questionable whether the EEZ has any business in regulating the construction or operation of a platform built on the continental shelf for the exploration and/or exploitation of that shelf. The EEZ State could, by means of undue or onerous restrictions, effectively prevent the shelf State from ever undertaking construction, thereby depriving it of the benefit of the seabed under its jurisdiction.
Such an argument does make two assumptions. The first is that all construction on the seabed is intended to further exploration and exploitation of the continental shelf. While the bulk of such activities may be categorised in those terms, there are certain structures which are used for other purposes. Examples could include the construction of artificial reefs and other structures as fish aggregation devices, or the platforms constructed by Britain in the North Sea during the Second World War, used for the purposes of defence. These structures, particularly the former, would seem to be more closely allied to the use of the water column, and therefore would fall into the remaining rights possessed by the EEZ State. The second assumption is that the construction of a platform does not interfere with the enjoyment of the water column for the EEZ State. Clearly, this is not so, as a State with jurisdiction over a seabed platform is entitled to proclaim a safety zone around the feature. This safety zone can only extend to a radius of 500 metres, so the interference is not great, yet it amounts to as substantial an interference as that caused by the physical presence of an artificial structure on a portion of the seabed to the enjoyment of the shelf State, with a similar safety zone around it.
With this in mind, it would seem reasonable that, where seabed and water column are subject to separate jurisdiction, the right of a coastal State to engage in offshore construction should be determined by the use to which the facility will be put. Where seabed mining is intended, the structure would fall under the exclusive jurisdiction of the shelf State, whereas if fish aggregation is intended, then jurisdiction falls to the EEZ State. This raises the question of whether a shelf State ceases to have jurisdiction after a structure is abandoned, and where its only purpose after abandonment would be to act as a de facto fish aggregation device. In practice, this would seem unlikely, as the Law of the Sea Convention does provide for the State responsible for construction to have responsibility for removal and warning of remaining features. A transferral of jurisdiction upon the completion of seabed mining would make the fulfilling of this obligation difficult.
The resolution of direct inconsistency by abdicating EEZ rights over the seabed does not resolve other less direct problems. Coastal States when exercising jurisdiction over the EEZ do not merely have that jurisdiction restricted to resource activities, but can exercise control over other events. The two principal areas outside of resource exploitation where jurisdiction can be exercised are the fields of marine pollution and marine scientific research. There is a significant potential for the exercise of jurisdiction in both of these fields to impact upon the situation of separated continental shelf and EEZ.
Jurisdiction over protection and preservation of the marine environment is dealt with in Article 56, where a coastal State is given control over these matters within its EEZ. The Convention deals with the subject of marine environmental protection more generally in Part XII, where Article 194 vests all States with the power to take such measures, as are consistent with the Convention, to prevent, reduce and control pollution from any source, and to ensure that activities under their jurisdiction are conducted so as to avoid damage to other States.
Where the seabed is subject to a different State’s jurisdiction to the State with responsibility for the water column, it is possible to envisage two distinct situations where the overlap may cause problems. The first is where activities taking place in the water column damage the seabed, or more particularly the living resources of the seabed. Such damage caused by pollution from a vessel falls under Article 211 which provides for coastal States implementing domestic anti-pollution measures in the absence of effective international protection. For a shelf State, it appears that Article 211 would be unavailable as the provision refers to the coastal State’s EEZ rather than its continental shelf. On that basis, action would have to be based on the general duty imposed on States under Article 194 not to permit pollution to spread, and on general rules of international law on liability for pollution that has spread to another jurisdiction. In any case, this situation is unlikely to occur, although it is by no means impossible.
A more likely scenario is the second category of potential problem, namely that seabed activities cause pollution within the water column. Oil drilling operations offshore potentially could cause damage to the sea around an oil platform, in terms of drilling, the risk to pipelines around the platform, in the transfer of oil from a platform to a tanker, and from the presence of the platform, and the pollution it may generate. In such situations it might be argued that both coastal States retain jurisdiction, given the interests of both States would be directly affected: the shelf State, which would have a legitimate interest in the regulation of mining and its consequences; and the water column State, the interest of which in the marine living resources of the polluted area may be detrimentally affected.
A similar problem arises in the context of marine scientific research. Authority for marine scientific research falls under the EEZ regime, which grants the coastal State exclusive power to undertake such research. However Article 246, which is contained in Part XIII of the Convention, directed towards the regulation of marine scientific research, provides that the coastal State has the right to “regulate, authorise and conduct” marine scientific research in their EEZ and continental shelf. While logically this should mean research into the continental shelf and its resources is the appropriate subject of regulation by the State claiming the shelf, the nature and scope of the EEZ is such that all research activities falling within its area are within the province of the coastal State. Accordingly, if the continental shelf and EEZ are separated, and depending on the precise nature of the research, then there may be two coastal States who are capable of purporting to regulate research activities in the same maritime space.
Article 246(5) goes on to provide that a coastal State can withhold its consent to permit research in certain circumstances, including where the research is of direct relevance to the exploration and exploitation of marine resources, living or non-living. This could effectively give either of the two States in an area of jurisdictional separation a power of veto over any research or exploration of the seabed. Similarly, Article 248 provides that coastal States have a right to receive scientific data drawn from the research in its maritime zones. Given that much seismic and related data gleaned in oil exploration research is commercially valuable, and highly prized by corporations, the transmission of such data to two States would be disconcerting to those who collected it.
Even if the jurisdiction over marine scientific research is read down to authority over water column research to the EEZ State, and seabed research to the shelf State, the problems are not entirely resolved. Seabed exploration may require some studying of the adjacent water column. Knowledge of the currents, water temperature, and the marine species in the vicinity of a planned oil platform may all be vital to its operation, and would seem to be within the jurisdictional bailiwick of the water column State, even if its jurisdiction is read down.
One response to this problem is to narrow the definition of marine scientific research to exclude research undertaken in the exploration of the seabed and its subsoil. Exploration by its very nature requires the collection and analysis of scientific data, and this in turn may provide a way of distinguishing it from other marine scientific research. Churchill and Lowe describe this distinguishing of “pure” marine scientific research from “applied” marine scientific research, although they are careful to note these terms are not found in the Law of the Sea Convention. While it is possible to make an argument that exploration of the seabed is not marine scientific research, it is difficult to sustain in view of Article 246(5), which provides a coastal State may withhold its consent to the research if the project “is of direct significance for the exploration and exploitation of natural resources, whether living on non-living”.
It therefore appears where there is the overlap of the EEZ and continental shelf under the respective authority of different coastal States, the Law of the Sea Convention would clearly seem to grant both States jurisdiction.
That does not mean however that the problem has not been considered in international law, having been considered by the International Court of Justice and in practice between States.
Since there is no doubt the continental shelf and EEZ co-exist, the debate has focused on whether the boundary line between neighbouring States must delimit all maritime zones, or whether there can be a multiplicity of lines for the different zones. Judge Oda in the Tunisia v Libya Continental Shelf case asked the parties if they believed there had to be a single line or not. The answers by the two States reflect the two (obvious) positions that can be taken, as well as kernels of the arguments that can be made in support of each position. Libya stated:
Libya considers that, as between States with opposite or adjacent coasts, the delimitation of their respective continental shelf areas and of their economic zones ought not, in the majority of cases, to be different. Nevertheless, there may be factors relevant to fishing, such as established fishing practices, which have no relevance to shelf resources; and, conversely, there may be factors relevant to shelf resources — such as geological features controlling the extent of a natural prolongation — of no relevance to fishing. It therefore follows that the two boundaries need not necessarily coincide.”
Libya clearly supported the notion that the boundaries for the EEZ and continental shelf could diverge. Tunisia, on the other hand, took a different approach:
Given that the coastal State, under Article 56 of the draft convention, possesses, in the Exclusive Economic Zone, sovereign rights for the purpose of exploring and exploiting the natural resources of the sea-bed and its subsoil, it is difficult to conceive how the limits of the Exclusive Economic Zone could differ from those of the continental shelf inside the 200 miles.”
A closer examination of the arguments for and against a single line is warranted.
There are a number of arguments in support of multiple boundary lines. More than one author has noted that the two regimes have different origins, and different bases in international law. The continental shelf represents the prolongation of a coastal State under the sea, and the right to exploit it flows from the littoral State’s possession of the land, and exists ipso jure, without having to be proclaimed. It gives jurisdiction over (primarily) non-living resources. The EEZ is not based on natural prolongation, geology, nor water depth, but on distance. It permits exploitation of the water column as well as the subsoil and seabed. It relates to living resources as well as non-living. The rights to exploit the EEZ are not unfettered as are those of the continental shelf, as rights are given to land-locked or geographically disadvantaged States in the same region. The conclusion made is that, as the regimes are different in their nature, so the relevant factors to produce an equitable delimitation will vary between the regimes. An EEZ boundary will be unaffected by the geomorphology of the seabed, or by the existence of a vast trough between the concerned States. A tribunal might find that a long existing fishing practice is relevant to the EEZ boundary. However, geomorphology will be relevant to a continental shelf boundary, but fishing rights will not. With differing factors of relevance, it follows that there ought to be different boundaries.
McRae has also raised a technical argument that can be made against the use of a single line. He poses the situation where a common boundary is delimited between two States, A and B, and the continental shelf extends beyond 200 nautical miles. Unless the common boundary runs through an equidistance point at 200 nautical miles from both States, there will be a “grey area” where jurisdiction will overlap. An area will exist where State A’s jurisdiction over the continental shelf will extend into an area that is within 200 nautical miles of State B, yet State A will not have jurisdiction over the water column. McRae considers that this will split jurisdiction, creating, in the words of Judge ad hoc Arechaga, “a vertical superimposition of rights”.
Supporters of multiple boundaries have also drawn from the ICJ and State practice. Judge Arechaga in the Tunisia v Libya Continental Shelf case stated that in the vast majority of cases the lines would coincide. Such a statement certainly implies there will be situations, albeit uncommon, when the boundaries will diverge. Similarly, the Chamber in the Gulf of Maine case noted the failure of the parties in the proceedings to consider the possibility of multiple boundaries. The Chamber noted that there was “certainly no rule to the contrary” in respect of their assumption of the single line, but there was no “material impossibility” to multiple boundaries either.
In its most recent consideration of a maritime boundary delimitation, the ICJ appeared to indicate that multiple lines were possible, although apparently unlikely. The parties to the delimitation in the Jan Mayen case were not agreed that the Court should provide them with a single all-purpose line, so the Court chose to examine the jurisprudence for a boundary based on Article 6 of the Continental Shelf Convention as against a boundary based on customary international law. After doing so, the Court concluded that it would not be “surprising” if a delimitation done by either method, of a continental shelf, a fisheries zone or a single boundary, produced the same result. Such a statement can be cited in support of multiple lines because it does not preclude the possibility of the unusual situation where the methods for delimiting the shelf do produce a substantially different result.
Bowett has made the point that the 1982 Convention does not indicate that the boundaries delimiting the continental shelf and the EEZ ought to be combined in a single line. The delegates at UNCLOS III were happy to utilise the same formula for delimitation, and they easily could have specified that a single line should be the boundary within 200 nautical miles.
The primary objection to multiple maritime boundary lines is one based on jurisdiction and sovereignty, and it was eloquently expressed by Judge Oda in the Tunisia v Libya Continental Shelf case:
Is it congruous or conceivable that the same marine/submarine column should be placed under different national jurisdictions for the same purpose of resource exploitation, however different the resources may be, and that the same area of ocean be consequently policed by two different States? One is entitled to enquire whether superimposition of two different boundaries is tolerable as a matter of international ordre public.
If State practice is to be the test of congruity used in answering Judge Oda’s question then the answer appears to be no. Orrego Vicuña cites some 28 agreements between 1976 and 1983 which sought to delimit all maritime areas with a single boundary. Further, Attard notes that all EEZ delimitation agreements concluded up to 1986 adopted a common boundary. There appears to be overwhelming support in State practice for a single unified boundary.
The text of the 1982 Convention can also be utilised in support of a single boundary. The EEZ is not simply a fisheries zone. It gives the littoral State jurisdiction over all living and non-living resources within 200 nautical miles, including the seabed and subsoil. This presents some difficulties if the continental shelf of one State is to be superimposed on the EEZ of another, with regard to jurisdiction over the seabed.
The development of Articles 74 and 83 at UNCLOS III also strengthens the single-line case. Except at the early sessions of the Conference, the draft articles for the delimitation of the continental shelf and the EEZ were always identical, and were considered at the same time. While there was no consensus as to the method of delimitation, there was consensus that whatever formula was ultimately arrived at, it would be the same formula for the EEZ and the continental shelf. The connection that is evident here did not escape the Chamber in the Gulf of Maine case, which described it as “particularly significant”.
Judicial support for the single boundary can also be found. Orrego Vicuña cites the Arbitral Award between Dubai and Sharjah, which drew a single line, as establishing a limited precedent. While the value in citing that award before an international tribunal may be limited, there is some consideration in more notable cases, although less cut and dried. The difficulty with the ICJ’s statements concerning the single line are that the ICJ has not had to determine the question of the single line. In the Tunisia v Libya Continental Shelf case and the Libya v Malta Continental Shelf case, the parties requested delimitation of the shelf alone. In other cases, the parties themselves requested that the Court provide them with a single boundary. However, within the judgments, there are statements which are of assistance. Certainly Judge Oda, in his dissenting judgment in the Tunisia v Libya Continental Shelf case believes that the two zones ought to be delimited on a common boundary. Judge Evensen, in the same case, indicated that he thought it “hardly conceivable” there could, in that case, “be a different line of delimitation” and that the lines for the EEZ “should coincide with those laid down for continental shelf purposes”.
The approach of the ICJ to the cases where they have been asked to provide a single delimitation line is also illuminating. When presented with a request for a single line in the Gulf of Maine case, the Chamber was faced with deciding which factors ought to be taken into account in drawing the line. Even though the United States and Canada were parties to the 1958 Continental Shelf Convention, the Chamber said Article 6 of that Convention could not be applicable, as they were being asked to delimit more than the continental shelf. As such, the Chamber drew on customary international law, and took account of what jurists have described as “neutral factors”, obtaining the term from the following passage:
[With]…an increasingly general demand for single delimitation, so as to avoid as far as possible the disadvantages inherent in a plurality of separate delimitations, preference will henceforth inevitably be given to criteria that, because of their more neutral character, are best suited for use in a multi-purpose delimitation.
Rather than attempt to take account of all relevant circumstances and factors, for both the continental shelf and the EEZ, the Chamber focused on those factors that were of relevance to both regimes. The Chamber ignored the impact on Canadian fisheries, and American arguments based on geomorphology and the unity of Georges Bank. A similar analysis has been made of the Tribunal’s decision in the Guinea v Guinea-Bissau arbitration. A single maritime boundary was also requested by the parties in the St Pierre and Miquelon arbitration, and there the Court of Arbitration specifically approved of the approach of the ICJ in the Gulf of Maine case, noting that there was no impediment to having a single line in international law. The Court of Arbitration also observed that the use of a joint line had the effect of precluding the relevance of certain factors (such as natural prolongation and geology) which would only be of assistance in delimiting a continental shelf boundary.
The perceived decline in the utility of the notion of natural prolongation has been coupled with recognition by the ICJ that a littoral State is entitled to a continental shelf, by virtue of distance, as prescribed by the Law of the Sea Convention, as well as by natural prolongation. The move to recognise a distance-based entitlement to a continental shelf brings it closer to the EEZ, in terms of what factors will be relevant to a delimitation. Given that what have been described as “water column equities” (that is to say, factors relevant to the delimitation of the EEZ based on fisheries and resources not on the seabed) have not been influential in the delimitation of single boundaries, it is submitted the movement towards the distance-based continental shelf strengthens the use of “neutral criteria” in delimitation. Factors such as fisheries, and historic fishing rights, geomorphology, and undersea topography will be less likely to be of assistance to a tribunal, while geography will be of greater utility. An exception may be the existence of, for example, a large petroleum deposit, but it is submitted, given the dual character of the EEZ (dealing with both water column and seabed), this would be a relevant factor in a delimitation of both regimes.
This movement to “neutral criteria” is borne out in the approach of the ICJ in the Jan Mayen case, where the Court noted:
Although it is a matter of categories which are different in origin and name, there is inevitably a tendency towards assimilation between the special circumstances of Article 6 of the 1958 Convention and the relevant circumstances under customary law, and this if only because they both are intended to enable the achievement of an equitable result… It cannot be surprising if an equidistance-special circumstances rule produces much the same result as an equitable principles-relevant circumstances rule…whether in the case a delimitation of continental shelf, of fishery zone, or of an all-purpose single boundary.
The Court is indicating that, as all delimitations are being swayed by the same factors, all should produce, in the vast majority of cases, the same result. If the use of “neutral criteria” continues in further cases, it would seem the single line, while not obligatory, will become entrenched in international practice and in delimitation disputes before international tribunals.
While the ICJ seem to be of the view that it is possible to have separate and distinct boundaries for the continental shelf and the EEZ, the implementation of the possibility presents some difficulties. These stem from the nature of the two regimes. The continental shelf as a concept has nothing to do with the water column, except where depth becomes a relevant consideration in its calculation beyond 200 nautical miles. The jurisdiction over the continental shelf gives a coastal State sovereign rights over the seabed and subsoil only, although by necessity activities to exploit the shelf would require access to the superadjacent water column, to be able to reach the shelf. The 1982 Convention gives the coastal State sovereign rights to explore and exploit its continental shelf, and no other State may undertake such activities without the express consent of the coastal State.
The resolution of these problems is complex but by no means impossible, and has been undertaken by States in one of two ways. The first has been to create zones of joint jurisdiction, where limited and prescribed jurisdictional rights are shared between adjacent States over an area of seabed. The second is to proclaim separate boundaries for different purposes, and to attempt to resolve the logical inconsistencies this generates. Both techniques have been used in international practice and are considered below.
While not common, in the sense that there are only a small number of such zones worldwide, Joint Development Zones (JDZs) have proved particularly useful in potentially resources rich areas that are the subject of a boundary dispute. In fact, it can be argued that their raison d’être is that they provide a way of disposing of a boundary dispute (temporarily or permanently) to permit exploitation of valuable shelf resources or fisheries in the disputed area as soon as possible. Other less pragmatic motivations for neighbouring States to create a JDZ may be to ensure resource management and/or preservation, or to promote or maintain closer political ties between the two States.
The small number of JDZs in existence disclose a number of different approaches to the establishment of a joint zone. The treaty creating the JDZ may not attempt to specify a boundary, but simply indicate an area in which revenues are to be shared, as in the case of the Japan/South Korea JDZ. A variation on this theme is the JDZ made by Saudi Arabia and the Sudan, which creates a JDZ in the Red Sea between the countries, on the continental shelf below the 1000 metre isobath. The agreement does not delimit any shelf boundary.
The JDZ may not delimit the boundary because it is viewed as temporary by the States that created it. The JDZ is simply a mechanism to permit exploitation, with benefits to both countries, without prejudice to either State’s position. The JDZs established by Malaysia and Thailand, and by Australia and Indonesia in the Timor Gap, are examples of temporary zones. Prescott has suggested that what may be provisional today, may in time become more permanent, and he cites the Thai-Malaysian JDZ which is to run for 50 years, with an option to renew for another 50 years. This view is probably correct, but it is worth noting that, in time, the reason for dividing the disputed area will fade too. Most JDZs are in place to permit the exploitation of petroleum reserves. In 50 or 100 hundred years time, the relevant area of shelf may have little or no commercial value, and the removal of this value may also do much to remove the seemingly entrenched positions the opposing States were demanding. However, as the oldest JDZ is yet to reach 40 years, it may be some time before these predictions can be tested.
Where the agreement setting up the JDZ specifies a boundary, there are a number of different permutations possible, and these are represented in the JDZs in existence. First the JDZ may be located entirely on one side of the boundary, permitting the neighbouring State a share of the revenue. An example of this is the Bahrain/Saudi Arabia JDZ. The JDZ may also straddle the boundary, seeking to give equal parts of the zone to the two States. The JDZ between the Dominican Republic and Colombia is such a JDZ. The remaining type of JDZ also lies across the maritime boundary, but with most of its area in the one State’s sphere of influence. The Iceland/Norway JDZ near Jan Mayen is biased with more of its area on the Jan Mayen side of the boundary, thereby benefiting Iceland. This was in recognition of the reliance of the Iceland economy on fisheries, and the fact that Jan Mayen is uninhabited and desolate. Similarly, the Torres Strait Treaty creates an area for the benefit of the native populations of the Strait, to ensure the maintenance (at least as far as possible) of the traditional way of life and culture of these people.
As already noted, there are relatively few JDZs, and certainly they do not provide a universally applicable solution to all the potential maritime boundary disputes around the world. There are criticisms of their lack of certainty, the expense to maintain their joint administrations, and the legal complexity that arise. However, the JDZ does give parties to a dispute an alternative, and can provide for more creative solutions to boundary disputes. The ICJ in the North Sea Continental Shelf cases did expressly approve the JDZ as a mechanism for dispute resolution, although it did note that it could only be used where the parties concerned agreed to it. As such, it is submitted that the JDZ does have a continuing role to play in the delimitation of maritime boundaries.
At the present time there are two maritime boundary treaties which separate the continental shelf boundary from the boundary of the EEZ. Both pertain to the waters to the north of Australia, the first being between Australia and Papua New Guinea, and the second between Australia and Indonesia. Both deal explicitly with the problem of overlapping jurisdiction between the continental shelf boundary and the EEZ boundary, although do so in slightly different ways.
The first of the two agreements in issue was the Torres Strait Treaty, which was concluded in 1978, and entered into force in 1985. A complex range of considerations necessitated the division of the seabed and fisheries jurisdictions, and the Treaty sets up an equally complex division of jurisdiction through the islands of the Torres Strait.
For the bulk of the maritime boundary between Australia and Papua New Guinea, a common seabed/fisheries “all-purpose” boundary is used. However, in the central area of Torres Strait, the fisheries and seabed boundaries diverge. The seabed line essentially follows a modified median line between the mainlands of Australia and Papua New Guinea, therefore running south of a number of Australian islands. The fisheries jurisdiction turns sharply to the north, to enclose those Australian islands which are inhabited, and abruptly turns south to rejoin the seabed line. Although the inhabited islands are south of the fisheries boundary, several small sand cays are to the north of the common boundary, and are therefore Australian territory enclaved within the Papua New Guinea EEZ.
The seabed and fisheries lines do not represent the only boundaries in the Strait. All Australian islands north of the seabed line generate three-mile territorial seas, including those to the north of the common boundary. Accordingly, each island north of the seabed line possesses a narrow belt of Australian territorial sea, surrounded by a Papua New Guinean seabed, and in some cases Papua New Guinean fisheries jurisdiction as well. These arrangements necessitated extremely detailed arrangements for the calculation of territorial seas of very small features. For example, Turnagain Island, although less than a mile wide and seven miles long required some 74 basepoints for the calculation of its territorial sea and Deliverance Island and nearby Kerr Islet at less than a square mile in area have 40 basepoints.
These details are further complicated by the implementation of a Protected Zone over most of the central region of the Strait. The Protected Zone functions as a JDZ for certain purposes, permitting freedom of movement for the traditional inhabitants, the preservation of traditional rights of use, cooperation in environmental management, and a shared system of marine living resource management. Cooperation in the assessment of total allowable catches in the Protected Zone is to take place, and actual catches are to be divided depending on where in the Zone fish are caught. In areas under Australian jurisdiction south of the fisheries boundary, Australia is to receive 75 per cent of the catch, with an equivalent situation of 75 per cent for Papua New Guinea in the areas subject to its jurisdiction. Around the enclaved Australian islands north of the fisheries boundary, catches are to be shared 50 per cent each. The Treaty permits both States to negotiate on varying these ratios and with respect to access for particular stocks. In practice, there have been negotiations and arrangements concluded in respect of particular stocks, as well as substantial cooperation and coordination of effort in fisheries research. There is also cooperation in joint licensing, and potentially in enforcement, where one party could arrest one of its flag vessels for breaches of the fisheries laws of the other party.
Even though the Treaty was negotiated prior to the conclusion of UNCLOS III, at a time when Australia had not proclaimed its own EEZ, and Papua New Guinea had only proclaimed its EEZ earlier that year, it was recognised by the parties that other aspects of jurisdiction, outside what could adequately be described as relating to the seabed or to fisheries, did exist. These were intended to be covered by a “catch-all” category of jurisdiction described as “residual jurisdiction”. Marine scientific research, protection of the environment and the production of energy from wind, current and water are expressly noted as part of what is encompassed by “residual jurisdiction”, but the concept is somewhat wider. It takes in any other form of jurisdiction over the seabed or fisheries not related to the exploration and exploitation of these areas.
Residual jurisdiction is shared by the parties in the area of overlap. Article 4(3) requires that neither can exercise this jurisdiction without the concurrence of the other. This effectively gives either State a veto over any activity that cannot be categorised as relating to the regulation of fisheries or the exploration and exploitation of the continental shelf. The veto is qualified by a duty to consult with a view to reaching an effective solution, but this falls short of any binding requirement to reach an effective agreement.
On the whole, the Torres Strait Treaty has operated effectively for over a decade, and the two parties appear to be satisfied with it. While there have been problems affecting the operation of the Treaty, such as numbers of Papuans settling on Australian islands in the north of the Strait, apparently misusing the freedom of movement concessions, jurisdictional problems engendered by the separation of seabed and fisheries jurisdiction have not occurred. A number of explanations can be proffered as to why.
First, there has been little relevance in the continental shelf and fisheries boundaries. Between 1985 and 1995 there was a complete moratorium under the Treaty in the waters of the Torres Strait region on all mineral resource activities. More recently this has given way to a limited right of either State to explore, though to the present only a limited amount of exploration in the Strait region has taken place. As a result, the continental shelf boundary has only been of practical utility in determining which State might have jurisdiction over pearl shell, which as a sedentary stock was subject to the shelf regime. Further, even though there are not insignificant fisheries in the region, there is resource sharing in varying percentages between the two States, and both can license vessels from either State to fish in the waters subject to their jurisdiction. These cooperative arrangements tend to diminish the impact of the boundary, and, when coupled with a general right of traditional fishermen from either State to fish throughout the region unimpeded, the practical significance is diminished still further. Finally, both States have made effective use of the Torres Strait Joint Advisory Council, a body set up to promote continuing consultation between the parties to ensure coordinated and practical management of the Strait. Regular consultation, a commitment to the Treaty, and an absence of offshore mining have ensured that jurisdictional problems have been minimised.
The Australia-Indonesia Maritime Boundary Treaty was concluded in 1997, and at the time of writing had yet to enter into force. It was intended to provide a comprehensive boundary settlement between Australia and Indonesia, after 25 years of periodic negotiation. Aside from a permanent continental shelf boundary which will need to be concluded upon the winding-up of the Timor Gap JDZ, all outstanding maritime boundary issues were resolved. The negotiating positions of the two States had been quite far apart during most of this period, and so the mechanism of dividing the boundary for different purposes was used as a mechanism to bring the two parties together. The agreement provides for separate EEZ and continental shelf boundaries, creating quite substantial areas of Australian continental shelf overlapping with Indonesian EEZ.
The problem of separate boundaries for the continental shelf and the EEZ is dealt with in Article 7. In the areas of overlap, Article 7 provides that EEZ sovereign rights and jurisdiction are limited to the water column, and that continental shelf sovereign rights and jurisdiction are applicable to the seabed. There appears to be an implicit assumption that the content of continental shelf seabed rights and jurisdiction equates to the scope of EEZ rights over the seabed, as to do otherwise would mean there was a lacuna of jurisdictional competence in relation to certain seabed activities. Such an assumption certainly appears reasonable given that all present uses of the seabed that could ordinarily be regulated by the EEZ regime would equally fall under the continental shelf regime.
The content of both the EEZ and continental shelf rights is expressly drawn from the Law of the Sea Convention. However, recognising that so simple a division would not answer all the potential conflicts, provisions are put in place for jurisdiction over, and notice of, certain activities. For the most part, the provisions seek to allow both States to exercise their jurisdiction independently of the other party. At the same time, certain uses of the sea and seabed that could potentially interfere with the other’s jurisdiction and/or enjoyment require notice of the activity that is to take place. For example, the construction of any installation or structure that is not an artificial island must be preceded by “due notice”. The Treaty does not prescribe how long this notice period should be, but the term is used in the Law of the Sea Convention in the same context, and was selected to permit flexibility in the time between the decision to construct an installation, and its actual construction. The same “due notice” requirement is imposed upon the construction of fish aggregating devices. Where a State has constructed an installation, structure or fish aggregation device, it retains exclusive jurisdiction over it. Equivalent duties to those in the Law of the Sea Convention with respect to removal, and publicity over abandoned structures are also found. As the shelf State, Australia is also obliged to give three months notice of the granting of any exploration or exploitation rights. What is clear is that where a State wishes to engage in the construction of an installation or other structure on the seabed, it does not require the concurrence of the other party, merely to inform it in advance of its intentions.
However, the Treaty does not indicate whether both States have an unfettered power to construct installations in the overlap area. It is evident that the right to construct structures on the seabed is not restricted to the shelf State, Australia. Article 7(h) provides that the party responsible for the construction of the feature has jurisdiction over it. This implies that in certain circumstances both States will have the right to construct structures in the areas under their jurisdiction. Logically, if this is the case, Indonesia as the water column State, ought to be entitled to construct structures to assist in the exploitation of the waters under its jurisdiction. Such a view was expressed by the Australian Attorney-General’s Department in submissions on the Treaty made to a Parliamentary inquiry, and can be easily accommodated under Article 7(g), which provides that the construction of a fish aggregation device should be subject to “due notice”.
The only area where each party can directly interfere with the other’s exercise of jurisdiction is the rather restricted category of artificial islands. An artificial island is defined as an area of land, clear of the water at high tide, but only by reason of human intervention. Consequently, it can be distinguished from a platform or other installation, which is clearly not land. Both parties retain the right to refuse the construction of an artificial island, as the agreement of both is necessary for construction to go ahead. In practice, the overlap areas are in areas where water depth would mitigate against the construction of artificial islands, so neither State is likely to be adversely affected by the granting of a veto to the other.
Other aspects of jurisdiction are also dealt with in the Treaty. Marine scientific research is provided for in Article 7(i). It provides that marine scientific research is to be carried out in accordance with the Law of the Sea Convention, with notification to the other party of such research. Given the Convention is ill-equipped to deal with the separation of jurisdiction, the provision gives limited guidance into its actual operation. In theory, the application of Part XIII would be subject to the jurisdiction of both States with respect to marine scientific research, given that both are coastal States for the purposes of the Convention. Such an arrangement would be problematic, and appears to have been recognised as such by the parties, even if not expressly spelled out in the Treaty itself. Again, in submissions to a Parliamentary Committee by the Australian Attorney-General’s Department, it was stated that in the course of negotiations it was settled that Australia would have jurisdiction over research taking place into the seabed, and Indonesia would have jurisdiction over research into the water column. On that basis, the lack of certainty on the face of the provision could easily be resolved with recourse to the travaux préparatoires.
However, the issue of the collection of water column data to support exploration of the seabed would still not be resolved. Although related to the seabed, and therefore capable of authorisation by Australia, the subject matter of the research is the water column, falling under Indonesian jurisdiction. There are two possible interpretations. The first is that research that is incidental to seabed exploration is entirely under Australian jurisdiction, and accordingly the only obligation to Indonesia is the notification of such activities under Article 7(i). The second is that Indonesia has jurisdiction over such research. While it is unlikely that jurisdiction would translate into an ability to withdraw consent, as that would inhibit Australia’s exercise of its rights to conduct exploration by virtue of Article 7(m), it may certainly have an entitlement to the data collected from such research.
The Treaty is also not overly effusive on the subject of marine pollution. Article 7(j) provides that each party will take effective measures as may be necessary to prevent, reduce and control pollution of the marine environment. Logically, the measures a State can take to control pollution must fall within its jurisdiction, which would mean marine pollution of the water column would be subject to Indonesian regulation. Where such pollution originated from activities associated with exploitation and exploration of the seabed, it would follow that Australia would be able to regulate such matters as an incidental part of its regulation of exploitation or exploration.
As such, marine pollution from an oil platform would potentially be subject to the jurisdiction of both States, necessitating some level of cooperation and coordination by both parties. The Treaty provides no further help, other than attributing liability on the basis of international law for pollution caused by matters under its jurisdiction. Therefore, oil pollution emanating from a platform would be Australia’s responsibility, as the structure would be subject exclusively to Australia’s jurisdiction by virtue of Article 7(h). In practice, Article 7(h) would appear to be the most effective way of removing the likelihood of conflict. Indonesian jurisdiction over marine pollution would only be attracted when the water column was affected. Its jurisdiction could not pre-empt the act of pollution, as Australia is guaranteed exclusive jurisdiction over activities on the structure. Consequently, if Indonesia’s jurisdiction is only manifested by pollution, its principal concern will be restoration of the environment, and compensation for damage. Article 7(k) by expressly fixing liability would mean Australia would assume that responsibility. Indonesian interest would therefore be directed at a State level, to ensure Australia met this obligation, rather than the operator of the platform.
The parties have also recognised that, given there is an overlap of jurisdiction, coordination of efforts to prevent damage from an accident is most desirable. This was recognised even before the conclusion of the Treaty with the adoption of a Memorandum of Understanding with respect to oil pollution preparedness and response. This MOU strongly suggests that both parties are committed to a cooperative approach to the issue of marine pollution in the overlapping area.
These arrangements have been criticised by Herriman and Tsamenyi on the basis that they do not satisfactorily resolve the division of jurisdiction in all instances, and that the agreement fails to address all areas where potential conflict could occur. They are of the view that the present agreement is heavily dependent on the goodwill of the parties, and their ability to resolve amicably any potential problems that could arise.
The agreement itself attempts to deal with this problem by requiring that neither party exercise its rights and jurisdiction in a manner which unduly inhibits the rights and jurisdiction of the other, and that both cooperate in relation to the exercise of their rights and jurisdiction. Certainly, while relations between the two States are strong, then it is reasonable to assume these provisions will operate satisfactorily. However should relations seriously deteriorate, then the criticisms raised would not be without foundation.
The separation of the continental shelf and the EEZ provides States with a useful technique in the delimitation of maritime boundaries. It gives negotiators significantly greater flexibility in bargaining, and allows for a greater number of areas where concessions might be made to increase the likelihood of resolution. However, as is noted above, the Law of the Sea Convention is ill-equipped to deal with the jurisdictional difficulties that separation gives rise to, and consequently States leave issues open, postponing them to another day, or to negotiate their way through a set of complex and difficult issues. State practice has tended towards the former solution rather than the latter, although given the relative satisfaction of Australia and Indonesia with their boundary arrangements, there is certainly room for optimism in the success of complex arrangements if States are prepared to support them. However if the separation of jurisdiction in delimitation is used with greater frequency in the future, States will have to give increasing attention to the nature of their jurisdiction over the continental shelf and EEZ, and develop techniques for the complementary and joint exercise of jurisdiction over the seabed and the ocean.
What is clear, is that where jurisdiction is separated or where joint development is pursued, the arrangements are heavily dependent upon the goodwill and active cooperation of the State parties. Given that such arrangements will generally mean the physical presence of both parties in the affected area, an absence of goodwill could quickly make it extremely problematic for either party effectively to conduct its activities. In areas such as marine pollution, where the interests of all parties will be in issue, parties must have confidence in each other that effective measures are in place to prevent pollution. Cooperation would also be essential to deal with accidents, given that few States will possess all the resources in all circumstances necessary to cope with a large-scale pollution problem. Certainly, the separation of EEZ and continental shelf jurisdiction give rise to complex legal issue that were not seriously contemplated during UNCLOS III, and that where States would seek to utilise such techniques, they should carefully contemplate the consequences of such action.
[*] Senior lecturer in Law, University of Tasmania.
 The first 200 nautical mile zone was claimed by Chile in 1947: Presidential Declaration, 23 June 1947, 1 United Nations Legislative Series 6.
 Presidential Proclamation No 2667, “Policy of the United States with respect to the natural resources of the subsoil and seabed of the continental shelf”, 28 September 1945: reprinted in SH Lay, RR Churchill and M Nordquist (eds), New Directions in the Law of the Sea (vol 1, 1973) 106.
 DJ Attard, The Exclusive Economic Zone in International Law (1987) at 136-139; MD Evans, “Delimitation and the common maritime boundary” (1993) 64 British Yearbook of International Law 283 at 286-293.
 United Nations Convention on the Law of the Sea (December 10 1982), reprinted in (1982) 21 International Legal Materials 1261 [hereafter cited as LOSC].
 Continental Shelf (Libya v Malta) Case  ICJ Rep 13, 33.
 An excellent discussion of the debate and the changing position in international law over the single all-purpose maritime boundary has been undertaken by Weil: see P Weil, The Law of Maritime Delimitation: Reflections (1989) at 117-135.
 For a succinct history of the development and content of the regime of the continental shelf and EEZ in international law see RR Churchill and AV Lowe, The Law of the Sea (2nd ed, 1988) at 133-176.
 Convention on the Continental Shelf (June 10 1958), 499 UNTS 311.
 As much was explicitly recognised by the Chamber of the International Court of Justice in 1984 in the Gulf of Maine Case  ICJ Rep 246, 294.
 LOSC, n 4 above, Article 77(1).
 Ibid. Article 80.
 Ibid. Article 81.
 Ibid. Article 85.
 Ibid. eg Articles 60-73.
 Ibid. Article 68, which states: “This Part [ie Part V] does not apply to sedentary species as defined in Article 77, paragraph 4.”
 Attard, n 3 above, at 140-143.
 This is explicitly spelled out in identical terms for both regimes under LOSC, n 4 above, Articles 74 and 83.
 See below at Divided Boundaries: International Practice.
 LOSC, n 4 above, Articles 56(1)(b)(i) and 60.
 Ibid. Article 80.
 Ibid. Article 60(2).
 Ibid. Articles 60(4) and 60(5). See B Kwiatkowska, The 200 Mile Exclusive Economic Zone in the New Law of the Sea (1989) at 120-123.
 One of these features was subsequently proclaimed as independent by its occupiers under the name “Sealand”. For a discussion see SP Menefee, “‘Republics of the reefs’: nation-building on the continental shelf and in the world’s oceans” (1994) 25 California Western International Law Journal 81.
 LOSC, n 4 above, Articles 60(4) and 60(5).
 The safety zones cannot be used to cause interference to recognised international sea lanes: ibid. Article 60(7).
 Ibid. Article 60(3).
 For discussions of marine protection within the EEZ see F Orrego Vicuña, The Exclusive Economic Zone (1987) at 83-90; Kwiatkowska, n 22 above, at 120-123.
 For example, see Trial Smelter Arbitration (US v Canada) (1938 and 1941) 3 RIAA 1905.
 Interestingly, a situation of this type did occur in the vicinity of an area now subject to split water column and seabed jurisdiction. In 1970, the Oceanic Grandeur ran aground in Torres Strait, spilling oil. The pearl oyster industry of the Strait was decimated by a strange disease in the 18 months following the oil spill. Suspicions of a causal link between the spill and the collapse of the industry have been periodically raised: see SB Kaye, The Torres Strait (1997) at 122.
 LOSC, n 4 above, Article 56(1)(b)(ii).
 See Kwiatkowska, n 22 above, at 134-155.
 Churchill and Lowe do not suggest that exploration is not research, merely that there is a difference in treatment for applied and pure research under the Convention: Churchill and Lowe, n 7 above, at 293.
 Continental Shelf (Tunisia v Libya) Case  ICJ Rep 18.
 Ibid. 232.
 Evans provides an excellent summary of the differing positions on the relationship of the regimes: Evans, n 3 above, at 286-293.
 Attard, n 3 above, at 214-221; DW Bowett, The Regime of Islands in International Law (1979) at 189; Orrego Vicuña, n 27, at 196-197; DM McRae, “The single maritime boundary: problems in theory and practice” in ED Brown and RR Churchill (eds), The UN Convention on the Law of the Sea: Impact and Implementation (1987) 225 at 227.
 McRae, ibid. at 227.
 The same argument is raised by MD Evans, Relevant Circumstances and Maritime Delimitation (1989) at 55.
 See n 33 above, at 130; McRae, n 37 above, at 230-232.
 Tunisia v Libya Continental Shelf case, ibid. at 115.
 Gulf of Maine case, n 9 above, at 246, 257; Attard, n 3 above, at 219.
 Jan Mayen Case  ICJ Rep 38, 57.
 See generally North Sea Continental Shelf Cases  ICJ Rep 3.
 Ibid. at 62.
 Bowett, n 37 above, at 189.
 See n 33 above, at 232.
 Orrego Vicuña, n 27 above, at 207-208.
 Attard, n 3 above, at 214.
 LOSC, n 4 above, Article 56(1).
 Evans, n 3 above, at 56-58.
 Gulf of Maine case, n 9 above, at 295.
 Orrego Vicuña, n 27 above, at 199.
 Tunisia v Libya Continental Shelf case, n 33 above.
 Libya v Malta Continental Shelf case, n 5 above.
 See n 33 above, at 232.
 Ibid. at 288; cited in Attard, n 3 above, at 213.
 Tunisia v Libya Continental Shelf case, ibid. at 296.
 Gulf of Maine case, n 9 above, at 301-302.
 Attard, n 3 above, at 220-221; Orrego Vicuña, n 27 above, at 202.
 Gulf of Maine case, n 9 above, at 327.
 Orrego Vicuña, n 27 above, at 201-203.
 Guinea v Guinea-Bissau Arbitration, reprinted in (1986) 25 International Legal Materials 251; Orrego Vicuña, n 27 above, at 205; Attard, n 3 above, at 221.
 Agreement establishing a Court of Arbitration for the Purpose of Carrying out the Delimitation of Maritime Areas between France and Canada, 30 March 1989, (1992) 31 International Legal Materials 1151, Article 2(1).
 St Pierre and Miquelon Arbitration reprinted in (1992) 31 International Legal Materials 1148 at 1163.
 Ibid. at 1165.
 For example see Weil, n 6 above, at 25-45.
 Libya v Malta Continental Shelf case, n 5 above, at 20-21.
 Ibid. at 35.
 Evans, n 3 above, at 61.
 Ibid. at 61-62.
 See n 43 above, at 62.
 LOSC, n 4 above, Article 76.
 Ibid. Article 77.
 The most useful summary of the then existing JDZs and other maritime joint arrangements was undertaken by a research team under the auspices of the British Institute of International and Comparative Law in 1989: H Fox (ed), Joint Development of Offshore Oil and Gas (vol 1, 1989) at 53-113.
 Not surprisingly, this has been argued before: see JRV Prescott, “On the resolution of maritime boundary conflicts” in JP Craven, J Schneider and C Stimson (eds), The International Implications of Extended Maritime Jurisdiction in the Pacific (1989) 38; RR Churchill, “Joint Development Zones: international legal issues” in Fox, n 75 above, vol 2, 55 at 57-58.
 The desire to preserve the traditional rights and way of life of the Torres Strait Islanders was an important factor in the establishment of a joint zone in Torres Strait: H Burmester, “The Torres Strait Treaty: ocean boundary delimitation by agreement” (1992) 76 American Journal of International Law 321 at 322.
 I Townsend-Gault, “Recent developments in the cooperative development of offshore petroleum resources” in TA Clingan (ed), The Law of the Sea: What Lies Ahead? (1988) 215.
 Agreement between Japan and the Republic of Korea concerning Joint Development of the Southern Part of the Continental Shelf Adjacent to the Two Countries, 30 January 1974, reprinted in M Nordquist and KR Simmonds (eds), New Directions in the Law of the Sea (vol 4, 1981) at 113; Townsend-Gault, n 78 above, at 217-220; Orrego Vicuña, n 27 above, at 209; GH Blake, “World maritime boundary delimitation: the state of play” in GH Blake (ed), Maritime Boundaries and Ocean Resources (1987) 1 at 9-10; JRV Prescott , The Maritime Political Boundaries of the World (1985) at 242; Fox, n 75 above, vol 1, at 57-59; see also M Miyoshi, “The Japan/South Korea Joint Development Agreement of 1974” in Fox, n 75 above, vol 1, at 89.
 Agreement Relating to the Joint Exploitation of the Natural Resources of the Sea-bed and Sub-soil of the Red Sea Common Zone, 16 May 1974, 18 United Nations Legislative Series 43; see Attard, n 3 above, at 218; Blake, n 79 above, at 9-10; Orrego Vicuña, n 27 above, at 209; Townsend-Gault, n 78 above, at 217; Fox, n 75 above, vol 1, at 60.
 Memorandum of Understanding Between Malaysia and the Kingdom of Thailand on the Establishment of a Joint Authority for the Exploitation of the Resources of the Seabed in a Defined Area of the Continental Shelf of the Two Countries, 21 February 1979, reprinted in (1983) 1 LOS Bulletin 113; see Townsend-Gault, n 78 above, at 220-221; Prescott notes that a line is drawn through the zone to indicate criminal jurisdiction, but the agreement specifically states that this line is not to be the boundary: JRV Prescott, The Gulf of Thailand: Maritime Limits to Conflict and Cooperation (1998) at 32-33; Fox, n 75 above, vol 1, at 61-62; see also I Townsend-Gault, “The Malaysia/Thailand Joint Development Arrangement” in Fox, n 75 above, vol 1, at 102.
 Treaty between Australia and the Republic of Indonesia on the Zone of Cooperation in an Area between the Indonesian Province of East Timor and Northern Australia, 11 December 1989, (1991) 9 Australian Treaty Series.
 Prescott, n 81 above, at 86; Fox et al also note that the Thailand-Malaysia JDZ Agreement can be terminated at any time prior to the expiration of 50 years by agreement: Fox, n 75 above, vol 1, at 61.
 LOSC does countenance the use of temporary arrangements. Articles 74(3) and 83(3) expressly urge States to pursue temporary arrangements of a practical nature to assist in the resolution of delimitation disputes.
 Agreement Concerning Delimitation of the Continental Shelf between Saudi Arabia and Bahrain, 22 February 1958, 16 UNTS 409; see Townsend-Gault, n 78 above, at 216; Orrego Vicuña, n 27 above, at 209; Prescott, n 81 above, at 169; Blake, n 79 above, at 9-10; Fox, n 75 above, vol 1, at 54.
 Agreement on the Declaration of Marine and Submarine Areas and Maritime Co-operation, 13 January 1978, reprinted in M Nordquist and KR Simmonds (eds), New Directions in the Law of the Sea (vol 8, 1981) 78; see Blake, n 79 above, at 10; Prescott, n 81 above, at 344.
 Agreement on the Continental Shelf Between Iceland and Jan Mayen, 22 October 1982, reprinted in (1982) 21 International Legal Materials 1222.
 RW Smith, “A geographical primer to maritime boundary making” (1982) 12 Ocean Development and International Law 1 at 1-9; Attard, n 3 above, at 218; Fox, n 75 above, vol 1, at 62-63.
 Treaty between Australia and the Independent State of Papua New Guinea concerning Sovereignty and Maritime Boundaries in the area between the Two Countries, including the area known as Torres Strait and Related Matters, 18 December 1978, (1985) 4 Australian Treaty Series [hereafter cited as Torres Strait Treaty]; see also Burmester, n 77 above, at 322; Attard, n 3 above, at 217-218.
 Prescott, n 81 above, at 76; Townsend-Gault, n 78 above, at 221; for a general discussion of joint arrangements on both land and sea in terms of oil deposits, see WT Onorato, “Apportionment of an international common petroleum deposit” (1968) 17 International and Comparative Law Quarterly 85.
 North Sea Continental Shelf cases, n 44 above, at 1, 52.
 For a background to the Treaty see generally Burmester, n 77 above, at 321-333; Kaye, n 29 above, at 87-101.
 The path of the boundaries are described in Article 4, together with Annexes 5 and 8 of the Torres Strait Treaty.
 The seabed boundary runs to the north of a median line between the two mainlands due to the presence of a number of significant Australian islands in the south of the Strait: see Kaye, n 29 above, at 95; Burmester, n 77 above, at 333.
 This configuration has been described as a “top hat”: Burmester, n 77 above, at 338; B Opeskin and DR Rothwell, “Australia’s territorial sea: international and federal implications of its extension to 12 miles” (1991) 22 Ocean Development and International Law 395 at 399-401.
 Torres Strait Treaty, n 89 above, Article 3. One small island, Pearce Cay, lies less than three miles north of the common seabed/fisheries boundary, and possesses a three-mile territorial sea to the north of the boundary, and a 12-mile territorial sea to the south of the boundary: Opeskin and Rothwell, ibid. at 400-401.
 The basepoint provisions are found in Torres Strait Treaty, Annex 3; see Prescott, n 81 above, at 69.
 The Protected Zone is established under Article 10 of the Torres Strait Treaty, and its limits are described in Annex 9.
 Torres Strait Treaty, Article 11(1).
 Ibid. Articles 11(2) and 12.
 Ibid. Article 13.
 Allocation of commercial catches is dealt with in Part 5 of the Torres Strait Treaty. See generally KW Ryan and MWD White, “The Torres Strait Treaty”  AUYrBkIntLaw 5; (1981) 7 Aust YBIL 87 at 103.
 Torres Strait Treaty, Articles 21 and 22.
 Ibid. Article 23.
 Ibid. Article 23(7).
 See generally Commonwealth of Australia, Torres Strait Protected Zone Joint Authority Annual Report 1993-94 (1995) at 24-25; K Mfodwo and BM Tsamenyi, Enforcement of Maritime Fisheries Law and Regulations: A Case Study of Papua New Guinea in International and Comparative Perspective (1992) at 151-157.
 Joint monitoring and consultation encouraged under Articles 23 and 24, Torres Strait Treaty, has taken place with respect to dugong, spanish mackerel and green turtle: Commonwealth of Australia, ibid. at 10-11.
 Papua New Guinea proclaimed an EEZ under its National Seas Act 1978 (PNG) with effect from 31 March 1978.
 Residual jurisdiction is defined in Article 4(4), Torres Strait Treaty.
 Torres Strait Treaty, Article 4(4), while expressly referring to marine scientific research, preservation of the marine environment, and the production of energy, was not intended to be exhaustive, and these areas were merely cited as examples. See Mfodwo and Tsamenyi, n 106 above, at 135-136.
 Torres Strait Treaty, Article 4(3)(b).
 See generally D Renton, “The Torres Strait Treaty after 15 years: some observations from a Papua New Guinea perspective” in J Crawford and DR Rothwell (eds), The Law of the Sea in the Asian Pacific Region (1995) 171.
 See R Babbage, The Strategic Significance of Torres Strait (1990) at 296-97; Kaye, n 29 above, at 11-12.
 Torres Strait Treaty, Article 15.
 Ibid. Article 26.
 Ibid. Article 11.
 Treaty between the Government of Australia and the Government of the Republic of Indonesia establishing an Exclusive Economic Zone Boundary and Certain Seabed Boundaries, 14 March 1997, reprinted in (1997) 36 International Legal Materials 222 [hereafter cited as Australia-Indonesia Maritime Boundary Treaty].
 The Timor Gap arrangements were expressly preserved by virtue of Article 8, Australia-Indonesia Maritime Boundary Treaty.
 For background see SB Kaye, “The Australia/Indonesia Maritime Boundary Treaty: a review” (1997) 94 Maritime Studies 28; SB Kaye, “Australia and Indonesia tie the maritime knot” (1997) 71 Australian Law Journal 916.
 For the water column: Article 7(a), Australia-Indonesia Maritime Boundary Treaty; and for the continental shelf: Article 7(b), Australia-Indonesia Maritime Boundary Treaty.
 Australia-Indonesia Maritime Boundary Treaty, Article 7(e).
 LOSC, n 4 above, Article 60(3).
 Attorney-General’s Department, Submissions to the Joint Standing Committee on Treaties Inquiry into the Australia-Indonesia Maritime Delimitation Treaty, 5 November 1997, at 3a-3d.
 Australia-Indonesia Maritime Boundary Treaty, n 117 above, Article 7(h).
 Ibid. Article 7(f).
 Ibid. Article 7(d).
 This is confirmed by the submission of the Attorney-General’s Department to the Parliamentary Treaties Committee Inquiry into the Treaty, an interpretation that was expressly adopted by the Committee in its Report: Attorney-General’s Department, Submissions to the Joint Standing Committee on Treaties Inquiry into the Australia-Indonesia Maritime Delimitation Treaty, 5 November 1997, at 3c.
 Ibid. at 3b.
 Australia-Indonesia Maritime Boundary Treaty, n 117 above, Article 7(c).
 See n 127 above, at 3c.
 Pursuant to Vienna Convention on the Law of Treaties 1969, Article 32, (1969) 8 International Legal Materials 679.
 Australia-Indonesia Maritime Boundary Treaty, n 117 above, Article 7(k).
 Ibid. Article 7(k): “each Party shall be liable in accordance with international law for the pollution of the marine environment caused by activities under its jurisdiction.”
 Memorandum of Understanding between the Governments of Australia and Indonesia on Oil Pollution Preparedness and Response, 3 September 1996 and 3 October 1996, unpublished. I am grateful to Max Herriman for providing me with a copy of the MOU.
 M Herriman and BM Tsamenyi, “The 1997 Australia-Indonesia Maritime Boundary Treaty: a secure legal regime for offshore resource development?” in Submissions to the Joint Standing Committee on Treaties Inquiry into the Australia-Indonesia Maritime Delimitation Treaty — 12th Report, 17 November 1997, 111-131.
 Australia-Indonesia Maritime Boundary Treaty, n 117 above, Article 7(m) and 7(n).
 For example see SB Kaye, Australia’s Maritime Boundaries (1995) ch 2.