Problems and Processes of Restricting Navigation in Particularly Sensitive Sea Areas

Particularly Sensitive Sea Areas (PSSAs) are a form of marine conservation measure established by the International Maritime Organization (IMO) to protect the marine environment against damage caused by navigation. The politicisation of the PSSA designation process and the shortcomings of the 2015 IMO Revised Guidelines for the Identification and Designation of PSSAs have been inimical to improving the PSSA regime. This article first examines the law and practice of PSSAs and discusses the shortcomings of the 2005 Guidelines. It then explores how politicisation outside and inside the IMO has aggravated the institutional weaknesses of the PSSA regime in three aspects: the relationships between Associated Protective Measures (APMs) and existing navigational measures; the links between the ecosystems and PSSAs; and the lack of stringent APMs.


Introduction
In the Philippines, there is a beautiful coral reef area with extensive lagoons and coral islands: the Tubbataha Reefs Natural Park (the Park).1 It is a habitat for internationally threatened and endangered marine species, supporting 374 species of coral reef that amount to 90 per cent of the coral species in the Philippines.2 The Park has been preserved to a near-pristine status, providing a crucial source of fish reproduction and dispersal within the marine ecosystem.3 The Park is also known to be the eighth best diving location in the world, generating tourism revenues for the local and national economies.4 The Park supports the fisheries industry as it is a crucial source of coral and fish larvae on which nearly 2 million Filipinos depend for their livelihood. Hence, small ecological changes in the Park by international shipping translate into substantial effects for the Filipino population.
In spite of this, navigation has always threatened the marine ecosystem of the Tubbataha Reefs Natural Park. Located in the Sulu Sea, the Park is situated in the navigation route connecting the South China Sea to the Celebes Sea and the Pacific Ocean.5 The Park is vulnerable to both operational and accidental impacts of vessel traffic, particularly ship groundings and collisions.6 In 1988, the Philippines government adopted a buffer zone to protect the Park through administrative fines and criminal penalties, but is has been difficult to protect the area from the increased number of foreign vessels navigating through the area.7 The Park has been threatened by non-compliance with park regulations of foreign vessels. 8 To tackle these difficulties in raising publicity and ensuring compliance of foreign vessels with these regulations, a Particularly Sensitive Sea Area (PSSA) was suggested to protect the Tubbataha Reefs Natural Park in 2011.9 Designated by the International Maritime Organization (IMO), a PSSA is put in place to protect vulnerable marine ecosystems by tackling threats from international shipping activities. The PSSA designation does not itself provide any legal protection for the area, but the IMO requires that legally binding associated protective measures are agreed to at the time of the PSSA designation. These measures are known collectively as Associated Protective Measures (APMs). APMs can regulate shipping in PSSAs and take a tailor-made approach to each PSSA based on the threat each PSSA is facing. After the Philippines proposed the Tubbataha Reefs Natural Park as a PSSA on 15 January 2016, the IMO designated it as a PSSA on 7 July 2017 with an Area To Be Avoided (ABTA) as its APM. 10 The case of the Tubbataha Reefs Natural Park demonstrates that PSSAs have considerable environmental and legal significance in an era of increased shipping activity. Ocean shipping is responsible for carrying 90 percent of international trade.11 As such, PSSAs are environmentally significant as the IMO can adopt more stringent measures than national measures in restricting navigation and upgrading navigational measures. Hence, this article focuses on PSSAs as an environmental and institutional tool and their institutional processes and problems.12 7 Ibid., Annex 10, paras 61-63. 8 Batongbacal (n 3), at pp. 171-172. 9 Ibid., at p. 172. 10 Designation of the Tubbataha Reefs Natural Park as a Particularly Sensitive Sea Area, IMO Resolution MEPC.294(17), adopted 7 July 2017, IMO Doc MEPC 71/17/Add.1 (18 August 2017), Annex 18, p. 20. 11 Organisation for Economic Co-operation and Development, 'Ocean shipping and shipbuilding' available at https://www.oecd.org/ocean/topics/ocean-shipping/. 12 The Drawing from all PSSAs, it is clear that there is a gap between the practice of the PSSA regime and the potential the regime holds. This article seeks to shed light on the following questions: have States utilised the PSSA regime to its full potential? If not, what are the reasons for underutilisation of the PSSA regime? It will be argued that the PSSA regime is underutilised due to the politicisation of the PSSA designation process and the shortcomings of the Revised Guidelines for the Identification and Designation of PSSAs (the 2005 Guidelines).13 'Underutilised' means that the practice of the PSSA regime has not met the regime's potential of advancing environmental measures. The politicisation outside and inside the IMO has widened the gap made by the institutional weakness of the PSSA regime. This institutional weakness stems from the 2005 Guidelines.
The IMO's decision-making process for PSSAs and APMs is an arena of justified politics; with the IMO pursuing the promotion of international shipping as well as the protection of the marine environment, the IMO committees seek to strike a balance between ensuring the accessibility of commercial shipping and protecting the environment from vessel-based activities and pollution. In this vein, the IMO institutionally justifies the politicisation of the IMO committees. 'Politicisation' occurs when a Member State or a group of Member States advances and prioritises an issue based on their governmental or communal interests. The politicisation in an international institution helps the agenda develop and sheds light on any potential obstacles. However, if politicisation is not delimited properly by international instruments, it may lead to incoherent development of marine protected areas (MPAs) in both the legal and environmental sense. This unfortunate scenario is found in the PSSA regime.
To argue that the underutilisation of the PSSA regime is due to the politicisation of the PSSA designation process and the shortcomings of the 2005 Guidelines, one must first examine the concept of PSSAs and then explain what 'politics' and 'politicisation' means in the context of the PSSA. This will help us understand the legal scope of the PSSA regime and its inherent weaknesses. The discussion then turns to evaluating the practice of PSSAs, focusing on three aspects that illustrate the politicisation of the PSSA designation process: the relationship between APMs and existing navigational measures; the links between ecosystems and PSSAs; and the lack of stringent APMs. These PSSAs aim to tackle a wide variety of environmental threats; the 2005 Guidelines target the international shipping activities that incur environmentally harmful effects, including operational discharges, accidental or intentional pollution, and physical damage to marine organisms.17 The Guidelines recognise the harmful effects of substances, including 'oil and oily mixtures, noxious liquid substances, sewage, garbage, noxious solid substances, antifouling systems, harmful aquatic organisms and pathogens, and even noise' .18 Vessels can cause physical harm to marine organisms and their habitats through anti-fouling systems, anchors, or ship strikes.
In order to be designated as a PSSA, the proposed area has to meet the following three requirements: (1) recognised significance for its ecological, socioeconomic, or scientific attributes; (2) vulnerability to damage from international 14 Ibid. The designation of PSSAs is legally based on Articles 192 and 194 of the LOSC,22 which impose a general obligation to protect and preserve the marine environment and take measures necessary to prevent, reduce and control pollution of the marine environment. The designation of PSSAs can be seen as giving effect to Article 211(1) of the LOSC, which obliges States to establish 'rules and standards to prevent, reduce and control pollution of the marine environment from vessels' .23 The 2005 Guidelines also explicitly refer to Article 211(6) of the LOSC as a possible legal basis of the proposed APM.24 Article 211(6) prescribes that coastal States can establish a clearly defined area in the exclusive economic zone (EEZ) and adopt special mandatory measures to prevent vessel-source pollution. The PSSA regime, however, does not solely depend on Article 211(6) for its legal basis and can potentially expand from the measures prescribed in the LOSC. As the Division for Ocean Affairs and the Law of the Sea of the United Nations noted, the PSSA regime can be more 'detailed and liberal' than the LOSC by adopting a broader spectrum of protective measures under the competence of the IMO.25 The PSSA designation process enables the IMO to undertake a comprehensive assessment of the shipping threats to an area and devise the most appropriate protective measure to tackle the threats.26 The first step of the designation process is the PSSA and APM proposal submitted by a Member State.27 19 Ibid., para 1. The aim of the APMs is 'to prevent, reduce, or eliminate the threat or identified vulnerability' from vessel-source traffic.32 This wide scope for regulating substances and threats, however, is curtailed by the legal basis of the APMs; the IMO can only adopt APMs that are actions to be, or have been, approved or adopted by the IMO.33 In this vein, Harrison describes the PSSA to be a 'concept [that] does not itself offer any additional protection than would already be available under the existing legal framework' .34 The 2005 Guidelines state that the legal basis of the APMs should be one of the following: (1) existing IMO instrument; (2) measures possible through amendment or adoption of an IMO instrument; and (3) measures proposed for adoption in the territorial sea or pursuant to Article 211(6) of the LOSC.35 As such, the PSSA itself does not provide the legal basis for the enforcement of APMs; rather, the APMs require a separate approval process in the relevant sub-committee of the IMO. This raises the hurdle of adopting new APMs in the PSSA, as the APM approval process is required in addition to the PSSA adoption process. After examining the IMO instrument's prerequisites, the competent committee takes decisions and informs the MEPC. The MEPC designates the PSSA after the proposed APMs are approved by the competent committees.36 28 Ibid., para 8. In sum, the designation procedure essentially involves the proposing Member States, the MEPC, an informal technical group, and the competent committees such as the Marine Safety Committee, the NCSR, or the Assembly. Decisions to designate the PSSA are made by the MEPC, which holds the primary responsibility in considering PSSA applications.37 The whole designation procedure of a PSSA takes more than a year, as the duration between application and APM approval from the competent committees takes at least one year.38 The IMO has designated 17 PSSAs to date: Great Barrier Reef

Politicised Decision-making of Particularly Sensitive Sea Areas
With all Member States of the IMO participating, the PSSA designation process is crafted to be an arena of justified politics that is designed to balance environmental and shipping interests.39 Likewise, the 2005 Guidelines state that their purpose is to 'ensure that in the process all interests -those of coastal State, flag State, and the environmental and shipping communities -are thoroughly considered' .40 David Easton defines 'politics' as the process of authoritative distribution of values in a society.41 Using this definition in the context of the PSSA regime, politics would mean the authoritative process of deciding how much protection (i.e., the size of the PSSA, the range of APMs, etc.) is given to the proposed 37 Ibid., para 8. Whilst politics is a term used to illustrate the general picture of the distribution of values, politicisation is carried out by a State or a group of States. If a State or a group of States politicises the decision-making process, it means that the State or the group regards the issue as a part of their policies and tries to advance their national or communal interests in the distribution of values. Considering the issue as a part of their policies entails 'government decision and resource allocations or, more rarely, some other form of communal governance' .42 In contrast, non-politicisation occurs when a State does not find an issue significant enough to seek more values in the distribution process. When a State is not politicising the issue, it would not opine on the matter.
When applied to the PSSA regime, politicisation may be defined as when a Member State or a group of Member States prioritises an issue and advances their interests based on governmental or communal decisions. In this sense, the act of proposing a PSSA can also be an instance of politicisation, as it is steered by the interests and planned actions of the Member State(s). Likewise, a parallel comment can be made about an act of actively opposing a PSSA proposal. In contrast, when a Member State does not deem the issue to be important and posits no opinion on the matter, the State is not politicising the issue. For example, when a State proposes a PSSA site and all the other States are not interested in the proposal, the proposing State is politicising the proposal whereas all other States are not politicising it. Hence, politicisation and nonpoliticisation can occur on an issue simultaneously.
The IMO designed the PSSA designation process as an arena of justified politics; all Member States of the IMO, regardless of being a proposing State for the PSSA or not, are eligible to vote for a new PSSA candidate site. This means that States with not only environmental interests in the proposed PSSA area, but also those with shipping and navigational interests, influence the PSSA designation process. Moreover, not only States but also non-governmental organisations participate actively in the MEPC to advance an agenda. Environmental organisations such as the World Wildlife Fund and the International Union for Conservation of Nature submit documents to the MEPC to improve the PSSA review process.43 In contrast, shipping organisations such as the International For the PSSA regime to retain its legitimacy, consistency in the IMO's decisions is necessary. It is important to ensure that PSSAs and APMs are not swayed purely by the interests of powerful States. For this, the PSSA regime needs to be consistent in adopting environmental measures. This consistency can be guaranteed through the 2005 Guidelines, which sets the limits of the degree of autonomy in the decision-making process. Such limits include the application criteria, such as geographical scope, ecological and biological criteria, and threats to the marine environment. Moreover, the legal strength of the PSSA regime lies in the stricter environmental measures to meet the very founding purpose of the PSSA regime: to protect the marine environment against the threats posed by shipping.
Unfortunately, the 2005 Guidelines have not fulfilled their role in trying to maintain a coherent approach to PSSAs. With the weak legal basis provided by the 2005 Guidelines, the more stringent APMs are often 'watered-down' in the political process.45 As discussed below, the PSSA regime in practice has rendered the 2005 Guidelines not as genuine guidelines. What is worse, this may lead to politics solely deciding the PSSA designation process and undermining the legitimacy of the PSSA regime. This is unfortunate when the PSSA regime has such great potential for protecting and preserving the marine environment; the PSSA regime provides a single platform for States aiming to promote their MPAs and to adopt environmental measures. States can also adopt more stringent measures in the EEZ through the PSSA. PSSAs have the potential to be designated in the high seas, as the 2005 Guidelines merely state that PSSAs can be designated 'beyond the territorial sea' .46 The PSSA regime can also modify the legal norms on navigation and environmental protection in the LOSC. As the IMO is delegated as the 'competent international organisation' under the LOSC, PSSAs can be a means to fill the gaps in the LOSC by addressing contemporary environmental concerns without going through complicated amendment procedures. APMs in the PSSAs can be a promising alternative to adopt unprecedented environmental measures and strengthen the enforcement jurisdiction of the coastal State in both the territorial sea and the EEZ.47 In this vein, Ringbom defines the PSSA to be 'a curious concept, the full implications of which have yet to be ascertained' .48 Despite the potential it holds, the IMO has underutilised the PSSA regime. This is due to the shortcomings of the 2005 Guidelines and the politicisation of the PSSA designation process. The 2005 Guidelines do not provide any detailed guidance to prevent this politicisation and therefore leads to misuse of the PSSA regime. How much has the politicisation dominated the PSSA practice and rendered the decision-making process inconsistent? What interests have made the IMO miss the opportunity to develop the PSSA regime? The following section discusses these issues by exploring all the adopted PSSAs and APMs.

Evaluations of Particularly Sensitive Sea Areas in Practice
Existing PSSAs are evaluated in three aspects: the relationships between APMs and existing navigational measures, PSSAs and ecosystems, and the adoption of stringent APMs. Largely, these three aspects can be divided into politicisation outside and inside the IMO; the first aspect involves how the motives of States and other international organisations have shaped the outcome of the PSSAs and APMs. These political motives were formed outside the forum of the IMO and affected the outcome in the IMO's decision-making process. The latter two aspects, on the lack of links between the PSSAs and ecosystem and lack of stringent APMs, show the politicisation within the IMO; they involve the politicised decision-making process of PSSA designation inside the committee room of the IMO. Taken together, these factors have led to the underutilisation of the PSSA's potential and practical function. 46 2005 Guidelines (n 13), para 4.3. See also Freestone  The APMs' mirroring of existing measures suggests that States have used the PSSA as a means to publicise the special status of the area and existing measures, rather than using the function of introducing stronger navigational measures. Both the Wadden Sea and the Strait of Bonifacio PSSAs were already heavily regulated with multiple layers of regulations at the national, regional, and international levels. In the case of the Strait of Bonifacio, with only one APM proposed, the proposal of France and Italy seems to hold a symbolic significance rather than a practical purpose. The Wadden Sea PSSA was adopted without any new APMs, as its designation was for the purpose of international recognition and administrative efficiency. Moreover, in the Western European PSSA, the introduction of the Western European Tanker Reporting System was the only new APM adopted. A similar instance can be also found with the Great Barrier Reef, as its identification as a PSSA was seen as a way for the Australian government to receive international recognition of the Great Barrier Reef as an environmentally sensitive area that needs special protection.75 A considerable number of PSSAs show that States have neglected the practical function of the PSSA of being able to impose stricter navigational measures. If PSSAs are solely used for promoting international recognition without implementing any new measures, States are underutilising the practical function of PSSAs. As mentioned above, States can adopt more stringent APMs in the EEZ, which is only legally possible via the PSSA regime. Instead, the cases discussed here neglected this potentially important function. This also means that the scope of the PSSA is limited to use with an MPA and existing measures. This underutilisation may lead the PSSA regime to be 'an additional administrative burden, due to the additional documentation required and the involvement of several different committees within the IMO' .76 However, the result of PSSA designation raising international awareness cannot be ignored. The designation of a PSSA itself without stringent APMs can be effective in protecting the marine environment in terms of international awareness.77 The area marked as a PSSA on navigational charts alone can raise awareness among ships navigating the area to take additional care.78 Another advantage is administrative convenience. An area that is recognised as a World Heritage Site means that the international community has already recognised the area for its ecological values.79 This allows the IMO to skip the assessment of the ecological criteria of a proposed PSSA.
Nevertheless, the IMO should be more stringent in considering new PSSA applications without any proposed APMs. Unlike World Heritage Sites or other existing MPAs without restrictive measures for vessels, the aim of the PSSA is not only to raise international awareness of the area, but also to protect areas that are vulnerable to international shipping activities with effective measures. If the proposing States aim to raise international awareness through then use of a PSSA, they need to convince other States of the environmental importance of the area and the need for advanced protection.
Until now, the cases discussed here are those where States have politicised the PSSA regime with the motive of international recognition, which was 75 Freestone and Gjerde (n 12), 'Introduction:

Particularly Sensitive Sea Areas and Ecosystems
The 2005 Guidelines state that a PSSA fulfilling the ecological criteria needs to be 'a biologically functional unit, an effective, self-sustaining entity' .80 They require that the IMO should also consider 'the linkage between the recognized attributes, the identified vulnerability, the associated protective measure to prevent, reduce, or eliminate that vulnerability, and the overall size of the area, including whether the size is commensurate with that necessary to address the identified need' .81 In other words, the size of the area should closely link to the environmental threat posed to the ecosystem of the area, or what we could call the 'ecosystem criterion' . The Guidelines' wording confused States on how to interpret this criterion, that is, should a PSSA only contain a singular biologically functional unit or contain multiple ecosystems.82 This confusion surfaced as a contentious issue in the Western European PSSA designation process, but the IMO adopted the PSSA without settling on which interpretation to use.83 Because the IMO was undecided on how to interpret the ecosystem criterion, the politicisation of the MEPC worsened the situation. Amidst the clashes of political interests, the IMO easily overlooked the ecosystem criterion and made inconsistent decisions in the Western European PSSA and the Baltic Sea PSSA. The Western European PSSA neglected the ecosystem criterion and is overinclusive of ecosystems, as the area contained different ecosystems raising doubt as to whether it is a single biologically functional unit.84 In contrast, the Baltic Sea PSSA overlooked the criterion by being underinclusive, including only part of an ecosystem due to political opposition.
The following discussion illustrates what kind of political motives were present in the MEPC and describes how this affected the outcome of these PSSAs. This is not to argue that politicisation of the MEPC is inappropriate; as mentioned above, the PSSA regime is designed to embody such clashing interests. What is problematic here is that the States' politicisation of an ambiguous 80 2005 Guidelines (n 13), para 4.4.9; Kachel (n 12), at p. legal norm has led to the decisions regarding PSSA designation to be incoherent. In this discussion, this ambiguous legal norm is the ecosystem criterion. The Western European PSSA is overinclusive of ecosystems due to the European Union's (EU) effort to include large areas of EU waters. This was for the purpose of expanding the EU maritime policy. The proposed area included the territorial sea, the EEZs of the proposing States, and the Strait of Dover, an international strait.85 In proposing this PSSA, the EU held the primary role in advancing the application through its Member States.86 The EU started to actively regulate vessel-source pollution after the Erika and the Prestige accidents in 1999 and 2002. Along with the EU legislation and establishment of the European Maritime Safety Agency,87 the EU led the designation for the effective protection of European ports.88 The EU approached the PSSA designation in the IMO as a general EU maritime policy in the post-Prestige era.89 Moreover, the newly-proposed APMs banned single-hull tankers from EU waters and adopted a 48-hour mandatory reporting system for ships carrying heavy crude and fuel oil.90 As these measures heavily regulated oil tankers, the motive for the Western European PSSA application appeared to be to universalise the oil tanker regulation policy of the EU.
The most contentious aspect of the proposed PSSA was the size of the proposed area. Due to its size, the area contained different ecosystems, which raised doubt as to whether it was a single biologically functional unit. The technical group was not able to reach a conclusion about whether the proposed area as a whole satisfied the ecosystem criterion; it was difficult to confirm whether such a large area, with multiple ecosystems, was required to tackle the shipping threat.91 This resulted in opposition from other States, which argued that PSSA designations can only be allowed in 'geographically limited sea 85 Identification Nevertheless, the political and economic pressure applied by the EU in the IMO committees enabled such a large PSSA, the Western European PSSA, to be designated. The Baltic Sea PSSA is another example of a PSSA that fails to reflect the ecosystem of the area. The Baltic Sea PSSA did not include the whole ecosystem due to political matters, in contrast to the Western European PSSA which spans too many ecosystems. The increase of Russian oil exports through the Baltic Sea stimulated the Baltic Sea PSSA application.93 As expected from the motive for the PSSA, Russia strongly opposed the Baltic Sea PSSA.94 Without its consent, the Baltic Sea PSSA could not include Russian waters. Furthermore, the proposing Baltic States and Russia disagreed on the precise coordinates of the delineation line of the EEZ. This nearly led to the failure to adopt the Baltic Sea PSSA, which would have been left with partial coverage of the Baltic Sea and unclear boundaries. The MEPC designated the Baltic Sea PSSA eventually after Russia was assured that the PSSA excluded areas under Russian sovereignty and jurisdiction. The MEPC resolution designating the Baltic Sea PSSA provides that the area 'shall not prejudice the sovereignty or such sovereign rights and jurisdiction of the Russian Federation under international law' .95 In spite of the success in designating the Baltic Sea PSSA, the exclusion of Russian waters means that not all of the ecosystems of the Baltic Sea are protected. The Baltic Sea PSSA failed to encompass Russian waters within the PSSA, even though the threat of the oil pollution was apparent with increased exports of Russian oil.96 Even though the IMO resolution designating the Baltic Sea PSSA stated the geographical scope to be 'the Baltic Sea proper, the Gulf of Bothnia, the Gulf of Finland, and the entrance to the Baltic Sea' ,97 the PSSA could not encompass Russian waters in the Gulf of Finland. This undermines the purposes of designating the Baltic Sea PSSA in the first place, which was motivated by the desire to alleviate the effects of Russian oil exports from Russian ports. Considering that the IMO recognises the vulnerability of the Baltic Sea to 'man-made disturbances' ,98 the exclusion of Russian waters is disappointing in terms of reflecting the ecosystem of the Baltic Sea in the PSSA. These adopted PSSAs show widely different approaches to the ecosystems in the area to be protected. In the Western European PSSA and the Baltic Sea PSSA, the ecosystem criterion was inconsistently applied because of the politicisation of the MEPC. Justified politics in the MEPC not only caused inconsistent decisions, but has also curtailed the potential legal development of the PSSA regime. Likewise, politicisation inside the IMO has hindered the development of the PSSA regime by watering-down APMs, as will be discussed below.

Adopting Stringent Associated Protective Measures
The 2005 Guidelines limit the extent of APMs to 'actions that are to be, or have been, approved or adopted by IMO' .99 Other than measures adopted under MARPOL 73/78 and the 1974 International Convention for the Safety of Life at Sea (SOLAS), other measures can be developed and adopted as long as they have an identified legal basis.100 In other words, the IMO can develop and adopt new APMs. This section now delves into the APMs adopted in existing PSSAs and evaluates how stringently the IMO has regulated international shipping for the protection of the marine environment. After addressing the APMs with the case studies, it will be clear that due to politicisation within the IMO, the IMO committees have 'watered down' the more stringent APMs. 101 Two PSSAs, those in the Torres Strait and the Strait of Bonifacio, demonstrate situations where more stringent proposed APMs were watered down. Both cases represent how the politicisation shaped the APMs proposed, with environmental interests being watered down by shipping interests.
Efforts authority throughout the concerned area and to comply with the authority's instructions on navigational routes. 103 The proposed APMs were highly controversial amongst the Member States due to their possible infringement of the right of transit passage. From the perspective of the strait States, the adoption of compulsory pilotage was consistent with the LOSC. The proposing States argued that compulsory pilotage would not impede transit passage, but rather would ensure the safety of the passage.104 States supporting the proposal deemed the compulsory pilotage proposal to be compliant with freedom of navigation. They also recognised that compulsory pilotage was a necessary measure to protect the sensitive marine ecosystem in the Straits. 105 Those doubting the legality of such measures highlighted the measure's infringement of the right of transit passage. They argued that compulsory pilotage has the practical effect of denying, impairing, or impeding the right of transit passage. Further, they suggested that compulsory pilotage 'implied the intention to impose some form of sanctions on those vessels, which did not take a licensed pilot' .106 These States also commented that just because the LOSC does not prohibit compulsory pilotage in international straits does not mean it permits such a measure. 107 Facing these doubts, the MEPC only 'recommended pilotage' in the Torres Strait instead of compulsory pilotage.108 The MEPC resolution does not state any compulsory nature of the pilotage. Yet, Australia promulgated Australian Marine Notice 8/2006 that required ships navigating the Torres Strait to engage in compulsory pilotage and imposed penalties for non-compliance. 109 With regard to enforcement, Australia does not stop ships not complying with compulsory pilotage mid-passage, but enforces the law when the ships enter an Australian port.110 This later entry does not have to be on the same voyage but can be on a separate voyage.111 Similar to the Torres Strait, the Strait of Bonifacio PSSA only adopted recommended pilotage, not compulsory pilotage. 112 Another example is provided by the failure to adopt the ban on single-hull tankers in the Western European PSSA. The proposal to ban single-hull tankers in the PSSA was controversial, as the area of the Western European PSSA proposal included the territorial sea, the EEZ, and an international strait. This meant that the rights of innocent passage, transit passage, and freedom of navigation may have been threatened.113 Faced with heavy opposition, the proposal to ban single-hull tankers in the Western European PSSA was withdrawn.114 The proposed stringent APMs were watered down because of the weak legal basis of IMO resolutions designating PSSAs. The 2005 Guidelines clearly state that the legal basis for APMs must be found in one of the following: (1) an existing IMO instrument; (2) measures possible through amendment or adoption of an existing IMO instrument; or (3) measures proposed for adoption in the territorial sea or pursuant to Article 211(6) of the LOSC.115 This is because the IMO resolutions designating PSSAs do not have a legally binding character.116 As mentioned above, APMs rely on routeing or navigational measures which are already approved by the IMO under treaties such as MARPOL 73/78 and SOLAS. Since existing instruments provide a limited spectrum of protective measures, the PSSAs inherit this limitation.
This means that PSSAs have an inherently complementary role in protecting the marine environment against vessel-source pollution.117 States seeking environmental protection against shipping activities do not necessarily have to seek the PSSA designation to implement the same measures. The first two Kim The International Journal of Marine and Coastal Law 36 (2021) 438-463 of the APM legal bases, an existing IMO instrument, and measures possible through amendment or adoption of an existing IMO instrument, are available without the need to resort to the PSSA regime. As regards the third legal basis, measures proposed for adoption in the territorial sea or pursuant to Article 211(6) of the LOSC, the measures adopted in the territorial sea do not necessarily need to be adopted under the PSSA regime. Coastal States have sovereignty over the territorial sea, allowing navigational measures to be adopted as long as they do not obstruct innocent passage. In terms of measures adopted pursuant to Article 211(6), the provision itself does not stipulate any specific navigational measures that are permitted in the EEZ. Instead, it prescribes how the coastal State can adopt a clearly defined area and adopt special mandatory measures through the IMO. Although the PSSA regime refers to this provision as the legal basis, it is generally accepted that the regime of 'clearly defined area' under Article 211(6) has not developed in the way the drafters intended. As such, most of the APMs adopted hitherto in PSSAs exhibit similar kinds of measures, namely, recommended pilotage, ATBA, traffic separation schemes, no-anchoring areas, routeing and reporting systems, precautionary areas, and two-way routes.
The PSSA regime's reliance on existing IMO legal sources has caused the Member States to forego PSSA applications and instead to request similar measures through other IMO committees, such as the Maritime Safety Committee. The PSSA proposals require an onerous process of preparing information on the vulnerability of the proposed area posed by international shipping activities,118 which is not required when requesting navigational measures through other IMO committees. Moreover, the PSSA approval process in the IMO is more time-consuming as it requires approval from both the MEPC and the APM-related committees. For example, Indonesia submitted two information papers in 2017 and 2018 on establishing a PSSA in the Lombok Strait. In their information papers, they indicated that they planned to apply for a traffic separation scheme and ship reporting system and an ABTA as APMs.119 However, despite what they had said in their information papers, Indonesia did not in fact submit a PSSA proposal to the MEPC. Instead, Indonesia applied for the traffic separation scheme and associated routeing measures via the Sub-Committee on Navigation, Communications, and Search and Rescue.120 As a result, Indonesia achieved the analogous environmental protection in the Lombok Strait faster than the time that it would have required if it had pursued a PSSA designation.
To tackle this evasion of the MEPC process, the Maritime Safety Committee adopted a new procedure in 2019 to encourage the proposing States to 'consider first a submission to the MEPC with a view to establishing PSSAs, and/or associated protective measures' when drafting or proposing ships' routeing systems or ship reporting systems for the protection of the marine environment and wildlife.121 However, as the procedure only encourages States to 'consider' submitting the PSSA proposal, States' compliance with the new procedure is yet to be confirmed. For example, in the same year, Brazil proposed the establishment of an ABTA in the Santos Basin region to protect the marine environment and reduce the risk of maritime incidents. 122 The NCSR did not approve Brazil's proposal at its seventh session for reasons that are not yet clear.123 How successful this procedure will be in tackling States foregoing the PSSA designation process needs to be seen with more time and cases.
Moreover, States have resorted to politicised means to enforce their preferred measures. For example, the implementation of compulsory pilotage in the Torres Strait was based on Australian national rules.124 If Australia did not have the willingness to implement the compulsory pilotage system and had merely followed the recommendatory language of the IMO resolution, Australia would not have implemented compulsory pilotage. There have also been cases where proposing States or actors imposed political and economic pressure on other States concerning their application. For example, during the negotiation of the Western European PSSA proposal, the EU dominated the negotiations by pressuring the IMO Member States to impose unilateral Kim The International Journal of Marine and Coastal Law 36 (2021) 438-463 actions against foreign ships.125 This pressure was to silence the complaints concerning the size of the Western European PSSA, which were mostly from the larger shipping States. This move was effective, due to the heavy reliance of ship owners on Western European trade and the high density of international shipping routes within the proposed area.126 This economic pressure was coupled with the effective coordination by the EU with its Member States.127 It was interesting to see States that rely on international shipping, such as Greece and Malta, also supported the Western European PSSA.128 Without innovative APMs, the only advantage of the PSSA regime now is the international recognition it draws after the designation. The advantage of international recognition is fading, as seen from the Indonesian example in the Lombok Strait, because States are able to achieve the identical environmental protection of the PSSA through other IMO sub-committees. Without any new or innovative APMs to offer as they are watered down in the politics within the IMO, it is predictable that the States will continue to resort to other measures that are easier and faster to be approved by the IMO.

Conclusions
Despite the potential it holds, the PSSA regime has been underutilised due to the inappropriately drafted 2005 Guidelines as well as the politicisation surrounding the PSSA regime. For political reasons the IMO has failed to resolve the legal ambiguities and weaknesses in the 2005 Guidelines, and has further aggravated the situation by adopting inconsistent decisions and weak APMs.
Notwithstanding this history, PSSAs have the potential for further development. The IMO should realise that the PSSA is an alternative navigational measure to adopt that is more detailed and progressive that those that the LOSC expressly prescribes. The LOSC was negotiated during the 1970s when concerns about the marine environment were not as imperative as they are now. There were few measures explicitly allowed by the LOSC to restrict navigational rights and freedoms for environmental purposes. In this situation, PSSAs can be a means to remedy the inadequacies of the LOSC by addressing contemporary environmental concerns without going through the complicated LOSC amendment procedures. Since the LOSC gives the IMO the power to adopt international rules and standards regarding vessel-source pollution, APMs in the PSSAs could provide a promising alternative route to adopting more stringent environmental measures.129 This is particularly crucial since it is very rare for the bodies which designate MPAs to have the explicit power to restrict navigation that the IMO possesses. The PSSA regime still retains a great deal of potential for the better protection of the marine environment that the IMO and its Member States need to utilise properly.