Article 23 seeks to address this situation by providing a bridge between two legal regimes, the law of international watercourses and the law of the sea.368 In so doing, the Article complements provisions contained in various treaties dealing with marine environments. Such treaties include the UN Convention on the Law of the Sea, which requires states to ‘adopt laws and regulations to prevent, control and reduce pollution of the marine environment from land-based sources, including rivers, estuaries, pipelines and outfall structures, taking into account internally agreed rules, standards and recommended practise and procedures’.369 The latter Convention goes on to stipulate that ‘states, acting especially through competent international organisations or diplomatic conference, shall endeavour to establish global and regional rules, standards and recommended practices and procedures to prevent, reduce and control pollution of the marine environment from land-based sources’.370

While there is no legally-binding global instrument dealing exclusively with land-based pollution, a nonbinding set of recommendations and guidelines have been adopted by UNEP’s Global Programme of Action for the Protection of the Marine Environment from Land-based Activities (GPA) (see figure 20.6).371 At the regional level a number of legally-binding instruments deal with land-based sources of pollution. While most regional regimes only include coastal states within their membership, some allow for non-coastal states to become party.372 In its reference to taking into account, ‘generally accepted rules and standards relating to the protection and preservation of the marine environment’, Article 23 seeks to ensure that watercourse state practice reflects these global and regional instruments. In reference to the obligation to ‘take into account’, Tanzi and Arcari comment that the obligation, ‘is not to impose on watercourse states the straightforward application of rules and standards drawn from different agreements, but, more modestly, that of ensuring that the measures that states are planning or implementing on an international watercourse under Article 23 of the Convention be at least consistent with the pertinent rules and standards governing the protection and preservation of the marine environment.’373 Additionally, through the use of the term ‘take all measures… that are necessary to protect and preserve’, Article 23 adopts the same standard of responsibility contained, and discussed, under Article 7, namely that of due diligence (see Glossary of Terms). What may be deemed as appropriate can be gleaned from the global and regional instruments noted above. Measures that might be considered ‘appropriate’ could therefore include environmental impact assessments, monitoring, notification, information exchange and consultation, scientific and technical cooperation, assistance to developing countries, development of control strategies, and so forth.374

The same standards to protect and preserve are also included, which would incorporate the precautionary approach (see Glossary of Terms). Additionally, the same requirement as contained in Article 20 is included, namely to cooperate, ‘where appropriate’, with other states. 375 However, a slight variation occurs in reference to ‘other states’ rather than ‘watercourse states’. This deviation reflects that scenario whereby states sharing a particular marine environment, but not necessarily the same watercourse, may find it advantageous to cooperate.

The ILC Commentary makes it clear that the obligation set forth in this Article is not an obligation to protect the marine environment in the strict sense of the term, but rather a more precise one to take measures with respect to an international watercourse that are necessary to protect the marine environment.376 The latter commentary also makes it clear that the requirement in Article 23 is separate from the obligations contained in Articles 20-22. Activities that cause pollution to an estuary may therefore not meet the threshold of significant harm, as stipulated for in Article 21, but could still be deemed to have breached the requirement contained in this article to protect and preserve an estuary.377

364 UN General Assembly, ‘Oceans and the Law of the Sea, Report of the Secretary-General,’ (18 August 2004), UN Doc A/59/62/Add.1, 29.

365 Y Tanaka, ‘Regulation of Land-based Marine Pollution in International Law: A Comparative Analysis Between Global and Regional Legal Frameworks’ (2006) 66 Heidelberg Journal of International Law 533.

366 S Vinogradov, ‘Marine Pollution via Transboundary Watercourses – An Interface of the ‘Shoreline’ and ‘River-Basin’ Regimes in the Wider Black Sea Region’, (2007) 22(4) The International Journal of Marine and Coastal Law 585, 585-586.

367 Ibid.

368 A Chircop, ‘Marine Pollution from Land-Based Activities: Legal Regimes and Management Frameworks’, in D Vidas and W Ostreng, eds., Order for the Oceans at the Turn of the Century (Kluwer Law International 1999), 174.

369 UN Convention on the Law of the Sea, Article 207.

370 UN Convention on the Law of the Sea, Article 207(4).

371 UNEP, ‘Global Programme of Action for the Protection of the Marine Environment from Land-Based Activities’ (5 December 1995), UN Doc UNEP(OCA)/LBAIIG.2/7.

372 S Vinogradov, ‘Marine Pollution via Transboundary Watercourses – An Interface of the ‘Shoreline’ and ‘River-Basin’ Regimes in the Wider Black Sea Region’, 590-591.

373 A Tanzi and M Arcari, The United Nations Convention on the Law of International Watercourses, 278.

374 See generally, Y Tanaka, ‘Regulation of Land-based Marine Pollution in International Law: A Comparative Analysis Between Global and Regional Legal Frameworks’; Also see UNEP, ‘Global Programme of Action for the Protection of the Marine Environment from Land-Based Activities’.

375 See Section 20.1.

376 Refer to 1994 Draft Articles at 124-125.

377 1994 Draft Articles at 124.

The Global Programme of Action for the Protection of the Marine Environment from Land-based Sources recommends that states:

A. Identify and assess problems related to the:

1. nature and severity of problems in relation to: food security and poverty alleviation; public health; coastal and marine resources and ecosystem health, including biological diversity; and economic and social benefits and uses, including cultural values.
2. severity and impacts of contaminants including sewage, persistent organic pollutants, radioactive substances, heavy metals, oils, nutrients, sediment mobilisation and litter.
3. physical alteration, including habitat modification and destruction, in areas of concern.
4. sources of degradation, including: coastal and upstream point sources; coastal and upstream non-point (diffuse) sources; and atmospheric deposition caused by transportation, power plants and industrial facilities, incinerators and agricultural operations.
5. the affected or vulnerable areas of concern such as critical habitats, habitats of endangered species, ecosystem components, shorelines, coastal watersheds, estuaries, special protected marine and coastal areas, and small islands.

B. Establish priorities for action by assessing the five factors above, reflecting the relative importance of impacts upon food security, public health, coastal and marine resources, ecosystem health, and socio-economic benefits, including cultural values in relation to

1. source categories,
2. the area affected
3. the costs, benefits and feasibility of options for action. In the process of establishing priorities, states should (amongst others):

1. apply integrated coastal area management approaches, including provisions to involve stakeholders.
2. recognise the basic linkages between the freshwater and marine environment through application of watershed management.
3. recognise the basic linkages between sustainable development of coastal and marine resources, poverty alleviation and protection of the marine environment.
4. apply environmental impact assessment procedures in assessing options.
5. integrate national action with any relevant regional and global priorities, programmes and strategies.

C. Set management objectives for priority problems for source categories and areas affected on the basis of established priorities. D. Identify, evaluate and select strategies and measures to achieve these objectives. E. Develop criteria for evaluating the effectiveness of strategies and measures.

Download Fact Sheets

No Significant Harm Rule Protection and Preservation of Ecosystems