The Japan nuclear incident and the protection of the marine environment

Last week, it was reported that Japan had started releasing radioactive water from the Fukushima Daiichi nuclear plant.  More than 11,00 tonnes of radioactive water have been released into the Pacific Ocean in order to make room in storage containers for further radioactive water.  Whilst officials have asserted that the risks are low, neighbouring states are understandably concerned about the effects of these releases.  It also raises the question of whether such activity is in compliance with international law.  In response to the release, the Chinese government has expressly said that “We hope Japan acts in line with international laws and takes effective steps to protect the marine environment.” What does international law have to say about this situation?
Several relevant international legal obligations are found in the 1982 United Nations Convention on the Law of the Sea.  In particular, Article 192 requires states to “protection and preserve the marine environment” and Article 194 requires states to “take all measures necessary to ensure that activities under their jurisdiction or control are so conducted as not to cause damage by pollution to other States and their environment and that pollution arising from incidents or activities under their jurisdiction or control does not spread beyond the areas where they exercise sovereign rights in accordance with this Convention.”  Clearly these provisions do not create strict liability for states to prevent all pollution but they do establish a benchmark against which states can be judged for releases of polluting substances into the marine environment.  Further provisions of the Convention provide more detailed rules on the control of pollution from land-based sources and the control of pollution by dumping.
These provisions on the protection of the marine environment must also be read in light of the general principles of international law.  Two general principles may be relevant to the nuclear incident in Japan and may help to excuse Japan from any potential responsibility.
First is the principle of distress.  Distress excuses a breach of international law if the state has no other reasonable way of saving the lives of persons entrusted to its care.  [Article 24 of the International Law Commission’s Articles on State Responsibility]  It could be argued that the actions of Japan are directed to saving the lives of Japanese citizens living in the vicinity of the power plant.   However, there are further conditions to the use of distress.  Firstly, the situation of distress must not be due, either alone or in combination with other factors, to the conduct of the State in question.  Secondly, distress is not available as a justification if the act in question is likely to create a comparable or greater peril.  This condition raises evidentiary questions about the risks posed by releasing radioactive water into the marine environment and the extent to which it raises serious perils for other states.
Second is the doctrine of necessity according to which, states may not be held responsible for breaches of international law if they acted out of necessity if “the act is the only means for the State to safeguard an essential interest against a grave and imminent peril; and [it] does not seriously impair an essential interest of the State or States towards which the obligation exists, or of the international community as a whole.” [Article 25 of the International Law Commission’s Articles on State Responsibility]  In addition, necessity is not available as a justification if a state has contributed to the situation of necessity.  The protection of its population against a nuclear incident may be considered an essential interest of Japan but similar questions arise under this doctrine as to whether the release of radioactive water potentially impairs the essential interests of other States (in relation to their own waters) or the international community (in relation to the high seas).
Both of these principles recognise that the situation of a country can be taken into account when deciding whether or not it should be held responsible for breaches of international law.  Thus, in some circumstances, state may be excused from not complying with their international obligations.  At the same time, these principles recognise that the interests of a state trying to justify a breach of international law must be balanced against the interests of other states.  Both of these principles provide a legal framework in which to balance those interests.
Another legal aspect of this situation is the duty of Japan to notify neighbouring states of “cases in which the marine environment is in imminent danger of being damaged.”  [Article 198 of the United Nations Convention on the Law of the Sea]  In a recent case, the International Court of Justice made clear that the duty to inform other states was a duty incumbent on the state and it could not be satisfied by the release of information from other sources.  In the context of the duty of Argentina to notify the Commission of the River Uruguay of any activities which may harm the River Uruguay, the Court held in the Pulp Mills Case (at para. 110):

The Court considers that the information on the plans for the mills which reached [the Commission] via the companies concerned or from other non-governmental sources cannot substitute for the obligation to inform laid down in Article 7, first paragraph, of the 1975 Statute, which is borne by the party planning to construct works referred to in that provision.

Arguably, a similar observation can be made about the duty of parties to the United Nations Convention on the Law of the Sea under Article 198.  Indeed, such notification should be made in a timely manner in order to allow the parties to consult and to reach an agreement on the appropriate action where possible.  These provisions recognise that other states may have an interest in how Japan deals with the very serious situation at the Fukushima Daiichi nuclear plant.