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Marine Environmental Law Research Guide: 2. International Treaties

A comprehensive legal research guide on the international control, regulation and enforcement of pollution on the High Seas, created by Reed Elcott.

Status of Convention Fact Sheet

A quick checklist with basic information on IMO Convention Adoption Dates and Signatories (as of Nov. 30, 2009).

Key International Treaties

Marine Pollution from large tankers primarily occurs on the High Seas. A handful treaties administered by the IMO govern the issue of marine pollution and can be found below. Click on the treaty title for more comprehensive information from the IMO homepage. Treaty texts can also be found using the United Nations Treaty Database.


International Convention for the Prevention of Pollution from Ships, as modified by the Protocol of 1978, Nov. 2, 1973, 1340 U.N.T.S. 184. ("MARPOL")   


The MARPOL Convention is the main international convention covering prevention of pollution of the marine environment by ships from operational or accidental causes. It is a combination of two treaties adopted in 1973 and 1978 respectively and updated by amendments through the years.


International Convention Relating to Intervention on the High Seas in Cases of Oil Pollution Casualties, Nov. 29, 1969, 26.1 U.S.T. 765 ,970 U.N.T.S. 211.  

This convention affirms the right of a coastal State to take such measures on the high seas as may be necessary to prevent, mitigate or eliminate danger to its coastline or related interests from pollution by oil or the threat thereof, following upon a maritime casualty. The 1973 Protocol extended the Convention to cover substances other than oil.    


Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter, Dec. 29, 1972, 26 U.S.T. 2403, 1046 U.N.T.S. 120.

 This Convention regulates the dumping of wastes at sea. The 1996 Protocol prohibits the dumping of any wastes or other matter with the exception of those listed in an Annex.


International Convention on Oil Pollution Preparedness, Response and Co-operation, Nov. 3, 1990, U.S. Treaty Doc. 102-11, 1891 U.N.T.S 51.

In July 1989, a conference of leading industrial nations in Paris called upon IMO to develop further measures to prevent pollution from ships. This call was endorsed by the IMO Assembly in November of the same year and work began on a draft convention aimed at providing a global framework for international co-operation in combating major incidents or threats of marine pollution.

Protocol on Preparedness, Response and Co-operation to Pollution Incidents by Hazardous and Noxious Substances, Mar. 14, 2000, HNS-OPRC/CONF/11/Rev 1.  

The Protocol on Preparedness, Response and Co-operation to pollution Incidents by Hazardous and Noxious Substances, 2000 (OPRC-HNS Protocol) follows the principles of the International Convention on Oil Pollution Preparedness, Response and Co-operation, 1990 (OPRC) and was formally adopted by States already Party to the OPRC Convention at a Diplomatic Conference held at IMO headquarters in London in March 2000.


International Convention on the Control of Harmful Anti-fouling Systems on Ships, Oct. 5, 2001, AFS/CONF/25

The International Convention on the Control of Harmful Anti-fouling Systems on Ships will prohibit the use of harmful organotins in anti-fouling paints used on ships and will establish a mechanism to prevent the potential future use of other harmful substances in anti-fouling systems.


International Convention for the Control and Management of Ships' Ballast Water and Sediments, Feb. 13, 2004, BWM/CONF/36

Instituted regulations for the control and management of ships' ballast water and sediments in order to protect against the introduction of foreign and invasive species of wildlife that can have ecological consequences.


International Convention on Civil Liability for Bunker Oil Pollution Damage, Mar. 23 2001, LEG/CONF 12/19.

This Convention was adopted to ensure that adequate, prompt, and effective compensation is available to persons who suffer damage caused by spills of oil, when carried as fuel in ships' bunkers.

Treaty Locators

United Nations Treaty Collection

Although not as extensive as the IMO Library, you can also locate treaty and amendment documents using the United Nations Treaty Database. Click Here to vist the 'Popular Name' search function.

U.S. Treaties and Agreements at HeinOnline*

HeinOnline provides a comprehensive list of official U.S. treaty publications, available in pdf format (requires Adobe Reader).

*HeinOnline is a subscription-based service. Otherwise, visit the IMO Convention treaty citator page.