MARPOL (1973 Convention): International Convention for the Prevention of Pollution from Ships

The 1973 International Convention for the Prevention of Pollution from Ships (MARPOL Convention) was developed under the auspices of the International Maritime Organization (IMO). It aims to protect the marine environment from pollution by oil and other harmful substances from ships, superseding an older convention focused on the same issue. The 1973 MARPOL Convention includes two protocols and several annexes, which specify regulations for the management and transportation of different forms of potential pollutants. In 1978, in response to big oil spills that occurred in the 1970s, a separate Protocol was adopted that modifies some of the provisions in the 1973 Convention. As the 1973 MARPOL Convention (with its original protocols and annexes) had not yet entered into force at the time, the 1978 Protocol effectively absorbed the 1973 Convention. This created a combined instrument which is now referred to by the acronym “MARPOL”. MARPOL (the combined instrument) entered into force in 1983. Since the 1973 Convention and 1978 Protocol were developed, MARPOL (the combined instrument) has been updated and amended several times, including through the addition of a new protocol in 1997, and through the addition or amendment of annexes at different points in time. As of 2026, MARPOL has six annexes, each addressing different forms of pollution from ships, and each with its own specific set of Contracting Parties. : • Annex I - Regulations for the Prevention of Pollution by Oil (in force since 1983) • Annex II - Regulations for the Control of Pollution by Noxious Liquid Substances in Bulk (in force since 1983) • Annex III - Prevention of Pollution by Harmful Substances Carried by Sea in Packaged Form (in force since 1992) • Annex IV Prevention of Pollution by Sewage from Ships (in force since 2003) • Annex V Prevention of Pollution by Garbage from Ships (in force since 1988) • Annex VI Prevention of Air Pollution from Ships (in force since 2005) The implementation of MARPOL is coordinated by the IMO, headquartered in London, UK.