MARPOL

MARPOL (short for 'marine pollution') is the cornerstone of the international regime that limits how ships may discharge harmful substances into the sea and air. It was developed by the International Maritime Organization and combines the original 1973 convention with a 1978 protocol, which is why it is often written MARPOL 73/78. Every ship trading internationally must comply, and flag states enforce it through surveys and certificates while Port State Control officers check compliance in foreign ports.

The convention is divided into six annexes, each dealing with a distinct source of pollution. Annex I covers oil, including the operational discharge limits, the oily-water separator and the oil record book. Annex II governs noxious liquid substances carried in bulk by chemical tankers. Annex III covers harmful substances carried in packaged form. Annex IV addresses sewage, and Annex V regulates garbage, effectively banning the disposal of plastics at sea. Annex VI, added later, controls air pollution from ships, including limits on sulphur and nitrogen oxides and, increasingly, measures aimed at greenhouse-gas emissions such as the EEXI and CII requirements.

MARPOL is written in terms seafarers meet daily. The oil record book, the garbage management plan and garbage record book, the shipboard marine pollution emergency plan, and the special areas and emission control areas where stricter rules apply all flow directly from its annexes. Breaches carry heavy penalties, and deliberate illegal discharges (bypassing pollution-prevention equipment, for example) have led to major fines and criminal prosecutions of companies and individual officers. Alongside SOLAS for safety and STCW for crew training, MARPOL is one of the three pillars of international shipping regulation, and it is the reason a modern ship treats every discharge to sea and air as a controlled, recorded event.