Ships and vessels arriving at Shanghai ports will be subject to tighter checks and face tougher fines if they break a revised national regulation on the prevention and control of marine pollution, the Shanghai Daily reported.

Shanghai maritime supervisors will also be given more powers over marine pollution when the regulation comes into force by March.

They will be authorised to open containers on cargo ships to check goods they suspect are hazardous and have contamination risks.Officials will also be able to look at the goods without the presence of cargo owners.

"The clean and safe water environment is not only a key to the coming Expo but also a threshold to the city's efforts to build a shipping center," said Xu Guoyi, head of the Shanghai Maritime Safety Administration.

Owners of a ship that carries liquid cargo such as oil should first sign agreements with local certificated clearing services, according to the regulation.

In the event of an oil leak, the clearing-up companies, together with the maritime supervisor, will be responsible for dispersing slicks and stopping them spreading.

Fines for violators are expected to top US$43,950, triple the maximum fine in the 1983 regulation.

There were five major oil leaks last year as against 10 in 2008. The city suffered its worst oil slick in 10 years on August 5, 2003, when two ships collided in the upper reaches of the Huangpu River. An eight-kilometer stretch of water was affected after 85 tonnes of oil leaked out. More than 150 people were involved in the clearing-up operation.