The levy rate will reduce from 14.25 cents to 11.25 cents per net registered ton per quarter. The minimum payment of $10 per quarter remains unchanged.
The levy applies to ships of more than 24 metres in length entering an Australian port carrying more than 10 tonnes of oil in bulk as fuel or cargo.
It funds AMSA's environmental protection activities - preventing and combating ship-sourced pollution in the marine environment.
The levy rate was increased in June 2010 to meet part of the cost of cleaning up the oil spill from the Pacific Adventurer incident, which occurred off the south-east coast of Queensland in March 2009.
The funds generated by the higher levy were also used to establish a $10 million pollution response reserve.
The rates for AMSA's other two levies, the Marine Navigation Levy and the Marine Navigation (Regulatory Functions) Levy, remain unaltered.
