Ships must keep records about their ballast water and report how they managed it before they enter an Australian port. While at sea, ships can replace all the seawater in the ballast tanks with seawater from the ocean to avoid transporting pests. The ship must exchange at least 95% of its ballasts with water in the deep ocean to be allowed into Australia.
Many organisations have been researching ways to treat ballast water and kill any organisms contained in the water.
Possible technologies include:
The International Maritime Organization (IMO) (www.imo.org) have developed guidelines for all ships to be fitted with treatment systems by 2016.
Most of these methods will kill marine organisms in ballast water. The main problem is the enormous volumes of ballast water that needs to be treated. Queensland exports more than 81 million tonnes of coal per annum, into 800 ships. One ship can discharge about 74,000 tonnes of ballast water per day.