Ballast water from the ships of Tung Chee-hwa's family controlled Orient Overseas Shipping Line is to be examined in an attempt to discover just how far potentially fatal bacteria can travel. Marine creatures and microscopic bacteria are routinely transported across oceans by container ships. But the inadvertent stowaways can cause havoc in new environments where they upset the ecological balance. In one incident in the 1980s, Zebra mussels ended up in the Great Lakes of North America, where they flourished. 'It has just gone crazy, clogging up pipes and it has cost them billions of dollars to try to control it,' said Professor Mike Dickman, a Hong Kong University ecotoxicologist. US laws now require container vessels to exchange coastal ballast water for clean mid-ocean water before they enter port, called re-ballasting. Hong Kong lacks such laws and a three-man team - Professor Dickman, marine engineer Lambrose Bakounpouzis and a microbiologist - will examine the bacteria brought in. Professor Dickman said bacteria absorbed by shellfish and eaten by humans could be imported. 'We were curious: are there things coming into Hong Kong which we might not want?' Research had established there were fewer species in mid-ocean water than coastal waters. 'The question is whether the species which do come from mid-ocean are different and less likely to be toxic ones,' he said. The other part of the project involves devising alternatives to re-ballasting, which can destabilise ships in rough weather, according to Mr Bakounpouzis, a lecturer at Hong Kong University's Department of Mechanical Engineering. He is looking at flushing out and pumping in clean ballast water through a series of tanks or heating the water to kill organisms. A spokesman for the shipping firm said it was keen to help projects like this.