Local students can compete for a place on the world's first expedition testing how to clean up a floating patch of plastic waste more than 1,000 times bigger than Hong Kong. The estimated 4 million tonnes of plastic waste floating on the Pacific Ocean was discovered in 1997 by boat captain Charles Moore. He caught sight of the trash while on his way home after finishing a Los Angeles-Hawaii sailing race. Called the Plastic Vortex, the trash inspired Project Kaisei, an America-based environmental organisation that studies marine pollution, to plan an expedition in July and August - and it will look for volunteers in Asian universities. 'This is one of the top 10 man-made disasters ever, but no one knows about it,' said Doug Wood- ring, ocean and conservation expert from the Hong Kong team. 'It's in the ocean and no one sees it.' Project Kaisei's pilot mission aims to test technologies and evaluate the problem before a full-scale cleanup in 18 months. Twenty-five professionals - scientists, crew and media - and 10 volunteers will sail from San Francisco to Hawaii in two 25-day trips. A 160 foot sailing boat will carry 30 people each time to the vortex. They will study the efficiency of different types of nets to collect the plastic, how the waste can be regenerated into diesel and how the area can be mapped by satellite. Mr Woodring had not decided how many local volunteers he would enlist. The group was looking to get students and teachers from universities, but had not started recruitment. The whole mission will cost about US$1.5 million. Each volunteer will need to raise a corporate donation of US$10,000 for their trip expenses. The Pacific Ocean could sound remote to Hongkongers, but Mr Woodring said: 'It all comes back to how we use plastic on land.' Some 8 million items of litter are estimated to enter oceans every day, according to the United Nations Environment Programme. Hong Kong's Marine Department collected 12,913 tonnes of floating rubbish last year, its spokesman said. There were no 'islands' of floating garbage in the city's waters as the department cleaned surrounding seas daily, he said. A mattress and wooden boards were among bulky items that the department had fished out before, he said. Most of the trash was dumped from the land, not by boat people. Separately, Friends of the Earth Hong Kong said the plastic bag levy - which covers any retail chain that has at least five stores, and large individual retailers - should be reviewed a year after its implementation in July. 'The government should then set a timetable for the second phase of the scheme so as to remind the public and retailers that have not been covered by the scheme, including pharmacies, bakeries, department stores and wet markets, that reducing plastic shopping bags at source is our shared responsibility,' senior environmental affairs officer Michelle Au said.