Extended controls on fishing urged
The ban on bottom trawling in Hong Kong waters due to take effect at the end of next year will need to be supported by other controls if it is to be fully effective in restoring the region's once-abundant marine life, fisheries experts say.
They are worried that many trawler operators, who now account for 80 per cent of fishing, may switch to smaller-scale operations that the government is still working out ways to control.
Bottom trawling - one of the most destructive fishing methods - destroys coral, sea pens, sponges and other organisms, destroying marine ecosystems.
'If all the trawler operators switch to small-scale fishing, then it will be the same situation,' Stanley Shea, project co-ordinator of the marine conservation group Bloom Association, said.
'There need to be other regulations to help. You can't just do some things and not others.'
Yvonne Sadovy, fisheries expert and professor at the University of Hong Kong's School of Biological Sciences, said that controls on recreational fishing, for which the government has no plans, would also be needed.
'That will have to be controlled just like commercial fishing is controlled. In other words, with licensing and a cap on the number of recreational fishermen,' she said.
Under legislation passed last month after a seven-year campaign by conservationists, the ban on bottom trawling will take effect on December 31, 2012 after distribution of a HK$1.73 billion package to buy back boats and compensate affected fishermen that was approved by legislators on Friday.
But it is likely to be at least a decade before the waters around the mouth of the Pearl River Delta begin to display the impressive array of marine life that once helped make Hong Kong an important fishing port.
Experts expect that the ban will have a big impact but more data about current catches needed to be collected to assess what the outcome would be.
'Hong Kong will have to be patient. Smaller fish will come back quickly, but in terms of the ones we want to eat, the bigger ones ... they're more like elephants. They take a longer time to recover,' Sadovy said. 'So I think at least 10 years, maybe 20, before we get something that's really going to make a difference here.'
Andy Cornish, director of conservation at the World Wide Fund for Nature (WWF) in Hong Kong, said most of the marine life had been wiped out and trawling had played a big part.
'It's quite rare that you go so drastically from total overfishing to removing 80 per cent of your catchers,' Cornish said, describing the ban as an 'amazing experiment'.
'I can promise you the situation in Hong Kong is going to become a really, really interesting case study for fisheries scientists who want to know what happens when you do these kinds of things.'
Sadovy said Hong Kong's marine life had once been very diverse. 'We had spawning grounds. We had the coral reef-associated fish. Very productive and very diverse, this particular area,' she said. But today, fish caught by trawlers average only 10 grams, or about the length of a finger.
Shea said a licensing system should be established, and the mesh size for nets should be regulated to prevent the unsustainable practice of catching small fish.
Scientists such as Sadovy predict the recovery of Hong Kong's marine ecosystem will have a spill-over effect into neighbouring waters, as fish populations spread out from areas where trawling has been banned.
Conservationists faced little opposition in the final push to have the law passed and most controversy is now centred on the division of the compensation money.
There are around 1,100 trawlers registered in Hong Kong, 400 of which fish primarily in Hong Kong waters, while the remainder fish further afield. Some 700 offshore trawlers will receive only about HK$150,000 but the inshore trawlers can get up to HK$5.5 million each. Officials said that offshore trawlers were less affected by the ban.