Fish numbers in waters around Hong Kong are expected to increase dramatically in the next five years because trawling is banned from today.
The Agriculture, Fisheries and Conservation Department has written to all fishermen's groups informing them of the ban and warning of penalties of up to six months in prison and HK$200,000 fines for those who defy it.
The prohibition comes under the Fisheries Protection Ordinance, which bans destructive catching methods such as poison, explosives, electricity, dredging and suction devices. Now, any apparatus that drags or tows a net on the seabed or through the water is outlawed.
A spokesman for WWF-Hong Kong said members are delighted by the action, for which they have campaigned since 2005.
"We applaud the ban and see it as a bold and encouraging step taken by the government on local marine conservation," he said.
"This first-ever fisheries management measure will safeguard the diversity of marine life."
Fish such as croaker and grouper should increase by 20 to 30percent, he predicted.
As for those hit by the ban, "WWF hopes the government will continue to provide support to the affected fishers and help them switch to other livelihoods such as marine eco-tourism.
"We also urge the government to implement marine spatial planning, which will allow Hong Kong to allocate resources sparingly to achieve ecological, social and economic objectives."
Trawling has seen indiscriminate catching of species and damage to the seabed for decades, he said. It is held to be a main reason for the almost total collapse of the marine ecosystem.
Fisheries scientists agree with the WWF view of better days at sea, saying populations of squid and cuttlefish should increase by 40 percent and reef fish by 10-20percent during the next five years. Larger fish, such as croaker and grouper, should surge by 30-45percent.
In the long term, the experts add, there will be an increase in fish catches that use less harmful methods. That should see stability in the supply and quality of local seafood, and the public will enjoy a healthier marine environment.
Responding to the argument that the trawling ban may impact the livelihoods of fishermen, WWF-Hong Kong senior conservation officer Samantha Lee said the group has been engaging with fishing communities and operators of marine-related business along with government officials and experts for a year.
"We believe that developing marine eco- tourism will unlock the potential of the sea and provide viable alternative livelihoods for the fishermen," Lee said.
But WWF is also urging the government to continue to help those who need new lines of work and to consult those with stakes in the marine environment in shaping "a holistic policy" in sustainable marine eco-tourism.