For years, WWF has been trying to raise awareness and concern for the world's declining fish stocks. The destruction is bad news for everyone, not least fishermen.

An article in the April 2007 edition of National Geographic magazine profiled the destruction of the world's fisheries and the potential for irreversible damage to ocean ecosystems. The story is grim reading, and unfortunately, it parallels much of what is happening locally, according to Clarus Chu of WWF Hong Kong.

"Large-sized fish species, like the Chinese Bahaba, are nearing extinction thanks to over fishing and pollution," Chu says. The Chinese Bahaba, which can grow up to two metres, was once a common fish found primarily in the estuaries of southern and eastern China. Hong Kong fishermen in the 1930s would have been able to catch up to 50 tonnes of the Chinese Bahaba. Now, they are so rare that Hong Kong diners are unlikely to ever see one again, according to Chu.

The Chinese Bahaba is one of the WWF Hong Kong's Ocean's 10 - a group of ten species that are endemic to Hong Kong waters and whose survival is threatened. Like the giant Bluefin Tuna of the Mediterranean and North Atlantic featured in National Geographic, over fishing doomed the Chinese Bahaba.

"The Chinese Bahaba make a certain noise when they are spawning, and fishermen learnt to easily find them by listening through the hull of the boat," Chu says.

Despite the decimation of large-fish populations, there are reasons for optimism. The April 2007 edition also profiles the effects of creating a number of fully protected marine reserves in New Zealand, and how they've brought damaged fisheries back to life.

WWF Hong Kong has long advocated establishing a series of similar zones in which all fishing is banned, in the hope of restoring local marine life, and even local fisheries. There is time, but not much.

The sight of a shark with bits of human limb falling out of his or her mouth is more than enough to put anyone off their lunch.