Keung Pak-ho first went out to sea at the age of eight, helping his father steer their wooden fishing sampan. By the age of 14, he was a skilled fisherman on a shrimp trawler, supporting his widowed mother and brothers. Today, the 65-year-old father of two sons is facing up to the fact that the industry that has been his livelihood for four decades is no more. The government's ban on trawling, which came into effect at midnight last night, means his trade, long an inseparable part of Hong Kong's identity, belongs to history. "It really is a pity to see that the skills and techniques I have learned in the past 40 years will become obsolete and history all of a sudden," Keung said, as South China Morning Post reporters joined him on board his trawler for one of his last fishing trips in northeastern waters. "Give me a few more years and I can still contribute to the society, bringing the fish they want," he said, as he mulled over moving his ageing fishing boat to operate in mainland waters. On board Keung's shrimp trawler are three deckhands, including his younger son, and his wife, who cooks and helps steer the boat when all the men are on the deck. The trawling cycle takes about two hours, with eight nets lowered into the sea at the back of the boat and lifted one by one when the cycle ends. The routine requires a deep understanding of the process, as it is difficult for the crew to communicate verbally in a noisy and dangerous environment. The crew must also sort and screen the catches, keeping the sellable items such as crabs and shrimp and throwing the rest back into the sea. In between the cycles, several of which take place during each overnight trawl, the crew seek shelter in a room too small for them to stretch out in. The trawling ban is costing the taxpayer HK$1.7 billion in compensation. It is an attempt to reverse the long-term depletion of fish stocks caused by the use of trawlers, which indiscriminately harvest the fruits of the sea and inflict damage on the seabed. The reasons for the trawler ban are not hard to fathom. Long gone are the days when fishermen reported catching metre-long mud grouper, 100kg Chinese Spanish mackerel near Po Toi or two-metre giant perch which swam down from the Pearl River, all detailed in a marine ecology book edited by Professor Brian Morton. Alarm bells have been ringing since 1998, when officials released a study of fisheries resources in Hong Kong waters. A total of 17 species were found to have been "over-exploited", including five found to be "fully exploited" - sardine, mantis shrimp, southern velvet shrimp and whiskered velvet shrimp. The warning was repeated a decade later, when a sustainable fisheries report found that the local fleet was taking 30 per cent more fish than the sea could afford to give. Government figures show the fish catch peaked at almost 240,000 tonnes in the late 1980s and slipped to about 170,000 tonnes by 2011. But fishermen like Keung reject the idea that overfishing is the cause of the declining stocks. Instead, they say marine pollution is the chief culprit. "There used to be 70 trawlers in Tai Po and there was no problem at all, as the fish and shrimp repopulated in the clear and clean waters as soon as they were harvested. Nowadays, we have about a dozen of trawlers left here, but still the fish never come back," he said. In the 1960s, there were about 10,000 fish vessels, most of them not mechanised, in Hong Kong. The number dropped to fewer than 4,000 by 2010. However, these boats come equipped with diesel engines as well as radar and fish detection technology. Dr So Ping-man, assistant director of the Agriculture, Fisheries and Conservation Department, said: "What marks the difference between the old and modern fishing is that the mechanised fishing boats are now very powerful and capable of causing significant and irreversible damage to the seabed." But Keung argues that the government has never admitted reclamation projects in areas such as Tolo Harbour and North Lantau throughout the '80s and '90s - which saw the sea filled in for roads and the rail link to the airport - killed off many rich breeding and nursery grounds. Rapid urbanisation and industrialisation in Guangdong has hastened the decline of fisheries resources, he said. "The development of the Yantian port in Shenzhen has also polluted northeastern waters, as the channel leading to the port needs to be dredged every year and the dredged mud is often improperly dumped in the sea," he said. Keung also believes the mainland's moratorium on fishing in summer will do little to reverse the decline as the mud deposits and all kinds of other rubbish will accumulate on the seabed. "When a container ship approaches the port, it stirs up all the dirty mud and spoils the environment," he said. He claimed that, far from ruining the seabed, trawling actually cleaned it up. Keung said the industry was dying long before former chief executive Donald Tsang Yam-kuen announced the trawling ban in 2010. "I miss the past when there were lots and lots of fish in the sea. But the sea is now different from what it used to be," he said. "I don't see any reason for me, at this age, to keep dragging on." There is little doubt that fishing in Hong Kong is now a sunset industry. Its economic contribution to the city's gross domestic product of HK$1.8 trillion last year was just HK$2.4 billion. Along with mariculture - fish cultivation at sea - it provides less than a quarter of the fish consumed in Hong Kong, and the workforce of 50,000 in 1970 has dwindled to fewer than 9,000. The exodus of fishermen started in the 1960s when Hong Kong began to industrialise. Keung's parents quit fishing out of Tolo Harbour and sold their boat to become textile factory workers in Tsuen Wan, hoping for a better and more stable income. But after his father died of an illness, the family returned to the sea with a shrimp trawler operating out of Peng Chau. Keung moved back to Tolo Harbour almost 30 years ago. He says he must harvest fish and shrimp worth HK$5,000 to meet the basic costs of each 12-hour fishing trip, including fuel and wages for his deckhands. But hard work is not enough to guarantee success. The weather, sea currents, pollution, competitors and, of course, luck, all play their part. On a really bad trip, the catch can be full of rubbish, discarded fish nets, mud and low-value or undersized fish. The income from trawling would not be enough to support his family. His wife and younger son run a fish stall in a wet market in Tai Po, selling the catch from Keung and other fishermen. Whether the trawling ban will be the final nail in the coffin of the flagging industry is not known. But for Ko For-kun, 25 years younger than Keung, the ban marks the end of the road, "I have never been educated, and I have done nothing else but fishing since I was born to a fishing family," he said. But with a wife and four children to support, Ko says he has few options but to try to find a new career on dry land. "It would be too risky for me to fish mainland waters because it will require more investment and manpower. "It would make a lot more sense for me to become a construction worker, riding on the building boom," he said. Ko said unscrupulous fishing practises by mainland fishermen, like electrifying fish or using poison, had made it even tougher for the seas to restore their productivity. "The fish in Hong Kong all come from the open seas, but the areas surrounding Hong Kong are now badly damaged by these dirty practices," he said. The bleak prospects have dissuaded new blood from joining the industry. According to a Central Policy Unit-commissioned report in 2011, monthly income could range from HK$2,000 for small gill netters to HK$110,000 for deep sea fishermen. "I told my eldest son not to help us as it just earns you a few pennies for the huge efforts and labour spent. So he became a bus driver 11 years ago," Keung said. His younger son helps out reluctantly. "He told me, 'I help you only because you are too old now,'" Keung said. Even if they were willing to enter the profession, Keung said, the younger generation does not have the necessary experience. "They don't know where and how to find the fish and they have yet to be tested more in harsh conditions," he said. Keung said the sea was always unpredictable to fishermen, no matter how experienced they might be. A misjudgment could cost lives. "Years ago, we had a horrible experience. We almost got lost in a very familiar territory near Tap Mun when a sudden storm moved towards us. We were so lucky we escaped but we saw some sampans overturned and people fell into the sea and disappeared," he said. While offshore fishing has its risks, deep sea fishing is far more hazardous. "To go to deep sea, you need people who understand it, knowing where to hide when there is a storm. You need a stronger, more powerful boat, and bravery to ride on rough seas," Keung said. Keung said a fishing boat fitted out for the deep sea would cost about HK$10 million. Even with a HK$9 million loan available from the government, it would not be a sensible investment for a man of his age. Another challenge for local fishermen, he said, was the mainland fishing fleet, which enjoyed much more policy support from government. The mainland authorities, mindful of the problems of food security in a nation of 1.3 billon people, provide fuel subsidies which could amount to more than one million yuan (HK$1.2 million) for a large trawler, as well as other concessions. Keung said some local fishermen had started selling more of their produce on the mainland to take advantage of the booming economy and the strength of the yuan. But Dr So said the trawler ban was not intended to eradicate the local fishing industry. "We are not killing it, but it might need to adopt other modes of operation less damaging to the environment," he said. So says that when the sea becomes healthier, there will be more catches, of higher-value produce. "By that time, it will be more cost-effective to fish. That means the production costs will be lower while the earnings will be proportionately higher," he said. "The trawling ban is the right way to go, and it is our responsibility to protect our precious fisheries resources," he said.