Takeshi Yamazaki is the fourth generation of his family to operate their sushi shop in the heart of Tokyo's Tsukiji fish wholesale market. Sprawling over 23 hectares in the capital's Chuo Ward, the market handles more than a million tonnes of marine products, vegetables and fruit a year, worth about 600 billion yen (HK$39.64 billion). Business at the sushi counter is as brisk as ever, but the main difference between the fish that Mr Yamazaki serves and those his father carefully sliced is that far more of the catch is being taken in nearby Tokyo Bay. The menu includes hamachi (yellow tail), anago (salt-water eel) and hirame (halibut), all from the bay. In his father's day, industrialisation left the waters grey with pollution and marine life in decline. Nature has again triumphed over the worst of man, with a liberal dose of help from legislation designed to return the 1,320-sq-km bay to picture-postcard perfection. Tokyo Bay is home to the busy ports of Tokyo, Chiba, Kawasaki, Yokohama and Yokosuka, as well as naval bases belonging to the Japanese and US naval forces. The west coast of the bay, stretching 50km from Tokyo to Yokohama, was first developed in the Meiji era (1868-1912). Industrialisation of the northern and eastern shores began after the second world war. The development included reclaiming around 250 sq km of land for industrial purposes. In the race to rebuild after the devastation of the war, little emphasis was placed on the environment. By the end of the 1960s, its waters, beaches and seabed were polluted with heavy metals, PCBs, chemicals and dioxins from household effluent and industrial dumping. More pollution flowed into the bay from 60 rivers and streams. Misguided coastal development destroyed stretches of coral, seaweed beds and tidal flats that were crucial to the fragile ecosystem. Some estimates put the level of habitat destruction in the bay as high as 90 per cent. With growing awareness of the environment in the late 20th century came efforts to protect the bay. But the wrecking of the supertanker Diamond Grace on a reef in 1997 - which released more than 1,300 tonnes of crude oil - did not help matters. Since then, however, the cleanup has gathered momentum. Tougher rules are finally having an effect and, in a report that was commissioned by the Fisheries Agency, the subcommittee on dietary culture is now urging people to eat seafood from the bay. According to the report, 285 species of fish and shellfish inhabit the waters, and 5,000 fishermen are employed catching them. There have been significant increases in the size of the harvests, particularly of conger eel and clams. But, while the fish may lead healthier lives, the sushi cutting boards still await.