Amazingly, we continue to take fresh water for granted. This precious resource is vital for our survival and that of a vast array of other species, from microscopic creatures and aquatic insects, to fish and hordes of birds. In Lake Baikal in Siberia, at 1,737 meters the deepest lake in the world, there is even a freshwater seal.

For all that we depend on it, fresh water has become an increasingly scarce commodity, while natural freshwater habitats -- lakes, ponds, pools, swamps, bogs and even rivers and streams -- have become exceedingly rare.

Where natural marshes and flood plains once soaked up seasonal rains and snow melt, now there are levees and hard, engineered river banks ducting valuable fresh water speedily to the sea. Similarly, where coastal mudflats and salt marshes once buffered the land against tidal surges, now there are concrete embankments, sea walls and tetrapods.

Hard engineering, whether inland or on the coast, works until a time of very severe floods. Then the damage can be catastrophic, as many European countries were reminded this summer, when exceptional rains led to massive, widespread inundations. We currently have in Japan, as they found to their cost in Europe, few buffers against such meteorological extremes.

The invaluable functions of freshwater habitats have largely been forgotten in the rush to drain and "develop" them. Meanwhile, we spend fortunes purifying our own used water, and then squander it bizarrely -- even using potable water in our toilets!

The importance of wetlands and fresh water was given suitable attention last month at a meeting in Spain. There, representatives of many of the 133 parties to the Gland, Switzerland-based intergovernmental Ramsar Convention on Wetlands of International Importance met to further promote the conservation and wise use of these habitats. Suddenly, Ramsar (the name of the Iranian city where the convention was adopted in 1971) hit the national news too, because at that meeting the Environment Ministry announced the designation of two new Ramsar sites in Japan.

At the time of that conference, I visited an established Ramsar site at Sagata in Niigata Prefecture. Designated in March 1996, this consists of an attractive pair of spring-fed lakes just southwest of the city of Niigata. The lakes support a dense growth of hydrophytes (water-loving plants), including the most extraordinary spiny water lily (oni-basu). However, Sagata is most notable as an important wintering site for many waterfowl species, especially Bewick's swans that arrive there from their breeding grounds on the Siberian tundra more than 3,000 km to the north. Each evening as dusk falls, hordes of swans fly to the lakes to roost for the night, only to depart again in bugling flocks at dawn to forage across the area's stubble fields.

Although designation on the Ramsar List does not solve all ills, recognition of international significance provides additional ammunition with which to contest any threats to a site that may be a crucial habitat for resident species, a stopping-off point for some migrants and the destination for others.

This year in Japan, two very important locations -- Fujimae in Nagoya and Miyajimanuma in Hokkaido -- were brought into this fold of some 1,300 sites worldwide, covering almost 106 million hectares.

Though the 112-hectare Fujimae mudflats are a mere vestige of those that ringed Ise Bay before Japan's once beautiful eastern seaboard was transformed to concrete over the last 50 years, they are a critical link for thousands of shorebirds that migrate along the East Asian flyway between Australasia and northeast Asia. Although it has long been recognized internationally that failure to protect stepping-stone wetlands along a migratory flyway makes a mockery of conserving those at either end, throughout the 1990s, Fujimae was the most threatened wetland in Japan.

Paradoxically, while Nagoya was then bidding to host the ecofriendly 2005 World Fair and being promoted as a model of environmental protection and development for Asia, its authorities were planning to use Fujimae as a garbage landfill. Fortunately, though, international pressure, backing a stalwart struggle by residents and nongovernmental organizations, finally persuaded the Nagoya mayor to protect the site in 1999 -- and to pledge to reduce garbage as a step toward creating a sustainable recycling society.

Additionally, the Ramsar designation also provided desperately needed stimulus to workers in the field of environmental-impact assessment -- a field which, until now, has all too often been reduced to paying mere lip-service to seemingly inevitable squanderings of public funds on environmentally damaging public-works projects.

In contrast to Fujimae, Miyajimanuma in the city of Bibai is a small, 30-hectare lake that freezes over in winter. A century ago, the Ishikari River basin where it lies was a massive flood plain, with swamps and marshes where cranes bred and countless waterfowl congregated on migration.

Today, tiny Miyajimanuma is the setting for one of the most extraordinary wildlife sights in Japan. There, every year during spring and autumn migrations, tens of thousands of geese fill the air as they descend on the lake to roost at dusk or depart at dawn. Theirs is a stirring cacophony of sound, and they present a spectacle that is drawing more and more visitors from across the country. This autumn, bird numbers have topped 60,000, with almost the entire migratory population of white-fronted geese in Japan passing through. After resting at Miyajimanuma and feeding on the Ishikari Plain for several weeks, they then continue on their way south from the Siberian tundra to overwintering sites in northern Honshu, many of them around the Izunuma Ramsar site in Miyagi Prefecture.

The designation of these two new sites in Honshu and Hokkaido is wonderful news. However, the continuing absence of similar stepping-stone sites in Kyushu remains a dangerous gap in the chain of protection along the East Asian flyway.