In October, I spent some time in Vancouver. I have grown-up children there, as well as grandchildren and a lot of old friends, most of whom I met while working for the Environmental Protection Service. Even though I left Canada in 1978 to come to Japan and pursue the often dubious course of a writer, I have always kept my Canadian ties, and have especially followed the river-enhancement programs there that are aimed at improving the habitat for salmon.

Genuinely wild rivers don't need improving. However, those that have been messed up by "development" -- with erosion caused by logging, pollution of various sorts, and other despoiling human influences -- generally can use some help to increase their fish stocks, especially of sensitive species like salmon.

Canada must be doing some things right, because this year on the mighty Frazer River they saw a historical record run of pink salmon. My friends estimated 40 to 50 million of them. I and my friends Dr. Ken Ashley (a biologist who has been doing some revolutionary work on freshwater nutrients; see this column, June 6, 2002) and Fred Koch (from the University of British Columbia), were taken out on the river by Dr. Marvin Rosenau and a very experienced field technician, Bob Land. Marvin is a senior fisheries biologist with the provincial government.

We left Vancouver by car early in the morning, launched the jet boat near Abbotsford, and went upstream to the Harrison River, slowing along the way to look at the incredible numbers of dead salmon strewn like smelly flotsam along the gravel banks, and to peer over the gunwales at the spent and dying fish still swimming in the water.

I wished I'd been there to see the run earlier, when the river would have been alive with flashing shoals of fish powering against the current in a bid to end their lives in final rushes of milt and gold. When I mentioned the stink, Ken said, "Ah, but this is the smell of life, too!"

Pink salmon (also called "humps" because the males get a very pronounced hump on their backs when they come into freshwater to spawn) are the most abundant of the five wild salmon species in British Colombia. Although they enter coastal rivers and streams in September and October, as they have a two-year life cycle, the populations from odd-numbered and even-numbered years remain totally separate and never interbreed.

When they come back, the mature fish range from 1.5 to 2.5 kg, with the females carrying between 1,500 and 1,900 eggs. They lay their eggs in gravel, so the flow of water must be just right; too much and both gravel and eggs would wash away, too little and the gravel would get choked with silt. The eggs hatch in late February into what are known as alevins (which I used to think sounded like a kind of cocktail) that still have an egg sac attached. The tiny fish, called fry, finally emerge from the gravel in April or May and soon after begin to migrate downstream. Having reached the sea, the young fish spend their first summer in coastal waters, after which they move offshore.

Please note here that other salmon, such as the chinook, coho, chum and sockeye, all have very different life patterns, with some of them spending as much as three years growing in freshwater and up to seven years at sea. However, whether it be the relatively small pink salmon, or the chinook which can reach a mighty 40 kg, they all need clean, fresh, well-oxygenated water and gravel in which to ensure the continuation of their species.

The Canadian success in bringing back salmon to damaged streams and ecosystems is wonderful news, and their efforts could well be emulated in Japan. However, a serious dilemma is developing. Ever since Canada actively encouraged entrepreneurs and their money from Asia, there has been an unprecedented building boom in Vancouver and the lower mainland of British Columbia. As in Japan, this has been combined with an insatiable demand for concrete. For high-quality concrete, the best kind of gravel is river gravel, which is generally uniformly sized and has no salt in it to attack the steel reinforcing.

People who have been raised where there are no wild rivers, otters, bears, herons, kingfishers, loons or anadromous fish (and who may think that concrete boxes are beautiful), feel little sympathy with others who believe that salmon returning to their native rivers to spawn, die, and thus enrich the waters with their young and their nutrients, are beautiful and sustainable -- and infinitely precious.

All too often rich people -- and dare I stick my neck out and say especially those involved in large-scale construction -- not only have a strong tendency to disregard wildlife, but are also the most prone to use their money in dishonest and underhand ways to get whatever they want.

In British Columbia they want river gravel.

I saw gravel pits beside the river filled with garbage. Hey guys! Gravel is porous; pollution from that garbage is bound to reach the river. A big river like the Frazer rises and falls. The areas of gravel essential to the alevins are huge. Yes, of course, gravel and sand are constantly coming into the river from the mountains by natural processes, but gravel takes eons to form. If a gravel bar is removed, it will alter the river flow.

In Canada, fish biologists and wildlife experts are very alarmed by current trends, but -- as in Japan -- all too many politicians, senior bureaucrats and construction-industry moguls soon form very cozy little daisy chains, and start playing their games to coerce and bully the people out in the field. Sure, the latter tend to be a bit naive, but they are usually extremely honest -- and many of them are passionate about their beliefs. These are the ones who can lose their jobs if they speak out. This old Celtic bear has been there, done that, and the forms the monster takes are nearly always the same.

Studies go on to determine how much gravel and sand is being transported by the river. In my field notebook I scribbled that it was estimated that some 20 million tons of sand, gravel and silt wash into the Frazer system each year. However, in the natural system, that is all very thinly spread out. Gravel extraction hits hard on certain spots and definitely alters ecosystems.

I say that you cannot just remove huge volumes of gravel from a living, flowing river system and not degrade its ecosystem. Go get your raw materials for your concrete from somewhere where there's no fish or wildlife. And if that makes concrete more expensive, maybe we'd be a lot more careful about how and where we put it. Now wouldn't that be a blessing for Japan?

Come to that, if the folks over in Vancouver would come and see the tragedy of Japan's rivers, they could easily learn how not to do it.