Putting cotton before fish

Everybody has a use for water, a snout in the trough. Scientists and engineers who might usefully dip into this volume include irrigation engineers and fisheries ecologists, dam-builders and hydroelectric engineers, flood managers and chemists. All have a legitimate professional interest in water quality. Collectively they have great wisdom. But individually their reductionist approaches, homing in on water as a raw material for their own activity, has led, as James Perry and Elizabeth Vanderklein argue, "to a long list of unidimensionally acceptable and multidimensionally tragic water projects".

Most obviously the problem arises with large dams. The world is dotted with hydroelectric dams that destroyed downstream fisheries and river-valley irrigation, caused coastal erosion or raised the risk of flooding. And they are still being built. The Three Gorges dam now rising on the Yangtze river in China could become the world's largest source of hydroelectric power, or the defender of the Yangtze flood plain from killer floods. But, since one task requires a reservoir kept full and the other a reservoir kept empty, it assuredly cannot, as the Chinese maintain, do both.

The politics of water is often about one group of experts gaining ascendancy over all others. In Japan, all rivers are controlled by the Ministry of Public Works. Result: a lot of concrete and very few fish.

Perhaps the most tragic of many such cases of failed policy outlined in this book is the Aral Sea in central Asia. Once the world's fourth largest inland sea, it has been largely emptied by irrigation engineers bent on diverting as much river water as possible away from the sea and into irrigated cotton fields. The strategy, likely to be completed with the emptying of the sea early next century, was deliberate. Cotton to clothe the Soviet empire mattered more than all the fish in the sea.

The result is huge saline lakes of drainage water, some tens of kilometres long, in the arid hinterland around the irrigated fields. Worse, the fields are clogged with salt, sand storms carrying salt and agricultural pesticides are causing epidemics of diseases across four nations, and even the region's climate is being changed as the sea disappears. With bitter irony, the climate is becoming unsuitable for growing "Commissar Cotton" itself.

This book claims, rightly, to be the first academic work to put water quality and aquatic ecosystems in a political, cultural and economic context. Written for students of water quality management and for the decisionmakers that many of them will become, its watchword is "integration". Integrated thinking, integrated policy making: a final plea, perhaps, for the technocrats to get it right.

As befits a text written by American authors, there are numerous North American examples of the conflicts and confusions of water policy. The saga of the remaking of the Mississippi river for the benefit of bargees is told, along with the later story of environmentalists fighting back in defence of the river's ecosystem. Those campaigners now find themselves in alliance with the guardians of the public purse, who are tiring of paying out more than $400 million a year to keep the river dredged.

There is the story of how 20 per cent of the world's fresh water, stored in the Great Lakes of North America, came to be almost terminally polluted by the constant drip of poison from millions of individual sources, few of them large enough to attract so much as a second look from a pollution inspector. In the mid-1960s, Lake Erie all but died, choking on nutrients washing in from fields and factories and sewers. Even so, the myth that the lakes are too large to become polluted persists, say the authors. "Many communities cannot conceptualise that their small outputs could lead to significant basin-wide impacts."

But for once, this is an American text that takes a properly international outlook in its choice of examples and sources. The summary of the complex history of competing uses, nations, legal systems, political ideologies and scientific dogmas on the management of the Danube river and its ten-nation basin is splendid.

Find here too the sorry story of the Nile perch in Lake Victoria. Introduced to increase the productivity of fisheries in the world's largest tropical lake, the Nile perch might, if viewed with suitable blinkers, be regarded as a success. The perch has indeed grown fat and bolstered fishermen's catches by eating the lake's less marketable endemic fish. But it has been so successful that today two-thirds of those endemic fish have become extinct, and the lake's ecosystem has become so disrupted that the waters are clogged with blooms of blue-green algae.

And there is plenty of didactic cultural analysis. Readers who reach page 5 will be brought up short by the statement that: "In Mexico, defence of the environment is largely a class issue", in which "Mexico's environmental catastrophe is an integral aspect of economic dependency on the United States". Economists as much as ecologists may be intrigued by the book's analysis of the interaction between the different development and environmental strategies in the city-states of Hong Kong and Singapore. While the latter, a centrally organised economy in the Asian manner, "has an umbrella environmental agency with a full set of legal provisions", the British-ruled Hong Kong has adopted a laissez-faire approach that has seen poor regulation and a rising tide of untreated sewage.

Not too many books manage this mix of scientific rigour and cultural sophistication. It makes a student text feel like part of the real world.

Fred Pearce is environment consultant,New Scientist.