Once upon a time, according to Richard Wagner, three beautiful maidens disported in the river Rhine. They sang happy songs. Their long, golden hair floated prettily in the water. Their principal occupation was to guard an immense nugget of pure gold – the Rheingold.
Until the 19th century, traces of gold washed down from the Alps could indeed be found in the gravel beds of western Europe's longest river. "Rheingold" became the title of a Wagner opera but also the name of a German express train and a German beer. Natural historians insist, however, that the true and original "Rhine gold" was a fish – the salmon.
We associate salmon with the open sea and with rocky streams and windswept lochs in Scotland or Ireland. But the Atlantic salmon (Salmo salar) was once a source of food and glittering wealth for towns and villages along all 820 miles of the Rhine. The noble, migratory fish used to swim from the western Atlantic through the North Sea to Rotterdam and up the great river to spawn in the streams of the Alpine foothills in Switzerland and Germany.
To this day, many old buildings in Alsace, on the French bank of the river, have wooden carvings of salmon on their doors or eaves. In the 18th century, the Rhine was the most productive salmon stream in Europe.
Native salmon disappeared from the river 50 years ago, finally defeated in their heroic quest to return to their birthplace by industrial pollution, human sewage, canalisation and hydro-electric dams. Eight bedraggled, native salmon were caught in the Rhine in Germany as late as 1958. They were too impregnated with carbolic acid to be eaten.
Over the past decade, thanks to a concerted campaign by several European governments, salmon have made a spectacular return to the Rhine. The once fetid and rank waters of the river in the industrial heartlands of the Netherlands and Germany have been de-toxified.
The Rhine is now one of the cleanest large rivers in Europe. Salmon fry have been released in tributaries of the Rhine in Germany and France. Giant fish-ladders – or by-passes for salmon – have been built on two dams between France and Germany. During the past 12 months, adult salmon have swum upstream as far as Strasbourg, the city which is the capital of Alsace and, according to the French, also the joint capital of Europe.
But France is at the centre of a squabble with its neighbours about how far the salmon can reasonably be expected to go. Hydro-electric dams owned by the French power giant Electricité de France (EDF), still bar the Rhine in half a dozen places in the 60 miles between Strasbourg and the Swiss border at Basle. A "salmon by-pass" or " passe à poissons", which opened last year at Gambsheim, 10 miles north of Strasbourg, is the most spectacular of its kind in Europe. It consists of a 200m-long cascade of inter-connected pools which allow salmon and other migratory fish to swim up to the level of the dam and then down to the river on the other side.
In recent months, visitors have been allowed to enter a viewing platform below water-level with large plate-glass windows, where they can watch salmon and other fish making their way up or down stream. The cost of similar works on dams south of Strasbourg is estimated at about ¿100m (£71m). EDF – which would have to foot most of the bill – has baulked at the cost. The French government, heavily influenced by EDF, has been trying to wriggle out an EU commitment, approved by Paris in 2001, to make the Rhine a "natural" river from mouth to source by 2020.
France proposed instead that migrating fish should be scooped out of the river, placed in trucks and transported to Switzerland by road. The Swiss and German governments were not amused. Neither were nature campaigners in Alsace. Last month, the French President, Nicolas Sarkozy, convened a two-day environmental summit which was intended to pole-vault France to the forefront of ecological policy-making in Europe. Attempts to raise the salmon issue were forced off the agenda after lobbying by EDF. The cost of new fish by-passes south of Strasbourg simply could not be justified, EDF argued.
An idealistic "green" goal – a natural Rhine from its mouth to source – must give way to a more concrete "green" goal, the need to preserve and increase "renewable" sources of energy. Hydroelectric power, the company suggested, was more important than the ancient rights-of-way of salmon. Some progress has been made in resolving this dispute in recent weeks but the argument is far from over.
A few days ago the International Commision for the Protection of the Rhine (ICPR) held its 14th annual ministerial meeting in Bonn. The German, Dutch and Swiss governments and the European Commission confirmed their intention to make the Rhine a "natural" and fish-friendly river from the North Sea to the Alps by 2020.
Paris did not oppose the declaration but did not formally re-state it either. It did, however, abandon the idea of giving the salmon a lift in lorries. It also agreed to build a new ¿10m fish by-pass at a hydro-electric dam near Strasbourg by 2015, and to "study" the building of another fish ladder around the next dam to the south at Gerstheim. It was agreed that a master plan for fish migration in the Rhine should be drawn up by 2009. No advance was made on how to "bust" the barriers of the three further EDF-owned dams between Gerstheim and the Swiss border.
"Progress is being made but France, and EDF in particular, are being rather selfish," said Jean Wencker, the vice-president of Alsace-Nature and an acknowledged expert on the fish populations of the Rhine. "Salmon can already reach all the tributary rivers on the Alsatian, or French, bank of the Rhine. Paris has, therefore, rather lost interest in the work needed to allow the salmon to reach Switzerland.
"The problem is that EDF has infiltrated all French government thinking on this problem. Its job is to produce electricity. It is not interested in fish. Fair enough. But it should not be allowed to make government policy at a time when the French government is proclaiming itself to be the ecological leader of Europe."
The French government argued for an annual mass netting of salmon which could then by placed in trucks and driven to Switzerland. This would be much cheaper, Paris suggested, than building elaborate new fish ladders around the remaining dams. Salmon are already transported by truck to avoid hydro-electric dams on the river Garonne in south-western France.
Willy Geiger, the deputy head of the Swiss federal environment agency, was Berne's delegate to the recent meeting in Bonn. "The idea of using trucks is now dead," he said. "The objective has always been to make the Rhine once again a natural river, right up to its sources. This is not an economic issue but a cultural and symbolic one, to show that we are capable of respecting and restoring the extraordinary natural cycle which mankind has destroyed.
"Catching a few salmon and transporting them by road would have made no sense, either ecologically or symbolically."
One possible solution now under discussion is to bypass the remaining French hydro-electric dams north of the Swiss border by persuading the salmon to enter the "old Rhine" – a gentle, slow-flowing river which runs parallel to the canalised Rhine proper. This would still require two large-scale fish ladders, at two dams further north at Gerstheim and Rhinau. It would also require expensive works to increase the water flow of the "old Rhine" and to encourage the fish to switch lanes, from one river course to another.
Under existing agreements between the Rhine-bordering countries, fish by-passes must be financed by the national electricity producers which operate the dams. All the hydro-electric works south of Strasbourg are wholly owned by EDF.
Officially, EDF says it is up to the French government and its European partners to decide what work is necessary to encourage the bio-diversity of the river. The company points out that it has already helped to build the two large fish by-passes north of Strasbourg.
These have allowed migratory fish, including salmon, access to all the French tributaries of the Rhine and all the important tributaries on the German side. Future works must take account of "all relevant factors," including economic ones, the company says.
Privately, the electricity giant has lobbied the French government to resist spending further large sums of money which would bring no benefit no French rivers. It has even argued privately that some of the salmon campaigners have a radical agenda – to destroy the economic case for hydro-electric power by establishing the principle that all rivers should be "natural".
Such a development, the French electricity industry says, would conflict with the French government's aim to reduce its reliance on oil and nuclear power and increase "renewable" energy sources over the next 20 years. It believes that one "practical" green issue should trump another "symbolic" one. It was this argument which forced Rhine salmon off the menu of President Sarkozy's national eco-conference last month.
M. Wencker of Alsace-Nature dismisses the EDF case. There is no ecological threat to hydro-electric power, he says. Salmon-friendly dams already exist – and remain viable.
He says the estimated ¿10m cost of each salmon by-pass compares favourably with the annual ¿500m profit from operating all French hydro-electric plants on the Rhine. (The level of profit is supposed to be a commercial and national secret but M. Wencker says he has obtained the ¿500m figure from a reliable government source.)
Why bother? Why is it important that salmon should breed in Alpine streams which the species has not reached, in any great numbers, for almost a century?
"I believe there is an important principle at stake," M. Wencker said. "Salmon was once an important part of the culture of the Rhine. We destroyed that. We speak of our renewed respect for nature and the environment. There could be no better test of that commitment than how we treat one of our great rivers."
Mr Geiger said: "Salmon used to be found all over Switzerland. They were so plentiful that, in the 17th century in Basle, there was a by-law that servants could not be fed salmon more than four times a week.
"Beyond Basle, we have already spent the money needed to allow salmon and other migratory species such as eels to re-conquer the rivers and streams where they were once plentiful. How wonderful a symbol of our new concern for the environment to see salmon once again reaching the small rivers and streams where they used to breed, 1,300 kilometres from the sea."